Familial MDS-overt leukemia patient treated with allogeneic cord blood stem cell transplantation in a graft-versus leukemia effect *
A 65-year-old male was presented with pancytopenia in April and was diagnosed as having MDS-overt leukemia with myelomonocytic differentiation in September. His son and brother had died of acute myeloid leukemia 28 and 25 years before, respectively. Leukemic cells expressed CD13, CD33, and CD34. He was treated with combination chemotherapy and the leukemic cells disappeared, but refractory anemia continued. Cord blood stem cell transplantation after reduced intensity conditioning（RI-CBT）was performed, and he promptly achieved donor-type hematopoiesis. No serious adverse effects were observed other than cutaneous graft-versus host disease（GVHD）of grade I. Six months after the CBT, he developed thrombocytopenia and liver dysfunction. Bone marrow aspiration revealed relapse of the leukemia expressing CD4, CD13, CD33 and CD56 antigens. After withdrawal of 0.5 mg tacrolimus ingestion every two days for the treatment of chronic GVHD, the leukemic cells disappeared and normal hematopoiesis returned. Chimerism analysis revealed that bone marrow cells consisted of 99.5％donor type cells. Therefore, this is a case where vigorous graft-versus-leukemia effect of cord blood cells against MDS overt leukemia was observed after withdrawal of immunosuppression. (Accepted on December ６，2007)
