Impaired lung function in adolescents with pulmonary tuberculosis during treatment and following treatment completion

Abstract

Little is known about post-tuberculosis lung disease in adolescents. We prospectively assessed lung function in adolescents with microbiologically confirmed pulmonary tuberculosis during treatment and after treatment completion. In a prospective study, we enrolled adolescents diagnosed with microbiologically confirmed tuberculosis and healthy tuberculosis-exposed household controls, between October 2020 and July 2021 in Cape Town, South Africa. Spirometry, plethysmography, diffusion capacity lung function tests and 6-min walking test (6MWT) were completed according to international guidelines 2 months into treatment and following treatment completion. Abnormal lung function was defined as abnormal spirometry (z-score<-1.64 for forced expiratory volume in 1s (FEV1) and/or forced vital capacity (FVC) and/or FEV1/FVC), plethysmography (total lung capacity (TLC)<80% of predicted, residual volume over TLC of >45%) and/or diffusion capacity (DLCO z-score<-1.64). One-hundred adolescents were enrolled; 50 (50%) with tuberculosis and 50 (50%) healthy tuberculosis-exposed controls. Of the 50 adolescents with tuberculosis, ten had multidrug-resistant tuberculosis. Mean age of the group was 14.9 years (SD 2.7), 6 (6.0%) were living with HIV and 9 (9.0%) were previously treated for tuberculosis. Lung function improved over time; during treatment abnormal lung function was found in 76% of adolescents with tuberculosis, compared to 65% after treatment completion. Spirometry indices were lower in adolescents with tuberculosis compared to controls, both at 2 months and after treatment completion. Plethysmography in adolescents with tuberculosis showed that air-trapping was more common during treatment than in controls (12% vs 0%, respectively, p=0.017); which improved following treatment completion. Adolescents with tuberculosis both during and after treatment completion walked a shorter distance than controls. Adolescents with tuberculosis have impaired lung function even after treatment completion. It is crucial to include adolescents in trials on the prevention and treatment of tuberculosis-associated respiratory morbidity. EDCTP, National Institute of Health, Medical Research Council, BMBF.