Association between Mucoid Pseudomonas Infection and Bronchiectasis in Children with Cystic Fibrosis

Philip M. Farrell, MD, PhD Jannette Collins, MD Lynn S. \Broderick, MD Michael J. Rock, MD Zhanhai Li, PhD Michael R. Kosorok, PhD Anita Laxova, BS William M.Gershan,MD Alan S. Brody, MD

Purpose: To correlate the severity of bronchiectasis in children with
cystic fibrosis with clinical and microbiologic variables in order to clarify risk factors for the development of irre­versible lung disease.

Materials and Methods: After institutional review board approval and parental in­formed consents were obtained, a HIPAA-compliant longi­tudinal epidemiologic evaluation was performed in pa­tients with cystic fibrosis who were enrolled in the Wiscon­sin trial of newborn screening from 1985 to 2009. Thin-section chest, computed tomography (CT) was used in a prospective cross-sectional design to study patients rang­ing in age from 6.6 to 17.6 years (mean, 11.5 years). Thin-section CT scores were determined objectively on coded images by multiple raters in a standardized fashion. Microbiologic data were obtained by means of culture of respiratory secretions by using methods for differentiation of Pseudomonas aeruginosa (PA) as either nonmucoid or mucoid.

Results:Eighty-three percent of patients (68 of 82) showed bron­chiectasis of varying severity. Of 12 potential risk factors, only respiratory infection with mucoid PA correlated sig­nificantly with bronchiectasis (P = .041).

Conclusion:The severity of bronchiectasis in children with cystic fibro­sis is significantly related to respiratory infection with mu­coid PA; attempts to prevent, bronchiectasis should include reducing exposure to and early eradication of PA.