Progression of traction bronchiectasis/bronchiolectasis in interstitial lung abnormalities is associated with increased all-cause mortality: Age Gene/Environment Susceptibility-Reykjavik Study

Eur J Radiol Open. 2021 Mar 10;8:100334. doi: 10.1016/j.ejro.2021.100334. eCollection 2021.

Abstract

Purpose: The aim of this study is to assess the role of traction bronchiectasis/bronchiolectasis and its progression as a predictor for early fibrosis in interstitial lung abnormalities (ILA).

Methods: Three hundred twenty-seven ILA participants out of 5764 in the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study who had undergone chest CT twice with an interval of approximately five-years were enrolled in this study. Traction bronchiectasis/bronchiolectasis index (TBI) was classified on a four-point scale: 0, ILA without traction bronchiectasis/bronchiolectasis; 1, ILA with bronchiolectasis but without bronchiectasis or architectural distortion; 2, ILA with mild to moderate traction bronchiectasis; 3, ILA and severe traction bronchiectasis and/or honeycombing. Traction bronchiectasis (TB) progression was classified on a five-point scale: 1, Improved; 2, Probably improved; 3, No change; 4, Probably progressed; 5, Progressed. Overall survival (OS) among participants with different TB Progression Score and between the TB progression group and No TB progression group was also investigated. Hazard radio (HR) was estimated with Cox proportional hazards model.

Results: The higher the TBI at baseline, the higher TB Progression Score (P < 0.001). All five participants with TBI = 3 at baseline progressed; 46 (90 %) of 51 participants with TBI = 2 progressed. TB progression was also associated with shorter OS with statistically significant difference (adjusted HR = 1.68, P < 0.001).

Conclusion: TB progression was visualized on chest CT frequently and clearly. It has the potential to be the predictor for poorer prognosis of ILA.

Keywords: AGES-Reykjavik Study, Age Gene/Environment Susceptibility-Reykjavik Study; Age Gene/Environment Susceptibility-Reykjavik Study; BMI, body mass index; HR, hazard ratio; ILA, interstitial lung abnormalities; ILD, interstitial lung disease; Interstitial lung abnormality; OS, overall survival; Pulmonary fibrosis; TB, traction bronchiectasis; TBI, traction bronchiectasis/bronchiolecetasis index; TBI-R2, traction bronchiectasis/bronchiolecetasis index on Round 2; Traction bronchiectasis; Usual interstitial pneumonia.