Complex IgE sensitization patterns in ragweed allergic patients: Implications for diagnosis and specific immunotherapy

Abstract

Background Ragweed (Ambrosia artemisiifolia) is one of the most important allergen sources, worldwide, causing severe respiratory allergic reactions in late summer and fall, in sensitized patients. Amb a 1 has been considered as the most important allergen in ragweed but 12 ragweed pollen allergens are known. The aim of our study was to investigate IgE reactivity profiles of ragweed allergic patients and to associate them with clinical symptoms. Methods IgE sensitization profiles from clinically well‐characterized ragweed allergic patients (n = 150) were analyzed using immunoblotted ragweed pollen extract. Immunoblot inhibition experiments were performed with two Amb a 1 isoforms and CCD markers and basophil activation experiments were performed with IgE serum before and after depletion of Amb a 1‐specific IgE. Results By IgE‐immunoblotting 19 different IgE reactivity patterns with and without Amb a 1‐sensitization were found. The majority of patients (>95%) suffered from rhino‐conjunctivitis, around 60% reported asthma‐like symptoms and about 25% had skin reactions. Patients with complex IgE sensitization profiles tended to have more clinical symptoms. Serum with and without Amb a 1‐specific IgE induced basophil activation. Conclusions Ragweed pollen allergic patients exhibit complex IgE reactivity profiles to ragweed allergens including Amb a 1 isoforms and cross‐reactive carbohydrates indicating the importance of Amb a 1 isoforms and additional allergens for diagnosis and allergen‐specific immunotherapy of ragweed allergy.

Relationship between IgE Levels Specific for Ragweed Pollen Extract, Amb a 1 and Cross-Reactive Allergen Molecules

“…Interestingly, IgE reactivity to nAmb a 1 was not significantly higher in patients with more different symptoms or associated with severe symptoms like asthma. Additionally, these findings suggest that, besides Amb a 1, other allergens also play a role in inducing allergy symptoms as previously reported [ 35 ]. So far, no significant association could be found in our study between IgE response to pan-allergens and different phenotypes of ragweed allergy, so in the future the complete panel of ragweed allergens needs to be tested.…”

“…Antigen E, now termed major ragweed pollen allergen Amb a 1, was considered to be the most important ragweed pollen allergen and to be sufficient for allergen-specific immunotherapy of allergy to ragweed pollen [ 34 ]. However, more recent studies conducted in western Romania [ 35 , 36 ] investigating the sensitization profiles of ragweed-allergic patients showed complex IgE reactivity profiles. These studies suggest that besides Amb a 1, other allergens from ragweed, including pan-allergens, may play a role in ragweed sensitization and, therefore, should be considered for diagnosis and immunotherapy.…”

Prospective assessment of pre-existing and de novo anti-HLA IgE in kidney, liver, lung and heart transplantation

“…Functionality of anti-HLA IgE antibodies in kidney recipients was assessed by means of an in vitro basophil degranulation assay. Basophil mediator release assays are commonly performed in the field of IgE-mediated allergy ( 33 ). IgE antibodies bind to basophils via the IgE high affinity receptor FcϵRI and trigger degranulation upon cross-linking through recognition of the respective antigen.…”

Insect Cell-Expressed Major Ragweed Allergen Amb a 1.01 Exhibits Similar Allergenic Properties to Its Natural Counterpart from Common Ragweed Pollen

“…Ragweed pollen allergy has become a major health problem worldwide and allergic patients display a complex and heterogeneous sensitization profile involving several allergenic molecules [15]. Due to the shortcomings of allergenic extracts [34] an accurate characterization of these profiles requires the use of pure allergen molecules with defined allergenic properties.…”

“…Due to its high allergenicity, ragweed pollen has become a significant health issue in infested areas, causing severe respiratory symptoms [14]. Ragweed-allergic patients exhibit heterogeneous and complex sensitization patterns [15] involving at least 11 described allergens [2].…”