A-284 Accuracy of cerebrospinal neutrophil gelatinase–associated lipocalin integrated with heparin binding protein as powerful biomarkers of bacterial meningitis

Background Bacterial meningitis (BM) is a life-threatening neurological emergency and require emergent diagnosis and management. Neutrophil gelatinase-associated lipocalin (NGAL) and heparin-binding protein (HBP) are potential early biomarkers, but the reports are few. Methods In a single center, prospective study, we investigated the accuracy of CSF NGAL, HBP and routine markers (i.e., WBC,glucose ratio, lactate, protein) for the diagnosis of infectious meningitis in hospitalized patients. All positive pathogens and determinations were grouped by CSF and blood cultures and physician confirmed feedback. Clinical effect was evaluated by retrospective chart review. Continuous variables were compared by Mann-Whitney test or Wilcoxon test. Spearman correlation test was used to evaluate the correlation between CSF and blood NGAL or HBP. A logistic regression model was used to evaluate the diagnostic efficiency of two or more variables combined. Results We enrolled 214 adult patients. A total of 120 (56.1%) bacterial infections of the nervous system were diagnosed and 32 patients (26.7%) had identified bacteria pathogens. All the target biomarkers in CSF were significantly different between BM and non-BM group (p < 0.001). Elevated CSF levels of NGAL and HBP distinguish between patients with bacterial meningitis and patients with other central nervous system infections. CSF NGAL achieved the AUC of 0.95 (95% confidence interval [CI], 0.92-0.98), which was higher than the other biomarkers: 0.91 (95% CI 0.87-0.95) for CSF HBP, 0.93 (95% CI 0.89-0.97) for CSF IL-6, 0.91 (95% CI 0.86-0.95) for CSF lactate, 0.88 (95% CI 0.83-0.94) for CSF protein, 0.83 (95% CI 0.77-0.90) for CSF PCT and 0.74 (95% CI 0.63-0.86) for CSF/Blood Glucose ratio. A diagnostic model consisting of CSF NGAL, HBP and classical makers resulted in the highest diagnostic performance for BM (AUROC, 0.99; 95% CI, 0.98-1.00) and presented a specificity of 100%, a sensitivity raised to 98.01%. Conclusion Cerebrospinal fluid NGAL and HBP are reliable diagnostic biomarkers in the identification of bacterial meningitis, and powerful diagnostic performance appeared to integrated with classic indicators. A timely and clear diagnosis contributes to accurately antibiotics use and solving the diagnostic difficulties caused by empirical antibacterial treatment.