Abstract
A 4-year-old boy with severe hemophilia A and high titer inhibitors was treated with anti-CD20 monoclonal antibody (rituximab) followed by plasma derived FVIII concentrate to induce immune tolerance. Rituximab was administered in 4 weekly doses, 375 mg/m2, and FVIII concentrate (100 U/kg/dose) was begun at the time of the 3rd rituximab administration and continued 3 times per week for 6 months. The titer of inhibitors decreased from 141 BU/ml to 80 BU/ml without anamnestic response to FVIII concentrate during the first 4 months, but it remained about 80 BU/ml thereafter. In addition, a prolonged hypogammaglobulinemia and severe neutropenia were observed without serious infection. Rituximab may be beneficial for patients with severe hemophilia A and high titer inhibitors; however, it is necessary to investigate many issues such as the availability of rituximab therapy, the appropriate method of rituximab administration, the validity of immune tolerance induction therapy together with rituximab therapy, the safety and the economic utility.
