血友病Aインヒビター患者におけるブタ第Ⅷ因子製剤(Hyate : C)の反応性

Abstract

Human and porcine factor Ⅷ inhibitor titers were measured in the plasma of 15 hemophilia A patients with inhibitor and binding fragment to human factor Ⅷ polypeptide was analyzed by immunoblot method. 1. Human factor Ⅷ inhibitor levels were 4-390 B.U/ml, and porcine factor Ⅷ inhibitor levels that were 0-58 B.U/ml were lower than inhibitor levels to human factor Ⅷ. Cross reactivity (ratio of porcine to human factor Ⅷ inhibitor titer) was 0-100%. 2. Two cases with factor Ⅷ inhibitor binding to 44 kDa fragment of human factor Ⅷ heavy chain had low crossreactivity (0.5%-0%). One case with inhibitor binding to 44 kDa fragment and 72 kDa fragment of human factor Ⅷ light chain had crossreactivity of 11%. 10 cases with inhibitor binding to 72 kDa fragment had high crossreactivity (24-100%). Two cases with inhibitor binding to 44 kDa and B domain had crossreactivity of 1% and 27%. 3. Hemostatic effect of the porcine factor Ⅷ preparation was observed in 3 cases with factor Ⅷ inhibitor.