The Effect of Chronic Infection With Aspergillus fumigatus on Lung Function and Hospitalization in Patients With Cystic Fibrosis

BackgroundThe relevance of Aspergillus fumigatus in patients with cystic fibrosis (CF) not affected by allergic bronchopulmonary aspergillosis is unclear. Our aim was to determine the effect of persistent infection with A fumigatus on pulmonary exacerbations and lung function in children with CF.MethodsThis was a retrospective cohort study of patients with CF followed at The Hospital for Sick Children from 1999 to 2006. Persistent A fumigatus infection was defined as the presence of two or more positive sputum or bronchoalveolar cultures for A fumigatus in a given year. The primary outcome measure was the annual number of hospitalizations for pulmonary exacerbations.ResultsTwo hundred thirty patients with CF were included in the analysis. The FEV1 of patients persistently infected with A fumigatus was 3.61% (P≤.0001) lower during the study period compared with uninfected patients. There was a significant interaction between A fumigatus and Pseudomonas aeruginosa on lung function (P=.0006). Patients not infected with either organism had the highest pulmonary function. Persistent A fumigatus infection (relative risk [RR]=1.94, P=.0002) and CF-related diabetes (RR=1.64, P=.028) were associated with an increased risk of pulmonary exacerbations requiring hospitalization, whereas there was no increased risk of pulmonary exacerbations among patients with allergic bronchopulmonary aspergillosis (RR=1.02, P=.94). When adjusted for baseline pulmonary function, none of these variables were associated with a significantly increased risk of pulmonary exacerbations, with only chronic A fumigatus infection trending toward significance (RR=1.40, P=.065).ConclusionsPersistent A fumigatus infection is an independent risk factor for hospital admissions in patients with CF.