Association of Quantitative CT Airway Metrics With Impaired Lung Function Among Adolescents With HIV in Nairobi, Kenya

Abstract Rationale: Lung disease is a common but poorly understood complication among children and adolescents with HIV (AWH). Airways disease is emerging as a predominant phenotype. Quantitative CT scoring has shown promise in pediatrics for airways diseases in other pathophysiologic processes but has not been evaluated in HIV-associated lung disease. We examined quantitative CT airway metrics of structural lung disease in AWH and hypothesized that CT airway metrics are associated with FEV1 z-scores (zFEV1). Methods: This is a cross-sectional secondary analysis of a prospective cohort study of AWH aged 10-19 years in Nairobi, Kenya (BREATHE II). We performed non-contrast HRCT using a standardized protocol with inspiratory and expiratory views at one site and applied quantitative metrics using YACTA for airway measurements. We obtained standardized questionnaires, focused respiratory exam, spirometry, and serum CD4/CD8. We used linear regression models to determine associations of segmental and subsegmental airway metrics separately with zFEV1, adjusting for age, sex, height-for-age z-score, and CD4 count. Results: Of 165 enrolled AWH, 152 had high-quality CT scans that could be scored quantitatively. Median age was 15.7 (IQR 13.4-18.5) years and 44% were female. Median age of ART initiation was 7.0 (IQR 3.2-12.1) years, 94% acquired HIV perinatally, and all were taking ART during the study (Table). Median CD4 count was 576 (IQR 361-783) cells/. Forty-two (25%) AWH had zFEV1 below the lower limit of normal (LLN). Based on visual radiologist interpretation, 27% had mosaic attenuation and 12% had bronchiectasis, while groundglass opacities (6%), consolidation (5%), emphysema (5%), and fibrosis (1%) were rare (Table). Increasing segmental and subsegmental airway wall thickness by 1mm was significantly associated with -0.97 (95% CI: -1.46, -0.48) and -1.31 (95% CI: -1.86, -0.76) lower zFEV1 among AWH, respectively. Conclusions: Quantitative CT airway metrics were significantly associated with lower zFEV1 among AWH. Quantitative CT scoring is a promising tool to detect structural and functional lung disease among AWH. Future directions include evaluating associations between sociodemographic, clinical, environmental, and immune factors with CT airway metrics among AWH.