Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 41 1 2003 03 15 66 68 Sharifian R Hosseini M Safai R Tugeh Gh Ehsani AH Lak M Jazebi M 2015 09 28 Development of inhibitor to factor VIII is the most serious complication of hemophilia therapy. To determine the prevalence of inhibitors in Iran hemophilia A patients exposed to blood products, 1280 hemophilia A patients (age range 9 months-84 years) were evaluated. All patients received several blood products such as fresh frozen plasma (FFP), cryoprecipitate, and factor VIII. 635 of 1280 patients (49.6%), 277 patients (21.6%) and 368 patients (28.8%) had severe, moderate and mild disease, respectively. 184 of 1280 patients (14.4%) developed inhibitor. The prevalence of inhibitor for severe, moderate and mild in hemophilia A patients was 22.8%, 9.4%, and 3.5% respectively. 41 patients (22.2%) and 143 patients (77.8%) were high responder and low responder respectively. Among 184 patients with inhibitor, 67 patients (36.4%) had blood group O and for B, A, AB blood groups, number of patients with inhibitor was 55 (29.9%), 50 (27.2%), 12(6.5%) respectively and 153 patients (83.1%) had Rh blood group. https://acta.tums.ac.ir/index.php/acta/article/view/2636 https://acta.tums.ac.ir/index.php/acta/article/download/2636/2618