TB Research
← Back to search

Age-stratified immune characteristics in central nervous system tuberculosis patients: a comparative T lymphocyte subset analysis within a cohort of 862 extrapulmonary tuberculosis patients.

Muxing Chen, Fan Zhang, Yiping Liu, Youfei Lin, Di Wu, Xiaohong Chen

BMC infectious diseases · 2025-12

Abstract

BACKGROUND: Central nervous system tuberculosis (CNS-TB) remains a critical clinical challenge with high mortality, and its underlying immunopathological mechanisms have not been fully elucidated. This study aimed to investigate age-dependent variations in T lymphocyte subsets among CNS-TB patients and their clinical implications.

METHODS: In this retrospective study, we analysed 862 patients with extrapulmonary tuberculosis (EPTB) admitted to Fuzhou Pulmonary Hospital between April 2018 and April 2024. The cohort comprised 177 CNS-TB patients and a control group of 685 non-central nervous system extrapulmonary tuberculosis (non-CNS EPTB) patients. We comprehensively compared demographic characteristics, medical history, nutritional parameters, T lymphocyte subsets (CD3, CD4, CD8, and CD45), and neutrophil-to-lymphocyte ratio (NLR) between groups, with detailed age stratification and correlation analyses.

RESULTS: Baseline characteristics, medical history, and nutritional parameters were not significantly different between the groups. CNS-TB patients exhibited markedly reduced T lymphocyte counts, which were most pronounced in the 25&#x2013;54&#xa0;year age group (CD3: 735.5 vs 1010.0 cells/&#x3bc;L,&#x2009;<&#x2009;0.001; CD4: 389.0 vs 576.0 cells/&#x3bc;L,&#x2009;<&#x2009;0.001; CD8: 285.5 vs 358.0 cells/&#x3bc;L,&#x2009;=&#x2009;0.013; and CD45: 1109.5 vs 1448.0 cells/&#x3bc;L,&#x2009;<&#x2009;0.001). These differences persisted but attenuated in the 55&#x2013;64&#xa0;years age group, with no significant disparities in the 18&#x2013;24&#xa0;years and&#x2009;&#x2265;&#x2009;65&#xa0;years age groups. Age-stratified analysis revealed a progressive NLR increase, peaking in patients&#x2009;&#x2265;&#x2009;65&#xa0;years (7.07 vs 4.67,&#x2009;=&#x2009;0.010), with diminishing intergroup differences. Correlation analysis revealed strong positive correlations among T-lymphocyte subsets (&#x2009;=&#x2009;0.52&#x2013;0.96,&#x2009;<&#x2009;0.001), significant positive correlations with lymphocyte counts (&#x2009;=&#x2009;0.52&#x2013;0.71,&#x2009;<&#x2009;0.001) and moderate negative correlations with the NLR (&#x2009;=&#x2009;&#x2212;&#x2009;0.27&#x2013;&#x2009;-0.37,&#x2009;<&#x2009;0.001).

CONCLUSION: CNS-TB patients display characteristic T lymphocyte depletion and elevated NLRs, with dynamic age-dependent immune characteristics most prominent in immunocompetent adults. Lymphocyte counts can predict T-cell subset levels, whereas NLR values can predict inflammatory and immune response states. This study provides the first comprehensive demonstration of age-dependent immune characteristics in CNS-TB patients, offering a theoretical foundation for age-stratified immune monitoring strategies.

CLINICAL TRIAL NUMBER: Not applicable.