Tests to Assess Sensitization to Aspergillus Fumigatus in Cystic Fibrosis

OBJECTIVE To evaluate the results of the tests used to identify the IgE mediated sensitization to Aspergillus fumigatus in patients with cystic fibrosis. METHODS This is a cross-sectional descriptive study with a convenience sample of 86 patients diagnosed with cystic fibrosis in the Reference Service in Cystic Fibrosis at a tertiary teaching hospital. The following tests were performed to assess the sensitization to A. fumigatus in patients with cystic fibrosis: Total serum IgE, eosinophil count, fungus detection through oropharyngeal swab or sputum culture, serum-specific IgE, and immediate-type hypersensitivity (IgE) skin tests. We compared the results of the different tests performed. RESULTS In 33 (38.4%) patients with cystic fibrosis, with ages ranging from 1 to 33 years (median of 8 years), the IgE-mediated A. fumigatus sensitization test results were: in 16 patients, there was an increase in serum-specific IgE (>0.35 kU/L); in 23, skin tests were positive; and six had sensitization in both tests. We observed two patients with eosinophilia (>1,000 eosinophils/mm3) and seven with increasing total serum IgE (>1,000 IU/mL), all of whom obtained negative results in skin tests and had no IgE increase specific to A. fumigatus. A. fumigatus was not detected in oropharyngeal swabs and/or sputum culture of any patients. CONCLUSIONS We conclude that, among the tests used to assess sensitization to A. fumigatus in cystic fibrosis patients, both serum-specific IgE and immediate-type hypersensitivity (IgE) skin tests are required. Serum eosinophilia and respiratory secretion culture were not essential in this study.