MMP3 and Arthritis: The median serum concentration of MMP-3 at arthritis diagnosis and during arthritis remission was 93.7 ng/mL (IQR, 68.9–132.3 ng/mL) and 20.3 ng/mL (IQR, 15.0–28.2 ng/mL, p < 0.001), respectively (Fig. 3).