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ORIGINAL RESEARCH article

Front. Allergy
Sec. Allergen Immunotherapy
Volume 5 - 2024 | doi: 10.3389/falgy.2024.1467245

Allergen immunotherapy using recombinant Culicoides allergens improves clinical signs of equine insect bite hypersensitivity

Provisionally accepted
Anneli Graner Anneli Graner 1Ralf Mueller Ralf Mueller 1Johanna Geisler Johanna Geisler 2Delia Bogenstätter Delia Bogenstätter 2Samuel White Samuel White 3Sigridur Jonsdottir Sigridur Jonsdottir 4Eliane Marti Eliane Marti 2*
  • 1 Centre for Clinical Veterinary Medicine, Ludwig Maximilian University Munich, Munich, Germany, München, Germany
  • 2 Vetsuisse Faculty, University of Bern, Bern, Switzerland
  • 3 York St John University, York, United Kingdom
  • 4 Institute for Experimental Pathology, Keldur, Biomedical Center, University of Iceland, Reykjavik, Iceland, Reykjavik, Iceland

The final, formatted version of the article will be published soon.

    Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis of horses caused by bites of Culicoides spp, sharing some common features with human atopic dermatitis. Allergen immunotherapy (AIT) using Culicoides whole body extracts has limited efficacy. This study aimed to evaluate AIT with a pool of major Culicoides recombinant allergens in a prospective, double-blinded, placebo-controlled study. The IBH lesion score was assessed during a pre-and 1 st treatment year (May to October) in 17 horses, and in May and July of a 2 nd treatment year. Nine horses were immunized subcutaneously 3x with a combination of nine r-allergens (20 µg each/injection) in alum and MPLA. Eight horses received a placebo. The immunization was repeated twice the following year. The specific antibody response to one of the AIT Culicoides r-allergen was assessed. In the first treatment year the decrease in average IBH lesion score was significantly larger in the AIT compared to the placebo group, with 67% of the AIT and 25% of the placebo horses reaching >50% improvement of the average IBH lesion score. The response to the AIT was enhanced in the 2 nd treatment year when 89% of the AIT versus 14% of the placebo horses showed such improvement (p≤0.01). IgG antibodies of all subclasses were induced, with IgG4/7 showing the most significant differences between groups. The post AIT sera showed IgE blocking activity. AIT using only few injections of small amounts of r-allergens in alum and MPLA as immunomodulator seems a promising approach for treatment of insect bite allergy.

    Keywords: allergen immunotherapy, horse, Insect bite hypersensitivity, Culicoides, recombinant allergens

    Received: 19 Jul 2024; Accepted: 26 Aug 2024.

    Copyright: © 2024 Graner, Mueller, Geisler, Bogenstätter, White, Jonsdottir and Marti. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Eliane Marti, Vetsuisse Faculty, University of Bern, Bern, Switzerland

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.