Theoretical advantages, but at a cost

Patients with haemophilia A lack only factor VIII. Why give them anything else as replacement treatment? Previously the answer to this question was determined largely by the practical difficulty in separating factor VIII from fibrinogen, fibronectin, and immunoglobulins, so that concentrates contained <1% of factor VIII protein by weight. The question is now determined largely by finances: concentrates of extremely high purity are available but are more expensive. Are there sufficient advantages to merit their greater cost and are these offset by any disadvantages?

The terminology of factor VIII concentrates is confusing. The term high purity has been applied to several concentrates prepared from plasma pools either by ion exchange and chromatographic techniques or by monoclonal antibody affinity columns. These achieve specific activities of 200 and >2000 U/mg respectively, but concentrates prepared using affinity columns require the addition of albumin as a stabiliser in the final product. In contrast the …