Matrix Metalloproteinase-9 as a Marker for Arteriovenous Fistula Stenosis in Chronic Kidney Disease

Abstract An arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis in chronic kidney disease (CKD) patients but is often complicated by stenosis. AVF stenosis arises primarily from neointimal hyperplasia, driven by smooth muscle cell proliferation and migration. Matrix metalloproteinase-9 (MMP-9) plays a key role in this process by degrading extracellular matrix proteins and facilitating neointimal hyperplasia. This study aimed to explore the association between MMP-9 levels and AVF stenosis in CKD patients. A cross-sectional study was conducted on CKD patients undergoing hemodialysis with AVF between July 2021 and January 2024. Plasma MMP-9 levels were measured using enzyme-linked immunosorbent assay and chromogenic peptide substrate assay. AVF stenosis was assessed through physical examination, duplex ultrasonography, and/or catheter angiography. Diagnostic value was determined using receiver operating characteristic curve analysis, and associations were analyzed using bivariate and multivariate models. Among 51 patients, 29 had AVF stenosis, and 22 had patent AVF. Plasma MMP-9 levels were significantly higher in the stenosis group (1384.2 ng/mL 801–4822) compared with the patent group (743.4 ng/mL 122–3195.6; p = 0.001). An MMP-9 cutoff of 962.2 ng/mL yielded an area under the curve of 83.3% (95% confidence interval CI: 0.71–0.95). MMP-9 levels were significantly associated with stenosis (p = 0.001, odds ratio OR: 7.00, 95% CI: 2.02–24.25), corroborated by multivariate analysis (p = 0.013, OR: 8.692, 95% CI: 1.575–47.986). Another associated factor for stenosis was radiocephalic AVF location (p = 0.002, OR: 16.618, 95% CI: 2.9–92.221). High MMP-9 levels were associated with AVF stenosis in CKD patients, suggesting MMP-9 as a potential biomarker for early AVF stenosis detection.