Frequency of Specific and Non-specific Inhibitors in Haemophilia A Patients

Objective: To determine the frequency of specific and non-specific inhibitors in haemophilia A patients. Study design: This is a cross-sectional study. Patients and methods: A total of 150 male haemophilia A patients were included in this cross-sectional study at the National Institute of Blood Diseases and Bone Marrow Transplant (NIBD), Karachi, Pakistan, from September 2019 to January 2022. Results: Among 150 patients included in this study, 23 (15.3%) had an inhibitor and 127 (84.6%) did not. All patients had specific inhibitors against Factor VIII (FVIII). Non-specific inhibitors were not identified in our population. Among the patients in the inhibitor group, there were 13 (56.5%) in the severe (<1%) category. There were 10 (43.5%) patients in the moderate (1-5%) category. There were no patients in the mild category. The median inhibitor level was 15.4 Bethesda unit (BU). Conclusion: The development of inhibitors has not been identified as a major problem in our population. However, it is noteworthy that only 15.3% of patients with haemophilia A developed inhibitors in this data set. They were essentially treated with plasma and its products.