Utility of the Neutrophil-to-Lymphocyte Ratio, in Differentiating Childhood Pulmonary Tuberculosis from Bacterial Pneumonia: A Cross-Sectional Study from a Peripheral Hospital in Suburban Mumbai

Abstract

Background: Childhood pulmonary tuberculosis (TB) can clinically mimic bacterial community-acquired pneumonia (CAP), making diagnosis difficult, particularly where microbiological confirmation is delayed or unavailable. Complete Blood Count (CBC)-derived parameters, especially the neutrophil-to-lymphocyte ratio (NLR), may provide a simple and low-cost adjunct for differentiation.
Objective: To evaluate whether routine CBC parameters and the NLR can help differentiate childhood pulmonary TB from bacterial CAP.
Methods: This cross-sectional comparative study included 30 hospitalized children aged 2–14 years from a peripheral hospital in suburban Mumbai (January–July 2026), comprising 15 bacterial CAP and 15 pulmonary TB patients. Clinical features and CBC parameters, including NLR, were compared between groups based on established diagnostic criteria.
Results: The mean age was 5.85±3.00 years in the pneumonia group and 7.47±3.25 years in the TB group (p=0.168). Males constituted 60.0% of the pneumonia group and 53.3% of TB group (p=1.000). Mean WBC count was higher in children with pneumonia than in those with TB (14,009.33±3,898.98 vs. 12,038.67±3,952.76/?L; p=0.180). The mean neutrophil percentage was also higher in pneumonia (74.52±12.70% vs. 66.46±12.32%; p=0.089), whereas lymphocyte percentage was higher in TB (25.23±10.96% vs. 18.71±11.82%; p=0.128). Mean platelet count was 282,867±71,773/?L in pneumonia and 328,200±77015/?L in TB (p=0.107). CRP was higher in pneumonia than TB (17.42±18.29 vs. 8.04±9.21; p=0.091). The NLR was significantly higher in bacterial pneumonia than pulmonary TB (7.26±6.67 vs. 3.21±2.08; p=0.038), with a mean between-group difference of 4.05.
Conclusion: Among the evaluated CBC-derived parameters, NLR showed the clearest discriminatory signal between bacterial pneumonia and pulmonary TB, with higher values observed in bacterial pneumonia and may serve as an inexpensive, readily available supportive marker for differentiation. Larger multicentre studies are needed to validate its diagnostic utility.