Venom Immunotherapy: From Proteins to Product to Patient Protection

In this review, we outline and reflect on the important differences between allergen-specific immunotherapy for inhalant allergies (i.e., aeroallergens) and venom-specific immunotherapy (VIT), with a special focus on Venomil® Bee and Wasp. Venomil® is provided as a freeze-dried extract and a diluent to prepare a solution for injection for the treatment of patients with IgE-mediated allergies to bee and/or wasp venom and for evaluating the degree of sensitivity in a skin test. While the materials that make up the product have not changed, the suppliers of raw materials have changed over the years. Here, we consolidate relevant historical safety and efficacy studies that used products from shared manufacture supply profiles, i.e., products from Bayer or Hollister–Stier. We also consider the characterization and standardization of venom marker allergens, providing insights into manufacturing controls that have produced stable and consistent quality profiles over many years. Quality differences between products and their impacts on treatment outcomes have been a current topic of discussion and further research. Finally, we review the considerations surrounding the choice of depot adjuvant most suitable to augmenting VIT.

Identification and Purification of Novel Low-Molecular-Weight Lupine Allergens as Components for Personalized Diagnostics

Lupine flour is a valuable food due to its favorable nutritional properties. In spite of its allergenic potential, its use is increasing. Three lupine species, Lupinus angustifolius, L. luteus, and L. albus are relevant for human nutrition. The aim of this study is to clarify whether the species differ with regard to their allergen composition and whether anaphylaxis marker allergens could be identified in lupine. Patients with the following characteristics were included: lupine allergy, suspected lupine allergy, lupine sensitization only, and peanut allergy. Lupine sensitization was detected via CAP-FEIA (ImmunoCAP) and skin prick test. Protein, DNA and expressed sequence tag (EST) databases were queried for lupine proteins homologous to already known legume allergens. Different extraction methods applied on seeds from all species were examined by SDS-PAGE and screened by immunoblotting for IgE-binding proteins. The extracts underwent different and successive chromatography methods. Low-molecular-weight components were purified and investigated for IgE-reactivity. Proteomics revealed a molecular diversity of the three species, which was confirmed when investigated for IgE-reactivity. Three new allergens, L. albus profilin, L. angustifolius and L. luteus lipid transfer protein (LTP), were identified. LTP as a potential marker allergen for severity is a valuable additional candidate for molecular allergy diagnostic tests.

Marker allergens in Hymenoptera venom allergy — Characteristics and potential use in precision medicine

Background A comprehensive diagnostic work-up is essential to ensure adequate patient management for the potentially life-threatening condition of Hymenoptera venom allergy (HVA). This includes an unambiguous identification of the allergy-relevant venom as prerequisite for successful venom-specific immunotherapy (VIT). If the clinical history does not allow the identification of the culprit insect, diagnosis is often hampered by positive test results to various venoms. Modern component-resolved diagnostics (CRD) applying marker allergens of Hymenoptera venoms has created new opportunities which facilitate therapeutic decisions and may allow personalized risk stratification for individual patients. Methods Comprehensive literature search and critical analysis of recently published studies on Hymenoptera venom allergens and CRD. Results and discussion Changing the research focus from whole venom extracts to individual allergenic molecules led to the development of CRD in HVA. The currently available CRD is a valuable tool to resolve cross-reactivity and primary sensitization, particularly in honeybee and vespid venom allergy. Hence, CRD has simplified therapeutic decisions in case of multiple positive test results, especially in patients who were not able to identify the culprit insect or in cases of discrepancies between clinical history and classical diagnostic results. Moreover, there is first evidence that sensitization to particular allergens might serve as biomarkers to predict risk for severe side-effects during VIT or even for VIT failure. To date, a clear limitation of CRD is the currently available allergen panel which does not allow a definite resolution of allergy to different vespid species such as yellow jackets and European paper wasps.

Shedding Light on the Venom Proteomes of the Allergy-Relevant Hymenoptera Polistes dominula (European Paper Wasp) and Vespula spp. (Yellow Jacket)

Allergic reactions to stings of Hymenoptera species can have serious or even fatal consequences. If the identification of the culprit insect is possible, venom-specific immunotherapy effectively cures Hymenoptera venom allergies. Although component-resolved diagnostics has strongly evolved in recent years, the differentiation between allergies to closely related species such as Polistes dominula and Vespula spp. is still challenging. In order to generate the basis for new diagnostic and therapeutic strategies, this study aims at resolving the venom proteomes (venomes) of these species. The venoms of P. dominula and Vespula spp. (V. germanica, V. vulgaris) were analyzed by liquid chromatography-mass spectrometry. Resulting proteins were characterized regarding their function, localization and biochemical properties. The analyses yielded 157 proteins in Vespula spp. and 100 in P. dominula venom; 48 proteins, including annotated allergens, were found in both samples. In addition to a variety of venom trace molecules, new allergen candidates such as icarapin-like protein and phospholipase A2 were identified. This study elucidates the venomes of closely related allergy-eliciting Hymenoptera species. The data indicates that relying on marker allergens to differentiate between P. dominula and Vespula spp. venom allergy is probably insufficient and that strategies using cross-reactive major allergens could be more promising.