Haemophiliac Died With But Not From Variant CJD

Featured Article
Main Category: CJD / vCJD / Mad Cow Disease
Also Included In: Blood / Hematology
Article Date: 17 Feb 2009 - 11:00 PDT

email to a friend   printer friendly   view / write opinions

The UK's Health Protection Agency said earlier today, 17 February, that a post mortem on a patient with haemophilia had found evidence in his spleen of abnormal prion protein that causes variant CJD (vCJD) but it did not kill him: he died with rather than from the disease which is commonly called mad cow disease.

The post-mortem is part of an ongoing study by the UK Haemophilia Centre Doctors Organisation and the National CJD Surveillance Unit that started in 2001.

The patient was a man in his seventies and had died of a condition unrelated to vCJD. He had not shown any symptoms of vCJD before he died, and had shown no other neurological problems either. The first sign of vCJD was from the post mortem.

The HPA, who are working with the UK Haemophilia Centre Doctors Organisation, said this will not change the way that haemophilia patients are cared for or treated, and are doing all they can to inform patients with bleeding disorders about this situation and that further investigations are also taking place.

Haemophilia patients already know from their doctors about the possibility that they may have been exposed to vCJD through use of clotting factors derived from plasma of infected donors.

All patients treated with plasma sourced and pooled in the UK between 1980 and 2001 were told in 2004 that they were classed as at risk of vCJD for public health reasons: in other words there was a risk they were infected and their blood could pass this onto others. At that time the risk was a theoretically calculated one, quite small, but not real until this latest finding.

The chances of a person infected with the vCJD abnormal prion protein developing symptoms of the disease are unknown, and probably depend on how susceptible they are; it may be the case that some infected people never develop symptoms.

The HPA said the latest finding does not change the public health vCJD "at risk" status of patients with bleeding disorders, even though this is the first time that abnormal vCJD prion protein has been found in a haemophilia patient, or anyone treated with plasma products. The risk status does not change because measures have already been in place for some years that are based on a theoretical risk which has now become real but not changed in size.

As professor Mike Catchpole, Director of the Health Protection Agency's Centre for Infections, explained:

"This new finding may indicate that what was until now a theoretical risk may be an actual risk to certain individuals who have received blood plasma products, although the risk could still be quite low."

"We recognise that this finding will be of concern for persons with haemophilia who will be awaiting the completion of the ongoing investigations and their interpretation," he added.

The HPA said the main priority now was to make sure patients were informed about this finding and can talk to a doctor at their haemophilia centre as soon as possible.

"This finding does not change our understanding of the risk from vCJD for other people in any specific way. But it does reinforce the importance of the precautionary measures that have been taken over the years," said Catchpole.

"UK plasma has not been used for the manufacture of clotting factors since 1999 and synthetic clotting factors are provided for all patients for whom they are suitable," he said.

The authorities don't know how the patient got vCJD; there are more investigations to do yet.

What they do know is that he was treated with several batches of clotting factors derived from UK donors before 1999, when the vCJD blood safety measures were brought in. This included one batch of Factor VIII (the blood clotting factor that is faulty in people with haemophilia) made using plasma from a donor that developed symptoms of vCJD six months after donating blood in 1996.

Click here for more information about vCJD (from the HPA).

Sources: HPA news release.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today