ABSTRACT
Leptin hormone, synthesized by the adipose tissue, binds with a receptor member of the class I cytokine receptor family. It plays a role in the pathogenesis of several autoimmune diseases. Idiopathic thrombocytopenic purpura [ITP] constitutes the prototype of autoimmune diseases characterized by the production of the autoantibodies against platelet antigens, resulting in enhanced destruction of the platelets by macrophages. Recently, more evidences have been found related to the effects of hormones on the immune system, including their effect on autoimmunity. The aim of this study was to evaluate serum leptin level in patients with chronic ITP in order to determine the role of leptin in the pathogenesis of ITP. This study comprised 40 patients with chronic ITP and 20 healthy controls of similar age, sex and body mass index [BMI]. Serum leptin level was measured by enzyme amplified sensitivity immunoassay [EASIA]. It was found that, the mean serum leptin level in patients with ITP was significantly higher [P<0.001] than in healthy controls. Furthermore, the positivity of platelet-associated antibodies [PAIgG] and platelet count was significantly different between leptin-positive [level greater than mean of control value + 2SD] and leptin-negative patients. From the present study we can conclude that leptin might play an important role in the pathogenesis of ITP