CT score and correlation with lung function and microbiology of adult patients with cystic fibrosis with predominant I1234V genotype in Qatar

Abstract

Background: Computed tomography (CT) features of cystic fibrosis (CF) lung disease can be objectively quantified using current CT scoring systems to assess the extent and severity of the disease. The aims of this study were to calculate the Santamaria CT scores in adult patients with CF with the predominant CFTR I1234V genotype, determine its reliability, and correlate these parameters with lung function, microbial colonization, compliance to treatment, and exacerbations. Methodology: This retrospective observational study was conducted on adult patients with CF who were regularly followed up in the adult CF service at Qatar via CT scans that were taken not during an acute exacerbation. CT scans were scored using the Santamaria scoring system. Corresponding spirometry, microbiological data of sputum culture, and relevant clinical data were correlated with individual CT scores. Results: Only 23 of the 31 patients underwent CT when not in an acute exacerbation and were included in the study analysis. A total of 20 (87%) patients had the I1234V genotype. There was good agreement between the two radiologists on the Santamaria CT scores with an intraclass correlation coefficient (ICC) value of 0.991. Bronchiectasis was the most consistent finding, followed by interlobular and intralobular septal thickening. Patients with poor lung function and frequent exacerbations had significantly higher CT scores (p = 0.015). The CT scores of patients colonized with Pseudomonas aeruginosa were higher but nonsignificant (p = 0.20). The mean CT scores were significantly higher in patients who were noncompliant to regular treatment than in those who were compliant (p = 0.012). Conclusion: Santamaria CT scores comprise a reliable scoring system for adult patients with CF and can be used to determine the extent and severity of lung disease. P. aeruginosa colonization causes more structural lung damage than other common colonizing organisms. Noncompliance to treatment has a significant impact on the increasing severity of CF lung disease.