1
DEPARTMENT OF HEALTH AND HUMAN
SERVICES
FOOD AND DRUG
ADMINISTRATION
CENTER FOR BIOLOGICS EVALUATION
AND RESEARCH
BLOOD PRODUCTS ADVISORY COMMITTEE
80th Meeting
This
transcript has not been edited or corrected, but appears as received from the
commercial transcribing service:
Accordingly the Food and Drug Administration makes no representation as
to its accuracy.
Thursday, July 22,
2004
8:00 a.m.
Holiday Inn
Gaithersburg
Two Montgomery Village
Avenue
Gaithersburg,
Maryland
2
PARTICIPANTS
James R. Allen, M.D., MPH, Acting Chair
Linda A. Smallwood, Ph.D., Executive
Secretary
MEMBERS
Kenneth Davis, Jr., M.D.
Donna M. DiMichele, M.D.
Samuel H. Doppelt, M.D.
Jonathan C. Goldsmith, M.D.
Harvey G. Klein, M.D.
Suman Laal, Ph.D.
ACTING CONSUMER REPRESENTATIVE
Katherine E. Knowles
NON-VOTING INDUSTRY REPRESENTATIVE
Michael D. Strong, Ph.D.
TEMPORARY VOTING MEMBERS
Liana Harvath, Ph.D.
Matthew J. Kuehnert, M.D.
Susan F. Leitman, M.D.
Keith C. Quirolo, M.D.
George B. Schreiber, Sc.D.
Donna S. Whittaker, Ph.D.
3
C O N T E N T S
PAGE
Welcome, Statement of Conflict of
Interest,
Announcements
Linda Smallwood, Ph.D. 5
James R. Allen, M.D. 11
Committee Updates
FDA Current Thinking on TRALI:
Leslie Holness, M.D. 13
Donor Blood Pressure
Determination:
Alan Williams, Ph.D. 23
Open Public Hearing
TRALI:
Kay Gregory, AABB, ABC 32
Michael Fitzpatrick, Ph.D.,
ABC 40
Donor Blood Pressure Determination:
Kay Gregory, AABB, ABC 50
I. Dating of Irradiated Red
blood Cells
Introduction and Background:
Ping He, M.D. 60
Presentation:
Gary Moroff, Ph.D. 80
Presentation:
Larry Dumont 114
Presentation:
Dean Elfath, M.D. 130
Presentation:
Jessica Kim, Ph.D. 137
Open Public Hearing
Allene Carr-Greer, AABB 159
Michael Fitzpatrick,
Ph.D. 162
Richard Davey, M.D.,
New York Blood Centers 174
4
C O N T E N T S
(Continued)
PAGE
FDA Current Thinking and Questions for
the
Committee:
Jaro Vostal, M.D., Ph.D. 177
Committee Discussions and
Recommendations 184
II. New Standard for Platelet Evaluation
Introduction and Background:
Salim Haddad, M.D. 231
Presentation:
James AuBuchon, M.D. 283
Presentation:
Edward Snyder, M.D. 218
Open Public Hearing
Allene Carr-Greer, AABB 308
Michael Fitzpatrick,
Ph.D. 308
Larry Dumont, Gambro BCT
Inc. 308
FDA Current Thinking and Questions for
the
Committee:
Jaro Vostal, M.D., Ph.D. 310
Committee Discussion and
Recommendations 312
III. Experience with Monitoring
of Bacterial Contamination of
Platelets
Introduction and Background:
Jaro Vostal, M.D., Ph.D. 342
Summary of ACBSA Meeting: Bacterial
Contamination:
Jerry A. Holmberg, Ph.D. 371
Presentation:
Steven Kleinman, M.D. 388
Open Public Hearing
Boris Rotman, Ph.D., BCR
Diagnostics 420
Committee Discussion and
Recommendations 430
5
1 P R O C E E D I N G S
2
Welcome/Statement of Conflict of Interest
3 DR. SMALLWOOD:
Welcome to the 80th
4
meeting of the Blood Products Advisory Committee.
5 I am Linda Smallwood, the Executive
6
Secretary. At this time, I will
read the conflict
7
of interest statement that applies to this meeting.
8
This announcement is part of
the public
9
record for the Blood Products Advisory Committee
10
meeting on July 22nd/23rd, 2004.
11 Pursuant to the authority granted under
12
the Committee Charter, the Director of FDA's Center
13
for Biologics Evaluation and Research has appointed
14
the following individuals as temporary voting
15
members: Drs. Liana Harvath,
Blaine Hollinger,
16
Matthew Kuehnert, Susan Leitman, Keith Quirolo,
17
George Schreiber, Donna Whittaker, Ms. Katherine
18
Knowles.
19 To determine if any conflicts of interest
20
existed, the agency reviewed the agenda and all
21
relevant financial interests reported by the
22
meeting participants.
6
1 For Agenda Topics I, II, III, and V, the
2
Food and Drug Administration has prepared general
3
matter waivers for the special government employees
4
participating in this meeting who required a waiver
5
under Title 18, United States Code 208.
6 Because general topics impact on so many
7
entities, it is not prudent to recite all potential
8
conflicts of interest as they apply to each member.
9
FDA acknowledges that there may be potential
10
conflicts of interest, but because of the general
11
nature of the discussions before the committee,
12
those potential conflicts are mitigated.
13 Based on a review of the agenda, all
14
relevant financial interests reported by the
15
meeting participants, and on the FDA draft guidance
16
on disclosure of conflict of interest for special
17
government employees participating in an FDA
18
product-specific advisory committee meeting, there
19
are no meeting participants who required a waiver
20
under Title 18, United States Code 208 for
21
discussions on hepatitis B virus nucleic acid
22
testing for donors of whole blood.
7
1 We would like to note for the record that
2
Dr. Michael Strong is participating in this meeting
3
as the Non-Voting Industry Representative acting on
4
behalf of regulated industry.
Dr. Strong's
5
appointment is not subject to Title 18, United
6
States Code 208.
7 He is employed by the Puget Sound Blood
8
Center and Program and thus has a financial
9
interest in his employer. He
also is a researcher
10
for two firms that could be affected by the
11
committee discussion. In
addition, in the interest
12
of fairness, FDA is disclosing that his employer
13
Puget Sound Blood Center has associations with
14
regional hospitals and medical centers.
15 With regard to FDA's invited guest
16
speakers, the Agency has determined that the
17
services of these guest speakers are essential.
18
There are interests that are being made public to
19
allow meeting participants to objectively evaluate
20
any presentation and/or comments made by the
21
guests.
22 For the discussions of Topic I related to
8
1
the Dating of Irradiated Blood, Dr. Gary Moroff is
2
employed by the American Red Cross Holland Labs.
3 For the discussions of Topic II on a New
4
Standard for Platelet Evaluation, Dr. Edward Snyder
5
is employed by the Yale-New Haven Hospital Blood
6
Bank. He also has associations
with clinical
7
trials that involve red blood cells.
8 Dr. James AuBuchon has grants and/or
9
contracts with firms that could be affected by the
10
discussions. He is also a
scientific advisor for
11
several affected firms.
12 For the discussion of Topic III on
13
Experiences with Monitoring of Bacterial
14
Contamination of Platelets, Dr. Steven Kleinman
15
receives consulting fees from two firms that could
16 be affected by the committee discussions.
17 Dr. Jerry Holmberg has a financial and
18
professional interest in several firms that could
19
be affected by the committee discussions.
20 In addition, there are regulated industry
21
and other outside organization speakers making
22
presentations. These speakers have financial
9
1
interests associated with their employer and with
2
other regulated firms. They were
not screened for
3
these conflicts of interest.
4 FDA members are aware of the need to
5
exclude themselves from the discussions involving
6
specific products or firms for which they have not
7 been
screened for conflicts of interest.
Their
8
exclusion will be noted for the public record.
9 With respect to all other meeting
10
participants, we ask in the interest of fairness
11
that you state your name, affiliation, and address
12
any current or previous financial involvement with
13
any firm whose products you wish to comment upon.
14
Waivers are available by written request under the
15
Freedom of Information Act.
16 At this time, I am asking if there are any
17
further declarations that have not been mentioned
18
that need before this meeting proceeds.
19 [No response.]
20 DR. SMALLWOOD:
Hearing none, thank you.
21 I would also just like to announce that
22
there is a new procedure and that for each day, and
10
1
also maybe for specific topics, there will be
2
another reading of a conflict of interest
3 statement. That is new, but just to let you know
4
that that is what is taking place.
5 Also, with regard to those speakers that
6
will be speaking in the open public hearing, there
7
will be a statement read by the chairman for each
8
open public hearing to remind you to make the
9
declaration of your name and affiliation and to
10
reveal any association that is pertinent to that
11
discussion.
12 At this time, I would like to make a few
13 announcements.
14 There will be a workshop on plasma
15
standards scheduled August 31st through September
16
the 1st, 2004. It will be held
on the NIH campus,
17
and there is an announcement on the FDA web site.
18
Additionally, the next meeting
of the
19
Blood Product Advisory Committee is tentatively
20
scheduled for October 21st/22nd, 2004 at this
21
hotel. There will be further
announcements.
22 At this time, I will introduce to you the
11
1
members of the Blood Products Advisory Committee.
2 Today, Dr. James Allen will be the Acting
3
Chairman in the absence of Dr. Kenrad Nelson, who
4
is expected to join us tomorrow.
Dr. Allen, would
5
you please raise your hand. Thank you.
6 As I call your names, would you please
7
raise your hand.
8 Dr. Kuehnert.
Dr. Harvath. Dr. Klein.
9
Dr. Goldsmith. Dr. Leitman. Dr. Doppelt. Dr.
10
DiMichele. Dr. Davis. Dr. Laal.
Dr. Quirolo.
11
Dr. Whittaker. Dr.
Schreiber. Ms. Knowles. Dr.
12
Strong.
13 Thank you.
14 As indicated on the agenda, we do have
15
times indicated for the speakers.
We would ask
16
that you would adhere to that.
Our Acting Chairman
17
says he will enforce that and we have a timer.
18 At this time, I would like to turn over
19
the proceedings of this meeting to the Acting
20
Chairman, Dr. James Allen.
21 DR. ALLE N: Thank you, Dr.
Smallwood.
22 Good morning and welcome to the meeting.
12
1
We have a very full agenda with a lot of important
2
items. I don't think in my
experience on the
3
committee I have ever seen so many questions being
4
asked in one meeting, so it is important that we
5
get the information before us from the speakers as
6
succinctly as possible, that we maximize the time
7
that we have for committee discussion and questions
8
of the speakers, and discussion among ourselves
9
before deciding to vote. So, I
really would like
10
to ask people, please, to keep your presentations
11
to the point and move along properly.
12 We have got two committee updates
13
initially and then we will follow that by an open
14
public hearing. There are
comments during the open
15
public hearing that will be addressing both of the
16
updates, but we will have both updates first with
17
time for questions of the speakers.
18 At this point, let's move into the first
19
committee update, Dr. Leslie Holness from the Food
20
and Drug Administration will give an update on
21
Transfusion Related Acute Lung Injury (TRALI).
22 Committee Updates
13
1 FDA Current Thinking on TRALI
2 Leslie Holness, M.D.
3 DR. HOLNESS:
Thank you, Dr. Allen.
4 Good morning.
5 [Slide.]
6 The FDA Fatality Program receives reports
7
of fatalities that occur as a complication of
8
transfusion or donation. We have
seen a steady
9
rise in fatalities due to TRALI since the first FDA
10
report in 1992.
11 [Slide.]
12 This slide covers reported fatalities for
13
three fiscal years. Between 2001
and 2003, the
14
three principal causes reported in terms of numbers
15
are TRALI, ABO hemolytic reactions primarily caused
16
by clerical errors, and bacterial contamination.
17 In Fiscal 2001 and 2003 TRALI led in the
18
number of fatality reports received.
In Fiscal
19
2002, reports of fatalities from bacterial
20
contamination of products were most numerous.
21
Other transfusion related fatality causes were
22
non-ABO, antibodies, and mishandling of products.
14
1
In this category, the transfusion may or may not
2
have contributed to the recipient's death.
3 In this category, the fatalities were not
4
transfusion related, and there are donor fatalities
5
and the total fatalities at the bottom of the
6
slide.
7 [Slide.]
8 If we look at the average of the key
9
causes for the last three years, TRALI leads with
10
16.3 percent followed by ABO hemolytic transfusion
11
reactions at 14.3 percent, and bacterial
12
contamination at 14.1 percent.
13 [Slide.]
14 So, the FDA Fatality Program reports that
15
TRALI was implicated in 16 to 22 percent of total
16
fatalities reported in each of the last three
17
years, and it was the most common cause of
18
transfusion related fatalities reported to the FDA
19
in 2003.
20 The majority of deaths were associated
21
with fresh frozen plasma followed by red blood
22
cells and apheresis platelets.
15
1 [Slide.]
2 Dr. Kathleen Sazama, of M.D. Anderson
3
Cancer Center at the University of Texas, looked at
4
20 years of FDA fatality reports from 1976 to 1995,
5
and found respiratory deaths as a percentage of
6
total reported deaths to be 15 percent, and many of
7
these are probably due to TRALI.
8 [Slide.]
9 This slide is a bar graph of TRALI
10
fatalities reported to the FDA and the total
11
fatalities reported to the FDA from 1995 to 2003.
12
There has been a steady increase in total fatality
13
reports to spike in 1998 and also a steady increase
14
in the TRALI fatalities.
15 [Slide.]
16 These are the TRALI fatalities broken out.
17
There is a slowing in 1999 and 2000, but all
18
together there is a steady increase in TRALI
19
fatalities up to 2003.
20 [Slide.]
21 Some of the fatalities are associated with
22
HLA or granulocyte antibodies, and they are sent in
16
1
with the fatality reports.
2 This is a graph of the number of
3
fatalities due to TRALI that were reported to the
4
FDA in these various years, and these are the
5
number of cases where HLA or antigranulocyte
6
antibodies were found. In most
cases, antibodies
7
were found in over 50 percent of the TRALI
8
fatalities.
9 [Slide.]
10 This slide shows the preliminary results
11
of a consensus conference held in Toronto, Canada,
12
in April of this year, 2004. The
conference was
13
sponsored by Canadian Blood Services, Hema-Quebec,
14
and the International Society for Blood
15
Transfusion, ISBT.
16 It was a two-day conference with over 19
17
speakers. There are preliminary
results. More
18
detailed results will be published at the beginning
19
of next year. So, the magnitude
of the TRALI risk
20
is unknown. Depending on the
studies, the
21
estimates are between 1 in 5,000 to 1 in 10,000
22
transfusions.
17
1 There is evidence for two mechanisms for
2
TRALI, and there is insufficient evidence for
3
screening tests and for donor exclusion measures at
4
this time.
5 [Slide.]
6 In April of 2003, the NHLBI convened a
7
working group of TRALI experts to develop a clear
8 definition to be used to clinical
investigation and
9
patient care. The definition
with limitations is
10
as follows:
11 In patients with no acute lung injury
12
prior to transfusion, the diagnosis of TRALI is
13
made if there is new acute lung injury and an onset
14
during or within 6 hours after the end of a
15
transfusion of one or more plasma containing blood
16
products, and there are no other risk factors for
17
acute respiratory distress syndrome.
This
18
definition is still being worked on.
19 [Slide.]
20 These are FDA actions taken in 2001. The
21
issue was presented to the Blood Products Advisory
22
Committee on June 15th of 2001.
We will see the
18
1
results in the next slide.
2 CBER has published a Health Alert in the
3
form of Dear Colleague letter to the blood
4
community in October of 2001. It
was to remind
5
physicians to include TRALI in a differential
6
diagnosis of a patient in respiratory distress
7
during or following a transfusion.
8 Pre-storage leukocyte reduction of blood
9
products was recommended to help prevent formation
10
of leukocyte antibodies in recipients.
11 We recommended voluntary Med Watch
12
reporting of non-fatal TRALI cases, and there were
13
several poster presentations to raise clinician
14
awareness of TRALI.
15
[Slide.]
16 This slide shows the BPAC vote on June 15,
17
2001. The question to the committee was: Should
18
the FDA consider regulatory action at this time to
19
identify donors and donations at increased risk to
20 producing
TRALI in a recipient?
21 The votes were:
1 Yes, 13 No, and there
22
were no abstentions.
19
1 [Slide.]
2 One member thought it was prudent to
3
identify and defer donors implicated in multiple
4
TRALI cases.
5 BPAC agreed that this should be the
6
responsibility of each establishment.
7 The committee also recommended research to
8
define the scope of the syndrome and a prospective
9
epidemiologic study to establish incidence, donor
10
and recipient risks.
11 [Slide.]
12 The further recommendations from the
13
committee.
14 The role of HLA, leukocyte antibodies and
15
other potential causative mechanisms need to be
16
investigated. A careful
evaluation of cases in
17
which the donor can be linked with the reaction.
18 A multi-center study to assess and
19
evaluate acute pulmonary reactions and lung
20
problems in the transfusion setting using a
21
standardized protocol, and the surveillance of
22
recipients of IVIG for TRALI reactions.
20
1 [Slide.]
2 These are possible future regulatory
3
strategies that are being discussed at the FDA at
4
this time.
5 Diversion of plasma from female donors to
6
components other than fresh frozen plasma. This
7
does not involve a new question and fresh frozen
8
plasma is most often involved in TRALI.
This is
9
being tried in the UK at this time, but there have
10
been no impressions of the results yet.
11
Our problem is that the
plasma in other
12
components are ignored and that shortages of FFP
13
may occur.
14 [Slide.]
15 Preventive antibody testing and
16
questioning of donors, female donors, on parity,
17 followed by plasma product diversion and red
blood
18
cell loss from donors at risk.
19 The problem here is that samples and
20
testing are not standardized.
All white blood cell
21
antibodies may not be equal in their ability to
22
cause TRALI in recipients.
21
1 [Slide.]
2 Defer donors implicated in a single unit
3
or in more than one multiple unit TRALI case
4
regardless of antibody status.
5 This allows the first case of TRALI to
6
occur which may be fatal, and it depends on
7
accurate case reports and donor tracing.
8 That's it.
With that, I end my
9
presentation.
10 DR. ALLEN: Thank you, Dr. Holness.
11 Questions from the committee members?
12 Obviously, this is very important data,
13
but it is limited in that it is reporting only of
14
fatalities. Do you have other
information in terms
15
of how well the research community has responded to
16
this issue? Are there any
recommendations coming
17
out of the recent meeting that you think should
18
come before the committee at least today or in the
19
near future?
20 DR. HOLNESS: I
think that probably the
21
best thing is to wait until the full report of the
22
committee is out before we make recommendations.
22
1 DR. ALLEN:
Okay. Other questions? Yes.
2 DR. SCHREIBER:
From your graph it looks
3
like we are seeing an increased frequency of TRALI,
4
but it is probably due to more awareness, don't you
5
think, of the reporting, particularly since all of
6
the activities that started around '99?
7 DR. HOLNESS:
That is true.
8 DR. SCHREIBER:
My other question is on
9
one of the slides from the Toronto, you had an
10
incidence, I think it was 1 in 5,000 to 1 in
11
100,000, and that is the incidence of TRALI
12
reactions, TRALI-type reactions, but the mortality
13
rate is somewhere closer to 1 in 750,000, I
14
believe.
15 DR. HOLNESS: I
think you are right on
16
that, yes.
17 DR. SCHREIBER:
Thank you.
18 DR. ALLEN: On
that slide, it said 1 in
19
5,000 and 1 in 100,000, but I think you read 1 in
20
5,000 and 1 in 10,000. Which is
the correct
21
number, the 10,000 or 100,000?
22 DR. HOLNESS: 1
in 100,000. It is my
23
1
mistake, I am sorry.
2 DR. ALLEN:
Thank you very much.
3 We will move on to the second committee
4
update, Donor Blood Pressure Determination
5
presented by Dr. Alan Williams.
6 Donor Blood Pressure Determination
7 Alan Williams, Ph.D.
8 DR. WILLIAMS:
Thank you, Jim, and good
9
morning.
10 As you will note from some of the
11
statements from the blood and plasma community that
12
have been distributed, FDA has been asked to
13
restate and reconsider its position with respect to
14
blood pressure determination as a criterion for
15
blood donation and plasma donation eligibility.
16
That is what I intend to do very briefly this
17
morning.
18 [Slide.]
19 The FDA regulatory position is stated
20
quite clearly in two regulations.
21 CFR
21
640.3(b)(2) requires donor's systolic and diastolic
22
blood pressure are within normal limits, unless a
24
1
physician, after examining the donor, is satisfied
2
that the donor is otherwise qualified.
3 This needs to be considered in conjunction
4
with another regulation, 21 CFR 606.100(b)(2),
5
which states that a blood collection facility
6 include in its Standard Operating Procedures
7
methods of performing donor qualifying tests and
8
measurements, including minimum and maximum values
9
for a test or a procedure when a factor in
10
determining acceptability.
11
[Slide.]
12 When reviewing Standard Operating
13
Procedures presented by licensed blood collection
14
establishments, in fact, we do look for SOPs that
15
define both an upper and a lower range of normal
16
blood pressure, and, in addition, if outside the
17
normal range, a donor must be medically evaluated
18
for donation eligibility.
19 Not only do we do that in current
20
submissions, but we, in fact, did a randomized look
21
at prior approvals of SOPs, and in all of the
22
licensed establishments that we looked at, they had
25
1
both lower and upper limits included.
2 FDA has not historically specified the
3
cutoff values to be used for a lower limit. This
4
is, in fact, controversial as to what the
5
predictive value of the lower limit is and what the
6
lower limit of normal, in fact, should be,
7
certainly a subject for future discussion.
8 But I will note that while there are some
9
studies which have been cited by some of the
10
position statements, what probably is lesser known
11
is that FDA has received some isolated reports of
12
severe vasovagal reactions in donors who were
13
found, upon review of the record, to have had
14
abnormally low blood pressures at the time of
15
donation.
16 [Slide.]
17 To summarize, I think what the basis is of
18
the industry request for policy clarification, on
19
the fact that the predictive value of a single low
20
blood pressure determination has not been finally
21
established, I think you can see a range in the
22
literature, and in some of the cases, particularly
26
1
the case-controlled studies, you can see that blood
2
pressure on a univariate analysis emerges as a
3
factor, but may not stand up to a multivariate
4
analysis.
5 This is evidence that it may not be an
6
independent factor, but, in fact, may be tied up in
7
interaction with demographic or other variables.
8
So, analyses of some of these studies require both
9
large studies and rather complex multivariate
10
analysis to determine what the interaction effects
11
and other potential impact might be.
12 The European community, particularly the
13
UK, in their blood collection procedures do not
14
determine a blood pressure value at all, although
15
if the donor has a history of reactions or of
16
hypertension, they maintain the equipment available
17
to make the determination, but, in short, in the
18
UK, the blood pressure is not determined.
19 The 2004 EU directive does not include a
20
blood pressure determination requirement, and the
21
current Council of Europe guide includes only an
22
upper blood pressure limit.
27
1 [Slide.]
2 And though not necessarily scientifically
3
based, the observation has been made that the
4
voluntary industry standards for blood collection,
5
which originally required both an upper and lower
6
blood pressure value, were modified to remove the
7
lower level requirement some time ago, in 1987, and
8
that some blood establishment SOPs may current
9
omit, or may have historically omitted, a lower
10
blood pressure cutoff value.
11 As I stated, licensed establishments are
12
reviewed for having an SOP that includes this
13
requirement, it is possible that some of the sites
14
that don't may be registered facilities which
15
should be following the regulation, but whose SOPs
16
are not reviewed by FDA.
17 [Slide.]
18 So, in summary, FDA strictly adheres to
19
the existing regulations, but FDA does not
20
recognize the need for scientific consensus on the
21
value of donor blood pressure determinations and
22
considers its regulations to require that they be
28
1
scientifically based.
2
So, I think some of the
uncertainties that
3
may be there in the published literature should be
4
looked at further.
5 Under the HHS Blood Action Plan, FDA
6
intends to propose rulemaking that will
7
comprehensively address donor eligibility
8
requirements including blood pressure, and as part
9
of this process, there will be an opportunity for
10
data presentation and comment to any proposed rule
11
that might emerge.
12 Thank you.
13 DR. ALLEN:
Thank you, Dr. Williams.
14 Questions or comments from the committee?
15
Yes.
16 DR. GOLDSMITH:
What were the blood
17
pressures in the FDA reports for the severe
18
reactions, how low were they really?
19 DR. WILLIAMS:
I do not remember the
20
actual values, but they were lower than what the
21
original industry standard was, which I believe the
22
lower limits were 90 and 50 for the systolic and
29
1
diastolic.
2 DR. KLEIN:
Alan, I am sure you are aware
3
that there may be a little bit of a reporting bias
4
in those reports you have. There
has been an
5
extensive literature on vasovagal reactions and
6
donor vital signs, and to the best of my knowledge,
7
there has never been any correlation between blood
8
pressure and vasovagal reactions, and knowing how
9
vasovagal reactions generally occur, I am not sure
10
that there should be.
11 DR. LEITMAN:
You quote a study, which is
12
an excellent one, a multi-center study published in
13
Transfusion in '99, where Trend and colleagues
14
looked at the effect of blood pressure and other
15
factors pre-donation on the incidence of vasovagal
16
during donation, and in a univariate analysis, low
17
blood pressure was associated with vasovagal
18
reactions, but in a regression analysis, which is
19
very important, when you put in the variables of
20
age, weight, and donor status prior donations, that
21
fell out.
22 So, you really have to go with the best
30
1
scientific data you have, I think, in a complex
2
analysis like this, and that is very helpful for me
3
to look at this data.
4 DR. WILLIAMS:
Yes, I agree. There was
5
probably a most sophisticated analysis to address
6 this
particular subject, but, you know, one could
7
argue was that study large enough to pick up a
8
potential interaction effect between the
9
demographic variables and blood pressure.
10 In fact, on univariate analysis, there was
11
quite a difference, 3 percent incidence of
12
reactions with the lower blood pressures versus 1
13
percent of the control group, so I think it just
14
bears a further look with more sophisticated
15
analysis.
16 DR. ALLEN:
Other questions or comments?
17
Okay. Thank you very much.
18 At this point, we will move on the open
19
hearing, to the public hearing.
20 Before we get started on that, I need to
21
read an open public hearing announcement for
22
general matters meetings.
31
1 Both the Food and Drug Administration and
2
the public believe in a transparent process for
3
information gathering and decisionmaking. To
4
ensure such transparency at the open public hearing
5
session of the Advisory Committee meeting, FDA
6
believes that it is important to understand the
7
context of an individual's presentation.
8 For this reason, FDA encourages you, the
9
open public hearing speaker, at the beginning of
10
your written or oral statement to advise the
11
committee of any financial relationship that you
12
may have with any company or any group that is
13
likely to be impacted by the topic of this meeting.
14
For example, the financial information may include
15 a
company's or a group's payment of your travel,
16
lodging, or other expenses in connection with your
17 attendance
at the meeting.
18 Likewise, FDA encourages you at the
19
beginning of your statement to advise the committee
20
if you do not have any such financial
21
relationships. If you choose not
to address this
22
issue of financial relationships at the beginning
32
1
of your statement, it will not preclude you from
2
speaking.
3 Open Public Hearing
4 DR. ALLEN:
Let's go ahead with the public
5
statements on TRALI. I have a
request from the
6
American Association of Blood Banks.
7 MS. GREGORY:
Thank you. My name is Kay
8
Gregory and I am the Director of Regulatory Affairs
9 for the AABB, and I have only financial
10
arrangements with them and no other companies.
11 AABB is an international association
12
dedicated to advancing transfusion and cellular
13
therapies worldwide. Our members
include more than
14
1,800 hospital and community blood centers and
15
transfusion and transplantation services as well as
16
approximately 8,000 individuals involved in
17
activities related to transfusion, cellular
18
therapies, and transplantation medicine.
19 For over 50 years, AABB has established
20
voluntary standards for, and accredited
21
institutions involved in, these activities. AABB
22
is focused on improving health through the
33
1
advancement of science and the practice of
2
transfusion medicine and related biological
3
therapies, developing and delivering programs and
4
services to optimize patient and donor care and
5
safety.
6 The AABB believes that TRALI is a
7
significant transfusion safety concern that merits
8
increased awareness and research.
In an effort to
9
educate our members about the clinical and
10
laboratory features of TRALI, AABB has issued
11
guidelines for the management of TRALI, and our
12
association considers this a priority transfusion
13
safety matter.
14 We commend the FDA for alerting physicians
15
to the risk of TRALI from transfusion of
16
plasma-containing blood products in 2001, however,
17
we are disappointed that the Federal Government has
18
not done more to advance needed research regarding
19
this important transfusion safety issue since the
20
Blood Products Advisory Committee last addressed
21
TRALI in 2001.
22 In order to allow for the most effective
34
1
and meaningful research and clinical understanding
2
of this condition, the AABB proposed that a
3
standard uniform definition of TRALI be established
4
and adopted by the medical community and
5
policymakers, including the FDA.
6 Earlier this year, Canadian Blood Services
7 and Hema-Quebec hosted
a valuable consensus
8
conference, bringing together the leading experts
9
to discuss the current state of knowledge regarding
10
TRALI.
11 At the end of this conference, the group
12
recommended definitions of TRALI and "possible
13
TRALI," and we have attached to our written
14
statement our current understanding of those
15
definitions.
16 In general, the group recommended that
17
TRALI should be diagnosed in patients with no acute
18
lung injury prior to transfusion who, during or
19
within six hours after transfusion, experienced
20
certain specific criteria. They
distinguished
21
"possible TRALI" cases, which would involve
22
patients with the same criteria who also had one or
35
1
more temporally associated ALI risk factors.
2 The AABB endorses the definitions set
3
forth during the consensus conference and urges the
4
FDA to adopt these definitions as well.
Emerging
5
data and research regarding TRALI should be
6
carefully monitored to determine if refinements to
7
these definitions are necessary over time.
8 Using the uniform definitions, AABB
9
recommends that additional research be conducted to
10
define the scope of the problem and its mechanisms
11
or pathophysiology. As we
proposed to BPAC in
12
2001, AABB continues to advocate a prospective
13
epidemiologic study to establish the incidence of
14
TRALI. For example, we propose a
multi-center
15
study of acute lung problems in the transfusion
16
setting to assess, evaluate, and analyze all
17
pulmonary reactions using a standardized protocol.
18 The AABB also continues to recommend that
19
the NHLBI establish a multi-center study to lead to
20 a
better understanding of the mechanisms that cause
21
TRALI. Once the mechanisms of
TRALI are better
22 understood,
the risk factors in donors and
36
1
recipients may become apparent.
2 The AABB continues to believe that more
3
data are needed before establishing donor deferral
4
criteria or other regulatory strategies for TRALI.
5
When a severe clinical reaction has occurred, an
6
antibody has been identified in the donor and the
7
recipient has the corresponding antigen, the
8
preventive measure is relatively clear.
9 In such cases, it is generally agreed that
10
blood from that donor should never again be
11
transfused to the same recipient.
However, it is
12
not so clear that such a donor should be
13
permanently deferred from donating any blood
14
component.
15 The appropriate preventive measures for
16
TRALI are even less obvious for the majority of
17
pulmonary reactions that occur in the transfusion
18
setting.
19
It is also important to
understand what
20
proportion of the donor population would be
21
affected by proposed deferral criteria or other
22
regulatory strategies, so that the potential impact
37
1
on the blood supply can be evaluated. These data
2
are especially critical, as we already too
3
frequently face blood shortages in regions across
4
the country.
5 A careful and thorough analysis of the
6
risks and benefits of any donor deferrals or any
7
other regulatory strategy must be completed before
8
taking steps that could unnecessarily hinder
9
patient access to life-saving blood components.
10 Thank you.
11 DR. ALLEN:
Thank you very much.
12 Questions or comments from the committee
13
in response? Yes.
14 DR. KLEIN: We
have heard on a couple of
15
occasions now about the Canadian Consensus
16
Conference and clearly it's an important one, but
17
the results haven't been published yet, and I would
18
certainly caution the FDA about the definition that
19
has been proposed. It's a
preliminary definition.
20 Many of the patients that we take care of
21
are in intensive care units, they are on
22
respirators, they do have some kind of underlying
38
1
lung disease, and they get a lot of blood
2
transfusions. By the definition
that has been
3
proposed, should any of them have what looks like
4
TRALI, they would be excluded under the proposed
5
definition.
6 I am not sure that is the permanent
7
definition. I think we ought to
wait before
8
adopting anything to see what the publication says.
9 DR. ALLEN:
Thank you. I think that is
10
very good advice.
11 Other questions or comments? Yes.
12 DR. HARVATH: I
would like to just address
13 a
couple of points about the recommendation for
14
supportive research from the NHLBI perspective.
15
There have been a number of ways we have been
16
trying to stimulate this during the past several
17
years.
18 One of the ways that we are going about
19
doing this is through the transfusion medicine
20
hemostasis clinical trial network, which is a
21
multi-center, 17 clinical centers throughout the
22
United States.
39
1 We have discussed with that committee
2
looking at prospectively any study which involved
3
the transfusion of components, and almost every
4
study does, looking prospectively to find any
5
evidence of TRALI in the patients in those studies,
6
so it will be the opportunity to look at both a
7
platelet transfusion study, which is our first
8
study, and possibly a second study that would
9
potentially involve FFP, and these would be
10
randomized studies, and the work would be done
11
prospectively.
12 The second point is that the NHLBI also
13
funds a multi-center acute respiratory distress
14
network, which involves the pulmonary specialists,
15
and they have become interested in this area, so
16
there are investigators who are also interested in
17
looking in that patient population.
18 So, these are existing clinical trial
19
networks where this would be possible to integrate
20
this type of research, and also to add that NHLBI
21
welcomes any investigator-initiated studies to come
22
forward to the institute and to let us know what
40
1
kinds of research investigators or groups of
2
investigators would like to pursue.
So, we are
3
very open to that.
4 DR. ALLEN:
Thank you. It is certainly
5
helpful to have both lung and blood in the same
6
institute from that perspective, I am sure.
7 Other questions or comments?
8 Okay. We will
move on to the next
9
statement on blood pressure lower limits by the
10
AABB. I am sorry, excuse me, we
do have one
11
additional statement on TRALI, Dr. Fitzpatrick from
12
the America's Blood Centers.
13 DR. FITZPATRICK:
Mike Fitzpatrick, Chief
14
Policy Officer for America's Blood Centers, and I
15
am employed by them.
16 America's Blood Centers, or ABC, is
an
17
association of 76 not-for-profit, community-based
18
blood centers that collect nearly half of the U.S.
19
blood supply from volunteer donors.
ABC thanks
20
FDA's Center for Biologics Evaluation and Research
21
for the opportunity to make public comments before
22
the Blood Products Advisory Committee.
41
1 Our members share FDA's concerns about
2 transfusion related acute lung injury. While rare,
3
this is a serious and sometimes fatal
4
transfusion-associated event. We
know that TRALI
5
is a complex phenomenon, and there is no agreement
6
in the published literature about the major
7
mechanisms of disease.
8 This was clearly documented at the
9
Canadian Consensus Conference that we have heard
10
about.
11 At least two mechanisms appear to play a
12
role, one involving antibodies to leukocytes, the
13
other involving biologically active mediators.
14
Interestingly enough, in the paper published by
15
Silliman--I won't quote the source here, but you
16
have got that--most of the TRALI events appear to
17
be related to biologically active mediators and
18
only one of the 90 reactions studied involved a
19
plasma unit.
20 Most reactions, 74, involved whole blood
21
derived and apheresis platelets.
Kopko has
22
indicated that many units implicated in TRALI
42
1
reactions carry antibodies to white blood cells.
2
However, she concluded from her studies that HLA
3
antibodies in a donor corresponding to HLA antigens
4
in a recipient are not sufficient to cause TRALI in
5
all recipients.
6 She also noted that based on lookback
7
studies, donors implicated in TRALI reactions can
8
cause TRALI in other recipients, regardless of
9
antigen-antibody correlations.
While presentations
10
also indicated a higher rate of female plasma
11
donors who have been pregnant carry anti-HLA
12
antibodies, data is lacking that would establish a
13
definitive link between gender and/or anti-HLA
14
antibodies and TRALI.
15 Dr. Holness from FDA presented the FDA
16
fatality data at that conference and a summary of
17
the data today here. He showed
an apparent
18
increase in TRALI associated fatalities in recent
19
years. He also indicated that
the majority of the
20
49 fatalities that occurred between 2001 and 2003
21
were associated with plasma transfusions. The
22
number or percent was not indicated.
43
1 The donor data presented did not include
2
donor gender or prevalence of antibodies to
3
leukocytes, so we cannot estimate the impact of the
4
three preventive strategies enumerated by FDA:
5
only transfuse plasma containing components from
6
male donors, perform preventive antibody testing,
7
defer donors implicated in TRALI cases.
8 We agree that FDA should review and
9
consider interventions to address the issue of
10
TRALI. The impacts of such
strategies must also be
11
considered by asking the following questions:
12 How many TRALI associated fatalities will
13
be prevented by the implementation of each
14
strategy? What blood components
should be included
15
in the strategy? TRALI has been
associated with
16
all blood components, including red blood cells,
17
apheresis platelet units, which contain as much or
18
more plasma than a unit of fresh frozen plasma.
19 What impact will this have on the
20
availability of components? Are
there other
21
strategies that could be considered?
22 The data presented by FDA, the current
44
1
literature, the recommendations made by BPAC in
2
2001 and the conclusions of the Canadian Consensus
3
Conference, while not yet published, that were
4
summarized at the meeting, do not provide a clear
5 basis for any of the regulatory strategies listed.
6
Whole blood, whole blood derived platelets,
7
apheresis platelets, and plasma have all been
8
implicated in TRALI. Why
restrict the approach the
9
plasma, what about apheresis platelets?
10 We carried out a survey to assess the
11
impact of using only male plasma and platelet
12
apheresis products among ABC members.
Forty-two
13
centers collecting a total of almost 4 million
14
whole blood and apheresis units a year responded.
15 Based on the gender distribution of ABC
16
donors, we estimate that a ban on female plasma and
17
apheresis platelets would lead to the loss of
18
113,000 donors and 275,000 donations in one year.
19
If we double this estimate to include collections
20
by the American Red Cross, 550,000 donations would
21
be lost in the U.S.
22 Females represent about 44 percent of all
45
1
apheresis donors. Our members indicated that they
2
could not effect these changes without seriously
3
impairing product availability.
When our members
4
were asked whether they could provide male plasma
5
only to their hospitals, 55 percent responded yes.
6 However, they indicated that it would take
7
them between 18 and 24 months to implement the
8
changes, including software modifications, and that
9
the change would create serious shortages of type
10
specific plasma, particularly type AB.
11 ABC members disagree with FDA's point of
12
view that strategy number 3, deferral of donors
13
implicated in TRALI incidents, is inadequate
14
because it allows for the first incident to occur
15
before donor deferral is instituted and does not
16
eliminate TRALI.
17 Unfortunately, all the proposed strategies
18
suffer from this deficiency because of the myriad
19
causes of TRALI. Strategy 1
addresses an
20
undetermined fraction of TRALI cases and has more
21
serious consequences for blood availability.
22 At the present time and with the present
46
1
knowledge, regulatory action should be restricted
2
to donors implicated in TRALI episodes, as stated
3
in the third strategy.
4 FDA also needs to support effective
5
training of physicians and other hospital personnel
6
for early recognition of TRALI, based on the case
7
definition being considered by an NHLBI task force,
8
which was not discussed this morning, under the
9
leadership of Dr. Pearl Toy.
This may be more
10
efficient in the prevention of fatalities than any
11
of the proposed strategies.
12 The implementation of a global strategy
13
such as the deferral of male donors may have other
14
adverse consequences. It may
convey to the medical
15
community and to the public the erroneous
16
impression that the problem of TRALI has been
17
addressed and resolved, leading physicians to
18
consider other diagnoses and prescribe
19
inappropriate therapy.
20 Finally, we will have to deal with the
21
frustration of female donors when they learn that
22
their donations are not good for transfusion.
47
1 ABC members thank FDA and the BPAC for the
2 opportunity
to comment.
3 Thank you.
4 DR. ALLEN:
Thank you very much.
5 Questions or comments with regard to Dr.
6
Fitzpatrick's presentation? Jay.
7 DR. EPSTEIN: I
just want to comment that
8
this was an informational update, and the intent
9
was more to get the issue on everybody's radar
10
screen than to propose action at this point in
11
time. I think that Dr. Holness'
presentation made
12
clear that we are aware of all the uncertainties
13
and the ambiguities.
14 It is also true that the UK, faced with
15
the same uncertainties and ambiguities, felt that
16
action should be taken and it has its pros and
17
cons, so this is not rush to judgment and I
18
appreciate all the cautionary notes that have been
19
sounded, but I think that, you know, we have been
20
living with awareness of TRALI without effective
21
intervention for some time, and the idea here is to
22
provoke ourselves to think about could we be doing
48
1
more and what should that be.
So, this is just an
2
early stage of thinking.
3 DR. FITZPATRICK:
We understand, Jay, and
4
we just appreciated the opportunity to make some
5
comments and present some questions.
6 DR. ALLEN:
Other questions or comments
7
from the committee members?
8 Dr. Davis.
9 DR. DAVIS: I
would like to speak as
10
somebody that treats a lot of people with acute
11
lung injury. TRALI is not
something that is on
12
most of our radar screens. Most
of the people that
13
have acute lung injury, if you look at the list of
14
risk factors, most of those people, as Dr. Klein
15
alluded, get multiple transfusions for a lot of
16
other reasons.
17 The other thing that I really haven't
18
heard, and I don't know if there is an answer to
19
the question, is what is the survival rate. I mean
20
we have heard what the fatality is, but how many
21
people get TRALI and actually survive.
22 I think it is going to be hard to isolate
49
1
those kinds of isolated transfusion-related
2
injuries. I am not sure how many
clinicians are
3
actually aware of TRALI.
4 DR. ALLEN: I
think those are very good
5
points and certainly go right along with what Dr.
6
Harvath was saying about the need for prospective
7
multi-center studies.
8 The comment was made earlier today also
9
about the definition of TRALI, and it sounds to me,
10
with two proposed mechanisms in place, that we may
11
actually be dealing with multiple different
12
clinical events that need to be teased apart and
13
separated, and it sounds to me as though there is a
14
lot of research that needs to be done.
15 It is an important issue given the
16
relative incidence in terms of serious events
17
related to transfusion. I am sure that we are not
18
ready for any regulatory consideration at this
19
point.
20 We will look forward to additional updates
21
and research findings.
22 Other questions or comments?
50
1 [No response.]
2 DR. ALLEN:
Okay. Thank you.
3 We will move on the statements with regard
4
to blood pressure lower limits.
AABB.
5 Could I ask you not to read the first
6
paragraph, please, and just to move on with the
7
statement itself. Thank you.
8 MS. GREGORY:
Thank you. I had every
9
intention of doing that.
10 I also wanted to make the committee aware
11
that I am speaking, not only on behalf of the AABB,
12
but I am also speaking on behalf of America's Blood
13
Centers. Your written statements
don't reflect
14
that simply because of the need to get it in
15
quickly, so that you could have it ahead of time,
16
but I am speaking for both organizations.
17 Neither the AABB nor ABC supports the need
18
for a lower limit for blood pressure for blood
19
donors. Blood collection
facilities have had only
20
upper limits for blood pressure in place for many
21
years.
22 The AABB Standards for Blood Banks and
51
1
Transfusion Services requires that the blood
2
pressure be 180 systolic and 100 diastolic. These
3
levels have been the requirement since 1987. This
4
particular standard was reviewed again in 2002 and
5
again in 2003, and the Blood Banks and Transfusion
6
Services Standards Program Unit found no scientific
7
evidence to warrant changing the standard.
8 I also want to explain the difference
9 between
the AABB standards and the AABB technical
10
manual because the written materials that you
11
received talked about statements that are in the
12
technical manual.
13 The AABB standards are where the
14
requirements are stated, and they include
15
requirements for both quality management and
16
technical requirements. The
technical manual is
17
published to provide background material, some
18
guidance, and methods and procedures, but does not
19
include requirements.
20 The technical manual may provide practices
21
that will assist facilities in implementing
22
standards, but the standards is the definitive
52
1 document.
2 Another reason why we do not see a need
3
for a lower limit for blood pressure is that we
4
know that blood pressure is not a requirement for
5
donor qualification in the latest European Union
6
Commission directive.
7 The Council of Europe Guide states: If
8
pulse and blood pressure is tested, then the pulse
9
should be regular and between 50 and 100 beats per
10
minute. It is recognized that
recording the blood
11
pressure may be subject to several variables, but
12
as a guide, the systolic blood pressure should not
13
exceed 180 millimeters of mercury and the diastolic
14
pressure 100 millimeters.
15 A review of medical textbooks revealed
16 that there is no consistency about what is
17
considered to be hypertension in asymptomatic
18
individuals, and that a low blood pressure is not a
19
matter of great concern or interest outside of the
20
emergency room or intensive care settings.
21 A number of researchers have published
22
articles in peer-reviewed journals showing a lack
53
1
of correlation between low pre-donation systolic or
2 diastolic blood pressure and adverse donor
3
reactions.
4 A 2002 study of 72,059 whole blood
5
donations at the American Red Cross showed no
6
statistical association between low pre-donation
7
systolic or diastolic blood pressure and adverse
8
reactions.
9 In addition, the American Red Cross
10
reviewed pre-donation blood pressure on all donors
11
with adverse reactions that resulted in
12
hospitalization from January of 1999 to December of
13
2002. This review showed no
over-representation of
14
low blood pressure in those donors.
15 Finally, a review of donor fatality
16
reports obtained under the Freedom of Information
17
Act showed no low pre-donation blood pressure
18
either.
19 There are two Code of Federal Regulation
20
requirements that FDA has quoted as the rationale
21
for adding a lower limit for blood pressure. 21
22
CFR 640.3(b)(2), which states that systolic and
54
1
diastolic blood pressure must be within normal
2
limits, and 606.100(b)(2), which states that the
3
standard operating procedures for donor-qualifying
4
tests and measurements must specify maximum and
5
minimum values.
6 It is unclear why FDA has recently chosen
7
to selectively enforce this particular requirement
8
for blood pressure. There are
other
9
donor-qualifying tests and measurements that do not
10
have both upper and lower limits. For example,
11
temperature has only an upper limit, and weight,
12
hemoglobin, and age only a lower limit.
13 We have already noted the lack of uniform
14
agreement as to what constitutes a low blood
15
pressure in asymptomatic individuals.
In short,
16
while there may be a regulation that can be cited
17
as justification for this change in policy, the
18
regulation has not been enforced in the past and a
19
change in policy is unnecessary.
20 A key element of the FDA's 2004 strategic
21
action plan is efficient risk management. This
22
plan states that in all of its major policies and
55
1
regulations, FDA is seeking to use the best
2
biomedical science, the best risk management
3
science, and the best economic science to achieve
4
health policy goals as efficiently as possible. A
5
change to the requirement for donor blood pressure
6
does not meet these criteria.
7 DR. ALLEN:
Thank you.
8 Questions or comments? Yes.
9 DR. DiMICHELE:
Thank you for that. It
10
seems to me that the question at hand here is
11
whether a low blood pressure is physiologic for the
12
individual or whether it might represent
13
dehydration or for vasomotor tone and inability to
14
vasoreact in the face of acute volume reduction,
15
those kinds of issues.
16 It appears based on the epidemiologic data
17
that most of it isn't. However,
when you speak
18
about asymptomatic hypotension or asymptomatic
19
blood pressure, low blood pressure, do you--remind
20
me, I should know this because we have looked at
21
those criteria and those questions time and time
22
again--but do you ask a question in the pre-donor
56
1
screening about symptomatic hypotension or
2
symptomatic low blood pressure in the pre-donation
3
screening questionnaire?
4 MS. GREGORY:
We don't ask that
5
specifically, but we do ask things like are you
6
being treated by a doctor, things that we think
7
would elicit that information, but not that
8
specific question.
9 DR. DiMICHELE:
And the second question I
10
have is again, it is obvious that if the blood
11
pressure is physiologic for the individual, it is
12
probably not going to tend to be pathologic in any
13
way in donation, so do you have a way for multiple,
14
when you have repeat donors, to actually track
15
their blood pressures over time and to be able to
16
identify a low blood pressure that might be
17
unphysiologic for that individual?
18 MS. GREGORY:
The blood pressure is
19
recorded at each donation, and we do keep those
20
records, so I think there probably would be a way
21
to track that if we needed to.
22 DR. DiMICHELE:
So, really, basically, a
57
1
decrease in routine blood pressure that wasn't
2
previously hypotensive or certainly symptomatic
3
hypotension might be ways of picking up symptoms
4
without necessarily initiating a lower limit.
5 MS. GREGORY:
Thank you.
6 DR. ALLEN: Let
me just clarify, though, I
7
don't think when a person comes in to donate blood,
8
the information is obtained for that donation only,
9
and I don't think they go back and look at a
10
sequence of past blood pressure determinations.
11 Certainly, a change in laboratory values
12
might be noted, but I don't think that they would
13
go back and look at the pre-, you know, they don't
14
have pulled up on a computer screen or a paper
15
record that would show what the blood pressure
16
determinations were at the last two or three
17
donations.
18 DR. DiMICHELE:
That is what I was asking,
19
if that information was readily available.
20 MS. GREGORY:
That's right, we would not
21
look at it right then, but we would have the
22
ability to look at it should we think there is a
58
1
need to look at it for some reason.
2 DR. ALLEN:
Thank you. Other questions or
3
comments? Yes, Dr. Williams.
4 DR. WILLIAMS: Kay, a comment and a
5
question.
6 This was characterized as a change in
7
regulatory policy. I think that
perhaps isn't
8
correct. It might be a rift in
communication
9
particularly with respect to the industry voluntary
10
standards, but the question is what is the risk
11
side of the equation.
12 We take the point that regulation should
13
be scientifically based, but what is the impact on
14
blood collection? I would pose
the same question
15
to the PPTA speaker. What is the
donor loss, what
16
are the operational implications of recording a
17
lower blood pressure? What is
the impact?
18 MS. GREGORY: I
think the operational
19 limitations
are that we already record everything
20
under the sun, and recording one more thing might
21
not seem like it would be that difficult, but it is
22
one more chance to record it wrong and you have to
59
1
keep track of it all, and it is not that it is
2
impossible to do, it is just we would like to be as
3
efficient as we possibly could, and we don't think
4
there is a reason for recording this.
5 DR. ALLEN:
Thank you.
6 We have a written statement also from the
7
Plasma Protein Therapeutics Association. Is there
8 a
need to read that, do we have a speaker or a
9
proposed speaker? Okay. Thank
you. I will just
10
note for the record that there is a written
11
statement from PPTA also.
12 The open public hearing is now closed.
13 We will move on to the next item on the
14
agenda, which is an open committee discussion of
15
Topic I, Dating of Irradiated Red Blood Cells. We
16
have a number of speakers and we will plan to spend
17
the rest of the morning on this discussion,
18
concluding with a series of questions for the
19
committee.
20
The first speaker with
Introduction and
21
Background is Dr. Ping He with the Food and Drug
22
Administration.
60
1 I. Dating of Irradiated Red Blood Cells
2 Introduction and Background
3 Ping He, M.D.
4 DR. HE: Good
morning. I am going to talk
5
about the introduction and background of dating
6
period for gamma irradiated red blood cells.
7 [Slide.]
8 Why do we have the irradiated blood
9
product? The answer is that the
irradiation of
10
blood products can prevent transfusion associated
11
graft-versus-host disease, GVHD.
GVHD occurs when
12 viable cytotoxic allogeneic lymphocytes are
13
transfused to a recipient unable to reject them and
14
cause disease.
15 Patients at risk are neonates,
16
immunocompromised patients for different reasons,
17
and the recipient is genetically related to the
18
blood donors.
19 [Slide.]
20 Here is the clinical pathological features
21
of GVHD. GVHD is a rare batch of
very fatal
22
complication of transfusion associated disease.
61
1
All cells with HLA antigens are affected. The
2
cause of disease starts with the lymphocytes from
3
donor, from the transfused blood and graft into
4
recipient.
5
These transfused donor
lymphocytes can
6
then proliferate and damage the target organs, such
7
as bone marrow, skin, gastrointestinal tract, and
8
liver. The symptoms may appear
two to 30 days
9
after blood transfusion with skin rash, diarrhea,
10
liver enzyme elevation and pancytopenia.
11 The occurrence is about 0.1 to 1 percent
12
with no effective therapy. The
mortality is high,
13
usually close to 100 percent.
14 [Slide.]
15
Fortunately, GVHD can be
prevented by
16
gamma irradiation of blood products prior to
17
transfusion to inactivate the donor lymphocytes
18
that cause the disease.
19 The blood products can be irradiated if
20
the recipient is immunocompromised or the blood
21
donor is genetically related to the recipient.
22 [Slide.]
62
1 The advantage of gamma irradiation of
2
blood products is that it can prevent GVHD,
3
however, the disadvantage of irradiation of red
4
blood cells can cause the decrease of
5
post-transfusion of red blood cell recovery and
6
increase the leaking of intracellular potassium.
7
This raises the concerns for the safety and
8
efficacy of the irradiated red blood cells.
9 Therefore, the irradiated red blood cells,
10
the storage period should be limited.
This issue
11
has received attention in the past and it was the
12
subject of a 1992 NIH workshop, and in 1994, a BPAC
13
discussion.
14 In July 1993, a memorandum was issued by
15
FDA and it recommended that the irradiation dosage
16
for RBC should be 2,500 centigray in the center
17
portion of the container and 1,500 centigray in the
18
other point. The dating period
for RBC should be
19
not more than 28 days from the date of the
20
irradiation, but not more than the dating period of
21
the original product.
22 This means that if an adequate solution
63
1
allows RBCs to be stored up to day 42.
The RBCs
2
can be irradiated anytime from day 1 to day 42
3
after collection. If the
irradiation happens from
4
day 1 to day 14, then, the irradiated RBCs will
5
have an additional 28 days for the storage.
6 [Slide.]
7 If the irradiation happened after the day
8
14 of the collection, then, the irradiated RBCs can
9
be stored up to day 42.
10 [Slide.]
11 Here is the BPAC 1994. FDA proposed
12
changing the dating period of irradiated red blood
13
cells based on updated data from American Red Cross
14
and NIH obtained since 1993. However, the committee
15
at that time recommended no change from 1993
16
memorandum, but the committee did suggest that the
17
criteria might be reconsidered should future data
18
become available.
19 In February 2000, FDA issued a Guidance
20
for Industry titled as Gamma Irradiation of Blood
21
and Blood Components: A Pilot Program for
22
Licensing.
64
1 This guidance recommended the same dating
2
period as it was stated in 1993 memorandum.
3 [Slide.]
4 Today, we would like to revisit this issue
5
again for following reasons: In
view of potential
6 safety
and efficacy concerns for RBCs irradiated in
7
new anticoagulant and additive solutions, FDA
8
requests that sponsors should submit data to
9
support licensure.
10 Recent data from the sponsors raised
11
concerns on the efficacy of RBCs irradiated in the
12
new anticoagulant and additive solutions. I am
13
going to briefly summarize some data to explain our
14
concern.
15 In addition, we also have concerns about
16
the FDA's current criteria for in vivo RBC
17
recovery.
18 [Slide.]
19 Here is the FDA current recommendations
20
for the in vivo RBC recovery evaluations. This
21
evaluation is to test the ability of RBC products
22
to circulate after autologous infusion of
65
1
radiolabeled RBCs.
2 The viability of RBC is assessed by
3
determining the RBC recovery 24 hours after
4
infusion of autologous cells.
Usually, we look for
5
equal or greater than 75 percent recovery.
6 The current criteria recommends that the
7
study site should be 20 to 24 in more than one site
8
with standard deviation of less or equal to 9
9 percent. If the sample mean is equal or greater
10
than 75 percent, then we will have a 95 percent
11
lower confidence limit greater than 70 percent.
12 This criteria will be further discussed by
13
Dr. Kim, the mathematical statistician from FDA
14
later this morning.
15 [Slide.]
16 Here is the study results of sample
17
failure 28 days after irradiation from Manufacturer
18
A. Sample failure is defined as
less than 75
19
percent recovery after reinfusion.
20 The sponsor conducted two groups of
21
studies. The first group, the
RBCs irradiated on
22
day 1, evaluated on day 28. The
second group, the
66
1
RBCs irradiated on day 14, and evaluated on day 42.
2 The study was carried out at three
3
different sites. For Site 1 and
Site 2, the RBCs
4
were irradiated for 500 centigray, and for Site 3,
5
the RBCs were irradiated for 3,000 centigray.
6 As you can see, the RBCs irradiated on day
7 1
and evaluated on day 28, there was 3 out of 22
8
failures, about 14 percent failure, but RBCs
9
irradiated on day 14 and evaluated on day 42, there
10
were 5 out of 21 failures, about 24 percent
11
failures.
12 [Slide.]
13 Here is another example of sample failure
14
28 days after irradiation from Manufacturer B. In
15
this study, the sponsors only did studies of RBCs
16
irradiated on day 14, and they were evaluated on
17
day 42.
18 The studies were carried out in two
19
different centers, and all the RBCs are irradiated
20
at 2,500 centigray. Two groups
of studies done,
21 one
is for tests, the other group is for control.
22
The test units, as you can see, there were about 21
67
1
percent failure, and for control group, there were
2
11 out of 24, about 46 percent of failure.
3 [Slide.]
4 So, from this data, we find out the longer
5
the storage or the later the irradiation, the
6
higher the failure rate.
7 [Slide.]
8 Here is the dating period of irradiated
9
red blood cells in Council of Europe Guide that was
10
published in the year 2003 just for the reference
11
here.
12 Here is the direct quote. "Red cell
13
products may be irradiated up to 14 days after
14
collection and thereafter stored until the 28th day
15
after collection."
16 "In view of the increased potassium leak
17
post irradiation, intrauterine or massive neonatal
18
transfusion should be used within 48 hours of
19
irradiation."
20 [Slide.]
21 Here are the issues for which we seek
22
advice from the committee.
68
1 [Slide.]
2 I am going to present the questions right
3
now just to highlight the issues we are going to be
4
focusing on this morning. These
questions will be
5
re-presented during the open committee discussion.
6 Questions on Dating Period of Gamma
7
Irradiated Red Blood Cells.
8 Question No. 1.
Do the committee members
9
agree that the current recommendations regarding
10
the dating period for gamma-irradiated red blood
11
cells should be modified?
12 [Slide.]
13 Question No. 2.
If you do agree to
14
modify, please comment whether the available
15
scientific data support the following candidate
16
modifications to FDA's current guidance on
17
irradiated RBCs.
18 a. For RBC
products that are irradiated
19
within the first 26 days after the date of
20
collection, the products should not be stored more
21
than 28 days from the date of collection.
22 b. For RBC
products that are irradiated
69
1
on or after 26 days from the date of collection,
2
the post-irradiated products should be stored no
3
more than 48 hours after irradiation.
4
[Slide.]
5 Question No. 3.
Does the committee have
6
any alternative modifications to FDA's current
7
guidance regarding the dating period for
8
gamma-irradiated red blood cells that should be
9
considered.
10 [Slide.]
11 Question No. 4.
Here are the questions on
12
RBC in vivo recovery acceptance criteria. Please
13
comment on the following options:
14 a. Keep the
current criteria, which is
15
sample mean equal or greater than 75 percent,
16
standard deviation equal or less than 9 percent,
17
and 95 percent lower confidence limit for the
18
population mean above 70 percent.
19 b. Proposed
new criteria 1: We propose
20
sample mean equal or greater than 75 percent,
21
standard deviation less or equal than 9 percent,
22
and a 95 percent one-sided lower confidence limit
70
1
for the population proportion of successes greater
2
than 70 percent. The success is
defined as greater
3
or equal than 75 percent of RBC recovery.
4 c. Proposed
new criteria 2: A 95 percent
5
one-sided lower confidence limit for the population
6 proportion
of successes greater than 70 percent and
7 a
minimum individual recovery of all samples equal
8
or greater than 60 percent.
These criterias will
9
be further discussed by Dr. Kim also in the later
10
session.
11 That is all I am going to say now.
12 DR. ALLEN:
Thank you, Dr. He.
13 Comments or questions relative to the
14
presentation? Yes.
15 DR. KLEIN: I
have two questions. The
16
first is on your slide about the Council of Europe,
17
that first recommendation, since I am not sure
18
other speakers will be addressing that, do you know
19
whether their standard is based on any data or on
20
what data their standard is based?
21 My second question is you are raising this
22
issue at this time for the committee.
Is there a
71
1
problem with the current standard, and, if so, what
2
is it?
3
DR. HE: Well, I am not very sure about
4
whether the Council of the European Guide is best
5
on data, but that is how their recommendation, it
6
is just for the reference.
7 The second, even though we don't have any
8 adverse
event report from the gamma-irradiated
9
product, however, from one of the control, you can
10
say that there was almost 46 percent of the
11
failure, which is of quite concern for the efficacy
12
and safety, probably mostly efficacy concerns. We
13
also feel that the data that is going to be
14
presented later today probably will explain some of
15
the concerns we have.
16 DR. ALLEN:
Yes.
17 DR. KUEHNERT:
I am a little confused
18
about what you just said. You
said a 46 percent
19
failure, but isn't that the control group?
20 DR. HE: Yes,
that is control. That
21
control is actually, it's a blood bag with
22
anticoagulant additive solutions cleared by FDA
72
1
years ago. That clearance, at
that time, it was
2
cleared for collecting of the whole blood and for
3
the processing of the red blood cells.
4 At that time, the bag, during the
5
clearance, there was no gamma-irradiated studies
6
done, but the blood centers just used that bag to
7
collect the blood and to irradiate the blood, sort
8
of like historical without any study at that time.
9 DR. KUEHNERT: But the control group,
10
there was no irradiation, hence, the term control
11
group, and I guess I am confused about the concern
12
there. Is the concern about the
anticoagulation,
13
anticoagulant that is used or is it--it's not about
14
the irradiation because that was the control group
15
actually, right?
16 DR. HE:
Perhaps not because of
17
irradiation, perhaps because of any unit, no matter
18
if it's the old anticoagulant or new anticoagulant
19
or in--we have kind of a collecting bag, that
20
irradiation should not happen later than day 14 or
21
should not be stored up to 42 days.
22 DR. VOSTAL:
Maybe I can help out here.
73
1
The reason we are looking at this issue right now
2
is that we received an application from
3
manufacturers that brought to us novel combination
4
of anticoagulants that were never tested after
5
irradiation.
6 So, we looked at that data and we realized
7
that we have never seen those before.
We looked at
8
the combinations. We realized we
had never seen
9
the data with irradiated cells, so we requested
10
that. The data came in and we
are in the process
11
of evaluating them right now.
12 Part of that submission, we looked at the
13
control cells, which actually I think were
14
irradiated, and we looked that there is a high rate
15
of failure in the control cells, control cells
16
being currently approved products.
17 So, we are looking at this in terms of
18
whether the current standard is appropriate or
19
whether it should be changed. We
are going to see
20
that control data again when the company presents
21
their data on their own.
22 DR. ALLEN: Let
me just clarify. The
74
1
control cells had been irradiated?
2 DR. VOSTAL: It
is my understanding that
3
they were irradiated cells. You
are comparing a
4
currently approved irradiated product to a novel
5
combination irradiated product.
6 DR. ALLEN:
Maybe that will be clarified
7
when we get the presentation further.
8 Dr. Leitman.
9 DR. LEITMAN:
This 75 percent standard
10
applies not only to products that are modified by
11
irradiation post collection, but applies to the FDA
12
evaluation of any new storage vehicle, new bag, new
13
anticoagulant. So, you gave us
three statistical
14
options to choose from.
15 That doesn't only apply to radiation, to
16
everything. It's a separate issue,
how does the
17
FDA decide that any modification to collection or
18
storage vehicle or treatment of the component is
19
okay. Is that what we are being
asked to look at?
20 DR. VOSTAL:
That's correct. The standard
21 for
red cell performance is 75 percent recovery at
22
24 hours of radiolabeled cells.
75
1 Now, the options that we have presented
2
are designs of the studies that are used to
3
evaluate those products, and you can either look at
4
the average performance of the study volunteers and
5
average it out to see if they are greater than 75
6
percent, and the issue there is if you allow that,
7
sometimes you see data that has a number of
8
failures, but still meets the average greater than
9
75 percent.
10 Some of these studies that we have been
11
looking at pointed to us that you have studies that
12 4
out of 20 fail even though they meet the 75
13
percent average, and we were wondering whether that
14
is appropriate.
15 The other way of looking at it is you
16
could fix the percentage of those donors that meet
17
the criteria, you know, fix the proportion, and
18
those are some of the other options.
19 You can say 80 percent of those donors
20
have to meet the 75 percent criteria, you know,
21
instead of looking at their average.
So, those are
22
the options that we are going to be discussing.
76
1 DR. ALLEN: Dr.
Klein.
2 DR. KLEIN: If
I could just follow up on
3
my question. Since one of the
options you are
4
going to ask us to look at is harmonization with
5
the European standard, do you know what data those
6
are based on, and anticoagulant bags, all of the
7
various things that we are concerned about since we
8
obviously wouldn't want to harmonize something that
9
doesn't make any sense?
10 DR. VOSTAL:
Right. I also don't know the
11
data for that decision in the Europe.
12 Could I just make one more point? We
13
would like to just make sure that you understand
14
that non-irradiated products do meet the 75 percent
15
criteria, so we are not questioning the 75 percent,
16
only the design of the studies that is used to
17
evaluate that.
18 DR. ALLEN: Dr.
Strong.
19 DR. STRONG:
Could I ask where the 75
20
percent number came from, is that based on
21
scientific evidence?
22 DR. VOSTAL: I
think it was decided back
77
1
in 1982, and that was a consensus decision, and it
2
was more or less an arbitrary decision.
3 DR. ALLEN: I
will just comment that I was
4
astounded as I looked through the materials in
5
preparation for the meeting at the extraordinarily
6
wide range. You know, 75 percent
as a mean may or
7
may not have scientific validity, but for any given
8
donor, there was an extraordinarily wide range, and
9
that surprised me. I had not
anticipated that.
10 DR. LEITMAN:
This is deja vu. This
11
conversation was held in 1994 at the BPAC
12
committee, and remember the consensus agreement
13
then was the discussion about the 75 percent, what
14
if you have 73 percent, 71 percent, 68 percent, how
15
much is enough for recovery of a red cell
16
component, and the comment was that if you don't
17
treat the components in that manner, and the option
18
is graft-versus- host disease, then, 68 percent is
19
good, it's acceptable.
20 So, a product treated in such a manner
21
that it avoids a fatal reaction, at two-thirds, I
22
think that comment was are available for the
78
1
patient, that's a good outcome, so it is quite
2
arbitrary.
3 DR. EPSTEIN:
There is another reverse
4
side to that argument, Susan, what you say is
5
certainly correct, but how often do you need to
6
irradiate an older unit and then hold it a long
7
time.
8 I mean as a practical matter, most units
9
are irradiated earlier in their shelf life, and
10
what we are really saying is if you have a need to
11
irradiate an older unit, just don't store it a long
12
time, and that will not be a frequent situation.
13 What we are really saying is we can
14
prevent a potential harm, we can improve the
15
quality of the delivered product.
We don't really
16
think that it is going to compromise product
17
availability or the availability of a given unit.
18 So, I understand what you are saying and I
19
agree, but the reverse side is that this is not
20
impractical. There will be those
who comment that
21
it is a recordkeeping issue and relabeling dating
22
is nightmarish, and we are going to hear that
79
1
argument.
2 DR. ALLEN:
Thank you. Go ahead.
3 DR. GOLDSMITH:
Do we really know the
4
implications of a safety and efficacy point of view
5
of infusing these units that have lower than 75
6
percent recovery? Do we actually
have clinical
7
information on outcomes?
8 DR. VOSTAL: I
think that is very
9
difficult to assess. I mean in a
single
10
individual, transfusing cells that would not meet
11
the 75 percent probably would not make that much of
12 a
difference unless there was a really damaged
13
unit.
14 But I think we are trying to apply this
15
across the whole population, and if you would
16
accept the percentage, a lower recovery for all
17
products, you would end up having decreasing
18
availability of the blood supply, and you might end
19
up in transfusing more frequently, which would also
20
decrease the availability of the blood supply.
21 DR. ALLEN: Why
don't we move on. We have
22
got other speakers and then we will come back to
80
1
general discussion. It sounds as
though it is
2
going to be a fairly significant discussion.
3 Our next speaker is Dr. Gary Moroff,
4 Holland Laboratory, American Red Cross.
5 Presentation - Gary Moroff, Ph.D.
6 DR. MOROFF:
Thank you very much.
7 What I want to present today is our
8
historic data, because it was generated in the
9 1990s, early to
mid-'90s, dealing with gamma
10
irradiation of whole blood derived ADSOL red cells.
11 [Slide.]
12 So, our study objective was to evaluate
13
the influence of gamma irradiation dose which we
14 deemed
optimal, and I will talk about this in a few
15
seconds, for inactivating T cells in red cell units
16
on red cell properties with different scenarios for
17
time of irradiation and total storage time, and
18
this relates to the discussion over the last five
19
or 10 minutes.
20 [Slide.]
21 Basically, I am going to start with
22
talking about the 2,500 centigray issue because we
81
1 conducted studies
before we did our red cell
2
studies to show that this was the optimal dose, and
3
then I will talk about the red cell property
4
studies.
5 [Slide.]
6 Just for review, these are the primary
7
types of instruments being used to irradiate blood.
8
There are free-standing irradiators with a cesium
9
or cobalt source, and also at hospitals, linear
10
accelerators are used, and the linear accelerators
11
are based on x-rays.
12 The irradiation effect is the same whether
13
it is the cesium source or the x-ray source when
14
you think in terms of total dose.
There is
15
currently now a free-standing x-ray machine that is
16
available also for blood units.
17 [Slide.]
18 Let me skip about the basics because that
19
was covered, but when we started thinking about
20
gamma irradiation in the early 1990s, we realized
21
that the optimal dose had not been identified in
22
appropriate studies with red cell units.
82
1 In collaboration with Dr. Luban and Dr.
2
Quinones at the Children's Hospital in Washington,
3
we identified 2,500 centigray as the optimal dose,
4
and I will talk about this for the next few
5
minutes.
6 [Slide.]
7 Before I do that, let me just say that the
8
dogma is that irradiation is needed to prevent GVHD
9
even when red cell units are leukocyte reduced.
10
The use of leukocyte reduction as an alternative
11
method has not been documented. Data on the log
12
reduction needed is not known.
All of our studies
13
were done on leukocyte-containing red cells.
14
Again, this is before the era of leukocyte
15
reduction.
16 [Slide.]
17 These are comments on the method that we
18
used in the assessment of the optimal dose of
19
irradiation. We used a very
sensitive limiting
20
dilution assay. The assay was
based on growth of
21
T-cells, and the assay measures up to approximately
22 5
logs of T-cell inactivation, and this work was
83
1
published in 1994 in Blood.
2 [Slide.]
3 This slide summarizes the results that we
4
found. This is a quantitative assay, but the
5
results are listed in qualitative fashion for this
6
presentation, and basically, what we found is that
7
there were still growth of T-cells at 2,000
8
centigrays, but at 2,500 centigrays, there was no
9
growth, and we did studies with 3,000 centigrays,
10
and there was also, of course, no growth at that
11
dose.
12 I should say that we also conducted
13
studies looking at two bags. We
looked at the
14
PL2209 bag, which is a citrate plasticized bag, and
15
the PL146 bag, which is a DHP plasticized bag for
16
red cells, and we found similar results.
17 We also conducted split unit studies where
18
we irradiated one-half with a linear accelerator
19
and one-half with the gamma irradiation source, the
20
free-standing cesium source, and we found no
21
difference. We have very
comparable results.
22 [Slide.]
84
1 I just wanted to mention that the current
2
nomenclature is centigrays. For
many years, the
3
nomenclature was rads - 2,500 centigrays equals
4
2,500 rads.
5 [Slide.]
6 I just briefly want to mention about how
7
we measured the dose that was delivered. The
8
studies documenting 2,500 centigrays as the
9
appropriate dose measured the delivery at the
10
center of the simulated blood units.
We used water
11
as the simulated blood units, and we embedded
12
thermal luminescent dosimeter chips in the blood
13
bags containing water.
14 Currently, there are commercial systems
15
for dose mapping, which are based on dose mapping
16
of the canister, and I will show you an example of
17
the canister.
18 With 1-unit irradiators, there is
19
essentially no translation issue.
With
20
multiple-unit irradiators, there is a translation
21
issue. With 2,500 centigrays
delivered to the
22
canister centerpoint, some units will have a
85
1
greater dose delivered to their centerpoint.
2 [Slide.]
3 This is what we used in our studies.
4
These are these TLD dosimeter chips.
5 [Slide.]
6 This just is an example of a free-standing
7
irradiator. This is by Nordians
[ph], this gamma
8
cell 3000, and this is the canister that is used
9
for placement of the units of red cells or, for
10
that matter, platelets or plasma.
11
[Slide.]
12 This just shows one of the systems
13
available for dose mapping of the canister.
14 [Slide.]
15 Let's now turn to the evaluation studies
16
that we conducted to evaluate the influence of
17
gamma irradiation dose, 2,500, as I said, deemed
18
optimal on the red cell properties.
We used a
19
paired study approach to compare red cell
20
properties with radiation and without radiation, so
21
my control is without radiation.
22 The emphasis was on the evaluation of the
86
1
in vivo red cell viability properties.
2 [Slide.]
3 This is some study background. Again, the
4
studies were conducted in the mid-1990s. The
5
studies were sponsored and coordinated by the
6
American Red Cross Holland Laboratory.
The studies
7
were conducted at two sites.
8 The principal site investigators were Dr.
9
James AuBuchon at Dartmouth-Hitchcock Medical
10
Center in New Hampshire and Stein Holme, who at
11
that point was with the American Red Cross,
12
Mid-Atlantic Region, in Norfolk, Virginia.
13 This data was presented to the Food and
14
Drug Administration and helped establish the
15
guidelines in the early-mid 1990s for irradiation
16
of red cell units.
17 [Slide.]
18 In terms of methods, we used four
19
scenarios, and I will show you these scenarios in
20
detail in a few seconds.
21 Protocols 1 and 2 was the original study,
22
and these studies were done at two sites. After we
87
1
saw the results from Protocols 1 and 2, we added
2
Protocols 3 and 4, and we did a small number of
3
studies at one site.
4 Each subject for all the protocols donated
5
two CBD whole blood units at
least 56 days apart.
6
The red cells were prepared with AS-1/ADSOL
7
preservative solution. On one
occasion, the AS red
8
cells were irradiated and stored, on the other
9
occasion, the AS red cells were stored with no
10
irradiation. That is our
control.
11 We used a PL2209 container, which was
12
being utilized at the time. This
container is not
13
utilized now, but as I said, there is no evidence
14
that the container influences the effects of
15
irradiation based on preliminary studies that we
16
conducted in the early 1990s.
17 [Slide.]
18 Again, the dose of irradiation was 2,500
19
centigrays delivered to the midsection of the blood
20
bag, as I explained before, and again the red cell
21
units were not leukocyte reduced.
22 [Slide.]
88
1 Our studies were stimulated by three
2
studies that predated our studies.
One study from
3 the NIH by Rick Davey
and co-workers showed that
4
when AS-1 red cells were irradiated on day zero
5
with 3,000 centigrays, the irradiated red cells
6
gave lower results, lower 24-hour recoveries than
7
control red cells.
8
There was also a study
published only in
9
abstract form from Ken Friedman at the University
10
of Mexico, and their means are listed here. They
11
irradiated red cells on day 1, and they stored red
12
cells in one protocol for 21 days, and in the
13
second protocol for 28 days, and they found that
14
the irradiated red cells had lower recoveries. The
15
N's were 6 in this study for both protocols, and N
16
in the NIH study.
17 [Slide.]
18
There was also a study by Paul
Mintz.
19
This is an unpaired study. The
other two studies
20
were paired studies where control and irradiated
21
red cells were from the same donor, but there was a
22
study also done with AS-1 red cells from the
89
1
University of Virginia where they showed, in an
2
unpaired fashion, that irradiation after 35 days of
3
storage had a small effect compared to controls, so
4
again emphasizing that irradiation did influence
5
the 24-hour recovery, which is the kay parameter as
6
we just heard about.
7 [Slide.]
8 This slide shows the four protocols that
9
were used in the Red Cross study in the mid-1990s.
10 [Slide.]
11 I will go through each of these protocols
12
in more detail.
13 In Protocol 1, irradiation was at day 1,
14
storage for 28 days. This was
the conclusion of
15
storage.
16 [Slide.]
17 In Protocol 2, irradiation was on day 14,
18
because we thought that there is the need to show
19
the properties of the red cells when irradiation
20
takes place during the storage period.
So, in
21
Protocol 2, irradiation was 14 days, and here,
22
again we stored for 28 days through day 42, which
90
1
is the routine conclusion of storage for additive
2
solution of red cells in the United States.
3 It was based on some result that we found
4
in this study, which I will show you in a minute,
5
which showed that there were reduced recoveries,
6
24-hour recoveries, recoveries with irradiated red
7
cells of less than 75 percent, which led us to use
8
the next two protocols.
9 [Slide.]
10 This is Protocol 3.
Here, we irradiated
11
again at day 14, but we only stored for 28 days.
12
We wanted to see whether there was anything unique
13
about day 14 irradiation.
14 [Slide.]
15 This is Protocol 4.
Here, we wanted to
16
look at all the red cells, and that was just
17
discussed before. We irradiated
the red cells at
18
day 26, and we stored the red cells for two more
19
days when we did the red cells viability survival
20
studies.
21 I didn't emphasize that in the other
22
protocols, but when I say conclusion of storage,
91
1
that is when samples were taken, and the in vivo
2
viability studies were carried out.
3 [Slide.]
4 Just a few comments about the methods, and
5 I
think I have covered this before basically, but
6
the autologous infusions were utilized, so the
7
individual received back a small portion of his
8
cells that were labeled with isotopes, and we
9
analyzed the red cell recoveries, 24-hour red cell
10
recoveries by the two standard methods, the single
11
label method which only involves the chromium
12
isotope, and by the double isotope method, which
13
involves chromium isotope and a 99 technetium
14
isotope.
15 [Slide.]
16 This is our data that we obtained from the
17
24-hour studies using the four protocols. This is
18
date of irradiation and this is total storage time.
19 Let's talk about Protocol 2, because this
20
is where the results showed values less than 75
21
percent in the irradiated arm.
22 The control red cells--this is for the
92
1
single label, I will emphasize the single label
2
data because of time--the control red cells showed
3 a
mean standard deviation of 76.3 plus or minus 7.0
4
percent, and the irradiated red cells had values
5
69.5 plus or minus 8.6, and there were comparable
6
values with the double label.
7 In the other protocols, the mean standard
8
deviation, the means were always above 75 percent.
9 I
want to point out that the N for Protocols 1 and
10 2
were 16 paired studies, an N of 8 at both
11
studies. At that time when we
did these studies,
12
that was the dogma, to use a N of 8 at each of two
13
sites.
14 In Protocols 3 and 4, we carried out
15
studies at one site, as I said, and we had a
16
smaller number of subjects involved.
17 [Slide.]
18 This is just a graphic representation of
19
the means for the four different protocols.
20 [Slide.]
21 This is the individual data, and I will
22
show the individual data for Protocol 1 and
93
1
Protocol 2, and you can see that for Protocol 1, in
2
the control arm, no irradiation, there is one
3
value, less than 75 percent. These
values were
4
after storage for 28 days, and you can see, as was
5
mentioned, that there is a large variability in the
6
values in a set of donors.
7 This is the data with irradiation, and
8
again this is at day 28, and you can see that the
9
pattern is different than the control pattern, and
10
here there is an increased number of values less
11
than 75 percent. This is at day
28 now with
12
irradiation on day 1.
13 [Slide.]
14
This is the data from
Protocol 2, the
15
individual 24-hour recovery data, and here again
16
you see this large interdonor variation in 24-hour
17
recoveries in the control arms, no irradiation, and
18
you get the same pattern or same width with
19
irradiated cells or really a greater width, but it
20
is the same pattern.
21 You can see that there is a difference in
22
the patterns between irradiated and control cells
94
1
as indicated in the data that I showed previously.
2
We had one low value, and this is with the single
3
label method of 47 percent in Protocol 2. This is
4
again irradiation on day 14 with storage for 28
5
days until day 42.
6 [Slide.]
7 This is the data from Protocol 1 and
8
Protocol 2 by site. I just
wanted to point out in
9
the control arm, for the studies in Protocol 2,
10
there is no irradiation, the mean from Site A was
11
above 75 percent, but as it turned out, with the
12
donors that were used at Site B, the mean was below
13
75 percent just slightly. So,
again, this
14
emphasizes the inner donor variability.
15 [Slide.]
16 This just combines all the data in a
17
summary slide, the data that I talked about that
18
was published in the three studies that predated
19
the American Red Cross study.
This is included in
20
the packet and I just wanted to show this in a
21
composite way.
22 This is when the irradiation was conducted
95
1
on day zero and day 1, and this is the data that I
2
have shown before, so I won't go over it now
3
because of time.
4 [Slide.]
5 This is a composite of the data where
6
there was mid-storage irradiation on day 14, the
7
University of Virginia study, and then the two
8
American Red Cross studies that I talked about
9
before.
10 [Slide.]
11 We also looked at long-term survival of
12
the red cells. Long-term
survival is not routinely
13
conducted when evaluating the viability properties
14
of stored red cells, but in view of the data from
15
the NIH study and from the University of Mexico
16
study, when we designed our studies, we decided to
17
also look at the long-term survival of the red
18
cells.
19 The long-term survival of red cells refers
20
to the survival of red cells that are circulating
21
24 hours after infusion, and we measured the
22
long-term survival of the red cells in terms of the
96
1
time that it took for the chromium to be reduced to
2
50 percent of initial values.
3 Without going into detail, we used a model
4
from the literature, and the circulating chromium
5
levels were determined in samples obtained from the
6
subjects. The samples were
obtained 7, 21, 28, 35
7
days after the labeled red cells were returned to
8
each subject, and we did not correct for elution of
9
chromium.
10 This has been an issue for many years
11
about elution of chromium, and there are still many
12
questions about how this elution occurs and what
13
influences the elution.
14 It is because of the questions, we decided
15
not to correct for elution.
Therefore, the
16
survival, and you will see the data in the next
17
slide, the survival time is in the range of 25 to
18
30 days, because we did not correct for elution,
19
and, of course, the normal red cell survival being
20
about 120 days total.
21 [Slide.]
22 This shows the data from the long-term
97
1
survival studies that we conducted.
We conducted
2
these studies with all four protocols, and
3
basically, there was no difference in the long-term
4
survival of the red cells for any of the protocols,
5
and also there was no difference between irradiated
6
red cells and control red cells, the values being
7
very similar.
8 This is the p value between irradiated and
9
control, and all of the p values were not
10
significant, p greater than 0.05, again, all the
11
values being around 25, 27 days in terms of the
12
mean values with limited SD values.
13 [Slide.]
14 Now, let me conclude by just briefly
15
presenting some of the in vitro results that we
16
obtained in these studies with the four protocols
17
that I have described.
18 ATP levels are used routinely to
19
characterize the quality of the red cells. Again,
20
we did everything in a paired fashion.
These are
21
from the same units. We took
samples from the same
22
units.
98
1 With the irradiated cells, there was a
2
slight difference, a slight reduction in the ATP
3
levels in all four protocols.
There were some
4
statistical differences, but from a biological
5
point of view, it appeared to us that these
6
differences were very small.
7 This is known from the literature also
8
that irradiation of red cell units does affect ATP
9
levels. ATP levels to some
degree correlates with
10
red cell viability. It is
probably the best in
11
vitro test that correlates with viability, but is
12
not a perfect correlation test.
13 [Slide.]
14 Hemolysis. We
also measured hemolysis at
15
the conclusion of storage with all four protocols.
16
We took samples for the in vitro tests after the
17
samples were taken for the in vivo viability
18
procedures where the donors receive back their red
19
cells.
20
Here again the irradiated red
cells had
21
slightly higher hemolysis, but nothing really
22
marked in terms of difference between control and
99
1
irradiated red cells.
2 [Slide.]
3 This is a composite slide of hemolysis
4
citing all the studies that I have talked about,
5
and overall, irradiated red cells in all the
6
studies have slightly higher hemolysis than the
7
controls. Again, the controls
are with no
8
radiation, but there is really no great increase in
9
hemolysis in my opinion.
10 [Slide.]
11 This slide talks about or addresses the
12
issue of potassium. It has been
known for many
13
years that potassium levels increase after
14
irradiation in stored red cells.
The potassium
15
levels increase during storage without irradiation,
16
but the irradiation enhances the leakage of the
17
potassium.
18
This slide shows that in
all four
19
protocols with what we expected, the irradiated red
20
cells at the conclusion of storage had greater
21
supernatant potassium levels than the control red
22
cells. Even in Protocol 4, where
the cells were
100
1
only stored for two additional days after
2
irradiation, there was a statistically significant
3
difference in potassium level, irradiated red cells
4
versus control red cells.
5 [Slide.]
6 This is a composite of the potassium data,
7
and this is in the packet, and because the red
8
light just turned on, I won't go into any detail.
9
Again, this just shows what I said before, that
10
irradiated red cells have higher potassium levels
11
at the conclusion of storage.
12 [Slide.]
13 This is my last slide, and this is the
14
summary slide. We concluded back
in the mid-1990s,
15
as I said, these are historic studies with whole
16
blood derived red cell units, irradiation reduced
17
the retention of red cell properties during storage
18
including the 24-hour in vivo recovery.
19 The extent of change depended on storage
20
times post irradiation based on our studies. For
21
the protocols utilized in the American Red Cross
22
study, the magnitude of the difference in the
101
1
24-hour red cell recovery between control and
2
irradiated units was limited.
The difference in
3
Protocol 2 was the greatest, and that was about 7
4
to 8 percent difference, albeit there were values
5
that were below 75 percent.
6 The last point is the long-term survival
7
parameter was comparable for control and irradiated
8
red cells under all the conditions that were
9
studied.
10 Thank you very much.
11 DR. ALLEN: Thank
you. Very important
12
information for us.
13 A general question I have got that I
14
haven't heard answered so far, in terms of the
15
graft-versus-host potential from non-irradiated
16
cells versus irradiated, does it make a difference
17
when the cells are irradiated?
In other words, do
18
they do better if you irradiate them within 24 or
19
48 hours of collection versus waiting until day 14
20
or, as proposed, even waiting until day 26 or day
21
28, if they are infused within 48 hours after that?
22 DR. MOROFF: I
don't think there is data
102
1
to answer that question. Susan
Leitman would be a
2
better person than I on that.
Before I let Susan
3
respond to that, let me mention to you--and I
4
didn't mention this before--in terms of our initial
5
studies, which looked at the inactivation of the T
6
cells, most of our studies were done on day 1, but
7
we also did studies where we stored the red cells
8
for 7 and 21 days, and we found that the 2,500
9
centigrays inactivated the T cells from those
10
stored units also, just like they did at day zero.
11 Susan, do you want to comment on this? I
12
think you are a better person to comment on this
13
than I am.
14 DR. LEITMAN:
There are older studies from
15
the '70s, it's a mean dose to inhibit mitotic
16
potential of circulation leukocytes is 200 rad, so
17
the reason we need to give 2,500 is simply that the
18
mechanism of irradiation is uneven and you want to
19
get every leukocyte in the bag.
20 But again if you get that dose in, you
21
inhibit the mitotic potential no matter when in the
22
life span of the cell it is given.
103
1 DR. MOROFF:
Dr. Allen, let me just be
2
clear. To answer your question,
the data does not
3
exist. Susan shook her head yes
as she agrees.
4 DR. ALLEN:
Thank you.
5 Other questions or comments? Yes, Harvey.
6 DR. KLEIN:
Just one small technical
7
question, Gary. These were paired
studies and, as
8 I
recall, you randomized the donations to
9
irradiation or non-irradiation.
10 DR. MOROFF:
Yes, they were randomized,
11
Harvey. I did not mention that,
but we randomized
12
the donations because we were bringing back the
13
donors two times with a difference of 56 days.
14 DR. ALLEN:
Yes.
15 DR. DiMICHELE:
I think your point about
16
the fact that these studies were done on
17
leukodepleted units is a very important one, and
18
you yourself said that you didn't know what the
19
impact would be.
20 In your opinion, are these studies that
21
need to be done, I mean given the fact that so many
22
of our units are now leukodepleted, do you think
104
1
this could reasonably change the standard for gamma
2
irradiation for red cell units?
3 DR. MOROFF: I
think the leukoreduction
4
systems that we now use remove 4, 5, 6 logs of
5
white cells, so I think potentially, you would not
6
need to irradiate gamma-irradiated red cells.
7 That is one point, but more direct to your
8
point, my assumption is that the white cells do not
9
influence the influence of the irradiation on the
10
red cell properties. There is no
data out there
11
suggesting that leukocyte-reduced red cells, in
12
terms of red cell properties, would behave
13
differently than the units that we used where there
14
were white cells in the units.
Susan might also
15
want to comment on that.
16 DR. ALLEN: Dr.
Leitman.
17 DR. LEITMAN:
We did that study. At NIH,
18
we performed a paired donation control study where
19
we leukoreduced and irradiated, and the same donor
20
donated on another occasion, and irradiated without
21
leukoreduction. We did that
because synthesis told
22
us that non-nucleated cells are not significantly
105
1
damaged by irradiation, but cells are
2
non-nucleated, and the damage you see might be
3
secondary to the damage done to leukocytes in the
4
unit.
5 What we found in that paired control study
6
was if you leukoreduced prior to irradiation and
7
long-term storage to 42 days, there was no effect
8
on the 24-hour recovery of the red cell, so
9
leukoreduction prior to irradiation prevents the
10
majority of the irradiation injury we see in these
11
studies.
12 That is a very good point because many
13
centers are practicing universal leukoreduction on
14
the day of collection prior to irradiation, so this
15 whole discussion is not relevant to a huge
16
proportion of red cells collected today.
17 DR. MOROFF:
Susan, I forgot about your
18
study. That is a very important point.
So, you are
19
saying there was no effect on 24-hour recovery.
20 DR. LEITMAN:
It was not significant. It
21
was the same, 70-something, I can't remember the
22
number.
106
1 DR. MOROFF:
Was the data from those
2
studies published?
3 DR. LEITMAN:
It's in abstract form.
4 DR. DiMICHELE:
I am sorry. In those
5
studies, the irradiation was day 1?
6 DR. LEITMAN:
Day 1.
7 DR. DiMICHELE:
And the evaluation was
8
day?
9 DR. LEITMAN:
Forty-two.
10 DR. MOROFF:
Forty-two.
11 DR. LEITMAN:
Yes, full shelf life.
12 DR. MOROFF:
You are saying your 24-hour
13
survivals at day 42 were above 75 percent overall?
14 DR. LEITMAN:
They were very close to 75
15
percent, maybe 76, just above 75 percent in both
16
groups.
17 DR. ALLEN: And
that was the mean, so
18
there was a range around that mean, or was that--
19 DR. LEITMAN: I
can't remember the data.
20 DR. ALLEN: Are
those data likely to be
21
published in a more complete form than the
22
abstract?
107
1 DR. LEITMAN:
We can get that out.
2 DR. MOROFF: I
think that would be
3
important to publish, I agree, that would be
4
important to publish that data.
5 DR. ALLEN:
Again, I get the sense that
6
the storage solutions, that the bags may not have
7
much effect on what happens, but that the solutions
8
do, and that probably is something else that needs
9
to be commented on as we try to compare studies
10
over time when the other study parameters may have
11
changed.
12 DR. LEITMAN:
These studies were done from
13
the late '80s to the late '90s, during which the
14
practice of transfusion medicine changed, so
15
different storage vehicles were used, initially,
16
non-additive storage solutions were used, and later
17
the XL-1, XL-2, XL-3.
18 The effect of that, no one looked
19
prospectively at different anticoagulants and the
20
effect of the same dose of radiation, but if you
21
compare different studies using different
22
additives, they seem to give the same data. It
108
1
does not seem to be a significant effective
2
additive.
3 DR. MOROFF:
That is my conclusion from
4
looking at the data that is out there.
We only
5
used one solution, but there were some studies with
6
AS-3 with neutrocil.
7 DR. LEITMAN:
They are done well, but even
8
the same study, then at two different sites gets
9
different results, so there is a lot of technique
10
related to doing these, so multi-site studies are
11
very helpful.
12 DR. MOROFF:
And there is a lot of donor
13
variability as we have been talking about.
14 DR. ALLEN:
Other comments or questions?
15
Dr. Strong.
16 DR. STRONG:
Just a couple of comments.
17
One, the issue of dosage, I think if you look back
18
into the '70s, as Susan commented, a lot of studies
19
were done in the transplantation era when we were
20
looking at, at that time, matching criteria for
21
using lymphocyte cultures that the dose of 2,500
22
was arrived at, which raises a concern about mixing
109
1
the data between 2,500 and 3,000, because one would
2
expect increasing effects with increasing doses of
3
irradiation as we see in lots of other biological
4
systems.
5 I had one question, Gary, about your data,
6
whether you have done any intergroup comparisons,
7
because of this wide variation between individuals
8
when you compare just looking at the data you have
9
presented, intergroup comparisons don't seem to be
10
very significant either. In
other words,
11
irradiation at day 1 versus day 14, if you compare
12
the 28-day storage of those two groups, it looks
13
like in some cases you have a better recovery in
14
the ones that were irradiated at day 14, so it just
15
seems to validate this problem on interdonor
16
variability, as well as interorganizational
17
differences.
18 DR. MOROFF: I
agree, Mike, it's the
19
interdonor variability which overpowers some of the
20
other comparisons, because there is such a wide
21
range in interdonor comparability or interdonor
22
values.
110
1 Let me mention about your first point.
2
Back in the '70s and '80s, a lot of the studies
3
which looked at dose were utilizing isolated
4
lymphocytes that were irradiated in the
5
transplantation model, and that is why we
6 irradiated in our dose
studies red cell units,
7
because that data did not exist in the early '90s.
8 So, again what we did differently, we
9
irradiated the red cells, then, we isolated the
10
lymphocytes to do the T cell killing studies. We
11
did not isolate the lymphocytes first.
12 DR. STRONG: My
only point here is I think
13
there is enough variability in the statistics that
14
are being presented that it is going to make it
15
difficult to make decisions about changing what we
16
have already established.
17 DR. ALLEN:
Other comments or questions?
18 DR. QUIROLO: I
just wondered if you could
19
comment on the feasibility of doing larger studies,
20
besides money, is that a possibility, or what would
21
be the impediments to that?
22 DR. MOROFF: I
think we are in an era
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1
where we are doing larger studies.
As I said, back
2
in the early '90s, the dogma was to use 8 donors
3
per site, and now, as we heard before, the dogma is
4
to use 10 to 12 studies per site.
Yes, I think it
5
is feasible to do studies.
6 There are a lot of logistics involved for
7
getting the finances, the financial issue, but I
8
would say that we can do larger studies if needed.
9 I
am not sure I understand your point. To
look
10
more at the donor variability issue?
11
DR. QUIROLO: Yes.
There are so few
12
subjects in the studies, and the donor variability
13
is so large, how many subjects would you need to
14
negate that, so you could get good statistics?
15 DR. MOROFF: I
think we need some analysis
16
to show that. More studies would
help in the
17
statistics, I agree, and I think the studies are
18
feasible. They would take
longer, but I think they
19
are possible.
20 The question is you have to ask whether
21
larger studies are needed and on a case-by-case
22
basis. We are going to be
hearing a discussion of
112
1
statistics later which will enlighten your
2
question, which probably will address your point.
3 DR. ALLEN: Dr.
Leitman.
4 DR. LEITMAN:
This data on the factors in
5
the donor that may lower 24-hour recovery, Dr.
6
AuBuchon either presented that in abstract form or
7 published
it, and we have similar data. Low MCV,
8
low red cell size, and iron deficiency in the
9
donors is clearly associated with poorer in vivo
10
recovery in the autologous setting.
11 In addition, we have data that donors who
12
take high doses of antioxidants, vitamin E or
13
vitamin C, have better in vivo recoveries, so we
14
don't know all the factors, but there are specific
15
donor-related factors that impact.
16 DR. MOROFF: We
did not control for these
17
factors in these studies, you are right, Susan.
18
There may be some ways to understand the situation
19
in a more comprehensive way.
20 DR. GOLDSMITH:
I think in your studies on
21
Table 1, the recovery and control in irradiated red
22
cells, the studies that were done at one site are
113
1
not different statistically, and the studies done
2
at two sites are different in a statistical
3
fashion.
4 Again, this must speak to some kind of
5
innate variability site to site, as well as donor
6
to donor. If you want to have
really robust data,
7
you have to have multiple sites, I guess, to make a
8
conclusion.
9 So, I think your data support the use of
10
multiple sites very nicely.
11 DR. MOROFF: I
think multiple sites are
12
important.
13 DR. ALLEN:
Thank you.
14 DR. LACHENBRUCH:
Tony Lachenbruch,
15
Biostatistics at FDA.
16 One of the concerns that I would have
17
about larger studies is if we are looking at means,
18
we can always find a large enough sample size to
19
show that the lower confidence bound is greater
20
than 75 percent, but we still may have 30 percent
21
of the individuals are below the criterion of 75
22
percent recovery.
114
1 So, I think Dr. Kim will be addressing
2
this, but I think it is really important to say big
3
studies aren't going to solve that problem.
4 DR. ALLEN: We
will move on to our next
5
speaker at this point. Thank you
very much. Larry
6
Dumont from Gambro BCT, Inc.
7 Presentation - Larry Dumont
8 MR. DUMONT:
Mr. Chairman, members of the
9
committee, ladies and gentlemen, good morning.
10
Thanks for invitation to present the data.
11
[Slide.]
12 My mortgage gets paid by those people
13
right there. Mike is actually the guy that designed
14
the studies in collaboration with CBER, and he
15
couldn't be here, so I am just reporting the news.
16 I
didn't make the news today.
17 [Slide.]
18 First of all, the groups that we worked
19
with, American Red Cross in Norfolk, Dr. Taylor and
20
Pam Whitley and that crew. From
21
Dartmouth-Hitchcock, Dr. AuBuchon and his lab.
22
Blood Center of Southeastern Wisconsin, Dr. John
115
1
Adamson, Loni Kagan, and others.
At Gambro was
2
Mike and Marge.
3 [Slide.]
4 The objective of these studies was to
5
determine the in vitro and in vivo characteristics
6
of gamma irradiated, apheresis red cells compared
7
to concurrent controls prepared from whole blood.
8 [Slide.]
9 I am going to describe the methods here.
10
For past reference, essentially in Dr. He's
11
presentation, we are Company B, and in Gary's
12
presentation, we are going to be Protocol 2.
13 [Slide.]
14 In some studies, the Gambro Trima was used
15
to collect red cells.
Anticoagulant for that is
16
ACDA. We get a packed red cell
of about 250
17
milliliters at an 80 percent hematocrit. Following
18
collection is added storage solution AS-3. In some
19
studies that i will show you, the product was then
20
leukocyte reduced with a Pall filter, some studies
21
they are not. I will make that
clear.
22 Following that treatment, samples were
116
1
taken for testing. The cells
went into the cold
2
for 14 days. Aliquots were taken
out for testing
3
at that point. The cells were
irradiated at 25
4
grays, put back in the cold for an additional 28
5
days, and then testing was performed at the end of
6
that period.
7 Control arms, which came up earlier, was
8
whole blood collected in the standard fashion with
9
CPD as the anticoagulant where you get about 500
10
milliliters of anticoagulated whole blood. This is
11
held for a couple hours, component processed into
12
two components, and storage solution is added, in
13
some cases filtered, some cases not, I will that
14
clear in a second.
15 What we tried to do at the different sites
16
is we wanted to use their standard procedures, so
17
we have got a couple different methods here.
18 One site actually used the Sepacell, which
19
is a whole blood filter, so that filtration, when
20
it occurred, happened right here prior to component
21
processing, and then AS-1 was added to the cells.
22 Another site utilized an AS-5, with the
117
1
Terumo bag, and they used the BPF-4 Pall filter.
2
For those products, this process actually happened
3
at 1 to 6 degrees.
4 Then, of course, after this processing,
5
testing was done and then things went into the
6 cold, they were irradiated, et cetera.
7 [Slide.]
8 The testing is the standard list of things
9
that you do with these studies - CBC, residual
10
white cells, pH, and gases, hemoglobin and the
11
plasma where we calculate hemolysis, ATP, sodium,
12
potassium, glucose, osmotic fragility, and
13
radiolabeled recoveries on the days indicated here.
14 [Slide.]
15 All the methods were standard. The
16
important ones for this discussion, gamma
17
irradiation was at 2500 centigrays with a 1,500
18
centigray minimum using IBL 437C.
19 Radiolabeled red cell in vivo recoveries
20
were conducted at two sites. The
Red Cross in
21
Norfolk used the double label method with chromium
22
51 and technetium 99 where the technetium is used
118
1
to estimate the blood volume, as published by Dr.
2
Heaton and others.
3 Milwaukee used just the chromium label, as
4
Gary had published previously.
5 [Slide.]
6 We really have two parts to this study
7
that I am going to show you. The
first part was
8
actually evaluating non-leukocyte-reduced red