OBJECTIVETo explore the immune tolerance induction (ITI) in a severe hemophilia A patient with inhibitor, and to improve the therapeutic efficacy for patient.

METHODSThe FVIII:C was assayed by one-stage method and FVIII antibody by Bethesda method. Mutation screening of FVIII gene intron 22 inversion was performed using LD-PCR.

RESULTSFVIII gene intron 22 inversion was detected in this patient. Clinical tolerance to FVIII was successfully induced after administration of the ITI regimen combined with immunosuppression. A fall of inhibitor titer from 8 BU to 0 BU after treatment for 3 months, and in vivo FVIII recovery (> 66%) was normalized. The patient had no bleeding episode in the following 6 months.

CONCLUSIONThis is the first case report on successful immune tolerance induction therapy in Chinese hemophilia A patient. ITI is the most effective therapy for hemophilia A with inhibitor.