Differences in the pattern of structural abnormalities on CT scan in patients with cystic fibrosis and pancreatic sufficiency or insufficiency

Background: Cystic fibrosis (CF) genotypes characterized by pancreatic sufficiency (PS) are generally associated with milder disease vs genotypes characterized by pancreatic insufficiency (PI); however, the correlation between pancreatic status and type and severity of structural lung changes has not been studied. We aimed to evaluate differences in the severity and distribution of pulmonary manifestations of CF in patients with PS vs PI. Methods: We retrospectively evaluated changes in individual lobes and the whole lung on chest CT scan with the modified Brody score. The study population included 84 (39 female, 45 male) patients with CF aged 4 to 68 years (mean, 20.5) treated from 2000 to 2010. Our institutional review board waived the requirement for informed consent. The severity of lung changes and distribution of pulmonary disease were compared by Student t test, nonparametric Pearson x 2 test, or mixed-design analysis of variance for 28 patients with CF-PS and 56 with CF-PI. Correlations were evaluated with the Pearson (continuous variables) or Spearman r (nonparametric variables) tests. A linear regression model was used for multivariate analyses. Results: Compared with patients with CF-PS, those with CF-PI had more-severe lung disease (P = .001) with predominant upper lobe involvement (P = .002) and significant differences in Brody scores for bronchiectasis and bronchial wall thickening. Lung manifestations in patients with CF-PS did not show predominant involvement of any one area (P = .133). Conclusions: In patients with CF-PI, structural lung changes are more severe with upper lobe predominance, prominent bronchiectasis, and bronchial wall thickening vs lower severity and more general distribution of changes in those with CF-PS.