The results of clinical observation and blood coagulation tests have been analyzed in 31 patients with haemophilia A in children in Odessa region. High incidence of haemophilia A with inhibitors (22,5 %) and the dependence of inhibitors rate on severity of coagulopathy (57,1 % in severe haemophilia A) was revealed in the investigated patients. The level of inhibitory antibodies did not associate with the haemophilia A severity. In 22 % of cases inhibitors developed during substitutive transfusion therapy. Clinically in a majority of the patients we observed signs of resistance to antihaemophilic preparations.
