Reduction in HTLV-I proviral load and spontaneous lymphoproliferation in HTLV-I-associated myelopathy/tropical spastic paraparesis patients treated with humanized anti-Tac

Ann Neurol. 1998 Dec;44(6):942-7. doi: 10.1002/ana.410440613.


Human T-lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurological disease that results from an interaction of retroviral infection and immune activation. In this study, five doses (1 mg/kg) of humanized anti-Tac antibody were administered to 9 HAM/TSP patients at weeks 0, 2, 6, 10, and 14. Preliminary immunological studies on HAM/TSP patients treated with humanized anti-Tac indicate that there is a selective down-regulation of activated T cells and a decrease in the HTLV-I viral load in peripheral blood lymphocytes, most likely through the selective removal of HTLV-I-infected, activated CD4+ lymphocytes.

MeSH terms

  • Antibodies / therapeutic use*
  • Blood Cells / pathology
  • Cell Division / physiology
  • Human T-lymphotropic virus 1 / isolation & purification*
  • Humans
  • Immunophenotyping
  • Lymphocyte Subsets / pathology
  • Lymphocytes / pathology
  • Paraparesis, Tropical Spastic / blood
  • Paraparesis, Tropical Spastic / therapy*
  • Paraparesis, Tropical Spastic / virology*
  • Proviruses / isolation & purification*
  • Receptors, Interleukin-2 / immunology*
  • Treatment Outcome
  • Viral Load


  • Antibodies
  • Receptors, Interleukin-2