C106-06 Change in Lung Function Overtime in Ugandan Pulmonary Tuberculosis Survivors

Abstract Approximately, 155 million people have survived tuberculosis (TB), and 62-96 million are estimated to have post-tuberculosis lung disease (PTLD), defined as chronic respiratory impairment partly attributable to prior TB. Despite this high burden, little longitudinal data on pulmonary function after TB treatment exist. Here, we report the lung function trajectory of a longitudinal cohort of TB patients in Uganda. Adults with confirmed pulmonary TB were enrolled at diagnosis from five health centers in Kampala, Uganda. Subjects performed pulmonary function testing (PFT) at post-TB treatment (6-9 months) and 1-year follow-up (10-13 months. PTLD was defined by post-TB treatment DLCO80%, TLC80%, or FEV1/FVC z-score -1.64 using 2012 Global Lung Function Initiative (GLI) global reference values. 164 individuals were enrolled, 109 completed post-TB treatment PFT’s and 54 individuals completed PFTs at post-TB treatment and 1-year follow up time points. Of the 55 participants who did not return for one-year follow-up: 40.0% (n = 22/55) had PTLD and 60.0% (n = 33/55) had non-PTLD. 8 participants without post-TB treatment visits returned for 1-year follow-up: 20% (n = 2/8) had PTLD and 80% (n = 6/8) had non-PTLD. Among the 54 participants with longitudinal follow up 37.0% (n = 20/54) had PTLD and 63.0% (n = 34/54) had normal lung function at post-TB treatment. In the PTLD group, 30.0% (n = 6/20) resolved PFT abnormalities at 1-year follow-up: resolved obstruction (n = 1), resolved restriction (n = 3), and resolved isolated DLCO reduction (n = 2). Conversely, 9.0% (n = 3/34) of non-PTLD subjects at post-TB treatment developed PTLD at one-year (1 obstruction, 1 restriction, and 1 isolated DLCO reduction). Longitudinal analysis of PFT parameters showed significant improvements within the PTLD group: mean FEV1/FVC z-score improved from -0.89 (SD 1.8) to -0.53 (SD 1.5) (p = 0.04), TLC percent predicted increased from 79% (SD 17%) to 86% (SD 19%) (p = 0.03), and DLCO percent predicted rose from 78% (SD 17%) to 86% (SD 17%) (p = 0.001). In the non-PTLD group, the FEV1/FVC z-score slightly declined from 0.23 (SD 0.8) to 0.07 (SD 0.7) (p = 0.05). Pulmonary function at the end and after TB treatment shows dynamic changes following microbiologic cure. One-third of those with PTLD post-treatment demonstrated resolution at one year. A small number with normal lung function post-treatment developed new-onset PTLD, suggesting ongoing lung injury despite microbiologic cure. The drivers of this progression remain unclear, but subclinical inflammation and additive pulmonary insults may contribute. Large, longitudinal studies are needed to characterize lung function trajectories, identify those at risk of progressive dysfunction, and inform post-TB care. This abstract is funded by: NIH FIC, Pulmonary Fibrosis Foundation