Immunodiagnosis of ABPA

Abstract

For the diagnosis of allergic aspergillosis demonstration of specific immune responses to allergens has been accepted as a significant paradigm. Elevated levels of total IgE and Aspergillus fumigatus specific IgE and IgG antibodies are important criteria for diagnosis of ABPA. Although reference antigens or standardized methods are not available, there are a number of relevant recombinant antigens, which have been isolated in recent years. Several techniques have been employed in the demonstration of specific antibodies against antigens of Aspergillus fumigatus in the sera of patients. Of these methods, the widely followed ones are ELISA, radioimmunoassay, Western blot, and agar gel double diffusion. Recently, semi-automated methods have been developed using recombinant allergens to detect circulating antibody against Aspergillus. However, these methods have not been evaluated widely. Here we review the immunodiagnostic methods currently in use for allergic bronchopulmonary aspergillosis.

Use of a Synthetic Peptide Epitope of Asp f 1, a Major Allergen or Antigen ofAspergillus fumigatus, for Improved Immunodiagnosis of Allergic Bronchopulmonary Aspergillosis

“…The ability of P1 to stimulate histamine release from ABPA patients and cytokines of Th2 type, although at a lower magnitude than SDA, suggests that it could be further explored for intradermal skin testing. There have been numerous reports of diagnostically relevant native and recombinant antigens for serodiagnosis of aspergillosis (12,14,15,16,19,25,28,30). The reported diagnostic sensitivity and specificity vary greatly among the different reports, even for similar antigen preparations.…”

“…The National Center for Biotechnology Information protein BLAST tool for short sequences in fungi showed that P1 has complete sequence similarity only to Asp f 1 and related ribotoxins of other Aspergillus species (E value, 1e-04) and partial similarity to elongation factor 2 of various species of Saccharomyces and Candida (only 7 out of 11 amino acid residues were identical, with an E value of 4.3). The comparable sensitivity of P1 to that of SDA may be due to the presence of homologous IgG binding epitopes in six immunodominant allergens and antigens (24,29,55,66,77, and 88 kDa) and homologous IgE binding epitopes in three immunodominant allergens and antigens (27,34, and 43 kDa) besides Asp f 1 (28).…”

“…In view of the progression of ABPA leading to irreversible damage of the bronchi and fibrosis in the lungs, an early diagnosis of ABPA is emphasized. ABPA also needs to be differentially diagnosed from tuberculosis, pneumonia, bronchiectasis, lung abscess, and bronchial asthma (1,8,17,28,31). Various groups have reported the utility of antigen-based serodiagnostic methods for the determination of specific IgG and IgE antibodies (28), but no World Health Organization or international reference diagnostic antigens or standardized assays are yet available.…”

“…ABPA also needs to be differentially diagnosed from tuberculosis, pneumonia, bronchiectasis, lung abscess, and bronchial asthma (1,8,17,28,31). Various groups have reported the utility of antigen-based serodiagnostic methods for the determination of specific IgG and IgE antibodies (28), but no World Health Organization or international reference diagnostic antigens or standardized assays are yet available. Intradermal testing, another supportive diagnostic test for ABPA, also suffers from a lack of well-characterized antigens.…”

Diagnosis of aspergilloma in a pleural cavity (persistent pneumothorax) using classic imaging methods

“…This latter form frequently occurs in patients with cystic fibrosis and may be the cause of chronic obstructive lung disease 1,21 . ABPA is diagnosed using specific immunological tests 22,23 . Saprophytic aspergillosis is defined by an infection of the bronchial system without any concomitant tissue invasion by the fungus.…”