Correlation of the expression of miR-146a in peripheral blood mononuclear cells of patients with ankylosing spondylitis and inflammatory factors

We investigated the expression of miR-146a in peripheral blood mononuclear cell (PBMC) of patients with ankylosing spondylitis (AS) and its correlation with inflammatory factors to explore the clinical significance. In total 45 patients with AS were selected at the Weifang People's Hospital from June, 2014 to January, 2016. At the same time, 30 healthy volunteers were also selected to serve as control group. Expression level of miR-146a in PBMC cells of patients in each group was detected by quantitative real-time-polymerase chain reaction (qRT-PCR). Levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 in serum and the supernatant of culture medium of PBMC derived from each group were detected by enzyme-linked immunosorbent assay (ELISA). Correlations between expression level of miR-146a and serum inflammatory factors, and clinical indicators were analyzed. Clinical indicators included bath ankylosing spondylitis disease activity index (BASDAI), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and duration of morning stiffness. Expression level of miR-146a in PBMC of AS patients was significantly higher than that of healthy control (P<0.01); levels of TNF-α, IL-1β and IL-6 in serum and the supernatant of culture medium of PBMC derived from AS patients were significant compared to those of control group (P<0.01); expression of miR-146a in PBMC of patients with AS was positively correlated with the levels of TNF-α, IL-1β and IL-6 in serum (r=0.632, P<0.01; r=0.574, P<0.01; r=0.483, P<0.01). In addition, expression level of miR-146a in PBMC of patients with AS was positively correlated with BASDAI, ESR, CRP and duration of morning stiffness (r=0.551, P<0.01; r=0.738, P<0.01; r=0.685, P<0.01; r=0.497, P<0.01). Expression level of miR-146a in PBMC of AS patients was significantly increased and the expression level was positively correlated with the levels of TNF-α, IL-1β and IL-6 in serum (P<0.05). In addition, expression level of miR-146a in PBMC of AS patients was also positively correlated with BASDAI, ESR, CRP and duration of morning stiffness. Those results suggest that miR-146a may be involved in the pathogenesis of AS, and the expression level of miR-146a in PBMC cells may be helpful for diagnosis of AS and judgment of disease activity.