Diagnostic accuracy of NGAL and HBP for the diagnosis of acute bacterial meningitis.

BACKGROUND

Acute bacterial meningitis (BM) is a life-threatening neurological emergency requiring rapid differentiation from viral/fungal central nervous system (CNS) infections. This study develops a multivariate diagnostic model integrating cerebrospinal fluid (CSF) neutrophil gelatinase-associated lipocalin (NGAL), heparin-binding protein (HBP), and classical biomarkers for improved distinction.

METHODS

In this single-center prospective study, 186 adults were enrolled and categorized into predefined groups, including 92 with BM, 63 with other CNS infections and inflammatory diseases (other CNS diseases), and 31 non-inflammatory controls. CSF and paired plasma samples were analyzed for neutrophil gelatinase-associated lipocalin (NGAL), heparin-binding protein (HBP), procalcitonin (PCT), interleukin-6 (IL-6), lactate, protein, and cell count. Diagnostic performance of biomarkers was assessed using AUROC, sensitivity, specificity, and multivariable logistic regression.

RESULTS

CSF NGAL and HBP levels were significantly elevated in BM patients (median: 260.9 ng/mL and 106.6 ng/mL, respectively) compared to other CNS diseases group (9.9 ng/mL and 5.9 ng/mL) and control groups (1.8 ng/mL and 5.9 ng/mL; p < 0.001). CSF NGAL demonstrated an AUROC of 0.95 (95% CI, 0.92-0.98), while CSF white blood cell count, IL-6, and HBP showed AUROC values of 0.93 (95% CI, 0.90-0.97), 0.93 (95% CI, 0.89-0.97), and 0.90 (95% CI, 0.85-0.95), respectively. A combined model incorporating CSF NGAL, HBP, WBC, IL-6, and PCT yielded AUROC of 0.99 (95% CI, 0.97-1.00). Plasma levels showed no significant differences, indicating intrathecal production of NGAL.

CONCLUSIONS

CSF NGAL and HBP provide incremental diagnostic value when combined with conventional CSF markers, enabling rapid (<2 h) and accurate differentiation of BM from other CNS diseases and supporting timely targeted antibiotic therapy.