Bacterial load and transforming growth factor-beta: Predicting the extent of lung damage in pulmonary tuberculosis patients.

BACKGROUND: Pulmonary tuberculosis (TB) remains a significant global health burden, with disease severity determined by the complex interplay between pathogen burden and host immune responses. Mycobacterial load and serum transforming growth factor-beta (TGF-β) are parameters potentially associated with disease progression and pulmonary tissue damage. TGF-β, as an immunoregulatory cytokine, plays a dual role in TB pathogenesis by suppressing protective immunity while contributing to fibrotic tissue remodeling. Despite their clinical relevance, the direct correlation between bacterial load, serum TGF-β, and radiological lesion extent in newly diagnosed patients remains insufficiently clarified in high-burden clinical settings. AIM: To analyze the correlation between bacterial load, serum TGF-β, and radiological lesion extent in newly diagnosed pulmonary TB patients. METHODS: This observational study employed a cross-sectional design involving 60 newly diagnosed pulmonary TB patients at Haji Regional General Hospital, Makassar. Laboratory examinations were conducted at the Hasanuddin University Medical Research Laboratory, Faculty of Medicine. Bacterial load was assessed using semi-quantitative categories of the Xpert MTB/RIF rapid molecular test, serum TGF-β levels were measured using the enzyme-linked immunosorbent assay, and radiological lesion extent was classified based on chest radiography into minimal vs moderate-extensive categories. Bivariate statistical tests were performed for analysis. RESULTS: A total of 60 newly diagnosed pulmonary TB patients were enrolled, with the majority being male (44 patients, 73.3%) and 16 female patients (26.7%). In terms of age, 70.0% were below 60 years and 30.0% were 60 years or older. Based on body mass index, 41.7% were underweight, 51.7% normal weight, and 6.7% overweight. Moderate-extensive lesions were observed in 85.0% of patients, while 56.7% had medium-high bacterial load. A statistically significant association was found between bacterial load and lesion extent (P = 0.032), with the medium-high group demonstrating a markedly higher risk of moderate-extensive lesions (odds ratio = 5.895; 95% confidence interval: 1.109-31.340). No significant associations were identified between serum TGF-β levels and lesion extent (P = 0.676) or bacterial load (P = 0.622). CONCLUSION: High bacterial load predicts severe radiological lung damage in TB, but systemic TGF-β does not reflect disease extent, suggesting localized activity and need for further tissue-level investigation.