![]() The homologous protein in apple Mal d 1 is an incomplete allergen, because it is unable (or: extremely inefficient) to induce IgE antibodies, but is able to elicit symptoms due to its ability to trigger mast cells loaded with IgE anti-Bet v 1.Ĭross-reactivity is sometimes seen as a property of a subgroup of antibodies: antibodies to some epitopes (recurring epitopes such as cross-reactive carbohydrate determinants (CCDs ) are more likely to be cross-reactive than antibodies to other epitopes. The major birch pollen allergen acts as the sensitizer or primary allergen, which by definition is able to trigger the immune system to produce IgE antibodies. In Northern Europe it is rare to find apple allergy in the absence of birch allergy. Another common clinical situation is the occurrence of symptoms upon exposure to allergenic sources that are unlikely to sensitise, such as apples. The latter, prediction of allergen cross-reactivity, is the topic of this communication, with emphasis on quantitative and methodological aspects.Ĭlinically, allergic cross-reactivity is often encountered as symptoms without prior exposure. This involves both prediction of de novo allergenicity as well as prediction of cross-reactivity. It is tempting to conclude that this result supports the notion that sequence identity is a useful predictor of cross-reactivity.įor various reasons, often related to regulatory safety issues, a discussion is ongoing on prediction of allergenicity. ![]() The two proteins with no demonstrable (cross)reactivity had sequence identities of 51 and 60% to two Aspergillus fumigatus proteins. The two (cross)reactive proteins had the highest sequence homology to known allergens: the enolase was 85% sequence-identical to the Alternaria enolase known as Alt a 6 and the aldehyde dehydrogenase was 71% sequence-identical to the Alternaria dehydrogenase Alt a 10. Support for (cross)reactivity was found for two of these four proteins. Based on homology in the amino acid sequence, four potentially cross-reactive proteins were cloned, expressed in E coli and tested for IgE (cross)reactivity using sera from patients with known fungal allergies. In a paper recently published in this Journal, the question was raised whether a fungus considered for biological pest control (Beauvaria bassiana) could elicit allergic reactions due to cross-reactive IgE antibodies induced by allergens from known allergenic fungi. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |