An autoaggressive process against bystander tissues in HTLV-I-infected individuals: a possible pathomechanism of HAM/TSP

Med Hypotheses. 1993 Dec;41(6):542-7. doi: 10.1016/0306-9877(93)90111-3.


Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a well-defined clinico-pathological entity in which the virus infection and the host immune responses are involved in the pathomechanism. It is generally agreed that the virus infection precedes the development of HAM/TSP and the infection is persistent during the course of disease. However, what plays the key role for the development of HAM/TSP remains to be elucidated. In this article, we emphasise the importance of the unique nature of HTLV-I-infected cells, which may have a potential ability to produce viral antigens outside of the blood flow, and we also review a variety of evidences supporting the following proposal. In our hypothesis, the supply of infected T cells from blood flow to central nervous system (CNS) is primary for the development of CNS lesions. Both anatomically determined hemodynamic conditions and adhesion molecule-mediated interactions between circulating infected T cells and endothelial cells may contribute to the localization of the main lesions. Following an induction of the HTLV-I antigens on the surface of infected T cells in CNS compartment, expansion of the responses of immunocompetent T cells against the viral proteins may result in CNS tissue damage which may be mediated by released cytokines. This is the first attempt to implicate a bystander damage mechanism in a human disease as an essential pathomechanism.

Publication types

  • Review

MeSH terms

  • Autoimmunity
  • Central Nervous System / immunology
  • HTLV-I Antigens
  • Hemodynamics
  • Human T-lymphotropic virus 1 / pathogenicity
  • Humans
  • Inflammation / etiology
  • Lymphocytes / physiology
  • Models, Biological*
  • Paraparesis, Tropical Spastic / etiology*
  • Paraparesis, Tropical Spastic / immunology


  • HTLV-I Antigens