Usefulness of plasma neutrophil gelatinase-associated lipocalin concentration for predicting the severity and mortality of patients with community-acquired pneumonia.

Background: The usefulness of plasma neutrophil gelatinase-associated lipocalin (NGAL) concentration for predicting the outcome of community-acquired pneumonia (CAP) is unclear. We evaluated the prognostic value of plasma NGAL concentration for predicting disease severity in comparison with other widely used biological markers of inflammation in patients with CAP.

Methods: NGAL, procalcitonin, and C-reactive protein concentrations were measured in 362 patients with CAP, who were followed for up to 30days. The Pneumonia Severity Index (PSI) and CURB-65 score were obtained for all patients.

Results: The median plasma NGAL concentration increased with CAP severity classified according to the PSI. Plasma NGAL concentration was higher in nonsurvivors than in survivors. The AUC for predicting mortality was highest for NGAL concentration (0.871), followed by that for PSI (0.865) and procalcitonin concentration (0.744). Multivariable logistic regression analysis showed that plasma NGAL concentration was an independent predictor of hospital mortality in CAP patients. Plasma NGAL concentration correlated positively with C-reactive protein and procalcitonin concentrations, CURB-65 score, and PSI.

Conclusions: Plasma NGAL concentration is a valuable biological marker in the assessment of the severity and prediction of the prognosis of patients with CAP in the emergency department.