Diagnostic relevance of neutrophil gelatinase-associated lipocalin in early detection of acute kidney injury

Objective: To evaluate the predictive and diagnostic accuracy of neutrophil gelatinase-associated lipocalin (NGAL) in acute kidney injury (AKI) and also to predict the renal replacement therapy (RRT) using NGAL as a marker. Methods: This prospective study was conducted among the patients admitted to intensive care units. Plasma samples were collected 24 hours after admission and NGAL was measured using Triage® NGAL test, a specific point of care test which is based on the mechanism of fluorescence immunoassay. The diagnostic accuracy of plasma NGAL (pNGAL) to predict AKI in critically ill patients of ICU was assessed by applying receiver operator curve (ROC) analysis and calculating the area under the curve (AUC). Results: In this study, 100 patients with the mean age of 49.56±19.2 years were included for the period of 18 months. The blood samples were withdrawn from the patients 24 and 44 hours after admission. Totally, 55% (n=55) of ICU patients were diagnosed with AKI. Plasma NGAL level was significantly increased in AKI patients as compared to non-AKI patients (742.65±734.72 vs. 255.62±440.09 μg/L; P<0.01). The sensitivity and specificity of NGAL for diagnosing AKI was 83.6% and 88.9%, respectively. The overall diagnostic accuracy was 86%. Diagnostic accuracy of NGAL for requirement of RRT was 51%. Conclusion: Plasma NGAL is a reliable marker for patients with AKI in ICU, in case the cause of kidney injury is not known. In addition, NGAL also predicts the RRT need based on AKI severity.