[Successful umbilical cord blood hematopoietic stem cell transplantation in a patient with adult T-cell leukemia/lymphoma initially achieving complete remission with anti-CC chemokine receptor 4 antibody combined chemotherapy].

A 62-year-old man with CHOP refractory adult T-cell leukemia/lymphoma (ATLL) received anti-CC chemokine receptor 4 antibody (mogamulizumab) combined with CHOP and achieved complete remission. At 71 days after the final administration of mogamulizumab, he received umbilical cord blood transplantation (CBT) using reduced intensity conditioning. Umbilical cord blood engraftment was confirmed on day16. Grade II acute graft-versus-host disease (GVHD) was diagnosed on day60 and was controlled by administration of methylprednisolone. There was no evidence of relapse at 9 months after CBT. Ratios of regulatory T cells in CD4 positive T cells were remarkably low during all of these periods. Since mogamulizumab reduces regulatory T cells, the frequency and severity of acute GVHD were reported to be increased in patients administered mogamulizumab before allogenic stem cell transplantation. Further experiences are needed for selecting optimal donor sources, the portability period and GVHD prophylaxis for patients using mogamulizumab before allogeneic stem cell transplantation.