Serum COX-2 and FOXO3a in patients with rheumatoid arthritis and correlation with disease activity

Expression levels of serum cyclooxygenase (COX)-2 and forkhead box O3a (FOXO3a) in patients with rheumatoid arthritis (RA) and the correlation with disease activity were investigated. Sixty patients with RA admitted to the People's Hospital of Guangxi Zhuang Autonomous Region (study group; 28 active patients and 32 remissive patients), and further 30 healthy subjects undergoing physical examinations during the same period (control group) were enrolled in this study. RT-qPCR and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression levels of COX-2 and FOXO3a in serum. According to DAS28 score, the patients were divided into active and remissive patients, between whom the expression levels were compared. Receiver operating characteristic (ROC) curves were plotted to analyze the diagnostic values of COX-2 and FOXO3a for disease activity. Pearson's correlation coefficient was used to analyze the correlation of the two markers with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and DAS28 score. The expression levels of COX-2 and FOXO3a in active and remissive patients were significantly higher than those in the control group (both P<0.05), and those in active patients were significantly higher than those in remissive patients (both P<0.05). The areas under the ROC curves (AUCs) of COX-2 and FOXO3a were 0.748 and 0.802, respectively, suggesting that the two markers have high diagnostic value. The expression levels of COX-2 and FOXO3a were positively correlated with ESR, CRP, and DAS28 score of active and remissive patients (both P<0.05). In conclusion, the expression levels of COX-2 and FOXO3a in patients with RA are upregulated, thus, the two markers may be involved in the development and progression of the disease. The expression levels of COX-2 and FOXO3a are related to the disease activity of RA, and therefore can be used as diagnostic indicators for the disease activity.