Tracking CF disease progression with CT and respiratory symptoms in a cohort of children aged 6-19 years.

Introduction: Cystic fibrosis (CF) lung disease is characterized by bronchiectasis and trapped air on chest computed tomography (CT).

Objective: We aim to validate bronchiectasis and trapped air as outcome measures by evaluating associations between changes in bronchiectasis, trapped air and patient-reported respiratory symptoms.

Methods: A longitudinal cohort study has been conducted. CF patients (aged 6-19 years) who had two routine CTs and completed twice a Cystic Fibrosis Questionnaire-Revised within 2 years (referred to as T1 and T2 ), in the period of July 2007 to January 2012 were included. Bronchiectasis and trapped air were scored using the CF-CT scoring system. Correlation coefficients and student's paired t tests were performed.

Results: In total 40 patients were included with a median age at T1 of 12.6 years (range 6-17 years), and at T2 14.5 years (range 8-19 years). At T1 , bronchiectasis (r = -0.49, P < 0.01) and trapped air (r = -0.34, P = 0.04) correlated with CFQ-R Respiratory Symptoms Scores (CFQ-R RSS). At T2 similar correlations were found with the CFQ-R RSS. Over 2 years, there was significant progression in bronchiectasis (P = 0.03) and trapped air (P = 0.03), but not in CFQ-R RSS. Changes in bronchiectasis and trapped air were not associated with changes in CFQ-R RSS.

Conclusion: Our results indicate that bronchiectasis and trapped are sensitive outcome measures in CF lung disease, showing a significant association with CFQ-R RSS at two-time points. However, progression of bronchiectasis and trapped air over 2 year does not necessarily correlate to changes in quality of life.