HUMAN T-LYMPHOTROPIC VIRUS TYPE-I (HTLV-I)-ASSOCIATED MYELOPATHY TROPICAL SPASTIC PARAPARESIS (HAM TSP) - RECENT PERSPECTIVES/

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropi cal spastic paraparesis (HAM/TSP) is a well-defined clinicopathologica l entity, and approximately 1,900 patients with HAM/TSP have been repo rted in the world. Improved polymerase chain reaction (PCR)-based in s itu techniques have allowed a better appreciation of the cellular loca lization of the virus activation in infected patients, and there is ac cumulating evidence that HAM/TSP is characterized by a distributional bias of viral activation between the blood flow and central nervous sy stem (CNS). This review summarizes the current status of our understan ding of HAM/TSP, and emphasizes the possible pathogenic involvement of cellular interactions between infected cells and responding immunocom petent cells in the CNS of patients with HAM/TSP. In addition, the not able systemic manifestations with or without myelopathy in HTLV-I-infe cted individuals are described.