Is plasma neutrophil gelatinase-associated lipocalin a predictive biomarker for acute kidney injury in sepsis patients? A systematic review and meta-analysis

Purpose: Neutrophil gelatinase-associated lipocalin (NGAL) is a useful biomarker for early diagnosis of acute kidney injury (AKI). However, the diagnostic value of NGAL for predicting AKI in sepsis patients is unclear. Methods: MEDLINE, EMBASE, and Cochrane Library databases were searched to identify research publications. Results: Twelve studies from 9 countries including a total of 1582 patients, of whom 315 (19.9%) developed AKI, were included in the study; plasma NGAL levels were significantly higher in adult sepsis patients with AKI than in those without AKI (mean difference, 274.65; 95% confidence interval [CI], 106.16-443.15; I² = 94%). Urine NGAL levels were not significantly different. The diagnostic odds ratio of plasma NGAL for predicting AKI in sepsis patients was 6.64 (95% CI, 3.80-11.58). The diagnostic accuracy of plasma NGAL was 0.881 (95% CI, 0.819-0.923) for sensitivity, 0.474 (95% CI, 0.367-0.582) for specificity, 0.216 (95% CI, 0.177-0.261) for positive predictive value and 0.965 (95% CI, 0.945-0.977) for negative predictive value. Conclusion: Plasma NGAL has a high sensitivity and a high negative predictive value for detection of AKI in adult sepsis patients. However, its low specificity and low positive predictive value could limit its clinical utility. The usefulness of urine NGAL was not revealed in this study.