Allergic bronchopulmonary aspergillosis in cystic fibrosis. A European epidemiological study

Allergic bronchopulmonary aspergillosis (ABPA) is a disease resulting from a hypersensitivity response to Aspergillus fumigatus, although the pathogenesis of the disease is unknown and its prevalence in cystic fibrosis (CF) is still poorly defined. Data from the Epidemiologic Registry of Cystic Fibrosis (ERCF) on 12,447 CF patients gathered from 224 CF centres in nine European countries were analysed. The ERCP definition of ABPA diagnosis is a positive skin test and serum precipitins to A. fumigatus, together with serum immunoglobulin (Ig)E levels >1,000 U . mL(-1) and additional clinical or laboratory parameters. The overall prevalence of ABPA in the ERCF population was 7.8% (range: 2.1% in Sweden to 13.6% in Belgium). Prevalence was low <6 yrs of age but was almost constant similar to 10% thereafter. No sex differences were observed. ABPA affected 8.0% of patients with a Delta F508/Delta F508 genotype and 5-6% with Delta F508/G551D, Delta F508/G542X and Delta F508/N1303K genotypes, ABPA patients presented a lower forced expiratory volume in one second (FEV1) than those without ABPA at any age and the prevalence ranged from 6.6% in patients with FEV1 greater than or equal to 20-12.9% in those with FEV1 <40%, ABPA was associated with higher rates of microbial colonization, pneumothorax and massive haemoptysis, and with higher IgG serum levels and poorer nutritional status. A mixed model regression analysis of lung function showed that FEV1 decline during the follow-up period was not substantially different in ABPA patients compared with non-ABPA patients for any subgroups based on age or disease severity at enrolment, To conclude, allergic bronchopulmonary aspergillosis is a frequent complication in cystic fibrosis patients, particularly after the age of 6 yrs, and it is generally associated with a poorer clinical condition. However, any clear independent influence of allergic bronchopulmonary aspergillosis on the rate of lung function decline in the short term was not shown.