Elevated expression of interleukin-33 in myasthenia gravis patients.

Myasthenia gravis (MG) is an archetypal autoimmune disorder of the neuromuscular junction. The imbalance of inflammatory cytokines are involved in the pathogenesis of MG. IL-33, a member of the IL-1 family, plays a key immune-modulation role in several autoimmune disease. However, its regulatory role in MG remains unclear. Here, we demonstrated that IL-33 expression in the serum of MG patients was significantly increased. We further proved that the serum levels of IL-33 were significantly negative correlated with the expression levels of TSLP. Increased serum IL-33 levels positively correlated with the upregulation of IL-17A levels and the quantitative myasthenia gravis (QMG) score in MG patients. Our findings indicate that IL-33 plays a potent immuno- enhancing role in the pathogenesis of MG by downregulating TSLP, consequently affecting the development of Th17 cells in MG.