Synthetic sorbents for removal of factor VIII inhibitors from haemophilic A plasma.

Human factor VIII (FVIII) is a protein of the blood coagulation system that is absent or defective in patients with haemophilia A. A most serious complication following replacement therapy in 10-15% of patients treated with available FVIII concentrate is the development of inhibitors of FVIII (anti-FVIII). Some polymers functionalized with suitable chemical substituents which mimic part of the epitope of FVIII recognized by the inhibitors might be used in extracorporeal circulation to reduce the concentration of antibodies to FVIII. For this purpose, insoluble polystyrene bearing sulfonate and L-tyrosine methyl ester sulfamide groups have been synthesized. The in vitro removal of anti-FVIII inhibitors from plasmas of patients with haemophilia A was performed. Different chromatographic parameters were studied and optimized.