Exploring tumor necrosis factor-alpha as a biomarker for post-tuberculosis pulmonary fibrosis: A case-control study.

BACKGROUND: Post-tuberculosis lung disease (PTLD), particularly pulmonary fibrosis, affects up to 50 % of TB survivors, contributing to chronic respiratory morbidity. This study investigates tumor necrosis factor-alpha (TNF-α) as a biomarker for post-tubercular sequelae (fibrosis) in patients cured of drug-sensitive pulmonary TB (DS-PTB).

METHODS: A case-control study included 76 DS-PTB patients who completed treatment within one year. Cases (n = 38) had chest X-ray evidence of fibrosis, while controls (n = 38) had no fibrosis. Fibrosis extent was assessed using a chest X-ray scoring system (0-20). Serum TNF-α levels were measured using ELISA. Statistical analysis included generalized linear models and receiver operating characteristic (ROC) curves to evaluate associations and discriminative performance.

RESULTS: Patients with fibrosis were older, predominantly male, and had significantly higher TNF-&#x3b1; levels (3242.7&#xa0;&#xb1;&#xa0;750.0&#xa0;ng/L) compared to controls (262.8&#xa0;&#xb1;&#xa0;93.8&#xa0;ng/L, p&#xa0;<&#xa0;0.001). ROC curve analysis revealed an area under the curve (AUC) of 0.79, indicating good discriminative ability for PTLD. A TNF-&#x3b1; threshold of 2787.3750&#xa0;ng/L yielded a sensitivity for predicting the number of zones was 86.7&#xa0;% (specificity: 16.4&#xa0;%), and for CXR severity, it was 83.3&#xa0;% (specificity: 20.3&#xa0;%), indicating strong discriminative capacity but low specificity.

CONCLUSION: Elevated TNF-&#x3b1; levels are associated with post-TB pulmonary fibrosis and have the potential to serve as a biomarker for its identification. Further studies are warranted to validate these findings and explore TNF-&#x3b1;'s role in guiding management strategies for PTLD.