Lung function trajectories after pulmonary tuberculosis in children and adolescents: a prospective cohort study

Background: Pulmonary tuberculosis during childhood and adolescence may disrupt lung development and alter long-term respiratory health. However, longitudinal data describing post-treatment outcomes in this age group remain scarce. We aimed to characterise respiratory outcomes during the first year after treatment completion and identify predictors of persistent impairment. Methods: Children and adolescents <19 years treated for pulmonary tuberculosis in The Gambia were prospectively enrolled at treatment completion and followed up at 6 and 12 months. At each visit, participants underwent symptom assessment, chest X-ray and spirometry. Mixed-effects regression assessed temporal changes. Group-based trajectory modelling identified spirometry patterns. Multivariable logistic regression identified predictors of persistent abnormal spirometry. Results: Seventy-nine participants (median age 15.6 years; 10% living with HIV) had valid baseline spirometry. At treatment completion, 35% (95% CI 25 to 47) reported respiratory symptoms, 47% (36 to 59) had abnormal chest X-ray and 57% (45 to 68) had abnormal spirometry. Over 12 months, symptom prevalence declined to 21% (13 to 32) and abnormal radiographs to 38% (27 to 50). In contrast, abnormal spirometry remained common (59% (47 to 71) at 12 months). Abnormal spirometry and underweight status at treatment completion predicted persistent impairment (adjusted OR (aOR) 12.7 (2.9 to 56.2) and 13.0 (1.9 to 91.0), respectively). Spirometry improved in a minority but remained stable in most participants. Conclusion: Respiratory morbidity remains common after childhood pulmonary tuberculosis. While symptoms and some radiographic abnormalities improve, abnormal spirometry frequently persists. Spirometry and nutritional status at treatment completion may identify children at highest risk of ongoing respiratory impairment and support targeted post-treatment follow-up.