Serum MMP-3 as a predictive factor for joint destruction in patients with rheumatoid arthritis who have achieved remission or low disease activity and the clinically relevant cut-off value for the structural remission

抄録

Objectives

　Joint destruction progression is often seen in RA patients achieving low disease activity (LDA) or clinical remission. In this study we evaluated whether increased MMP-3 (including prednisolone-induced elevation) is relevant to the joint destruction progression, and to explore the best cut-off value for the structural remission.

Methods

　RA patients whose CRP levels normalized following methotrexate (MTX) monotherapy or DMARD combination therapy (MTX together with other DMARDs) were divided into two groups based on their MMP-3 positivity at the end of 1-year observation period, and joint destruction progression was retrospectively compared. Radiological joint destruction was assessed using the modified van der Heijde total sharp score (mTSS). The cutoff value of MMP-3 was determined by ROC analysis.

Results

　Among MMP-3 positive patients who have achieved DAS28-ESR LDA or clinical remission, joint destruction progressed in 50.0% of prednisolone(-) and 45.7% of prednisolone(+) patients (p=1.00). Similarly, among MMP- 3 positive patients who have achieved CDAI LDA or clinical remission, joint destruction progressed in 48.3% of prednisolone(-) and 42.6% of prednisolone(+) patients (p=0.79). The ROC analysis in female patients revealed that the cut-off value of MMP-3 was 49.7 ng/mL (AUC 0.681; 95% CI 0.560–0.802, p < 0.01) for the structural remission (ΔmTSS < 0.5).

Conclusions

　The data presented here suggest that prednisolone-induced serum MMP-3 increase contribute similarly to the joint destruction compared with the MMP-3 increase without prednisolone. Also indicated is that the current cutoff value of serum MMP-3 (59.7 ng/mL) is too high to achieve the structural remission in female RA patients.