Progressive fibrotic interstitial lung disease emerging after pulmonary tuberculosis: a retrospective observational study

Background Post-tuberculosis lung disease (PTLD) is recognized as a localized sequela characterized by fibrotic scarring, bronchiectasis, or volume loss. However, whether a progressive fibrotic interstitial lung disease (ILD) phenotype can emerge after pulmonary tuberculosis (TB) remains unclear. Methods We conducted a retrospective observational study of HIV-negative patients with pulmonary TB at a single tertiary hospital. Baseline and longitudinal high-resolution computed tomography (HRCT) images were reviewed to identify ILD, interstitial lung abnormalities (ILA), indeterminate ILA (iILA), and radiologic evidence of progression. Patients were classified into a progressive fibrotic phenotype (PF) or non-PF, and their clinical and radiologic features were compared. Results Among the 255 patients, baseline HRCT identified ILD in 26, ILA in 18, and iILA in 5 patients. Sixteen patients underwent imaging follow-up for > 2 years, of whom 7 (ILD: 2, ILA: 3, iILA: 2; 2.7% of the total cohort) were classified into the PF group. Patients in the PF group had a higher Mycobacterium tuberculosis burden and a longer time to sputum smear and culture conversion. Radiologically, patients with PF developed pleuroparenchymal fibroelastosis-like lesions. None of the patients without baseline interstitial abnormalities developed ILD. Conclusion A progressive fibrotic ILD may emerge as part of PTLD, particularly in patients with baseline interstitial abnormalities, a high mycobacterial burden, and delayed sputum conversion.