Biomarkers & Social Determinants

1. Metabolic and Immunological Predictors of TB Risk

• TyG index as a risk indicator Elevated TyG index and its derivatives (TyG-WC, TyG-BMI, TyG-WHtR) are linked to increased risk of latent TB infection in adults with normal or impaired glucose tolerance. The association is especially notable in metabolically healthy individuals and is not significant in those with diabetes, indicating TyG is more predictive in earlier stages of metabolic dysfunction.
• Immune response differences after TB exposure Among individuals exposed to TB, those who remain uninfected show distinct immune gene expression profiles compared to those who develop latent infection. Key differences include heightened CD8+ T-cell activity in uninfected individuals and increased IL-17, TNF, and mast cell signaling in infected individuals.
• Potential biomarkers for early TB risk detection Specific genes such as ATG-7, CXCL-3, and TNFRSF1B may serve as early warning markers for TB susceptibility after exposure, offering opportunities for early diagnosis or risk stratification.

See also: Lin TB Lab

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2. Environmental and Behavioral Risk Factors for TB Spread and Management

• Exposure time strongly influences TB transmission Individuals exposed to active TB cases for more than 6 hours per day are nearly seven times more likely to contract the infection than those exposed for under 6 hours per week. Children under 5 and immigrants are particularly high-risk groups for TB transmission, suggesting the need for prioritized interventions in these populations.
• Health beliefs and treatment adherence TB patients with higher perceived risk (susceptibility), perceived treatment benefits, and support from others are more likely to follow their treatment regimen. Perceived barriers and low self-efficacy negatively affect adherence, highlighting the role of psychological and social factors in treatment outcomes.
• Behavior change can improve outcomes Tailoring interventions to improve risk perception, reduce perceived barriers, and build patient confidence may significantly boost adherence and overall TB control efforts.

See also: YL Samodra

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3. Long-Term Health Consequences of TB

• Pulmonary TB increases long-term risk of COPD Individuals with a history of TB are two to three times more likely to develop chronic obstructive pulmonary disease (COPD), even after accounting for smoking and other lifestyle factors. This association is strongest among older adults and people with lower education, indicating a compounded effect of biological vulnerability and social disadvantage.
• Implication for post-TB care TB history should be routinely considered in COPD risk assessment and follow-up care, even years after TB recovery. Preventing TB can have added benefits in reducing the future burden of chronic lung disease.

References:

1. Qi, M., Qiao, R. and He, J.Q., 2025. The association between triglyceride-glucose index and related parameters and risk of tuberculosis infection in American adults under different glucose metabolic states: a cross-sectional study. BMC Public Health, 25(1), pp.1-11.
2. Qi, X., Yang, Q., Cai, J., Wu, J., Gao, Y., Ruan, Q., Shao, L., Liu, J., Zhou, X., Zhang, W. and Jiang, N., 2024. Transcriptional profiling of human peripheral blood mononuclear cells in household contacts of pulmonary tuberculosis patients provides insights into mechanisms of Mycobacterium tuberculosis control and elimination. Emerging Microbes & Infections, 13(1), p.2295387.
3. Godoy, S., Parrón, I., Millet, J.P., Caylà, J.A., Follia, N., Carol, M., Orcau, A., Alsedà, M., Toledo, D., Plans, P. and Ferrús, G., 2024. Risk of tuberculosis among pulmonary tuberculosis contacts: the importance of time of exposure to index cases. Annals of Epidemiology, 91, pp.12-17.
4. Wang, J., Yu, L., Yang, Z., Shen, P., Sun, Y., Shui, L., Tang, M., Jin, M., Chen, B., Ge, Y. and Lin, H., 2025. Development of chronic obstructive pulmonary disease after a tuberculosis episode in a large, population-based cohort from Eastern China. International journal of epidemiology, 54(2), p.dyae174.
5. Suprijandani, S., Setiawan, S., Pathurrahman, P., Wardoyo, S. and Rahayyu, A.M., 2025. The behaviour of TB patients in East Lombok through a health belief model approach. Journal of Health, Population and Nutrition, 44(1), p.23.

Yoseph L. Samodra

TBC 067