Hepatitis C and haemophilia

BMJ 1995;311:754-755 (16 September)

Letters

Hepatitis C and haemophilia

EDITOR,--In her editorial on hepatitis C and haemophilia ChristineA Lee states that recombinant factor VIII "cannot transmit bloodborneviruses."¹ Although this belief is widely held, it is not correct.All biological substances can harbour infectious agents, andconsequently all biopharmaceutical products carry some riskof infection, however small. Recombinant factor VIII is preparedfrom mammalian cell lines containing viral DNA²; in addition,substances of bovine, murine, and human origin may be used atseveral stages in the manufacturing process.³ Even when technologythat inactivates viruses is used, each of these substances hasat least a theoretical risk of transmitting infectious agents.

Haemophiliac patients were infected with hepatitis C beforeeffective technologies to inactivate viruses had been developedand at a time when the risk and severity of viral infectionsfrom coagulation factor concentrates were not fully appreciated.⁴The degree of safety of plasma derived concentrates in whichviruses have been inactivated is now reasonably well establishedthrough extensive and detailed follow up of their widespreadclinical use.⁵ In the case of recombinant factor VIII, however,the equivalent clinical measurements of safety have still tobe carried out as this new product, which may advance care inhaemophilia, seeks to become established.

Development manager Principal scientist Principal scientistScottish National Blood Transfusion Service, Protein FractionationCentre, Edinburgh EH17 7QT

Peter R Foster, Ronald V Mcintosh, Alexander J Macleod