Objective: To probe the function of interleukin-17 (IL-17) in rheumatoid arthritis (RA) patients of accumulated dampness-heat obstruction in joints syndrome (ADOJS) by detecting levels of IL-17 in serum and the synovial fluid and analyzing its correlation with erythrocyte sedimentation rate (ESR) and C reactive protein (CRP).
Methods: From January 2011 to January 2013, recruited were 90 RA inpatients of ADOJS at Department of Integrative Medical Rheumatism, General Hospital of Chengdu Military Region, of which 28 patients had knee joint effusion. Besides, 30 healthy volunteers who received physical examination at our hospital were recruited as the normal control group, and 30 patients with osteoarthritis (OA) who had knee joint effusion were recruited as the synovial fluid control group. The expression levels of IL-17 in serum and the synovial fluid were detected by enzyme linked immunosorbent assay (ELISA), and contents of ESR and CRP were detected in RA patients. Then correlation analyses were performed between levels of IL-17 and contents of ESR and CRP.
Results: Compared with the normal serum control group, the expression levels of IL-17 in serum of RA patients significantly increased (P < 0.05). Compared with the serum of RA patients and the synovial fluid of OA patients, the expression levels of IL-17 in the synovial fluid of RA patients significantly increased (P < 0.05). The expression levels of IL-17 in serum of RA patients were not correlated with ESR or CRP (r = 0.092, -0.082; P > 0.05), and the expressional levels of IL-17 in the synovial fluid of RA patients were not correlated with ESR or CRP (r = 0.113, -0.034; P > 0.05).
Conclusions: IL-17 was the main effector cytokine of Th17 cells. The expressional levels of IL-17 significantly increased in serum and the synovial fluid of RA patients of ADOJS, but with no correlation to ESR or CRP. It indicated that IL-17 participated in the occurrence and development of RA. Concrete mechanisms needed to be further proved in larger samples.