Serum Matrix Metalloproteinase-7 Level is Associated with Fibrosis and Renal Survival in Patients with IgA Nephropathy

Background/Aims: In view of the latest findings that matrix metalloproteinase-7 (MMP-7) acted as a vital marker and pathogenic mediator of renal fibrosis in a murine model, we hypothesized that serum MMP-7 level might serve as a noninvasive prognostic biomarker in IgA nephropathy (IgAN) patients. Methods: We conducted a retrospective follow-up study of 244 IgAN patients for a median of 81.9 months. Serum MMP-7 was detected at the time of diagnosis, and renal progression was assessed by Cox proportional hazards method. Results: Compared with healthy populations, the serum levels of MMP-7 were significantly elevated in IgAN patients. Besides, serum MMP-7 levels were well correlated with renal scarring lesions characterized by glomerular sclerosis and interstitial fibrosis. Follow-up analyses revealed that increased serum MMP-7 levels were linked with a greater risk of poor renal outcome with a hazard ratio of 1.898 per doubling MMP-7 concentration. By contrast with the first quartile, the risk of deterioration in renal function elevated such that the hazard ratio for the second quartile was 1.805, 3.383 for the third, and 5.173 for the fourth quartile of the MMP-7 level. Conclusions: This study showed that the higher serum MMP-7 levels were independently associated with renal fibrosis and poor prognosis in IgAN.