POTENTIAL vCJD RISK FROM US LICENSED PLASMA-DERIVED FACTOR VIII (PDFVIII, ANTIHEMOPHILIC FACTOR) PRODUCTS: Summary Information
recent years, questions have been raised concerning the risk from variant
Creutzfeldt-Jakob disease (vCJD) to hemophilia A and von Willebrand disease
patients who receive US licensed plasma-derived Factor Eight (pdFVIII,
Antihemophilic Factor) products. †Since
2003, three people, all in the
principal concern is to what extent if any, there could have been contamination
∑ Variant Creutzfeldt-Jakob Disease originally came from a disease in cattle called bovine spongiform encephalopathy (BSE, or "mad cow disease"). Transmission of the BSE agent to humans, leading to vCJD, is believed to occur primarily via ingestion of cattle products contaminated with the BSE agent. Both BSE and vCJD are invariably fatal brain diseases with incubation periods typically measured in years.
1995 through October 2006, 196 human cases of vCJD were reported worldwide,
with 162 cases in the United Kingdom (UK), and with two cases in the
∑ Based on a recently completed risk assessment, the US Public Health Service, including FDA, CDC, and NIH, believes that the risk from vCJD to hemophilia A and von Willebrand disease patients who receive US licensed pdFVIII products is most likely to be extremely small, although we do not know the risk with certainty.
CDC, and NIH are not aware of any cases of vCJD having been reported worldwide
in patients with hemophilia or other blood clotting disorders. This includes
those who have received, over a long period of time, large amounts of blood
clotting products manufactured from plasma donations from the
∑ FDA used a computer model to assess the risk of vCJD from the current use of these products.† However, there are many major uncertainties in the computer model, and a precise estimate of the risk is not currently possible. Again, there is no test yet available to detect vCJD infection in healthy donors or recipients.
a hemophilia specialist such as one at a
o Centers for Disease Control and Prevention:† http://www.cdc.gov/ncidod/dvrd/vcjd/index.htm
o US Department of Agriculture:† http://www.usda.gov
o Information also may be obtained from:
1-800-HANDI; the National Hemophilia Foundation;
Hemophilia Federation of
people with hemophilia A and 250 people with severe von Willebrand disease use
pdFVIII products in the
The FDA, CDC,
and NIH have no knowledge of any connection between plasma-derived clotting
factor use, including pdFVIII, and the development of vCJD.† The steps used to manufacture plasma-derived
products have the potential to remove the vCJD agent if it were present.† Also, the
Because of the finding that blood cell transfusions probably can transmit vCJD, FDA used a computer model to conduct a risk assessment to estimate the possible risk of vCJD that might occur from the use of US-licensed pdFVIII products that are on the market today. †A person could be at risk if a blood donor unknowingly carried the vCJD agent at the time of donation.
assessment results suggest that the risk from vCJD to hemophilia A and von
Willebrand disease patients who receive US licensed pdFVIII products is most
likely to be extremely small in the
Because of many unknowns, it is not possible to precisely estimate a personís individual risk. There is no test to determine if a person has been exposed to vCJD. ††
There have been
no reports of vCJD in patients using any plasma-derived clotting factor in the
While the FDA, CDC, and NIH believe that the risk of vCJD is most likely to be extremely small, we think it is important that a person who receives pdFVIII be aware of this issue. We also believe it is important that the patient has the opportunity to discuss any questions he or she may have with a suitable health care provider, such as a hemophilia specialist.