Role of Neutrophil Gelatinase-associated Lipocalin (NGAL) and Other Clinical Parameters as Predictors of Bacterial Sepsis in Patients Presenting to the Emergency Department with Fever

Abstract

Background: Bacterial sepsis is associated with significant morbidity and mortality. However, to date, there is no single test that predicts sepsis with reproducible results. We proposed that using a combination of clinical and laboratory parameters and a novel biomarker, plasma neutrophil gelatinase-associated lipocalin (NGAL) may aid in early diagnosis.

Method: A prospective cohort study was conducted at a tertiary care center in South India (June 2017 to April 2018) on patients with acute febrile episodes fulfilling the Systemic Inflammatory Response Syndrome (SIRS) criteria. Plasma NGAL and standard clinical and laboratory parameters were collected at the admission. Bacterial sepsis was diagnosed based on blood culture positivity or clinical diagnosis. Clinically relevant plasma NGAL cut-off values were identified using the receive operating characteristic (ROC) curve. Clinically relevant clinical parameters along with plasma NGAL's risk ratios estimated from the multivariable Poisson regression model were rounded and used as weights to create a new scoring tool.

Results: Of 100 patients enrolled, 37 had bacterial sepsis. The optimal plasma NGAL cut-off value to predict sepsis was 570 ng/mL [area under the curve (AUC): 0.69]. The NGAL sepsis screening tool consists of the following clinical parameter: diabetes mellitus, the presence of rigors, quick sequential organ failure assessment (qSOFA) >2, a clear focus of infection, and the plasma NGAL >570 ng/mL. A score of <3 ruled out bacterial sepsis and a score >7 were highly suggestive of bacterial sepsis with an interval likelihood ratio (LR) of 7.77.

Conclusion: The NGAL sepsis screening tool with a score >7 can be used in the emergency department (ED) to identify bacterial sepsis.

How to cite this article: Paul A, Newbigging NS, Lenin A, Gowri M, Varghese JS, Nell AJ, et al. Role of Neutrophil Gelatinase-associated Lipocalin (NGAL) and Other Clinical Parameters as Predictors of Bacterial Sepsis in Patients Presenting to the Emergency Department with Fever. Indian J Crit Care Med 2023;27(3):176-182.

Keywords: Bacteremia; Biomarker; Emergency department; Neutrophil gelatinase-associated lipocalin; Sepsis; Systemic inflammatory Response Syndrome; quick sequential organ failure assessment.

Fig. 1

ROC curve for the plasma NGAL. At the plasma NGAL threshold (570 ng/mL) identified using Youden's J statistic. The AUC is 0.69 (sensitivity = 0.86, specificity = 0.46, crude RR = 2.91 (95% CI: 1.34–6.30)

Fig. 2

ROC curve for training set NGAL sepsis screening tool

Fig. 3

ROC curve for test set NGAL sepsis screening tool