Allergic bronchopulmonary aspergillosis with low serum IgE levels in a child with cystic fibrosis

A five-year-old girl was diagnosed with cystic fibrosis (CF) at age 8 months on the basis of failure to thrive, steatorrhea, and a positive sweat chloride determination of 95 mEq/L. She was seen in our outpatient clinic four times per year. During the last 4 years she remained well with mild pulmonary symptoms and no evidence of asthma. She had experienced a few episodes of infectious bronchitis without wheezing, which improved with oral antibiotic therapy. There was no history of production of brown sputum plugs, and she had never been treated with bronchodilators or oral or inhaled corticosteroids. At age 1 year, Staphylococcus aureus was cultured from her sputum. At age 2 years, Pseudomonas aeruginosa grew on her sputum culture without pulmonary involvement, and a 3-week course of intravenous antibiotic was given. Over the next three years, S. aureus, and sometimes P. aeruginosa, were cultured from her sputum. AspergiUus fumigatus (Aft only grew twice at age 2 and 3 years. Her routine chest roentgenogram showed minor changes, such as increased lung markings and mild hyperinflation, without acute changes. On routine clinical examination, clear lung fields were heard. Routine laboratory evaluation always showed a peripheral eosinophil count less than 300 cells/mm 3. Since June 1995, as part of the Allergic Bronchopulmonary Aspergillosis (ABPA) screening study, the patient was evaluated every 4 months with total serum IgE and IgE against Af (IgE-Af) by CAP ftuoroenzymeimmunoassay (Pharmacia, Uppsala, Sweden); precipitins against Af by means of the Ouchterlony technique; IgG, IgA, and IgM antibodies against Af (IgG-Af, IgA-Af, IgM-Af) assessed by ELISA; peripheral eosinophil count; and immediate skin testing with Af. In February 1996, when the patient was free of symptoms laboratory data showed a blood eosinophil count of 300 cells/ram 3, a total serum IgE of 41 kU/L (normal value <84 kU/L) and a negative IgE-Af (<0.35 kU/L). In August 1996 a left upper lobe infiltrate was seen on a routine chest roentgenogram. She had no symptoms, and clinical examination was normal. Sputum