COMPARISON OF ANTI-HUMAN AND ANTIPORCINE FACTOR-VIII INHIBITOR LEVELSIN 63 PATIENTS WITH SEVERE HEMOPHILIA-A

The levels of anti-human and anti-porcine factor VIII inhibitors, meas ured in 63 severe haemophilia A patients, lay in the ranges of <0.2-2, 600 and <0.2-1,300 Bethesda units per ml (BU/ml), respectively, with a median cross-reactivity of 33%. In 4 patients, human and porcine inhi bitor levels were determined using both plasma, either human or porcin e, and factor VIII concentrate, either very high purity human or porci ne (Hyate:C(R)). A good correlation between titres was found, whatever the source of factor VIII (plasma or concentrate). The cross-reactivi ty varies from 0 to over 100%, indicating that the evaluation of both human and porcine inhibitors should be mandatory before any treatment with Hyate:C. Results show that of the 46 patients with human inhibito r of more than 5 BU/ml, 21 (46%) with a low porcine inhibitor (<5 BU/m l) could benefit from Hyate:C.