Macrophage Migration Inhibitory Factor in Normal Human Skeletal Muscle and Inflammatory Myopathies

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine secreted by activated T cells and macrophages that has antiapoptotic, proproliferative, and chemotactic effects. Because these cells are major components of many muscle disorders with different etiologies, we investigated the amount and distribution of MIF in inflammatory myopathies. Concentrations of MIF in protein lysates from dermatomyositis (n = 6), polymyositis (n = 7), sporadic inclusion body myositis (n = 9) muscle samples and control biopsies without specific changes (n = 10) were determined by ELISA. In polymyositis, MIF concentrations were higher than in controls (p