RÉSUMÉ
Objective@#To explore the immune tolerance induction (ITI) in a case of severe hemophilia B patient with inhibitor.@*Methods@#The F Ⅸ∶C was detected using a one-stage method and FIX inhibitor was assayed using Bethesda method. ITI was performed with prothrombin complex concentrates (PCC) in combination with rituximab.@*Results@#His past exposure days (ED) with PCC were 20 ED and his peak FⅨ inhibitor titer was 56 BU/ml. When his FIX inhibitor titer decreased to 10.4 BU/ml in Nov. 2015 and after receiving the informed consent from his parents, ITI was started. PCC with low dose rituximab successfully eradicated the high titer inhibitor within 17 months. There was no anaphylaxis, thrombotic event and infection.@*Conclusion@#This is the first case report for successful immune tolerance induction therapy in Chinese hemophilia B patient. ITI using PCC combined with rituximab is an effective choice to induce immune tolerance of hemophilia B with inhibitor.