Increased Production of Inflammatory Cytokines in Cultured CD4⁺ Cells from Patients with HTLV-I-Associated Myelopathy

Abstract

We investigated the production of inflammatory cytokines derived from cultured T cells of peripheral blood lymphocytes (PBL) in 14 patients with HTLV-I-associated myelopathy (HAM). The production of inflammatory cytokines, such as tumor necrosis factor-α, interferon-γ, and granulocyte-macrophage colony stimulating factor, was significantly increased in patients with HAM, compared to HTLV-I seronegative controls. On the contrary, interleukin-4 production in cultured T cells was detected in only two patients with HAM, and not detected in HTLV-I seronegative controls. These results suggest that the production of inflammatory cytokines derived from TH1 cell population was simultaneously exaggerated in HAM patients. Interestingly, accelerated production of these cytokines was derived from CD4⁺ cells, which are main target cells in HTLV-I infection. These findings suggest that an inflammatory state in the central nervous system might be related to the pathogenesis of HAM.