In vitro modulation of lymphocyte proliferation by prednisolone and interferon-alpha in patients with HTLV-I-associated myelopathy (HAM).

One of the hallmarks of human T-lymphotropic virus type I (HTLV-I) infection is the proliferation in vitro of peripheral blood lymphocytes (PBLs) in the absence of growth factors. This phenomenon, the autologous proliferative response (APR), involves spontaneous growth of HTLV-I-infected T-cells and proliferation of T-cells in response to the infected cells. We studied the modulating effect of prednisolone (PSL) and interferon-alpha (IFN) on APR of PBLs obtained from five patients with HTLV-I-associated myelopathy (HAM). APR was significantly inhibited by PSL and IFN suggesting that APR is important in the pathogenesis of HAM.