Characteristics of Various Factor VIII Concentrates used in Treatment of Haemophilia A

Abstract

S ummary . Five different factor VIII concentrates, AHF‐Kabi (fraction I‐o), Krynativ‐Kabi (freeze‐dried cryoprecipitate), Hemofil‐Hyland, AHF‐profilate‐Abbott, Kryobulin‐Immuno, available in Sweden for treatment of haemophiliacs were compared with respect to in vivo recovery, half‐life of factor VIII clotting activity (VIII:C) and in vitro properties. The parameters studied were VIII:C, factor VIII related antigen (VIIIR:AG), crossed immunoelectrophoresis, ristocetin co‐factor activity (VIII: Rcof), fibrinogen content and factor XIII activity. AHF‐Kabi had the lowest concentration of VIII:C. All the preparations had higher values for VIIIR:AG than for VIII:C. The quotient was highest for Hemofil, Krynativ‐Kabi and Kryobulin and varied between 4 and 7. The lowest quotient, 1.3 to 4, was that of AHF‐Kabi. The number of units of VIII: Rcof was almost the same as that of VIII:C. AHF‐Kabi had the highest fibrinogen concentration and was the only preparation with high amounts of F XIII. In crossed immunoelectrophoresis AHF‐Kabi showed a similar pattern to that of normal plasma. The other preparations had a different pattern suggesting less heterogenicity of the molecule. The in vivo recovery was about the same for all the concentrates. The disappearance rate of VIII:C after infusion of corresponding doses of the different concentrates was studied in six patients with severe haemophilia A who were not bleeding. AHF‐Kabi had a half‐life between 18 and 26 h which was substantially longer than any of the other preparations. The half‐life of Hemofil, Krynativ‐Kabi, AHF‐Profilate and Kryobulin varied between 8 and 16 h. The concentrates were given to three patients with severe classical von Willebrand's disease. All the preparations caused an increase of VIII:C and VIIIR:AG as well as of VIII:Rcof, but only AHF‐Kabi corrected the prolonged bleeding time. Knowledge of the properties of various VIII concentrates is of importance for the choice of treatment in haemophilia and von Willebrand's disease.