<i>Cladosporium herbarum</i> and <i>Pityrosporum ovale </i>Allergen Extracts Share Cross-Reacting Glycoproteins

Abstract

Background: Patients sensitized to airborne fungi such as Alternaria alternata and Cladosporium herbarum often also show positive skin prick test results and specific serum IgE antibodies to a yeast, Pityrosporum ovale. We examined whether part of the IgE binding to these fungi is explained by cross-reacting mould and yeast allergens. Methods: Serum samples from 36 patients with positive skin prick test to A. alternata or C. herbarum were analyzed for IgE antibodies to fungal extracts by ELISA and immunoblot analysis. Cross-reactivity between mould and yeast extracts was studied by ELISA and immunoblot inhibition assays. In further analysis, the mannan-containing glycoproteins were removed from the yeast extract by concanavalin A-Sepharose chromatography, and the IgE binding properties of the extracts were compared. Results: SerumIgE reactivity to P. ovale was found in 40% of the mould-sensitized patients. The IgE antibody binding to A. alternata and C. herbarum moulds was partially inhibited by the yeast P. ovale in ELISA and immunoblot inhibition assays. When the glycoproteins were removed from the extract, cross-reactivity was markedly reduced. Conclusion: Part of the IgE binding to mould and yeast allergen extracts is due to cross-reacting glycoproteins. False-positive IgE and skin prick test results should be taken into account in the diagnosis of mould allergy.

Characterizing the Fungal Microbiome in Date (Phoenix dactylifera) Fruit Pulp and Peel from Early Development to Harvest

“…Alternaria is a genus known for the production of both host-specific and unspecific mycotoxins [25], but neither A. betae-kenyensis nor A. subcucurbitae have so far undergone genome sequencing or a thorough metabolomic analysis, so it is difficult to speculate about their role or effect in Phoenix dactylifera microbiomes. Cladosporium herbarum is mostly known as epiphyte on leaves, but also for its production of allergens [26][27][28][29]. However, dates are never consumed at this stage of development, so its presence does not pose a health risk.…”

Carrier‐bound Alt a 1 peptides without allergenic activity for vaccination against Alternaria alternata allergy

“…Micro‐arrayed rAlt a 1 allows the sensitive diagnosis of allergy to Alternaria . In a population of 80 patients with suspected Alternaria allergy, genuine sensitization to Alternaria was confirmed in 78 patients, whereas two patients were sensitized to Aspergillus and thus gave false positive test results with Alternaria extract, most likely because of the presence of cross‐reactive allergens, such as enolases, MnSODs or cross‐reactive carbohydrates . Micro‐arrayed rAlt a 1 can therefore be used for the diagnosis of allergy to Alternaria and for the identification of genuinely sensitized patients for allergen‐specific immunotherapy (SIT).…”

Immunoglobulin E (IgE)-mediated cross-reactivity between mesquite pollen proteins and lima bean, an edible legume

“…ELISA inhibition has been used previously to identify cross‐reactivity among pollen, fungi and other allergens [32–34], whereas immunoblot inhibition demonstrates a component‐based allergenic relationship. Using these methods, allergenic cross‐reactivity has been demonstrated previously between protein components of P. juliflora pollen and important tree pollens such as Ailanthus excelsa , Cassia siamea and Salvadora persica allergens [14].…”