Plasma levels and expression of interleukin-37 in patients with immune thrombocytopenia.

Interleukin (IL)-37 has an important role in autoimmune diseases by suppressing immunity and inflammation; however, the role of IL-37 in immune thrombocytopenia (ITP) has remained largely elusive. The present study aimed to investigate the expression of IL-37 and its potential role in the pathogenesis of ITP. The plasma levels and expression of IL-37 in the peripheral blood mononuclear cells of patients with active ITP, ITP patients in remission and healthy controls were measured by ELISA and reverse transcription-quantitative PCR, respectively. The levels of IL-37 in patients with ITP treated with and without glucocorticoids were also determined by ELISA. Specific anti-platelet glycoprotein (GP)IIb/IIIa and/or GPIb/IX autoantibodies were assayed by modified monoclonal antibody-specific immobilization of platelet antigens. The mean value of plasma IL-37 in ITP patients was slightly higher than that in healthy controls, but this was not statistically significant. There was no correlation between IL-37 and anti-platelet autoantibodies, and no significant difference in the IL-37 concentration was identified between patients treated with and without glucocorticoids. In addition, the correlation between IL-37 and the platelet count was analyzed, with no statistical significance observed. It was therefore concluded that IL-37 may not have a pivotal role in the development of ITP. However, the lack of significant differences may be due to the limited number of patients in different groups. A larger number of ITP patients should be enrolled in the future work and achieve more accurate results.