IL-22 expression in synovial membrane and serum correlated with the severity of PIA.

(A) Expression of IL-22 protein at 28 days in the synovial membrane was measured by Western blotting. (B) Concentration of IL-22 protein at 28 days in the serum was detected by using ELISA. (C) Correlation between IL-22 concentration and clinical score was analyzed. One representative plot and quantitative data from three independent Western blotting experiments are shown. Ratio indicates the optical intensity of IL-22 protein bands against β-actin. IL-22 concentration shown are represented as means ± SEM. Levels of significance between the PIA group and control group were calculated by using Mann-Whitney U test (*** P< 0.001). Correlation was measured by Spearman’s σ analysis.