Questions and Answers on vCJD and pdFVIII
Q. What is vCJD and how is it spread?
A. Variant CJD, or vCJD, is a very rare, fatal disease that can infect a person for many years before making them sick by destroying brain cells. Eating beef products contaminated with the infectious agent of bovine spongiform encephalopathy, or BSE (popularly known as “Mad Cow Disease”), is the main cause of vCJD.
cases of vCJD have occurred in the United Kingdom (UK). Individuals in the
incidence of vCJD in the
Only three cases of BSE have been found in US cattle, and safeguards are in place to help prevent infected beef products from entering our food supply. These safeguards include restricting importation of cattle and beef products from countries with BSE, a surveillance program to detect BSE in the USA, prohibiting the use of high-risk animal-derived proteins in cattle feed, prohibiting meat from sick cattle for human consumption, and requiring the removal of high-risk materials from carcasses of cattle over a certain age.
While vCJD is primarily
due to eating infected beef products, three people in the
Q. Is it known that pdFVIII can transmit vCJD?
A. No. However, pdFVIII is made from plasma. Plasma is the liquid part of blood remaining after the cells are removed. Animal studies show that if blood carries the vCJD agent, so can the unprocessed plasma.
Manufacturing steps used in making pdFVIII products have been shown to help remove infectious agents, including agents related to vCJD. They may reduce or eliminate most risk even if a vCJD infected donor contributed plasma.
Q. What is the likelihood that a patient who received pdFVIII could become infected with vCJD?
At this time FDA, CDC, and NIH are not aware of any cases of
vCJD having been reported worldwide in patients receiving plasma-derived
clotting factors, including pdFVIII.
This includes patients who have received, over a long period of time,
large amounts of clotting factor products manufactured from plasma donations
Q. Why did FDA do a vCJD risk assessment for pdFVIII?
A. We conducted a risk assessment for pdFVIII because it is made from the fraction of plasma that is likely to contain more of the vCJD infectious agent, if present, than the rest of the plasma, from which other products, such as albumin and immunoglobulins, are made. The FVIII containing fraction is further processed using a variety of methods that are likely to reduce or potentially eliminate vCJD from the final pdFVIII product.
Q. What is the risk of vCJD to patients who receive transfusion products like red blood cells and plasma?
A. The PHS, including the FDA, CDC, and
NIH, believes that the risk of vCJD to patients who receive transfusion
products like red blood cells and plasma is extremely small in the
The potential spread of vCJD through cell or plasma transfusion is limited by these deferral and quarantine measures that are in place. However, if there were to be a unit of blood cells collected from a donor at risk and it is infused, very few recipients would be affected. In contrast, hundreds of patients might potentially be affected with the use of a contaminated plasma derivative if there were not significant reduction of vCJD infectivity during the manufacturing process.
Q. Why is FDA informing patients, healthcare providers, and the public about vCJD and pdFVIII now?
FDA has recently completed its risk assessment. While the risk is most likely to be extremely
small, we do not know the risk with certainty.
We therefore think it is important that a person who receives pdFVIII be
aware of the results of the risk assessment and have the opportunity to discuss
any questions he or she may have with a suitable health care provider, such as
a hemophilia specialist. The first case
of probable vCJD infection transmission by transfusion in the
FDA, CDC, NIH, and Office of Public Health and Science (OPHS), with advice from patient advocates and communication experts, have now developed these key message points and communication materials to accurately convey the possible risk to patients, health care providers, and others who may have an interest.
Q. Should patients inform their primary health care providers about a possible vCJD exposure from US licensed pdFVIII?
A. Advising your primary health care provider (e.g. a family physician, internist, hemophilia specialist, etc.) about your history of having received pdFVIII can be beneficial in that your provider can tell you about any new information that may become available, interpret its significance, and advise you about further action that might be appropriate in the future. However, sharing your personal health information is your choice.
Q. Do patients who receive pdFVIII need to do anything special when seeking dental or surgical care?
At this time, the US Public Health Service (
PHS agencies will continue to monitor and reevaluate the situation as new information becomes available.
Q. What can recipients of pdFVIII do with this information?
A. While no new actions are recommended now,
you can stay informed by keeping in contact with a hemophilia specialist such
as one at a
Q. What are Hemophilia Treatment Centers, and where can I find out about them?
A. Hemophilia Treatment Centers (HTC) are a network of federally funded, comprehensive care clinics that promote the management, treatment, and prevention of complications experienced by persons with hemophilia and other hereditary bleeding disorders.
You can find information about HTC’s on the following CDC websites:
1. CDC informational posting, containing information about the kinds of services provided by federally funded HTC’s, at: http://www.cdc.gov/ncbddd/hbd/care_model.htm
2. A directory of federally-funded HTC’s is available at http://www.cdc.gov/hbd/htc_list.htm.
3. Regional HTC websites are also a good place for information
Q. Where can I find more information about vCJD and pdFVIII?
A. You can find additional information on these websites
1. FDA informational posting, containing current pdFVIII risk assessment, fact sheet, and briefing materials: http://www.fda.gov/ohrms/dockets/ac/cber06.html
2. Blood Products Advisory Committee meeting
– summary of recent TSEAC meeting and statement about FXI from the
3. TSEAC meeting with discussion of first
FXI draft risk assessment, on February 8, 2005, and discussion of
4. TSEAC Meeting with further discussion of the FDA risk assessment model, October 31, 2005: http://www.fda.gov/ohrms/dockets/ac/cber05.html#TransmissibleSpongiform
5. TSEAC Meeting with update on FXI risk
Information on vCJD: Center for Disease Control and Prevention, at http://www.cdc.gov/ncidod/dvrd/vcjd/index.htm
Regional HTC websites
Information on bovine spongiform encephalopathy (“Mad Cow Disease”): US Department of Agriculture, at http://www.aphis.usda.gov/newsroom/hot_issues/bse.shtml
National Hemophilia Foundation
Hemophilia Federation of
Committee of Ten Thousand
World Federation of Hemophilia
Questions to FDA may be addressed through the Office of Communication, Training, and Manufacturers Assistance (OCTMA), at 1-800-835-4709, or firstname.lastname@example.org.