A PREPARATION FOR THE TREATMENT OF HEMOPHILIA A INHIBITOR PATIENTS AND A PROCESS FOR PRODUCING SUCH A PREPARATION

摘要

A preparation for the treatment of hemophilia A inhibitor patients contains a protein or peptide having a specific Factor VIII:CAg activity of at least 0.5, preferably at least 1 VIII:CAg unit per mg protein, the ratio between the VIII:CAg activity and the VIII:C procoagulant activity being greater than 5:1, preferably greater than 10:1. A fragment of Factor VIII:C, which displays a doublet of a molecular weight of 80/77 kD in electrophoresis, is reactive hemophilia A inhibitor antibodies and has VIII:CAg activity. This fragment and more low-molecular fragments of Factor VIII:C are capable of neutralizing the coagulation inhibiting effect of all tested antibodies. Such fragments can therefore be used as active component in preparations for providing immunotolerance towards Factor VIII:C in high-dose treatment of inhibitor patients. The peptides are moreover useful as an immunosorbent in specific extracorporeal adsorption treatment of inhibitor patients. The inhibitor reactive peptides can e.g. be recovered from plasma fractions by affinity chromatography, hydrophobic interaction chromatography or cation exchange or they may by produced biosynthetically and recovered in a similar manner.