Serum and synovial fluid levels of matrix metalloproteinase-3 as a biomarker of joint damage in patients with rheumatoid arthritis

Abstract

Abstract Background Rheumatoid arthritis (RA) is one of the systemic autoimmune diseases characterized by chronic synovitis and progressive joint destruction leading to decline in functional capacity, eventual work disability, and reduced quality of life. Considering the common disease activity indicators are unspecific for arthritis, novel biomarkers have been rapidly developed for predicting structural destruction progression in RA. Matrix metalloproteinase-3 plays a special role in rheumatoid arthritis pathogenesis and has been suggested as a marker of disease activity and joint damage. Patients and Methods MMP-3 was measured by ELISA in serum samples of 40 early RA patients and compared to age and sex matched control group of 40 healthy volunteers. Synovial levels of MMP-3 were measured only in 8 RA patients, who were indicated for knee arthrocentesis. Joint damage was assessed using SENS score on plain radiography. Results Serum MMP-3 levels were significantly higher in RA patients than healthy volunteers (P-value <0.001). Measured synovial levels of MMP-3 were significantly correlated to the serum levels. There were statistically significant positive correlations between serum MMP-3 with RF titers, AntiCCP titres, CRP, and DAS28 -ESR activity score. There was no significant correlation to total SENS score. ROC curve was used to define the best cut off value of serum MMP3 to discriminate between RA and healthy controls, which was found to be >50ng/ml. Conclusion Serum levels of MMP-3 can be used as noninvasive biomarker of RA, and also indicator of disease activity in early RA patients.