Safety of the new generation recombinant factor concentrates

Haemophilia A and B are X-linked disorders resulting from deficiency of Factor VIII and IX, respectively. Clinical sequellae of Factor VIII or IX deficiency include spontaneous and traumatic haemorrhages into joints, soft tissues, and muscles. The cornerstone of therapy has been replacement of the deficient factor, historically with pooled-plasma derivatives. The unfortunate blood-borne infection transmission (such as HIV, hepatitis B and C viruses), inhibitor formation, immunosuppression, and, in certain cases, thrombosis by these products has spawned major advances and innovations in the manufacture of clotting products. Recombinant technology has virtually eliminated transmissible disease risk; yet, the presence of albumin in second and third generation recombinant products raises, at the least, theoretical risk of prions and parvovirus B19. Other non-infectious complications, including inhibitor formation, allergic reactions, and thrombosis, remain formidable concerns. Despite this, recombinant factors remain the most attractive treatment approach for haemophilia. Future improvement awaits the development of safe and effective gene transfer technology.