Serum tumor necrosis factor-α in pediatric tuberculosis with special reference to tuberculous meningitis: a clinicoradiological and microbiological study

Abstract

Objectives Childhood tuberculosis (TB) accounts for 10–20% of all TB cases, with tuberculous meningitis (TBM) being the leading cause of severe morbidity and mortality. Pathophysiology of TBM still remains obscure. Tumor necrosis factor-α (TNF-α) induces fever and activation of hypothalamus–pituitary–adrenal axis, and serum TNF-α level has been shown to be significantly raised and has a positive correlation with severity of disease in TBM. We aimed to assess serum TNF-α level in pediatric patients with TB in association with clinicoradiological and microbiological features, with special reference to TBM. Materials and methods Serum TNF-α level was estimated using enzyme-linked immunosorbent assay in clinically diagnosed (clinical history and Mantoux and/or contact history and/or radiological evidence) or microbiologically confirmed (≥1 of smear/culture/catridge-based nucleic acid amplification test) pediatric TB cases up to 12 years and healthy controls. Results Among 60 pediatric TB cases, 19 were TBM. Median serum TNF-α level among pediatric TB, TBM, and healthy controls was 53.10, 74.2, and 79.2 pg/ml, respectively, with the difference among the three being insignificant. Median TNF-α level in pulmonary TB cases was slightly higher (64.10 pg/ml) as compared with extrapulmonary TB (52.90 pg/ml), with the difference being statistically insignificant (P=0.816). Levels did not vary significantly with clinical features, microbiological diagnosis, and radiological features. Conclusion TNF-α level was not significantly associated with pediatric TB, which may be owing to ineffective immune response in children and also the resulting increased susceptibility to TB in children. Further studies comparing TNF-α level in cerebrospinal fluid of affected patients are required to look for local inflammation and rise in cytokine levels, thus contributing to lower levels in serum.