Nancy Hilda J Poster 2024

Nancy Hilda

Dr Nancy Hilda J

ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT), India

Immunosenescence and inflammation in cured tuberculosis patients: implications for revaccination program


Poster Abstract

BACKGROUND: Persistent immune activation and systemic inflammation despite cure in treated TB patients drive immuno-senescence resulting in the premature onset of aging that contribute to the higher rates of mortality in these individuals.

METHODS: The study population included two groups of people aged between 18 and 59 years namely previously treated and cured TB patients (Group 1) and healthy controls (group 2) with no prior history of TB matched for age, sex and lifestyle with group 1 participants. Data from 30 participants in each group is used for this analysis. Peripheral Blood Mononuclear Cells (PBMCs) were isolated from whole blood and used to measure β-galactosidase and telomere length. The remaining PBMCs were stimulated, cultured and measured for expression of IFNg, CD57 and CD28 by flow cytometry. Graphpad prism was used to compute statistical significance and P<0.05 was considered to be statistically significant.

RESULTS: CD8 cells and CD4 cells from group 1 had significantly increased expression of CD57 (p=0.0215) and IFNg (p=0.04) respectively as compared to Group 2. Meanwhile, the proportion of CD8 cells expressing CD28 (p=0.082) was significantly decreased in group 1 in comparison to group 2. β-galactosidase assay was done to measure cellular senesce in the study groups which showed significantly increased SA-β-gal activity as revealed by the presence of a higher number of stained cells in group 1 as compared to group 2 (p=0.001). We also observed a significant decrease in the length of telomeres of PBMCs in group 1 (2-3 kb) as compared to group 2 (5-15kb) (p=0.0358).

INFERENCE: The preliminary findings of the study such as increased senescence associated with increased beta galactosidase activity, increased senescence markers like CD57 and CD28 and reduced telomere length are clearly suggestive of accelerated immune senescence and premature onset of aging in cured TB patients.