[Imatinib mesylate as a novel therapeutic drug for systemic rheumatic diseases].

Platelet-derived growth factor (PDGF) is a topic in the pathophysiology of various systemic rheumatic diseases. For example, autoantibody against PDGF receptor was identified in patients with systemic sclerosis. Imatinib mesylate has been well tolerable and widely used for chronic myeloid leukemia and gastrointestinal stromal tomor. Imatinib also inhibits the activation of c-Abl, which is a key downstream molecule of transforming growth factor-beta signaling, and PDGF receptors. Thus, imatinib effectively suppresses the activation and proliferation of fibroblasts, mesangial cells and smooth muscle cells. Therefore, imatinib may overcome the limitation of current therapeutic strategy with corticosteroids and immunosuppressive agents for refractory diseases.