AUTHOR=Kuang Huang , Wan Hong-shan , Gu Qiu-hua , Jia Xiao-yu , Cui Zhao , Zhao Ming-hui 

TITLE=Serum matrix metalloproteinase-9 levels and enzymatic activity in patients with anti-glomerular basement membrane disease

JOURNAL=Frontiers in Medicine

VOLUME=Volume 12 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1668791

DOI=10.3389/fmed.2025.1668791

ISSN=2296-858X

ABSTRACT=BackgroundAnti-glomerular basement membrane (anti-GBM) disease is an autoimmune disorder with autoantibodies against GBM component, non-collagenous domain of the α3 chain of type IV collagen, α3(IV)NC1. Matrix metalloproteinase-9 (MMP-9) is an endogenous enzyme for the degradation of GBM to produce α3(IV)NC1. The current study was aimed to investigate the serum levels and enzymatic activity of MMP-9 and their clinical significance in patients with anti-GBM disease.MethodsMMP-9 serum levels and enzymatic activity were measured by enzyme-linked immunosorbent assay in 77 patients with anti-GBM disease and 20 healthy individuals. The association of MMP-9 levels and enzymatic activity with clinical-pathological features of patients was analyzed.ResultsMMP-9 levels and enzymatic activity were elevated in 53.2% (41/77) and 61.0% (47/77) of patients with anti-GBM disease, and in 0% (0/20) and 10% (2/20) of healthy individuals (P < 0.001, P < 0.001, respectively). MMP-9 enzymatic activity was negatively correlated with serum creatinine (r = –0.247, P = 0.030) and positively correlated with eGFR (r = 0.232, P = 0.043). It was higher in the patients with prodromal infection [512.8 (286.0–682.8) vs. 307.2 (203.2–487.0) ng/mL, P = 0.037]. Patients with combined ANCA positivity had a significantly weaker MMP-9 enzymatic activity than that of patients with only positive anti-GBM antibodies [241.0 (192.3–431.9) vs. 444.5 (255.2–659.5) ng/mL, P = 0.035)]. Univariate regression analysis suggested that neither MMP-9 levels nor enzymatic activity was a risk factor for kidney outcome in patients with anti-GBM disease.ConclusionThe serum MMP-9 levels and enzymatic activity were elevated in patients with anti-GBM disease. The association between MMP-9 activity and clinical-pathological features indicated that MMP-9 might play different roles in disease development.