Objective: To evaluate the frequency of sensitization to Aspergillus antigens and the prevalence of allergic bronchopulmonary aspergillosis (ABPA) in asthmatic patients.
Methods: Two hundred consecutive non-smoking outpatients with asthma (≥ 18 years) underwent skin testing with aeroallergens, peripheral eosinophil counting, measurements of total serum IgE level and specific IgE against Aspergillus fumigatus, radiologic investigations and pulmonary function tests.
Results: Eleven patients (5.5%) had a positive skin reactivity to Aspergillus antigens. Five of these 11 patients (45.5%) met the diagnostic criteria of ABPA, an overall prevalence of 2.5% (5/200). There were 2 males and 3 females, aging from 19 to 62 years, with a disease duration from 15 to 40 years. All of the patients had asthmatic symptoms such as cough and wheeze. Moderate to severe obstructive ventilatory defect was found in 4 patients. Total serum IgE levels and specific IgE against Aspergillus fumigates were elevated significantly in all the patients, and elevated eosinophil count was found in 3 patients. Three cases were diagnosed as ABPA-CB because of the presence of central bronchiectasis on HRCT.
Conclusions: The prevalence of ABPA in Chinese patients with asthma was underestimated. Clinical features of ABPA were similar to asthma alone, but with longer duration and more severe lung function defect. Sensitization to Aspergillus, increased eosinophils and total serum IgE levels were important indicators for the diagnosis of ABPA.