The choice of plasma-derived clotting factor concentrates.

The gloomy picture caused by the AIDS epidemic is now partially lightened by spectacular improvements in therapy. One important step forward toward elimination of the risk of transfusion of blood-borne infections by plasma products was the development of virucidal methods and their application to clotting factor concentrates. Another important advance was the production of ultrapure factor VIII concentrates by immuno-affinity chromatographic techniques. Not only are these concentrates at least as safe as less-pure concentrates in terms of transmission of blood-borne viral infections, but there is also a hint that the deteriorating immune system of HIV-positive haemophiliacs may be stabilized by these highly purified concentrates. Factor VIII produced by recombinant DNA technology is licensed for treatment of haemophilia A. Hopefully, it will be free of the risk of transmitting infections and will be available in sufficiently large amounts to meet the needs of haemophiliacs worldwide. The availability of concentrates containing only factor IX is another substantial step forward in the treatment of haemophilia B, while we wait for the cure of this disease through gene-transfer therapy.