Plasma and synovial fluid programmed cell death 5 (PDCD5) levels are inversely associated with TNF-α and disease activity in patients with rheumatoid arthritis

Context: Programmed cell death 5 (PDCD5), a novel apoptotic regulatory gene, has been reported to be associated with rheumatoid arthritis (RA) and osteoarthritis (OA), which can regulate the apoptosis of synoviocytes and chondrocytes cultured in vitro. Objective: To study expression characteristic of PDCD5 in plasma and synovial fluid of RA patients, and analyze its correlation with tumor necrosis factor alpha (TNF-alpha) and disease activity in RA. Methods: A total of 135 subjects were recruited into this study (44 RA patients, 46 OA patients and 45 healthy controls). PDCD5 and TNF-alpha concentrations in plasma and synovial fluid were analyzed by enzyme-linked immunosorbent assay. Results: Plasma and synovial fluid PDCD5 concentrations were significantly elevated in RA patients. Pearson correlation analysis indicated that plasma and synovial fluid PDCD5 levels were inversely correlated with TNF-alpha. Moreover, plasma PDCD5 levels were also inversely correlated with C-reactive protein and erythrocyte sedimentation rate. Conclusion: Plasma and synovial fluid PDCD5 could be useful for monitoring the activity and progression of RA, and its abnormal expression and dysfunction may be correlated to TNF-alpha in RA patients.