Cerebrospinal Fluid Cytokine Signatures in Real-Time PCR-Confirmed Acute Bacterial Meningitis: Diagnostic Insights from TNF-α and IL-1β.

BACKGROUND

Acute bacterial meningitis (ABM) is a rapidly progressive central nervous system infection where excessive neuroinflammation contributes significantly to morbidity and mortality. Cerebrospinal fluid (CSF) cytokines are key mediators of host immune responses; however, their association with molecular pathogen detection and host inflammatory responses remains incompletely understood

OBJECTIVE

To evaluate CSF cytokine responses and their association with molecularly confirmed acute bacterial meningitis

METHODS

A total of 246 CSF samples from patients with suspected meningitis, submitted to the department (February 2015 to January 2021) were evaluated. CSF supernatants were used for cytokine quantification, while sediments underwent bacterial culture and Real-time PCR. Cytokines (IL-1β, TNF-α, IL-12p70, IL-6 and IL-10) were measured using cytometric bead array. Receiver Operating Characteristic (ROC) curve analysis evaluated diagnostic accuracy.

RESULTS

Bacterial DNA was detected in 53/246 (21.5%) samples, with Streptococcus pneumoniae being the predominant pathogen, particularly in children under five. Real-time PCR-confirmed cases showed significantly higher CSF TNF-α and IL-1β levels compared with non-confirmed cases (p = 0.013 and p = 0.033), indicating a predominant pro-inflammatory cytokine. Elevated IL-10 levels suggested concurrent anti-inflammatory regulation. ROC analysis demonstrated modest overall discrimination for TNF-α (AUC = 0.657, p = 0.013) and IL-1β (AUC = 0.605, p = 0.162). However, at an optimal threshold of 0.60 pg/ml, TNF-α achieved 100% specificity, establishing high reliability.

CONCLUSIONS

Real-time PCR-confirmed acute bacterial meningitis is characterized by a distinct CSF cytokine signature reflecting coordinated pro-inflammatory activation and regulatory immune responses, highlighting CSF TNF-α as a high-specificity adjunctive to molecular assays.