RESUMEN
Alloantibodies occuring in haemophilia as a side effect of repeated treatment represents a severe complication. The antibody binds to a specific epitope within the factor molecule in a time dependent manner. If the alloantibody is present in excess, factor coagulant activity will be inactivated. Our study was conducted on 34 haemophilic patient and 10 control healthy children. All cases and control were subjected to the following: full history taking; complete clinical examination, laboratory investigation of Hb%, RBCs, WBCs, platelets counts, bleeding, coagulation, prothrombin and partial thromboplastin time. And assay of levels of FVIII and FIX, FVIII inhibitor level and FIX inhibitor.71% of haemophilia A were mild and 29% were moderate, 90% of haemophilia B were mild and 10% moderate. An inhibitor was detected in 16 cases [66.6%] out of 24 cases of hemophilia A, and 9 cases [90%] out of 10 cases of haemophilia B. These inhibitors were detected 2-11 years after the diagnosis. There was non significant correlation between inhibitor level in heamophiliaA to age, Hb% and FVIII% but there was negative correlation V.H.S [R< 0.001] to residual FVIII%. Also there was no correlation between inhibitor level in haemophilia B to age, Hb% and FVIII% but there was negative correlation V.H.S [R< 0.001] to residual FIX%. So we can conclude that development of inhibitor to FVIII and FIX although predominantly develop in severe heamophiliacs, they do occasionally appear in mild and moderate disease. Many of them are of low-level and perhaps transient. So we recommend to screen these patients at intervals for the inhibitor. The development of the inhibitor depends on the immunogenecity of the replacement therapy and also on a genetic predisposition