1. High burden of clonal mast cell disorders and hereditary ▫$α-tryptasemia$▫ in patients who need Hymenoptera venom immunotherapyPeter Korošec, Gunter Sturm, Jonathan J. Lyons, Tinkara Pirc Marolt, Manca Svetina, Mitja Košnik, Mihaela Zidarn, Mark Kačar, Nina Frelih, Nika Lalek, Ajda Demšar Luzar, Samo Zver, Matevž Škerget, Ewa Czarnobilska, Wojciech Dyga, Sanja Popović-Grle, Miroslav Samaržija, Lisa Arzt-Gradwohl, Urban Čerpes, Grzegorz Porebski, Branko Pevec, Eva Schadelbauer, Peter Kopač, Julij Šelb, Matija Rijavec, 2024, original scientific article Abstract: Background
In patients who require venom immunotherapy (VIT), there is a need to identify underlying mast cell (MC) disorders since these may affect the risk and severity of future sting reactions and the long-term effectiveness of VIT.
Methods
1319 individuals with Hymenoptera venom allergy (HVA) who needed VIT from referral centers in Slovenia, Austria, Croatia, and Poland underwent examination for KIT p.D816V in peripheral blood leukocytes (PBL) using a highly sensitive PCR test and tryptase genotyping by digital droplet PCR. We also included 183 control individuals with large local reactions (LLRs) to Hymenoptera stings and with asymptomatic sensitization to Hymenoptera venoms.
Results
285 of 1319 individuals recommended for VIT (21.6%) were positive for KIT p.D816V in PBL, preferably those who present with severe reaction (33.9% [n = 207 of 610] with Ring-Messmer grade 3–4 vs. 11% [n = 78 of 709] with Grade 1–2; p < .0001), whereas only 1.3% (n = 2 of 152) of controls with LLR and none with asymptomatic sensitization (n = 31) had KIT p.D816V. KIT p.D816V allelic burden was higher in those with severe reaction (median 0.018% [n = 207] in Grade 3–4 vs. 0.001% [n = 78] in Grade 1–2; p < .0001), and the majority had normal baseline serum tryptase levels (69% [n = 196 of 285]). All KIT p.D816V-positive individuals (n = 41) who underwent bone marrow (BM) biopsy were found to have underlying clonal diseases, principally BM mastocytosis. HαT was also associated with severe HVA and symptoms (p < .01), and remarkably, 31.0% (n = 31 of 100) were found to have concomitant KIT p.D816V. Concomitant HαT and KIT p.D816V showed an additive effect, and having both was associated with the highest risk for severe HVA, even higher than having either HαT or KIT p.D816V alone (OR = 3.8; p < .01).
Conclusions
By employing prospective universal tryptase genotyping and examination for KIT p.D816V in PBL in large HVA populations, we have demonstrated a high burden of clonal MC disorders and HαT in patients who require VIT. Keywords: anaphylaxis, hereditary α-tryptasemia, hypersensitivity, immunotherapy, mast cell, mastocytosis, venom Published in DiRROS: 17.06.2024; Views: 233; Downloads: 159
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2. Hymenoptera venom immunotherapy : immune mechanisms of induced protection and toleranceAjda Demšar Luzar, Peter Korošec, Mitja Košnik, Mihaela Zidarn, Matija Rijavec, 2021, review article Abstract: Hymenoptera venom allergy is one of the most severe allergic diseases, with a considerable prevalence of anaphylactic reaction, making it potentially lethal. In this review, we provide an overview of the current knowledge and recent findings in understanding induced immune mechanisms during different phases of venom immunotherapy. We focus on protection mechanisms that occur early, during the build-up phase, and on the immune tolerance, which occurs later, during and after Hymenoptera venom immunotherapy. The short-term protection seems to be established by the early desensitization of mast cells and basophils, which plays a crucial role in preventing anaphylaxis during the build-up phase of treatment. The early generation of blocking IgG antibodies seems to be one of the main reasons for the lower activation of effector cells. Long-term tolerance is reached after at least three years of venom immunotherapy. A decrease in basophil responsiveness correlates with tolerated sting challenge. Furthermore, the persistent decline in IgE levels and, by monitoring the cytokine profiles, a shift from a Th2 to Th1 immune response, can be observed. In addition, the generation of regulatory T and B cells has proven to be essential for inducing allergen tolerance. Most studies on the mechanisms and effectiveness data have been obtained during venom immunotherapy (VIT). Despite the high success rate of VIT, allergen tolerance may not persist for a prolonged time. There is not much known about immune mechanisms that assure longterm tolerance post-therapy. Keywords: allergy and immunology, hypersensitivity, immunotherapy, immune tolerance, venoms, Hymenoptera, Hymenoptera venom, short-term protection, long-term tolerance Published in DiRROS: 16.08.2021; Views: 1181; Downloads: 379
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3. The culprit insect but not severity of allergic reactions to bee and wasp venom can be determined by molecular diagnosisPia Gattinger, Christian Lupinek, Lampros Kalogiros, Mira Šilar, Mihaela Zidarn, Peter Korošec, Christine Koessler, Natalija Novak, Rudolf Valenta, Irene Mittermann, 2018, original scientific article Abstract: Background. Allergy to bee and wasp venom can lead to life-threatening systemic reactions. The identification of the culprit species is important for allergen-specific immunotherapy. Objectives. To determine a panel of recombinant bee and wasp allergens which is suitable for the identification of bee or wasp as culprit allergen sources and to search for molecular surrogates of clinical severity of sting reactions. Methods. Sera from eighty-seven patients with a detailed documentation of their severity of sting reaction (Mueller grade) and who had been subjected to titrated skin testing with bee and wasp venom were analyzed for bee and wasp-specific IgE levels by ImmunoCAPTM. IgE-reactivity testing was performed using a comprehensive panel of recombinant bee and wasp venom allergens (rApi m 1, 2, 3, 4, 5 and 10; rVes v 1 and 5) by ISAC chip technology, ImmunoCAP and ELISA. IgG4 antibodies to rApi m 1 and rVes v 5 were determined by ELISA and IgE/ IgG4 ratios were calculated. Results from skin testing, IgE serology and IgE/IgG4 ratios were compared with severity of sting reactions. Results. The panel of rApi m 1, rApi m 10, rVes v 1 and rVes v 5 allowed identification of the culprit venom in all but two of the 87 patients with good agreement to skin testing. Severities of sting reactions were not associated with results obtained by skin testing, venom-specific IgE levels or molecular diagnosis. Severe sting reactions were observed in patients showing < 1 ISU and < 2kUA/L of IgE to Api m 1 and/or Ves v 5. Conclusion. We identified a minimal panel of recombinant bee and wasp allergens for molecular diagnosis which may permit identification of bee and/or wasp as culprit insect in venom-sensitized subjects. The severity of sting reactions was not associated with parameters obtained by molecular diagnosis. Keywords: allergy and immunology -- diagnosis, allergens -- diagnosis, hymenoptera, immunotherapy, bee, wasp, venom, sting reactions, molecular diagnosis, systemic reactions Published in DiRROS: 23.11.2020; Views: 12713; Downloads: 1662
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5. Worldwide perspectives on venom allergyPeter Korošec, Thilo Jakob, Harfi Harb, Robert Heddle, Sarah Karabus, Ricardo de Lima Zollner, Julij Šelb, Bernard Yu-Hor Thong, Fares Zaitoun, David B. K. Golden, Michael Levin, 2019, review article Abstract: Venom immunotherapy is the standard of care for people with severe reactions and has been proven to reduce risk of future anaphylactic events. There is a moral imperative to ensure production, supply and worldwide availability of locally relevant, registered, standardized commercial venom extracts for diagnosis and treatment. Insects causing severe immediate allergic reactions vary by region worldwide. The most common culprits include honeybees (Apis mellifera), social wasps including yellow jackets (Vespula and Dolichovespula), paper wasps (Polistes) and hornets (Vespa), stinging ants (Solenopsis, Myrmecia, Pachycondyla, and Pogonomyrmex), and bumblebees (Bombus). Insects with importance in specific areas of the world include the Australian tick (Ixodes holocyclus), the kissing bug (Triatoma spp), horseflies (Tabanus spp), and mosquitoes (Aedes, Culex, Anopheles). Reliable access to high quality venom immunotherapy to locally relevant allergens is not available throughout the world. Many current commercially available therapeutic vaccines have deficiencies, are not suitable for, or are unavailable in vast areas of the globe. New products are required to replace products that are unstandardized or inadequate, particularly whole-body extract products. New products are required for insects in which no current treatment options exist. Venom immunotherapy should be promoted throughout the world and the provision thereof be supported by health authorities, regulatory authorities and all sectors of the health care service. Keywords: allergy and immunology, venoms, Hymenoptera, bee venoms, wasp venoms, insecta, ants hornet, bumblebee, mosquitoes, venom immunotherapy, immunologic desensitization Published in DiRROS: 23.09.2020; Views: 1993; Downloads: 1153
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