C28-09 Prevalence and Correlates of Structural Lung Abnormalities Among People With and Without Latent Tuberculosis Infection in Uganda

Abstract Rationale Tuberculosis (TB) is the leading infectious cause of morbidity and mortality globally. A quarter of the global population has Latent TB infection (LTBI) and has a 10% risk of developing active TB in 5 years. While the impact of active TB on lung health is well-documented, the effect of LTBI on structural lung health, particularly in TB-endemic regions, remains unclear. Methods We analyzed non-contrast chest CT scans for Ugandan adults ≥40 years enrolled in an observational cohort of people living with HIV (PWH) and age- and sex- matched people without HIV (PWoH). Participants without symptoms of active TB completed study questionnaires, had a tuberculin skin test (TST), and chest CT scans. We defined LTBI as a positive TST (≥5mm in PWH, ≥10mm PWoH) with no reported history of prior TB infection. We classified SLA based on Fleischner Society definitions and used a logistic regression model to identify correlates of 10 specific SLA sub-types: consolidation, cavitation, cysts, tree-in-bud pattern, emphysema, fibrosis, bronchiectasis, septal thickening, nodules, and ground-glass opacities. Results Among 445 participants (median age 57, 43% PWH, 48% women), 90 (20%) had LTBI. 297 (68%), had SLA with no difference among participants with versus without LTBI (p = 0.99). Common SLA sub-types were: nodules (42%), emphysema (30%), septal thickening (16%), fibrosis (9%), and bronchiectasis (10%), none of which differed by LTBI status. In adjusted models, correlates of SLA included older age (aOR 1.06 [1.01 – 1.11], p = 0.02 per year for fibrosis, aOR 1.06 [1.01 – 1.11], p = 0.01 for bronchiectasis, aOR 1.01 [1.00 – 1.08], p = 0.04 for septal thickening, and aOR 1.08 [1.03 - 1.13], p = 0.001 for ground-glass opacities), lower BMI (aOR 3.8 [1.6 - 9.0], p = 0.002 for fibrosis, aOR 2.5 [1.0 - 6.1], p = 0.04 for bronchiectasis and aOR 2.6 [1.2 - 5.7], p = 0.013 for septal thickening), males (aOR 2.8 [1.2 - 6.8], p = 0.02 for bronchiectasis), current smoking (aOR 2.2 [1.0 - 4.6], p = 0.04 for emphysema) and HIV (aOR 1.9 [1.2 - 2.9], p = 0.004 for emphysema). Conclusions Structural lung abnormalities are common among adults in Uganda, irrespective of LTBI status. Our work highlights demographic and clinical factors that identify individuals at increased risk of lung disease, which may inform strategies for integrating lung disease screening into routine clinical care for high-risk groups in TB-endemic regions. This abstract is funded by: NHLBI (National Heart, Lung, and Blood Institute)