Circulating Levels of MiR-146a and IL-17 Are Significantly Correlated with the Clinical Activity of Graves' Ophthalmopathy

Graves' ophthalmopathy (GO) is a common autoimmune disease that is difficult to deal with due to limited clinical evaluation methods. Recently miR-146a and Interleukin-17 (IL-17) have been found to be involved in autoimmune disorders and correlated with disease activity. However, it is unclear whether they are involved in Graves' ophthalmopathy (GO). The aim of this study is to investigate the correlation of circulating levels of miR-146a and IL-17 with clinical activity in GO patients. Fifty-seven study subjects were enrolled in four groups according to the corresponding criteria: active-GO, inactive-GO, Graves disease (GD) without ophthalmopathy, and healthy control group. The circulating levels of miR-146a and IL-17 were determined by qRT-PCR and ELISA, respectively. Serum IL-17 levels of GD, inactive-GO, and active-GO groups were all significantly higher than that of control (all P < 0.001). Active-GO group had significantly higher IL-17 level than inactive-GO and GD groups (P = 0.024 and P = 0.001, respectively). Active-GO and inactive-GO group had significantly lower miR-146a expressions than control (P < 0.05). Active-GO group had significantly lower miR-146a than inactive-GO group (P < 0.05). Serum levels of IL-17 and miR-146a were both significantly correlated with clinical activity score (CAS) in GO patients (P < 0.001, P < 0.001, respectively). There was a significant negative correlation of circulating miR-146a expression with serum IL-17 levels (P < 0.01). These findings indicated that circulating levels of miR-146a and IL-17 may be potential biomarkers of active GO, and may play a key role in the progression of GO.