Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by joint inflammation and destruction resulting in degradation of extracellular cartilage matrix. Osteoarthritis (OA) is also associated with degradation of molecular components of cartilage matrix with eventual loss of joint cartilage function. Matrix metalloproteinases (MMPs) are a family of proteinases modulated enzymes that play an important role in the pathogenesis of RA by inducing bone resorption and cartilage destruction.

Aim of the study:The present study aimed to evaluate the significance of MMP-1 and tumor necrosis factor-α (TNF- α) as markers of joint destruction in RA and OA, and to determine the relation between these markers and the routine clinical and laboratory markers of disease severity as number of swollen joints, and erythrocyte sedimentation rate.

Methods:Serum samples from 20 patients with RA, 20 patients with knee osteoarthritis and 20 healthy controls were analyzed for serum concentration of MMP-1 and TNF- α using ELISA method.

Results:Serum from RA and OA patients showed significantly higher levels of MMP-1 (p<0.001) and TNF- α (p<0.05) compared to control group, yet serum MMP-1 levels were found to be significantly higher in RA than in OA patients (p<0.01). Also a positive significant correlation was found between serum TNF- α and MMP-1 levels in RA patients (r=0.569, p< 0.001). The two parameters correlated significantly with markers of disease activity as ESR and the number of swollen joints.

 The results support the concept of probable usefulness of MMP-1 and TNF- α measurement in the assessment of disease activity and response to therapy.