Airway Disease Progression on Chest Computed Tomography in Children With Primary Ciliary Dyskinesia.

Rationale: The longitudinal trajectory of airway disease on chest computed tomography (CT) and risk factors for progression in primary ciliary dyskinesia (PCD) is largely unknown.

Methods: Longitudinal analysis of structural airway disease among children with PCD enrolled in a prospective, multicenter observational study, stratified by ultrastructural defect group. CTs were scored utilizing the Melbourne-Rotterdam Annotated Grid Morphometric Analysis for PCD, evaluating airway abnormalities in a hierarchical order: atelectasis, bronchiectasis (%BE), airway wall thickening, and mucus plugging/tree in bud opacities (%MP). Volume fraction of each component was expressed as % of total lung volume. %Disease (%DIS) is the sum of all components. Mixed effects regression analyses were utilized to describe the association between clinical predictors and CT scores adjusted for relevant covariates.

Results: Chest CTs (N = 424) were obtained from 142 children over a mean (SD) of 4.9 (3.7) years. Mean (SD) age at first CT was 8.5 (4.6) years. Mean %DIS increased with age for the cohort (0.09% per year, 95% CI: 0.02-0.15, p < 0.01), driven by increased %BE (0.06 higher per year, 95% CI: 0.04-0.08, p = 0.0001) and increased odds of MP (1.14 higher odds per year, 95% CI: 1.08-1.21, p < 0.0001). Children with inner dynein arm and microtubular defects had increased mean %DIS and increased odds of MP compared to other ciliary abnormalities (1.73% higher, 95% CI: 0.71-2.74, p = 0.001; 3.21 higher odds per year, 95% CI: 1.73-5.95, p < 0.001). Annual increase in CT scores did not differ between defect groups.

Conclusions: Children with PCD experience progressive bronchiectasis and worsening mucus plugging with age.