Investigators have reported diagnoses of sporadic Creutzfeldt-Jakob disease (sCJD) in two patients with bleeding disorders in the United Kingdom who died in 2014. The WFH has been monitoring the risk associated with a different form of CJD, variant Creutzfeldt-Jakob disease (vCJD), and plasma-derived medicinal products since the vCJD outbreak in the U.K. began two decades ago. This new report of sCJD in the users of plasma products is unexpected and may be the result of increased surveillance of all prion diseases combined with the higher incidence of sCJD in general. Sporadic CJD affects one to two people million per year in the general population. So these two cases may not have been caused by exposure to plasma-derived medicinal products such as clotting factor concentrates.
The authors of the new report state, “The balance of evidence indicates that, if sCJD is transmitted by blood transfusion, it must be a rare event, if it happens at all, and transfusion transmission is probably not the explanation for the two cases we describe.” Furthermore a recent study conducted by the Centers for Disease Control and Prevention and American Red Cross looked back for over 21 years on the risk of transfusion-transmitted CJD and no apparent transmissions were observed. The authors of that study concluded there is no evidence from their data and other epidemiologic studies that CJD is transmissible by transfusion.
The two sCJD patients were treated with different clotting factor products for their bleeding disorders. The first patient had von Willebrand disease and she had been treated with both plasma-derived and recombinant factor VIII, while the second patient had hemophilia B and had received plasma-derived and recombinant factor IX. She had also been treated with 6 units of fresh frozen plasma. This suggests no link product-related link between these two cases.
CJD is a rare progressive neurological disorder caused by defective prions in the brain. Prions are proteins found in all our bodies but they cause disease when they become misfolded. sCJD is believed to be a spontaneous disorder which occurs with equal frequency all over the world.
vCJD is an acquired disorder that is most likely caused by the consumption of meat or meat products contaminated with the bovine spongiform encephalopathy agent. Most cases of vCJD have occurred in the United Kingdom and three have been identified as cases of secondary transmission caused by the transfusion of non-leukodepleted red blood cell components from blood donors who were later diagnosed with vCJD. In one case reported in 2009, a patient with hemophilia who died of other causes was found to have been infected, most likely by treatment products manufactured in the U.K. before the outbreak was detected.
To read the synopsis of this report, click here. https://wwwnc.cdc.gov/eid/article/23/6/16-1884_article#r2
For the CDC ARC report, click here. http://onlinelibrary.wiley.com/doi/10.1111/trf.14145/abstract
The WFH will continue to monitor this development.