[Cytokine levels in patients with thrombotic thrombocytopenic purpura]

Plasma cytokine levels were examined in 13 patients with thrombotic thrombocytopenic purpura (TTP). Complete remission (CR) was attained in 7 of the 13 patients, but 6 died. Tumor necrosis factor (TNF), Interleukin (IL)-1, IL-6 and soluble IL-2 receptor showed marked increases at onset and decreased at CR. The prognosis tended to be poor in patients with increased IL-6 and soluble IL-2 receptor levels. Tissue factor production in human umbilical vein endothelial cell (HUVEC) cultured with TTP plasma was significantly increased, but the migration of HUVEC to TTP plasma was significantly lower. These findings suggest that immunological mechanisms and vascular endothelial cell damages are involved in the pathogenesis of TTP and are reflected in the plasma cytokine levels.