Human T-cell Leukemia Virus Type-l (HTLV-1) Tax Is Expressed at the Same Level in Infected Cells of HTLV-l-Associated Myelopathy or Tropical Spastic Paraparesis Patients as in Asymptomatic Carriers but at a Lower Level in Adult T-cell Leukemia Cells

Patients with human T-cell leukemia virus type-l (HTLV-1)associated myelopathy (HAM/TSP) generally harbor a much greater population of HTLV-l-infected T cells in peripheral blood mononuclear cells (PBMCs) than asymptomatic carriers. These cells are not malignant but frequently proliferate clonally. To investigate the possibility that higher expression of the viral activator Tax induces preferential proliferation of infected nonmalignant T cells in HAM/TSP patients, the expression of Tax mRNA in fresh PBMCs was analyzed by reverse transcriptase-mediated polymerase chain reaction. Total amount of Tax mRNA was higher in HAM/TSP patients