Fungal allergens are often suspected to have cross-reactivity even between organisms considered to be far separated in taxonomic organizations. Sequencing of fungal allergen component proteins has identified several families of proteins that appear in many species of fungi. To examine the observed cross reactivity in fungal specific IgE testing the following studies were conducted.
Results from all specific IgE testing performed for a 12 year period (2000 - 2012) at a hospital laboratory using ImmunoCap reagents were retrieved. Results for individuals tested for specific IgE against a combination of four fungi (Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum and Penicillium chrysogenum) were selected for comparison. Tests with values greater than 0.35 kIU/L were considered positive.
Results of 6565 individuals were retrieved. There were 26260 individual tests of which 7058 were positive with 2607 individuals having at least one positive test. The highest number of positive tests was to Alternaria (2156) and the fungus with the fewest positive tests was Cladosporium (1508). Of the persons testing positive to only a single fungus (785) Alternaria was the most frequent (465) followed by Aspergillus (139) Penicillium (138) and Cladosporium (43). Of those individuals testing positive for only two fungi Alternaria and Aspergillus dominated (151) and of those testing positive for only 3 fungi Alternaria, Aspergillus and Cladosporium dominated(143). Most significantly, of the individuals having at least one positive nearly half (1208) tested positive for all four fungi.
Specific igE testing indicated the possibility of significant cross-reactivity among these four fungi.
- AAAAI 2014 (70th)