HAM TSP - RECENT PERSPECTIVES IN JAPAN

Neurologic diseases associated with human T-cell lymphotropic virus ty pe I (HTLV-T) infection have a clinical spectrum that includes myelopa thy (HTLV-I-associated myelopathy/tropical spastic paraparesis, HAM/TS P) as the central manifestation. Many clinical signs of involvement ou tside the central nervous system (CNS) have been described in some pat ients with HAM/TSP and have triggered and advanced the discovery of so me HTLV-I-associated concepts In HTLV-I-infected individuals without s igns of CNS involvement. Most of these HTLV-I-associated diseases exhi bit common viroimmunologic characteristics that include a distribution al bias of HTLV-I activation between the blood flow and the affected l esions and accumulated cellular immune responses in the lesions. These facts suggest that the vulnerable tissue(s) in some HTLV-I-infected i ndividuals may not be defined by an exclusive tissue specificity, but that common steps df HTLV-I-versus-host interactions may have an impor tant role in the pathologic process(es) in these diseases. This review summarizes the recent perspectives of the clinical spectrum and the p athogenesis of HAM/TSP in Japan. Furthermore, the feasible pathogenic involvement of cellular interactions between infected cells and respon ding immunocompetent. cells in the affected tissues is emphasized.