Is haemophilia therapy now safer?
A Approximately 6,000 haemophilia sufferers receive treatment in the UK.
Initially, human plasma and cryoprecipitate were used directly, then plasma-derived factor concentrates became available.
But problems emerged with transmission of HIV and hepatitis A and C. Viral inactivation was introduced to the manufacturing of plasma-derived products, but the potential for new threats still remains due to the emergence of conditions such as vCJD and West Nile Virus.
The recent advent of recombinant, genetically engineered non-plasma derived products has improved safety.
All children under 16 are treated with recombinant Factor VIII, and the Department of Health is phasing it in for all adults in England, although most adults in Scotland and Wales can already use it if they wish.
The UK haemophilia community has been severely affected by the contamination of blood products used before 1986 leading to widespread HIV and hepatitis C. About 1,200 people were infected with HIV and most were also infected with hepatitis C. More than half have since died.
Latest estimates also show that around 4,800 UK haemophilia sufferers have been infected with hepatitis C.
The UK National Blood Service introduced screening for hepatitis C in donations in 1991.
Clinical trials have found both plasma-derived and recombinant factors to be effective in haemophilia treatment but some patients need higher doses of recombinant initially.
For patients who develop inhibitors to Factor VIII, a product is now available known as Recombinant Factor VIIa (rVIIa) which acts as a bypassing agent to produce a 'thrombin burst' to aid clot formation. Although rVIIa is proving highly effective, a typical treatment per patient can cost £3,000.
Barry Hill, chief biomedical scientist, haematology department,
Wigan Royal Infirmary