In the RemIT-JAV-RPGN study, the serum levels of MMP-3 and CXCL13 were significantly higher in patients before treatment than in healthy controls (MMP-3: 29.6 [16.7–46.3] ng/mL vs 16.5 [11.0–24.6] ng/mL, p <  0.001; CXCL13: 189.4 [113.6–242.4] pg/mL vs 67.6 [48.8–94.6] pg/mL, p <  0.001). Here, MMP3 is linked to rapidly progressive glomerulonephritis.