Increased levels of thymosin beta4 in synovial fluid of patients with rheumatoid arthritis: association of thymosin beta4 with other factors that are involved in inflammation and bone erosion in joints.

摘要

AIM: Thymosin (Tbeta4) may have various biological effects that are relevant to the pathogenesis of rheumatoid arthritis (RA). This study was performed to gain insight into the relevance of Tbeta4 in the pathogenesis of inflammatory arthritis. METHOD: The level of Tbeta4 in synovial fluid from patients with osteoarthritis (OA) or RA was measured by enzyme-linked immunosorbent assay. An association between Tbeta4 and matrix metalloproteinase (MMP)-1 and MMP-13 (collagenases), MMP-2 and MMP-9 (gelatinases), MMP-7, adiponectin, lactoferrin, vascular endothelial growth factor (VEGF), urokinase-type plasminogen activator (uPA), interleukin (IL)-6, IL-8 and prostaglandin E2 (PGE(2) ) in synovial joint fluids from OA and RA patients were investigated. RESULTS: The level of Tbeta4 in the synovial joint fluid of patients with OA and RA was (mean +/- SD) 145 +/- 88 and 1359 +/- 1685 ng/mL, respectively. The level of Tbeta4 in the synovial joint fluid of RA patients was significantly associated with the levels of MMP-9, MMP-13, VEGF, uPA, IL-6 and IL-8, but not with MMP-1, MMP-2, MMP-7, adiponectin and lactoferrin. In contrast, the level of Tbeta4 in the synovial joint fluid of patients with OA was not associated with any of these molecules. CONCLUSIONS: The results suggest that Tbeta4 may play an important role in bone degradation and inflammation in RA but not OA, although nothing is known about the molecular mechanisms mediating Tbeta4 in arthritic joints. The role of Tbeta4 in arthritis should be studied to understand its relevance to the pathogenic processes in arthritis.