[Adult T cell leukemia-lymphoma (ATL)]

Adult T-cell leukemia-lymphoma(ATL) is a distinct malignancy of CD4+/CD25+/ CCR4+/FoxP3+ or - Treg/TH2 cells etiologically associated with human T-cell lymphotropic virus type I (HTLV-1). ATL is a single HTLV-1 disease entity with diverse molecular features. Also, the clinical features and prognosis are diverse leading to subtype-classification into acute, lymphoma, chronic, and smoldering types defined by organ involvement, and LDH and calcium values. In case acute, lymphoma or unfavorable chronic subtypes (aggressive ATL), and favorable chronic or smoldering ATL (indolent ATL), intensive chemotherapy followed by allo-HSCT and watchful waiting until disease progression has been recommended, respectively in Japan. Several new agent-trials for ATL are ongoing and in preparation, including a defucosylated humanized anti-CC chemokine receptor 4 monoclonal antibody, IL2-fused with diphtheria toxin, histone deacetylase inhibitors, a purine nucleoside phosphorylase inhibitor, a proteasome inhibitor and lenalidomide.