The first ever case of a person infected with vCJD via plasma-derived products has been recently reported. Plasma derived products have been until now assumed safe. Now a new vCJD risk group has been identified among people who receive blood products.

The infected person was one of a group of one thousand haemophiliacs that in the past received plasma products from a donor who later on developed vCJD symptoms. Although the elderly haemophilia patient died of causes unrelated to variant Creutzfeldt-Jakob disease, vCJD prions were found in his spleen at autopsy. Haemophilia is a genetic blood clotting disorder that is treated with clotting factors. The clotting factors the patient was treated with were derived from UK-sourced plasma before 1999; a time before safe sourcing rules for these products came into effect. This is the first incident that connects transmission of vCJD abnormal prion proteins through plasma-derived products. There have been four reported cases of vCJD transmission via blood transfusions in the UK, but until now it has been thought that plasma derived products harboured no risk of vCJD risk. These products were assumed safe because the manufacturing process for plasma-derived medicinal products reduced infectivity if it were present in human plasma.

Prionics developing blood test for vCJD
In a recent media release, the UK Haemophilia Society calls for the testing of blood plasma for the infectious vCJD prion as soon as a test is available. Prionics is one of only three companies in the world that is working on a test for the detection of prion disease in human blood. Prionics uses the proprietary antibody 15B3 that specifically recognizes the disease-associated form of the prion protein. Prionics ELISA test reliably recognizes blood samples spiked with brain homogenate.

Post mortem vCJD testing
In addition to blood samples, the 15B3 ELISA test has been also successfully used on post mortem vCJD brain samples. The 15B3 test and the Prionics^®-Check WESTERN were both evaluated on 650 brain tissue samples previously tested negative for vCJD, and on 15 brain tissue samples of confirmed vCJD cases. Both detection methods achieved 100% sensitivity and 100% specificity on the post-mortem samples. The results were presented at the Neuroprion meeting in Madrid, in October 2008 by Prionics and the Czech CJD Reference Center.