We measured serum levels of Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), interleukin 15 (IL-15), monocyte chemoattractant protein 1 (MCP-1), and matrix metalloproteinase (MMP)-3 for patients with Psoriatic arthritis (PsA), and investigated whether TWEAK levels are associated with clinical disease activity and expression of proinflammatory cytokines.
Forty five patients with PsA and forty five patients with osteoarthritis (OA) were involved in this study between January 2008 and December 2009. At the time of blood sample collection, the disease activity of patients with PsA was assessed according to the 28-joint count Disease Activity Score (DAS28). Serum levels of TWEAK, IL-15, MCP-1, and MMP-3 were measured using commercial enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturers' protocol.
In patients with PsA, serum TWEAK, IL-15, MCP-1 and MMP-3 levels were significantly elevated, and serum TWEAK levels showed a significant correlation with DAS28 (r=0.405, p=0.006) and serum MMP-3 levels (r=0.375, p=0.011).
Serum TWEAK levels positively correlate with disease activity of PsA and confirm that TWEAK plays a crucial role in the pathogenesis of PsA. TWEAK may be a new important target for therapy in PsA.