NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN (NGAL) AND URINE ALBUMIN-TO-CREATININE RATIO (uACR) IN PATIENTS WITH CHRONIC KIDNEY DISEASE: A CROSS-SECTIONAL STUDY

Chronic kidney disease (CKD) remains a major global health burden with an increasing prevalence and a substantial risk of progression to end-stage renal disease. Urine albumin-to-creatinine ratio (uACR) is widely used as a conventional biomarker reflecting glomerular injury in CKD, whereas neutrophil gelatinase-associated lipocalin (NGAL) has been proposed as a biomarker associated with tubular injury and inflammatory processes. This study aimed to determine the correlation between serum NGAL levels and uACR in patients with CKD. The authors conducted an analytical observational study with a cross-sectional design on 32 CKD patients at Universitas Airlangga Hospital. Serum NGAL levels were measured using enzyme-linked immunosorbent assay (ELISA), while uACR was determined from spot urine samples. The association between serum NGAL and uACR was analyzed using Spearman's rank correlation test. The mean serum NGAL level was 98.92 ng/mL (median: 88.00 ng/mL), while the mean uACR was 483.90 mg/g (median: 414.05 mg/g). Statistical analysis showed no significant correlation between serum NGAL levels and uACR (r = –0.007; p = 0.968). Although both biomarkers were elevated among CKD patients, the absence of correlation suggests that NGAL and uACR may reflect distinct pathological processes, with NGAL predominantly associated with tubular injury and inflammation. In contrast, uACR represents glomerular permeability and chronic structural damage. In conclusion, serum NGAL levels were not significantly correlated with uACR in CKD patients. However, NGAL may serve as a complementary biomarker alongside uACR in the assessment and monitoring of CKD. Therefore, further large-scale and longitudinal studies are warranted to clarify the clinical utility of NGAL in combination with conventional renal biomarkers.