Human T cell leukemia virus type-1 (HTLV-1) is the only retrovirus known to be the etiologic agent of a human cancer, adult T-cell leukemia/lymphoma (ATLL), a highly aggressive cancer of mature T cells. Epidemiological reports suggest that 10 to 20 million people throughout the world are infected with HTLV-1, which is endemic in parts of sub-Saharan Africa, the Caribbean, Japan, and South Ameri...

In this issue of Blood, Bellon and Nicot describe an elegant mechanism used by HTLV-I to up-regulate telomerase gene expression and function in the absence of the viral tax oncoprotein. A dult T-cell leukemia was first reported as an entity in Blood in 1977. 1 Three years later, Gallo et al identified the human T-cell leukemia/lymphoma virus-I (HTLV-I), a deltaretrovirus, as the causative agent...

Adult T-cell leukaemia/lymphoma (ATLL) is an aggressive malignancy of mature activated T cells caused by human T-cell lymphotropic virus type I (HTLV-1). Prognosis is severe because of intrinsic chemoresistance and severe immuosuppression. Four different subtypes are described with different outcomes, and treatment strategies vary according to the different clinical courses. Japanese trials sho...

HTLV-I is a retrovirus now identified as the etiologic agent of two diverse disease processes: ATLL, an aggressive T-cell malignancy; and TSP/HAM, a chronic progressive myelopathy. Transmission can occur horizontally through blood transfusions, IV drug abuse and sexual intercourse. Vertical transmission may also occur. Available diagnostic modalities are serologic in nature and include the EIA ...

Human T lymphotropic virus type 1 (HTLV-1) causes a range of chronic inflammatory diseases and an aggressive malignancy of T lymphocytes known as adult T-cell leukaemia/lymphoma (ATLL). A cardinal feature of HTLV-1 infection is the presence of expanded clones of HTLV-1-infected T cells, which may persist for decades. A high viral burden (proviral load) is associated with both the inflammatory a...

Human T cell leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) are genetically related complex retroviruses that are capable of immortalizing human T-cells in vitro and establish life-long persistent infections in vivo. In spite of these apparent similarities, HTLV-1 and HTLV-2 exhibit a significantly different pathogenic potential. HTLV-1 is recognized as the causative agent of adult T-cell leu...