Matrix metalloproteinase-3 as a marker of subclinical activity in rheumatoid arthritis patients: Relation to ultrasonographic activity

Abstract

BackgroundRheumatoid arthritis (RA) is a chronic disease which may result in progressive joint destruction even with clinical remission. Ultrasound (US) can detect subclinical disease activity and matrix metalloproteinase 3 (MMP-3) has a role in disease activity in RA. Aim of the workTo evaluate the level of MMP-3 in RA patients and its ability to predict sonographic activity in patients with clinical remission or low disease activity (LDA). Patients and methodsThis study included 45 RA patients with a disease activity score (DAS28) <3.2 and 45 matched healthy control. US evaluation using modified German US7 score was performed and accordingly patients were classified into those with sonographic remission (grey scale 0–1) or activity. MMP-3 level was assessed by enzyme-linked immunosorbent assay. Results.The mean age of the patients was 45 ± 9.5 years and 86.7% were females. Sonographic remission was achieved in 20 (44.4 %) patients. There was a significant difference in serum MMP-3 between patients and control (17 ± 4.5 vs 6.3 ± 2.2 ng/ml; p < 0.0001). There was no difference between patients with clinical remission (n = 37) and those with LDA (n = 8). Serum MMP-3 tended to be higher in patients with sonographic activity than in those with sonographic remission (18 ± 5.3 vs 15.6 ± 2.8 ng/ml; p = 0.3). Serum MMP-3 significantly correlated with erythrocyte sedimentation rate (p = 0.002) and synovitis score (p = 0.002). ConclusionSerum MMP-3 was higher in RA patients than in control and was associated with the ultrasound synovitis score. However, serum MMP-3 was not able to differentiate patients with sonographic remission from those with subclinical activity.