The role of neutrophil gelatinase-associated lipocalin (NGAL) in cerebrospinal fluids for screening of acute bacterial meningitis.

Background: Acute bacterial meningitis is a rare but extremely severe disease. The aim of this study was to investigate whether neutrophil gelatinase-associated lipocalin (NGAL) is present and measurable in cerebrospinal fluid (CSF) and if its assessment may be useful for identifying patients with bacterial meningitis. Methods: Eligible specimens were all consecutive CSFs of patients with suspect acute bacterial meningitis that were referred from the Unit of Infectious Diseases for routine chemical and morphological analysis over a three months period. CSF measurements consisted in NGAL, glucose, and total protein concentrations, along with cell count and differential. Results: Eighty eight CSFs were received throughout the study period, 58 (66%) with CSF findings compatible with bacterial meningitis. The values of white blood cells (WBC), polymorphonuclear (PMN) and mononuclear (MONO) leukocytes, red blood cells (RBC), total proteins, and NGAL were significantly increased in positive CSFs, whereas that of glucose did not significantly differ. A significant correlation was found between CSF concentration of NGAL and CSF values of PMN, WBC, RBC and total proteins, but not with that of glucose and MONO. The concentration of NGAL in CSF showed an area under the curve (AUC) of 0.94 for identifying positive CSFs, with specificity and sensitivity of 1.00 and 0.741 at a diagnostic threshold of 13 ng/mL. Conclusions: NGAL is present in CSF of patients with bacterial meningitis and its measurement may be helpful for identifying positive CSFs.