vCJD

In 2004 and 2009, the Irish Haemophilia Society communicated with our members in relation to vCJD, and potential risk of past use of plasma-derived products manufactured from UK plasma. Some of you may recall that in 2004 a risk assessment was published in the UK due to the fact that a number of persons who had developed vCJD in the UK were blood donors and some of their plasma went into pools for the manufacture of plasma-derived factor concentrates in the UK. At that time the Health Protection Agency in the UK commissioned a risk assessment, which stated that people with haemophilia who had been exposed to UK plasma-derived factor concentrates between 1986 and 2001 were at 1% increased risk, for public health purposes, of developing vCJD. Measures were taken in relation to use of endoscopes, informing surgeons in the case of particular types of surgery and informing their GP’s and dentists. In Ireland, at that time this information was looked at very carefully. There were a number of people with haemophilia in Ireland who had used UK plasma-derived factor concentrates for rare bleeding disorders or indeed had been treated while living, working or visiting the UK. Each of these individuals was specifically informed about the situation by the National Centre for Hereditary Coagulation Disorders. A clear policy based on a practical evaluation of the risks was put in place in relation to ensuring that procedures were put in place for dealing with endoscopies and particular types of surgery involving lymphoid tissue. However, it was not deemed necessary for people with Haemophilia, who had been exposed to these products to inform their GP or their dentist. That is still the case.

In 2009, it emerged that a man with haemophilia in the UK in his 70’s who had died of other causes was found on autopsy to have Prions in his spleen. Prions are the abnormal proteins which are thought to cause vCJD. This gentleman had used UK plasma-derived product including several infusions of so-called implicated batches where it was known that a donor who later developed vCJD had donated plasma into the pool used in manufacture of these batches. Again as in 2004, a communication strategy was put in place by the I.H.S. in conjunction with the National Centre for Hereditary Coagulation Disorders. Members were informed by letter, a special phone line was set up, meetings were held and background information was given to the media.

This is all by way of preamble or introduction. There is no new risk or there has not been a new case which necessitates this article at this point in time. However, one of the problems in relation to vCJD is that there is no test for vCJD. There is no screening test, there is no confirmatory test and it is not possible currently to say if somebody has Prions in their tissues without doing a biopsy of those tissues. A number of companies are actively working on developing a screening test for vCJD. One Canadian company, Amorfix, appeared to be somewhat close to developing a screening test which would have a high degree of sensitivity and specificity. This test, however, was unable to detect real positive results so it is not now a possibility as a screening test. It is now very unlikely that there will be a screening test available for vCJD in the next year. However, the IHS wanted to be proactive in developing a policy setting out our views on such a test when and if it becomes available. It may seem logical to state that if a screening test is available then people with haemophilia should immediately be offered or avail of this test but on closer examination, this simplistic view would have to be challenged for a number of reasons.

Firstly, the ability of any screening test to determine a real positive from a false positive would have to be examined (and indeed the ability of the test to detect real positives as opposed to giving false negative results). Having a screening test in the absence of a confirmatory test may give an individual misleading information and it is to be hoped that a confirmatory test would be available prior to or at the same time as a screening test. If a person tests positive for HIV or Hepatitis C antibodies, there are confirmatory tests which can detect the virus and prevent the individual from having to deal with a false positive result or indeed the uncertainty of not knowing if the antibody test result is accurate. For this reason, it is our considered view that people with Haemophilia should not undergo a screening test for vCJD if and when such a test becomes available until there is an accurate confirmatory test also available.

Secondly, it must be remembered that there is no treatment for vCJD, no cure and no steps which can be taken to prevent the person from developing vCJD even if they have a positive screening test. Onward transmission risk would be limited primarily to the use of endoscopes or specific types of surgery and this risk can be prevented by the existing policies on quarantine of endoscopes used by those persons who were treated with UK plasma-derived products in the past and by the existing policy on notification in the event of specific types of surgery.

Thirdly, it was the experience in the UK that access to optimal health care (dental and endoscopy in particular) was compromised for some people with haemophilia in the UK following their being informed that they were on the at risk register. Thankfully, this did not occur in Ireland but the I.H.S. is strongly of the view that persons with Haemophilia should not consent to any screening and /or confirmatory test for vCJD until they received reassurance that their future access to and quality of healthcare would not be damaged or compromised by any result of such a test.

Finally, it is our view that, in the event of a screening test becoming available in the absence of a confirmatory test, such a test would have value in the screening of blood donors in preventing onward transmission by blood or blood products.

This policy was the result of an expert meeting we convened in June of this year attended by experts from Ireland, Canada, the USA and France, Haemophilia clinicians from Ireland and the UK and Haemophilia Society representatives from France and the UK ( the other countries where vCJD is a real issue at this point for the Haemophilia communities). I believe that this policy, which has been endorsed by all those in attendance, prepares us as a community to respond to the future challenge to be faced if and when a screening and hopefully a confirmatory test become available for vCJD.

The policy will be kept under review and amended when necessary in the light of scientific developments, any amendments will be published in the I.H.S. newsletter and on the website.

December 2015

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