Allergic bronchopulmonary aspergillosis in cystic fibrosis - Reported prevalence, regional distribution, and patient characteristics

Objectives: Using the large database from the Epidemiologic Study of Cystic Fibrosis (ESCF), the objectives of this study were to (1) estimate the rep orted prevalence of allergic bronchopulmonary aspergillosis (ABPA) in patie nts with cystic fibrosis (CF); (2) compare reported prevalence rates across geographic regions; (3) compare reported prevalence rates between patient subgroups based on demographic and disease characteristics; and (4) describ e the ABPA group with regard to their sex, age, and disease severity. Study design: All patients greater than or equal to 5 years of age enrolled in ESCF between December 1993 and May 1996 were eligible, Criteria for the diagnosis of ABPA were defined by the ESCF guidelines. Prevalence rates fo r ABPA were calculated, and potential risk factors for the diagnosis of ABP A were analyzed, including sex, age, pulmonary function, diagnosis of asthm a, presence of wheeze, and positive respiratory culture for Pseudomonas. Results: There were 14,210 eligible patients enrolled in ESCF during; this period, and ABPA was diagnosed in 281 patients (2%), Regional prevalence va ried from 0.9% in the Southwest to 4.0% in the West. Increased prevalence r ates occurred in female patients, the adolescent age group, and subjects wi th lower lung function, wheeze, asthma, and positive Pseudomonas cultures. Although most ABPA patients had evidence of airway obstruction, 10% had an FEV1 of > 100% of predicted. The rates of wheeze (17%) and asthma (30%) wer e lower than expected in the ABPA group. Conclusions: This observational study found a reported prevalence rate of A BPA of 2% of CF patients in a large database. This rate was lower than the 5 to 15% rate reported in smaller studies, suggesting that ABPA is underdia gnosed in the CF population, There was wide regional variation in reported prevalence rates, which is unexplained at this time. The characteristics of the patients with ABPA and the epidemiologic risk factors for diagnosis of ABPA were described, Simplified diagnostic criteria were adapted for ESCF with the intent of increasing awareness of ABPA among the participants in t his study.