A Study of the Association of Cerebrospinal Fluid Neutrophil-to-Lymphocyte Ratio with Severity and Mortality in Patients with Tuberculous Meningitis

The increasing severity of tuberculous meningitis (TBM) carries a poor prognosis. This study aimed to correlate cerebrospinal fluid (CSF)-neutrophil-lymphocyte ratio (NLR) with TBM severity and assess its ability to predict in-hospital mortality. A prospective observational study was conducted from February 2023 to February 2025, enrolling 148 confirmed cases of TBM. The severity of TBM was graded according to the British modified Medical Research Council criteria. The mean age was 38.0 ± 17.6 years, with 69 males and 79 females. Of these, 47 had grade 1, 67 had grade 2, and 34 had grade 3 severity of TBM. The CSF-NLR ratio showed no significant correlation (r = 0.113, P = 0.170) with TBM severity. Thirty-three patients died; among them, 27 had low CSF-NLR (≤0.82), while six had high CSF-NLR (>0.82). A CSF-NLR cut-off value of 0.82 had a diagnostic accuracy of 39.19% (sensitivity 81.82%, specificity 26.96%) for predicting mortality. The results negate the use of CSF-NLR as a diagnostic marker for grading TBM severity or predicting mortality.