Background Matrix metalloproteinase (MMP)-3, also known as stromelysis-1, is expressed in inflamed synovium of patients with rheumatoid arthritis (RA). It degrades components of articular cartilage, such as proteoglycans. In Japan MMP-3 has been used as a clinical biomarker of joint destruction and its predictive value for radiographic progression has been reported.
Objectives W aimed to confirm a relation between baseline MMP-3 and radiographic progression at 1 year and to examine the association of the MMP-3 level with ultrasonography (US) findings.
Methods A total of 259 (213 women) consecutive patients with RA were enrolled. We collected baseline data, that included the patient's age, sex, disease duration, use of glucocorticoid or disease modifying antirheumatic drugs, Disease Activity Score-28, and modified total Sharp score (mTSS); MMP-3 and, C reactive protein levels;, rheumatoid factor or anti-citrullinated peptide antibody status,; and the power doppler score (PD) of US assessment of digits and wrists. Baseline MMP-3 level was analyzed in association with the baseline PD value and changes (Δ) in mTSS, erosion score (ΔERN), joint space narrowing (ΔJSN) at 1 year from baseline by Pearson's correlation method. Correlations between ΔMMP-3 and ΔmTSS, or ΔPD were also analyzed. Multiple regression analysis was performed, with ΔmTSS as the outcome for baseline variables. Statistical analysis was performed separately by sex because the upper normal limits of MMP-3 differ between the sexes (men ≤121ng/ml, women ≤59.7 ng/ml).
Results There was a weak correlation between the baseline MMP-3 level and baseline PD score in men. There was also moderate correlations between baseline MMP-3 level and structural damage at 1 year only in men. There was no predictive value for baseline MMP-3 level in women in terms of structural damage at 1 year. Multiple regression analysis revealed that the baseline MMP-3 level correlated independently with the ΔmTSS only in men (p=0.0031), whereas in the women the baseline PD score was correlated independently with the ΔmTSS (p=0.0003).
Conclusions The baseline MMP-3 level was a good predictor of deterioration of the mTSS at 1 year in male patients with RA, but not in female patients. On the other hand, the baseline PD score was a useful predictor of joint destruction in female patients with RA.
Disclosure of Interest None declared