Adult T-cell leukemia/lymphoma

Abstract

Adult T-cell leukemia (ATL) is a neoplasm of activated helper T lymphocytes, which was the first human cancer found to be caused by a retrovirus, human T-cell lymphotropic virus type I (HTLV-I). It was around the year 1973 that ATL, previously an unknown disease entity, was first recognized in Japan (1), and it was internationally acknowledged in 1977 (2,3). HTLV-I was isolated from a cell line derived from a patient with aggressive cutaneous T cell lymphoma (4). The disease in this patient was later considered to be ATL. ATL cells were first cultured successfully in vitro by Miyoshi et al. (5),and these cell lines then were used to detect antibodies against virus-related antigens in ATL patients by an indirect immunofluorescence assay (6). Sera from ATL patients reacted to these cells, showing a relationship between the virus and ATL. The entire structure of this virus was determined by Yoshida and his colleagues (7). The discovery of ATL had far-reaching effects not only in medicine and virology, but also in oncology and biology. The presence of HTLV-I provirus enables us to analyze each step of leukemogenesis from infection to the highly aggressive acute or lymphoma types of ATL. Therefore, ATL is a good model to be analyzed to clarify the oncogenesis of lymphoid cells.