Adult T-cell leukemia development from a human T-cell leukemia virus type I carrier after a living-donor liver transplantation.

Adult T-cell leukemia (ATL) develops in a human T-cell leukemia virus type I (HTLV-I) carrier. The development of malignancy during immunosuppressive treatment following organ transplantation is one of the late fatal complications. We describe the development of three cases of ATL in eight HTLV-I carriers within 164 living-donor liver transplant recipients undergoing immunosuppressive treatment. All three cases were immunosuppressed with tacrolimus. Acute-type ATL was diagnosed at 6, 9, and 25 months after living-donor liver transplantation, based on increased numbers of CD4+25+ lymphocytes exhibiting "flower-like" nuclei, and the elevation of lactate dehydrogenase. Southern blot analysis demonstrated the clonal proliferation of ATL cells in peripheral blood. The ATL cells originated from the recipient, as demonstrated by fluorescence in situ hybridization analysis using sex chromosomal markers. Our observations suggest that immunosuppressive treatment for the prevention of graft rejection after living-donor liver transplantation may induce the development of ATL in an HTLV-I carrier.