Prevalence of factor VIII inhibitors among Afghan patients with hemophilia A: a first report.

: Prevalence of inhibitors in Afghan hemophilia patients has not been reported previously. Our aim was to determine the prevalence of factor VIII inhibitors among hemophilia A patients from the Kabul province of Afghanistan to identify and characterize the pattern of inhibitor formation. Clinical information and blood samples were collected from three hemophilia centers in Kabul, Afghanistan. Plasma samples were obtained from 62 patients with severe (80.5%) and 15 patients with moderate hemophilia A (19.5%) in this cross-sectional study design. All the patients were receiving on-demand treatment. The Nijmegen modification of the Bethesda assay was used to detect inhibitors. Multiplex PCR, inverse-PCR, Multiplex ligation-dependent probe amplification and direct sequencing were performed for genotyping. Inhibitor activity was detected in one out of 15 (6.7%) patients with moderate hemophilia and in six out of 62 (9.7%) with severe disease. Apart from the intron 22 inversion, five different mutations including one missense, two large and two small deletions were detected. This is the first report showing that the prevalence of inhibitors in Afghan hemophilia A patients is much lower than in other populations.