To investigate the value of serum matrix metalloproteinase-3 (sMMP-3) in the assessment of active disease in patients with rheumatoid arthritis (RA).
One hundred and ninety-one RA patients were recruited from the Department of Rheumatology of Sun Yat-sen Memorial Hospital from June 2010 to June 2014. sMMP-3 level of these RA patients and 58 healthy people was tested by enzyme-linked immunosorbent assay, while clinical data was collected simultaneously. Receiver operating characteristic (ROC) curve was used for the analysis of optimal cut-off point for the evaluation of disease activity.
There were 128 female patients and 63 male patients recruited. sMMP-3 was significantly higher in RA patients than healthy control and it was higher in patients with active disease than that in patients in remission (all P < 0.01). ROC curve analysis showed that the optimal cut-off point for diagnosing active RA was 84 μg/L with area under the curve (AUC) 0.822 in female and 168 μg/L with AUC 0.824 in male (both P < 0.01). According to the optimal cut-off points, the sensitivity of sMMP-3 + CRP combined detection was 97.2% for diagnosing active RA, which was significantly higher than that of sMMP-3 (84.7%) or C-reactive protein (CRP) (88.2%, both P < 0.05). The specificity of combined detection was 95.7%, which was significantly higher than that of sMMP-3 (68.1% , P < 0.01). And Youden's index of combined detection (0.951) was significantly higher than that of sMMP-3 (0.528) or CRP (0.754, both P < 0.05).
sMMP-3 is a helpful indicator for disease activity measurement in RA patients. Combined detection of sMMP-3 and CRP can improve the accuracy of disease activity assessment.