Sporadic CJD cases in the UK bleeding disorders community reported
A recent paper from the Centers for Disease Control and Prevention (CDC) covers the death of two people with inherited bleeding disorders from Sporadic Creutzfeldt-Jakob disease (sCJD) in 2014. Both of the people concerned were women. One had Type 3 von Willebrands and the other carried the Haemophilia B gene. These are the first deaths from sCJD in the bleeding disorders community anywhere in the world.
Most of the concern in the bleeding disorders community around CJD has been about variant Creutzfeldt-Jakob disease (vCJD). This is thought to be the human equivalent of bovine spongiform encephalopathy (BSE), known as mad cow disease. Many of our members were informed in 2004 that they are at increased risk from vCJD for public health purposes. This risk relates to being treated with blood products made from plasma donated by people in the UK who had eaten BSE implicated beef or went on to develop vCJD. Although in 2008 vCJD implicated prions were found at post-mortem in the spleen of a man with severe haemophilia A who died of other causes, nobody with a bleeding disorder has ever developed vCJD. To put that in context, a study found that 1 in 2000 people in the UK carry the implicated prion, which is the equivalent to 32,500 people. At the moment there have been 178 cases of vCJD in the UK.
The news from the CDC related to a different form of CJD, sCJD appears to occur at random in the population at the rate of about 100 a year in the UK (fewer than 10 in Scotland). It mainly affects people of middle age and older and has been known about since the 1920s. It is a rare condition which is why there being two cases in recipients of blood products is unusual enough to trigger an investigation. It is not known whether these cases are related to being treated with plasma derived clotting factor products or whether these cases are coincidental. The CDC paper says, “Assuming an annual incidence rate of sCJD of 1.5–2.0 per million population the occurrence of 2 cases of sCJD in this total population may not imply a causal link between the treatment and the occurrence of the disease.”
There is active surveillance both in the UK and internationally for both sporadic and variant CJD. In the UK the National CJD Research and Surveillance Unit is based in Edinburgh and examines all cases of CJD in detail. In these new cases they determined that they were sCJD (rather than vCJD ) by looking at how the disease progressed and where the CJD associated prions were found.
Prion diseases such as vCJD and sCJD are not well understood. There are still a lot of unanswered questions. Haemophilia Scotland have highlighted the CDC paper to the Scottish Government, the Scottish Inherited Bleeding Disorders Network, and are looking into any potential legal implications. We will be carefully monitoring the situation and will report any further developments on our website and to our members.
Further information about these cases can be found in a briefing paper produced by the European Haemophilia Consortium (ECH). There is more information about CJD on the NHS Choices website. The best place to go with specific medical questions about your health is your Haemophilia Centre.