Adult T‐cell leukemia developing during immunosuppressive treatment in a renal transplant recipient

We report a case of a 32‐year‐old male, an asymptomatic carrier of human T‐cell leukemia virus type 1 (HTLV‐1), who underwent a renal transplantation and developed adult T‐cell leukemia (ATL) during the course of posttransplant immunosuppressive treatment. He was treated with combination chemotherapies consisting of cyclophosphamide, vincristine, doxorubicin, prednisolone, cisplatin, cytosine arabinoside, etoposide, and methyl‐prednisolone, without any improvement. Bestrabucil (KM2210), a conjugate of chlorambucil and estradiol, was administered as an alternative therapy; this therapy successfully suppressed his leukemic cell growth, and partial remission was achieved. Posttransplant immunosuppressive therapy with prednisolone, mizoribine, and cyclosporin A might have been the predominant cause of the transition from an asymptomatic HTLV‐1 infection to overt ATL. A careful approach is required with HTLV‐1 asymptomatic carriers who need organ transplantation followed by immunosuppressive treatment. © 1992 Wiley‐Liss, Inc.