OBJECTIVETo analyze the clinical features of hemophilia A (HA), and the factors associated with the factor VIII (FVIII) inhibitor development.

METHODSOne huandred and thirteen patients with HA were recruited in this retrospective study, among whom, 85 were treated with FVIII replacement therapy. The FVIII inhibitor levels and factors associated with the inhibitor development were correspondingly investigated in these 85 patients.

RESULTSFVIII inhibitor developed in 28.24% of the 85 severe and moderate patients treated with FVIII. Factors of statistical significance (P < 0.05) associated with the low-titer FVIII inhibitor development were as follows: the first enduring adminstration of FVIII, the situation of the patients, and the high dose FVIII used in severe bleeding or major operation.

CONCLUSIONThe development of FVIII inhibitor by Bethesda assay in Chinese hemophilia A patients is not rare, especially that with low-titer. Most of them are severe and moderate patients. The inhibitor development was associated with the following factors: the first adminstration of FVIII for more than 5 days, the severe or moderate conditions of patients, the high dose FVIII used in severe bleeding or major operation.