Successful treatment with rituximab of a patient with coincident acquired hemophilia A and thrombotic thrombocytopenic purpura

Abstract

A 66-year-old man was admitted for oral hemorrhage, purpura, and APTT prolongation. Factor VIII (FVIII) activity was decreased, due to the presence of FVIII inhibitor. He was diagnosed with acquired hemophilia A (AHA) and treated with prednisolone. Eight months later, the FVIII inhibitor titer again increased. Upon readmission, thrombocytopenia and autoimmune hemolytic anemia were found. We suspected Evans syndrome accompanied by AHA, and we treated the patient with IVIG. However, his platelet count did not increase. Speech disturbance and delirium were observed from the 12th day of hospitalization. He was subsequently diagnosed with thrombotic thrombocytopenic purpura (TTP) because ADAMTS13 inhibitor was detected, causing a decrease in ADAMTS13 activity. We initiated plasma exchange (PE) and steroid-pulse therapy. After PE for 3 days, laboratory test results and psychiatric symptoms showed dramatic improvement. However, after a 2-day period without PE, the patient's platelet count decreased markedly. Therefore, we administered rituximab to eliminate these inhibitors. His platelet count recovered rapidly, and we were able to gradually wean the patient from PE. After two additional administrations of rituximab, neither inhibitor was detected. To date, the patient has remained in complete remission for approximately 3 years.