Background Behcet's disease is a chronic, multisystem, inflammatory disease characterized by the predominance of T-helper 1 cytokines. The disease is also characterized by infiltration of lymphocytes and neutrophils into the affected tissues. Because cytokines are involved in the regulation of lymphocyte and phagocyte functions, they may play an important role in the pathogenesis of Behcet's disease. Leptin, a member of the gp 130 family of cytokines, induces a strong T-helper 1 response and is regarded as a proinflammatory inducer. Recent studies have shown that serum leptin concentration was increased in patients with Behcet's disease and correlated with disease activity.