Expression of vaspin in the joint and the levels in the serum and synovial fluid of patients with osteoarthritis.

The aim of this study was to determine the expression of vaspin in the joint and investigate the distribution between paired serum and synovial fluid (SF) in osteoarthritis (OA) patients, and serum in healthy controls. The gene expression of vaspin was measured by quantitative real-time polymerase chain reaction (qPCR) in the OA joint tissues. The vaspin protein expression in the cartilage, synovium and osteophyte from OA patients who required total knee replacement (TKR) were detected by immunohistochemistry (IHC). Levels of vaspin in serum and SF were analyzed by enzyme-linked immunosorbent assay (ELISA), including 26 OA patients and 23 healthy controls. All the joint tissues including cartilage, synovium, meniscus, infrapatellar fat pad and osteophyte from OA patients expressed vaspin messenger RNA (mRNA), and the expression of vaspin protein was observed in OA cartilage, synovium and osteophyte. Furthermore, serum vaspin was reduced in OA patients compared to healthy controls, and serum vaspin levels from OA patients exceed those in the paired SF. Serum or SF vaspin were not related to age, gender, or body mass index (BMI). These results suggest that vaspin may be involved in the pathophysiology of OA and may have local effects in the joint during the process of OA.