Neutrophil Gelatinase-Associated Lipocalin for Predicting Intensive Care Unit Admission and Mortality in Patients with Pneumonia

Abstract

Pneumonia is one of the most common causes of hospital admissions and mortality, and it is responsible for significant socioeconomic burden worldwide. Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa protein; which is involved in iron trafficking and has chemostatic and bacteriostatic effects. NGAL is also known as an early marker of many inflammatory diseases. However, little is known about the role of NGAL in the management of pneumonia. Thus, this study aimed to investigate whether plasma NGAL levels can predict intensive care unit (ICU) admission and in-hospital mortality in patients with pneumonia. This retrospective observational study included 241 adults hospitalized with pneumonia who underwent NGAL measurement. We compared the prognostic values of plasma NGAL with pneumonia severity index (PSI) for prediction of ICU admission and in-hospital mortality. Of 241 patients, 47 (19.5%) died during hospital admission. There was no significant difference between NGAL and PSI for predicting ICU admission (area under the receiver operating characteristic curve [AUC] of log NGAL vs. PSI, P > 0.999). Although log NGAL was useful in predicting in-hospital mortality, its ability was inferior to that of PSI (AUC of log NGAL vs. PSI, P = 0.008). Multivariable analysis revealed that log NGAL was significantly associated with ICU admission (adjusted odds ratio = 10.76, P < 0.001) and in-hospital mortality (adjusted odds ratio = 5.04, P = 0.004). These results suggest that plasma NGAL level is a useful biomarker for predicting ICU admission and mortality in hospitalized patients with pneumonia.