Aspergillus/allergic bronchopulmonary aspergillosis in an Irish cystic fibrosis population: a diagnostically challenging entity.

BACKGROUND Patients with cystic fibrosis (CF) can become colonized by aspergillus, which can act as an allergen and cause allergic bronchopulmonary aspergillosis (ABPA). OBJECTIVE To determine the rate of aspergillus colonization and ABPA in a population of Irish patients with CF. METHODS In 50 consecutive patients with CF who presented with exacerbations, we looked for the presence of aspergillus in their sputum and signs and symptoms of ABPA. RESULTS Fifteen patients (30%) grew aspergillus species in their sputum cultures. Six patients (12%) had ABPA. Matched for age, sex, genotype, and microbiology, there was no significant difference in forced expiratory volume in the first second (percent predicted, FEV(1)%) in subjects with aspergillus-positive sputum compared to those not colonized with aspergillus. Subjects with ABPA experienced sharp short-term deterioration in lung function (mean 6.7% predicted FEV(1)), which returned to baseline following at least 4 weeks of treatment. CONCLUSIONS The prevalence of ABPA was 12%. Aspergillus-positive sputum of itself was not a poor prognostic sign in terms of lung function over the 5-year study course. ABPA produces short-term reversible declines in lung function and responds to treatment. The frequency of aspergillus isolates did not correlate with the occurrence of ABPA. A low threshold for the diagnosis of ABPA should be maintained in any patient with CF who does not improve with antibiotics.