Value of Determination of Specific IgE Against Recombinant Aspergillus fumigatus Allergens rAsp f1, 2, 3, 4 e 6 in the Diagnosis of Allergic Bronchopulmonary Aspergillosis

Abstract

RATIONALE: Allergic bronchopulmonary aspergillosis (ABPA) is a complex disease, triggered by a hypersensitivity reaction to the allergens of Aspergillus fumigatus, a fungus that opportunistically colonizes the lungs of patients with asthma. The diagnosis of ABPA is difficult. A major problem is the lack of standardized allergens used in the determination of specific IgE, but the use of recombinant allergens has been proposed to overcome this. METHODS: The aim of the present study is to evaluate whether serological tests for IgE specific to recombinant allergens of Aspergillus fumigatus (rAsp) can aid in the detection of sensitization to this fungus and in the diagnosis of ABPA. We carried out an observational, prospective, cross-sectional study in outpatient facilities for the treatment of asthma. The diagnosis of ABPA, using classical criteria, was searched in 65 asthmatics patients with immediate cutaneous reactivity to Aspergillus fumigatus. After that, serum titers of IgE against rAsp f1, 2, 3, 4 and 6 were determined. In order to compare the differences between patients with confirmed and excluded diagnosis of ABPA, we used the two-tailed Fisher's exact test. RESULTS: Although 19 of 65 patients had IgE against at least one recombinant, the disease was diagnosed in only 6 patients. One of them had IgE against all recombinant allergens tested and another one had antibody against f 3. CONCLUSIONS: The determination of serum IgE against allergens rAsp f1, 2, 3, 4 e 6 in this group wasn't helpful to make the diagnosis of ABPA, neither to detect sensitization to fungus.