Allergen-specific immunotherapy of Hymenoptera venom allergy - also a matter of diagnosis

The role of molecular diagnosis in anaphylactic patients with dual or triple-sensitization to Hymenoptera venoms

BACKGROUND

The poly-sensitization to Hymenoptera venom makes it difficult to select genuine allergens for immunotherapy and increases patients' costs. The objective of this study was to determine the culprit allergen in dual or triple-sensitized patients to three Hymenoptera venoms through molecular diagnosis and evaluating the results of incorporating the molecular diagnosis with skin tests.

METHODS

Thirty-two patients with anaphylactic reactions and dual or triple-sensitization to Hymenoptera venoms in skin tests entered this study. IgE-sensitization to whole extracts and molecules of Apis mellifera (Api m), Vespula vulgaris (Ves v), and Polistes dominulus (Pol d) was evaluated utilizing ALEX or ImmunoCAP.

RESULTS

Twenty-nine patients (90.6%) were male. IgE-sensitization to at least one of the allergenic molecules related to Apis mellifera, Vespula vulgaris, and Polistes dominulus was seen in 59.4, 53.1, and 21.9%, respectively. Among 32 patients, 14 (43.8) and 8 (25%), were mono-sensitized to Api m and Ves v components in ALEX, respectively. Double sensitization to Hymenoptera was identified in 18.8% of patients in ALEX. Api m 1+/Api m 2-/Api m 10- and Ves v 1+/Ves v 5+ demonstrated the most prevalent sensitizations patterns in our patients.

CONCLUSIONS

The molecular diagnosis of IgE-sensitization to Hymenoptera venoms can be valuable, especially in patients who show dual or triple-sensitization in skin tests, as the ALEX results revealed mono and double-sensitization to Hymenoptera venoms in 22 and 6 patients, respectively. Regarding the high cost and adverse reactions of venom immunotherapy, especially for two or three venoms, incorporating the molecular diagnosis alongside skin tests for accurate diagnosis of the culprit venom could help decrease costs for patients.

Aluminium in dermatology - Inside story of an innocuous metal

Aluminium, the third most abundant element in the earth's crust, was long considered virtually innocuous to humans but has gained importance in the recent past. Aluminium is ubiquitous in the environment, with various sources of exposure like cosmetics, the food industry, occupational industries, the medical field, transport and electronics. Aluminium finds its utility in various aspects of dermatology as an effective haemostatic agent, anti-perspirant and astringent. Aluminium has a pivotal role to play in wound healing, calciphylaxis, photodynamic therapy and vaccine immunotherapy with diagnostic importance in Finn chamber patch testing and confocal microscopy. The metal also finds significance in cosmetic procedures like microdermabrasion and as an Nd:YAG laser component. It is important to explore the allergic properties of aluminium, as in contact dermatitis and vaccine granulomas. The controversial role of aluminium in breast cancer and breast cysts also needs to be evaluated by further studies.

Skin prick tests are not useful for the qualification for venom immunotherapy in children

Background

The basis for qualification for venom immunotherapy (VIT) is the fulfilment of both the clinical and immunological criteria. Diagnostic tests that confirm the immunological criterion of an IgE-mediated sensitization include skin prick tests (SPT), intradermal tests (IDT), and serum specific IgE (sIgE) for the culprit venom.

Objective

This study aimed to assess the usefulness of SPT as the immunological marker in the diagnosis of insect venom sensitization in children with history of systemic reaction (SR) to insect sting evaluated by means of I-IV-grades Mueller's scale. There are no such studies in children.

Methods

This cross-sectional study sample consisted of 416 children aged 3-18 years (mean age 10.6 ± 3.8), 76% males, all with the history of a systemic reaction (SR) after a Hymenoptera sting (48% of grade III/IV according to Mueller scale), diagnosed between 1999 and 2019 in the tertiary referral centre. The standard diagnostic tests were used. Specificity, sensitivity, and positive and negative predictive values were computed to assess the diagnostic properties of the clinical tests to distinguish between mild and severe SR. To assess the relative value of an individual test in predicting the qualification to VIT we incorporated the Shapley value (SV).

Results

Positive SPT results were found in up to no more than 3% of children; among them less than 1% had only positive SPT and were negative for sIgE and IDT. Approximately 85% of the children had detectable venom sIgE, followed by positive IDT (75%). Almost 70% of children had positive both sIgE and IDT results. In children with grade III/IV reaction, about 80% of children had positive results of both of these tests. sIgE and IDT had sensitivity >0.80, whereas SPT had high specificity (>0.97) in differentiating between mild and severe SR. Relative value of diagnostic tests in predicting qualification to VIT varied between venoms. Bee venom IDT had higher SV (0.052) than sIgE (0.041). In contrast, wasp venom sIgE had higher SV (0.075) than IDT (0.035).

Conclusion

SPTs are not an useful immunological marker of venom sensitization in children, and eliminating SPT does not result in a loss of diagnostic accuracy. Limiting diagnostics to venom sIgE and IDT would shorten the procedure and reduce costs. Future studies are needed to determine if venom sIgE as the first line diagnostic test, with IDT added only if the venom sIgE is undetectable, is an optimal diagnostic process.

[Basophil activation test to follow-up of patients treated with hymenoptera venom immunotherapy: a review of current evidence]

Hymenoptera venom immunotherapy (HVI) is a long-term effective treatment to avoid new systemic reactions in patients with Hymenoptera allergy. The sting challenge test is considered the gold standard to confirm the tolerance. However, the use of this technique is not generalized in clinical practice, being the basophil activation test (BAT), which functionally explores allergen response, an alternative that does not entail any of the provocation risks associated with the sting challenge test. This study reviews the publications that used the BAT to follow up and evaluate the success of the HVI. Studies assessing the changes between a baseline BAT before the start and BATs performed between the starting and maintenance phases of the HVI were selected. Ten articles were found, comprising information from 167 patients, of which 29% used the sting challenge test. The studies concluded the importance of evaluating the responses with submaximal allergen concentrations, which reflect basophil sensitivity, to monitor the HVI using the BAT. It was also observed that changes in the maximum response (reactivity) could not reflect the clinical status of tolerance, particularly in the initial phases of HVI.

Time-dependent effect of desensitization with wasp venom on selected parameters of the immune system

The emergence of tolerance during Hymenoptera venom immunotherapy (VIT) is a complex process. The main goal of VIT is to induce a change from proinflammatory Th2 response to the Th1 response. However, the immune mechanism of acquiring rapid tolerance during VIT has not yet been fully understood. Therefore, we have analyzed (in 4-time points: 0, 2, 6, and 24 weeks after the initiation phase of VIT) the concentration of complement C3, C4, and C5 components, lymphocyte subpopulations (flow cytometry), as well as histamine and tryptase serum concentrations of 43 patients with wasp venom allergy (III and IV Müller grade) classified to ultra-rush treatment and 18 volunteers as the control group (CG). We observed that VIT affected the immune system by inducing changes in the complement system (decreased C3 and C4 compartment protein concentrations) and "normalized" the percentage of lymphocytes and neutrophils in the peripheral blood. Moreover, a significant increase in the percentage of nTreg in the blood of patients treated with VIT was observed. On the other hand, there were no changes in histamine or tryptase concentrations in the blood. Increased percentage of nTreg cells is a well-known mechanism by which VIT affects the immune system. Finally, VIT also modulated the concentrations of the complement components, which may be a previously unknown VIT mechanism of action.

Bioactive Peptides and Proteins from Wasp Venoms

Wasps, members of the order Hymenoptera, use their venom for predation and defense. Accordingly, their venoms contain various constituents acting on the circulatory, immune and nervous systems. Wasp venom possesses many allergens, enzymes, bioactive peptides, amino acids, biogenic amines, and volatile matters. In particular, some peptides show potent antimicrobial, anti-inflammatory, antitumor, and anticoagulant activity. Additionally, proteinous components from wasp venoms can cause tissue damage or allergic reactions in organisms. These bioactive peptides and proteins involved in wasp predation and defense may be potential sources of lead pharmaceutically active molecules. In this review, we focus on the advances in bioactive peptides and protein from the venom of wasps and their biological effects, as well as the allergic reactions and immunotherapy induced by the wasp venom.

Intralymphatic Immunotherapy (ILIT) With Bee Venom Allergens: A Clinical Proof-of-Concept Study and the Very First ILIT in Humans

Background

Subcutaneous venom immunotherapy (VIT) represents an effective treatment against bee venom allergy. However, it involves long treatment times, high costs, and the risk of adverse events (AEs). Shorter, safer, and cheaper treatment options are therefore pursued.

Objective

To determine the safety, immunogenicity, and efficacy of bee venom intralymphatic immunotherapy (ILIT).

Methods

In an open pilot study, 12 patients received bee venom ILIT in three sessions with 14-day intervals: 0.1–5 μg/dose. Ultrasound imaging was applied to guide an injection and to document the lymph node structure. In a second study, 67 patients from 15 centers in Europe and Australia were randomized to receive four doses of either 10- or 20-μg bee venom ILIT with 28-day intervals. Clinical endpoints included specific IgE and IgG and protection after a bee sting challenge. These studies were performed in the years 2000–2003.

Results

In a proof-of-concept study, no serious AEs were observed. An increase in allergen-specific IgG1 but no IgG4 and IgE was observed. ILIT induced the protection against a bee sting challenge in 7 out of 8 challenged patients. In a multicenter study, an increase in allergen-specific IgG and IgE was observed, with the highest increase in patients receiving a higher ILIT dose. The study was terminated due to several serious AEs upon the sting challenge provocation after the completion of treatment. However, out of 45 patients challenged, 15 (65%) and 18 (82%) patients in the 10- and 20-μg group, respectively, showed an improvement of two grades or more. No correlation was observed between antibody levels and sting protection.

Conclusions

While a pilot study suggested the safety and efficacy of bee venom ILIT, a high number of AEs seen after the sting challenge following a randomized study indicate that the immunology protection offered by bee venom ILIT is insufficient. Of note, the bee venom allergen extract used in the two studies were from the two different providers. While the first study used a formulation approved for use in subcutaneous VIT, the second study used a nonapproved formulation never tested in humans. Further studies on approved formulations should be performed to generate conclusive results regarding the safety and efficacy of bee venom ILIT.

Management of Double Sensitization to Vespids in Europe

Wasp allergy with a diagnostic profile of double sensitizations to vespid venom is a frequent clinical problem in areas where different genera of wasps are present. Identification of the insect responsible for serious reactions poses a diagnostic challenge as the only effective treatment to date is immunotherapy based on the specific venom. In southern Europe, the double sensitization to Vespula and Polistes venoms is highly frequent. It has been shown that the major allergenic proteins (Phospholipase A1 and Antigen 5) share sequences across the different genera and species, which would be the cause of cross-reactivity. Additionally, the minor allergens (Dipeptidyl-peptidases, Vitellogenins) have been found to share partial sequence identity. Furthermore, venom contains other homologous proteins whose allergenic nature still remains to be clarified. The traditional diagnostic tools available are insufficient to discriminate between allergy to Vespula and Polistes in a high number of cases. IgE inhibition is the technique that best identifies the cross-reactivity. When a double sensitization has indeed been shown to exist or great uncertainty surrounds the primary sensitization, therapy with two venoms is advisable to guarantee the safety of the patient. In this case, a strategy involving alternate administration that combines effectiveness with efficiency is possible.

Honey Bee Products: Preclinical and Clinical Studies of Their Anti-inflammatory and Immunomodulatory Properties

Inflammation is a defense process triggered when the body faces assaults from pathogens, toxic substances, microbial infections, or when tissue is damaged. Immune and inflammatory disorders are common pathogenic pathways that lead to the progress of various chronic diseases, such as cancer and diabetes. The overproduction of cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, is an essential parameter in the clinical diagnosis of auto-inflammatory diseases. In this review, the effects of bee products have on inflammatory and autoimmune diseases are discussed with respect to the current literature. The databases of Google Scholar, PubMed, Science Direct, Sci-Finder and clinical trials were screened using different combinations of the following terms: “immunomodulatory”, “anti-inflammatory”, “bee products”, “honey”, “propolis”, “royal jelly”, “bee venom”, “bee pollen”, “bee bread”, “preclinical trials”, “clinical trials”, and “safety”. Honey bee products, including propolis, royal jelly, honey, bee venom, and bee pollen, or their bioactive chemical constituents like polyphenols, demonstrate interesting therapeutic potential in the regulation of inflammatory mediator production as per the increase of TNF-α, IL-1β, IL-6, Il-2, and Il-7, and the decrease of reactive oxygen species (ROS) production. Additionally, improvement in the immune response via activation of B and T lymphocyte cells, both in in vitro, in vivo and in clinical studies was reported. Thus, the biological properties of bee products as anti-inflammatory, immune protective, antioxidant, anti-apoptotic, and antimicrobial agents have prompted further clinical investigation.

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.

Reducing the sting: Diagnosis and management of Hymenoptera venom allergy

ABSTRACT

Hymenoptera species include stinging insects such as wasps, hornets, bees, and fire ants. Allergic reaction to the venom of these insects is a common presenting complaint for patients in primary care and emergency medicine during warmer months. Patients' clinical presentations may vary, and clinicians must identify the type of reaction to determine treatment and follow-up plans. Treatment of patients allergic to Hymenoptera venom should be individualized based on risk factors, reaction type, and associated comorbidities. This article reviews common features of clinical presentation, diagnosis, and the current mainstays in management of Hymenoptera venom allergy.

The role of component-resolved diagnosis in Hymenoptera venom allergy in clinical practice

Background: Hymenoptera venom allergy is an immunoglobulin (Ig) E mediated hypersensitivity reaction to Hymenoptera venoms. Obvious identification of the culprit insect that causes the clinical symptoms and, hence, the accurate selection of venom for curative treatment, is of great importance for the effectiveness and safety of venom immunotherapy. Objective: In this study, the contribution of component-resolved diagnostics (CRD) is evaluated in the diagnosis of Hymenoptera venom allergy. Method: Ninety-three patients from four different centers in Turkey were included in the study. Conventional tests, including prick and intradermal skin tests, with commercial venom extracts and serum specific IgE (sIgE) levels for whole venoms were performed. An sIgE analysis for venom allergen components, including rApi m 1, rApi m 2, rApi m 10, rVes v 1, rVes v 5, were evaluated by immunoblotting. Results: In conventional test results, 17 of 35 patients with bee venom allergy were positive to honey bee venom, whereas 18 patients were positive to bee and wasp venoms. In 28 of 35 patients with bee venom allergy, the diagnosis was confirmed with CRD. CRD revealed a sensitivity of 80% in patients with bee venom allergy. According to conventional tests, 7 of 24 patients with vespid venom allergy demonstrated sensitivity only to Vespula species, whereas 17 patients revealed double positivity. The total diagnostic sensitivity of Ves v 1 and Ves v 5 was calculated as 87.5%. Ten of 23 patients with a history of hypersensitivity to both venoms showed double sensitivity with CRD; one patient had cross-reactivity, one patient was found to be sensitive only to bee venom, and, eight patients were sensitive only to Vespula species. Eleven patients had an uncertain history in terms of the culprit insect type and six of them had double sensitivity in CRD. Conclusion: CRD seemed to be more helpful in diagnosing vespid venom allergy than bee venom allergy. It can also discriminate clinically significant sensitizations from irrelevant ones.

Global View on Ant Venom Allergy: from Allergenic Components to Clinical Management

Hymenoptera venom allergy is characterised by systemic anaphylactic reactions that occur in response to stings from members of the Hymenoptera order. Stinging by social Hymenoptera such as ants, honeybees, and vespids is one of the 3 major causes of anaphylaxis; along with food and drug exposure, it accounts for up to 43% of anaphylaxis cases and 20% of anaphylaxis-related fatalities. Despite their recognition as being of considerable public health significance, stinging ant venoms are relatively unexplored in comparison to other animal venoms and may be overlooked as a cause of venom allergy. Indeed, the venoms of stinging ants may be the most common cause of anaphylaxis in ant endemic areas. A better understanding of the natural history of venom allergy caused by stinging ants, their venom components, and the management of ant venom allergy is therefore required. This article provides a global view on allergic reactions to the venoms of stinging ants and the contemporary approach to diagnose and manage ant venom allergy.

Immunological Responses to Envenomation

Venoms are complex mixtures of toxic compounds delivered by bite or sting. In humans, the consequences of envenomation range from self-limiting to lethal. Critical host defence against envenomation comprises innate and adaptive immune strategies targeted towards venom detection, neutralisation, detoxification, and symptom resolution. In some instances, venoms mediate immune dysregulation that contributes to symptom severity. This review details the involvement of immune cell subtypes and mediators, particularly of the dermis, in host resistance and venom-induced immunopathology. We further discuss established venom-associated immunopathology, including allergy and systemic inflammation, and investigate Irukandji syndrome as a potential systemic inflammatory response. Finally, this review characterises venom-derived compounds as a source of immune modulating drugs for treatment of disease.

New Biomarkers of Hymenoptera Venom Allergy in a Group of Inflammation Factors

Hymenoptera venom allergy significantly affects the quality of life. Due to the divergences in the results of the available test and clinical symptoms of patients, the current widely applied diagnostic methods are often insufficient to classify patients for venom immunotherapy (VIT). Therefore it is still needed to search for new, more precise, and accurate diagnostic methods. Hence, this research aimed to discover new biomarkers of Hymenoptera venom allergy in a group of inflammation factors using set of multi-marker Bioplex panel. The adoption of a novel methodology based on Luminex/xMAP enabled simultaneous determination of serum levels of 37 different inflammatory proteins in one experiment. The study involved 21 patients allergic to wasp and/or honey bee venom and 42 healthy participants. According to univariate and multivariate statistics, soluble CD30/tumor necrosis factor receptor superfamily, member 8 (sCD30/TNFRSF8), and the soluble tumor necrosis factor receptor 1 (sTNF-R1) may be considered as effective prognostic factors, their circulating levels were significantly decreased in the allergy group (p-value < 0.05; the Area Under the Curve (AUC) ~0.7; Variable Importance in Projection (VIP) scores >1.2). The obtained results shed new light on the allergic inflammatory response and may contribute to modification and improvement of the diagnostic and monitoring methods. Further, large-scale studies are still needed to explain mechanisms of action of studied compounds and to definitively prove their usefulness in clinical practice.

Primäre Feldwespengiftallergie im Rheingau: selten oder vielleicht doch nicht so selten?

Die Hymenopterengiftallergie ist der häufigste Auslöser anaphylaktischer Reaktionen bei Erwachsenen und der zweithäufigste Auslöser bei Kindern nach den Nahrungsmitteln. In West- und Mitteleuropa sind Stiche der Faltenwespenarten Vespula vulgaris und Vespula germanica sowie der Honigbiene Apis mellifera die Hauptauslöser von Anaphylaxien. In Südeuropa, den USA sowie in tropischen und subtropischen Gebieten (v. a. Südamerika) sind Feldwespenarten (Polistes spp.) weit verbreitet und spielen dort als Auslöser von Stichanaphylaxien eine bedeutende Rolle.

Dargestellt wird der außergewöhnliche Fall einer primären Feldwespengiftallergie bei einem 65-jährigen Patienten aus dem Rheingau. Da die Feldwespengift-Immuntherapie in Deutschland keine Zulassung hat, konnte diese unserem Patienten als kausale Therapie nicht angeboten werden. Durch die klimatischen Veränderungen könnte die Feldwespengiftallergie sowohl aktuell als auch zukünftig in Nord- und Westeuropa eine wichtige Rolle einnehmen.

Wasp Venom Biochemical Components and Their Potential in Biological Applications and Nanotechnological Interventions

Wasps, members of the order Hymenoptera, are distributed in different parts of the world, including Brazil, Thailand, Japan, Korea, and Argentina. The lifestyles of the wasps are solitary and social. Social wasps use venom as a defensive measure to protect their colonies, whereas solitary wasps use their venom to capture prey. Chemically, wasp venom possesses a wide variety of enzymes, proteins, peptides, volatile compounds, and bioactive constituents, which include phospholipase A2, antigen 5, mastoparan, and decoralin. The bioactive constituents have anticancer, antimicrobial, and anti-inflammatory effects. However, the limited quantities of wasp venom and the scarcity of advanced strategies for the synthesis of wasp venom’s bioactive compounds remain a challenge facing the effective usage of wasp venom. Solid-phase peptide synthesis is currently used to prepare wasp venom peptides and their analogs such as mastoparan, anoplin, decoralin, polybia-CP, and polydim-I. The goal of the current review is to highlight the medicinal value of the wasp venom compounds, as well as limitations and possibilities. Wasp venom could be a potential and novel natural source to develop innovative pharmaceuticals and new agents for drug discovery.

Human Fatalities Caused by Hornet, Wasp and Bee Stings in Spain: Epidemiology at State and Sub-State Level from 1999 to 2018

Simple Summary

Although not frequent, hornet, wasp, and bee stings may be life-threatening. Over the 20-year period studied, a total of 78 fatalities were recorded in Spain, the annual mortality rates ranging from 0.02 to 0.19 per million inhabitants. The fatal events mainly affected men over 65 years of age, and took place in summertime, at “unspecified places”. At regional level, the deaths tended to concentrate in three communities: Galicia, Andalucía, and Castilla y León. Surprisingly, Galicia showed high mortality rates in hornet stings. The implication of the invasive species Vespa velutina, also known as the Asian hornet, is examined. In light of the findings, there is evidence to consider the health-related importance and consequences of Vespa velutina.

Abstract

Epidemiology of fatalities in Spain due to hornet, wasp, and bee stings (Cause Code of Death: X23) is described. Over a 20-year period (1999–2018), a total of 78 fatalities were recorded, mostly occurring in males (85.9%), of 65 years and older (52.6%), at “unspecified places” (67.9%), and in the months of July and August (50%). The X23 mortality rates (X23_MR) expressed in terms of annual rates and per million inhabitants, varied from 0.02 to 0.19 (mean value ± standard deviation = 0.09 ± 0.05), placing Spain at low levels in comparison with other countries. A more detailed and specific breakdown of the distribution of the yearly deaths at the sub-state level and across communities reveals some striking features. They were more concentrated in the communities of Galicia (35.8%), Andalucía (21.7%), and Castilla y León (12.8%). X23_MR were estimated in Galicia at 1.82, 1.10, and 2.22 in 2014, 2016, and 2018, respectively; and in Asturias at 1.88 and 0.97, in 2014 and 2017, respectively. The role of the invasive species Vespa velutina (VV) is examined. Due to its habits, abundance, and broader distribution, the risk that VV represents to human health is unmatched by other Hymenoptera native species.

Clinical outcomes related to molecular allergy diagnosis

PURPOSE OF REVIEW

Aim of this review is the description of the medical conditions in which the support of molecular allergy diagnostics (MAD) has an impact on the clinical outcomes, such as laboratory diagnostics, prognosis, and therapy of allergic diseases.

RECENT FINDINGS

The review of the literature of the last 2 years generated a wide number of results on this topic. As expected, not all were obtained by the use of MAD, but, in general, a clear trend is evident.

SUMMARY

Within the large number of works available, laboratory allergy diagnostics seems to be the most frequently discussed topic, in particular considering the complexity of the biological environment where these assays are used. Some interesting news arrive from the prognostic potential of MAD, whereas for allergen immunotherapy, waiting for a well-conducted prospective randomized clinical study, data from retrospective studies still confirms the added values of MAD in the management of the allergic patients.

Purification and molecular characterization of phospholipase, antigen 5 and hyaluronidases from the venom of the Asian hornet (Vespa velutina)

The aim of this study was to purify potential allergenic components of Vespa velutina venom, the yellow legged Asian Hornet, and perform a preliminary characterization of the purified proteins. Starting from the whole venom of V.velutina, several chromatographic steps allowed to purify the phospholipase (named Vesp v 1), as well as the antigen 5 (Vesp v 5, the only allergenic component described as such so far). The two hyaluronidase isoforms found (Vesp v 2A and Vesp v 2B) cannot be separated from each other, but they are partially purified and characterized. Purity of the isolated proteins in shown by SDSPAGE, as well as by the results of the N-terminal sequencing. This characterization and nLC-MS/MS data provide most of the sequence for Vesp v 1 and Vesp v 5 (72 and 84% coverage, respectively), confirming that the whole sequences of the isolated natural components match with the data available in public transcriptomic databases. It is of particular interest that Vesp v 1 is a glycosylated phospholipase, a fact that had only described so far for the corresponding allergen components of Dolichovespula maculata and Solenopsis invicta. The availability of the complete sequences of Vespa velutina components permits comparison with homologous sequences from other Hymenoptera. These data demonstrate the higher similarity among the species of the genera Vespa and Vespula, in comparison to Polistes species, as it is especially observed with the hyaluronidases isoforms: the isoform Vesp v 2A only exists in the former genera, and not in Polistes; in addition, the most abundant isoform (Vesp v 2B) exhibits 93% sequence identity with the Ves v 2 isoform of Vespula vulgaris. Finally, the isolated components might be useful for improving the diagnosis of patients that could be allergic to stings of this invasive Asian hornet, as it has been the case of an improved diagnosis and treatment of other Hymenoptera-sensitized patients.

Proteomic features characterization of Hymenoptera venom allergy

Background

Hymenoptera venom allergy is one of the most frequent causes of anaphylaxis. In its most severe form, the reaction to wasp and honey bee stings may be life-threatening. Therefore, immediate and proper diagnosis of venom allergy and implementation of suitable therapy are extremely important. Broadening the knowledge on the mechanism of the allergic reaction may contribute to the improvement of both diagnostic and treatment methods. Thus, this study aimed to discover changes in protein expression in serum of patients allergic to Hymenoptera (wasp and honeybee) venom and to point out proteins and peptides involved in the allergic inflammation.

Methods

Serum proteomic patterns typical to allergic patients and healthy volunteers were obtained with MALDI-TOF (matrix-assisted laser desorption/ionization-time of flight) mass spectrometer. The spectra were processed, analyzed and compared using advanced bioinformatics tools. The discriminative peaks were subjected to identification with liquid chromatography coupled with tandem mass spectrometry.

Results

This methodology allowed for the identification of four features differentiating between allergy and control groups. They were: fibrinogen alpha chain, coagulation factor XIII chain A, complement C4-A, and inter-alpha-trypsin inhibitor heavy chain H4. All of these proteins are involved in allergic inflammatory response.

Conclusions

Extending the knowledge of the Hymenoptera venom sensitization will contribute to the development of novel, sensitive and specific methods for quick and unambiguous allergy diagnosis. Understanding the basis of the allergy at the proteomic level will support the improvement of preventive and therapeutic measures.

IL-4 receptor α blockade prevents sensitization and alters acute and long-lasting effects of allergen-specific immunotherapy of murine allergic asthma

BACKGROUND

Allergen-specific immunotherapy (AIT) is the only causal treatment for allergy. However, success rates vary depending on the type of allergy and disease background of the patient. Hence, strategies targeting an increased therapeutic efficacy are urgently needed. Here, the effects of blockade of IL-4 and IL-13 signaling on different phases of AIT were addressed.

METHODS

The impact of the recombinantly produced IL-4 and IL-13 antagonist IL-4 mutein (IL-4M) on allergic sensitization and AIT outcome in experimental allergic asthma were analyzed in a murine model. The effects of IL-4M administration were assessed prior/during sensitization, immediately after AIT under allergen challenge, and two weeks post-treatment.

RESULTS

Intervention with IL-4M prior/during sensitization led to strong induction of IgG1, IgG2a, IgG2b, and IgG3, decrease of specific and total IgE, as well as of IL-5 in serum. Similar effects on the serum immunoglobulin levels were observed immediately after IL4M-supplemented AIT during allergen challenge. Additionally, IL4M markedly suppressed type-2 cytokine secretion of splenocytes beyond the effect of AIT alone. These effects were equaled to those of AIT alone two weeks post-treatment. Intriguingly, here, IL-4M induced a sustained decrease of Th2-biased Tregs (ST2⁺ FOXP3⁺ GATA3^intermediate ).

CONCLUSIONS

IL-4 and IL-13 blockade during experimental AIT demonstrates beneficial effects on immunological key parameters such as immunoglobulin and cytokine secretion immediately after AIT. Although two weeks later these effects were dropped to those of AIT alone, the number of potentially disease-triggering Th2-biased Tregs was further significantly decreased by IL-4M treatment. Hence, IL-4/IL13-targeting therapies prime the immune memory in therapy success-favoring manner.

Venom allergy treatment practices in Poland in comparison to guidelines: next edition of the national audit

Introduction

Venom immunotherapy treatment (VIT) is the only causal treatment of hymenoptera venom anaphylaxis, which aims to provide long-lasting immunoprotection against severe reactions to subsequent stings.

Aim

To reassess the compliance of VIT procedures in the Polish allergy centres with the European guidelines.

Material and methods

A structured questionnaire survey conducted in all 33 VIT-centres. The response rate was 94%.

Results

The ultrarush initial protocol was the most common protocol (71%, n = 22), usually lasting for 3.5 h (50%, n = 7). The most frequent (36%, n = 11) time interval from the initial to the first maintenance dose (MD) was 14 days, ranging from 7 to 35 days. All centres used an MD of 100 μg. The most frequent time interval between subsequent MDs was 4 weeks (58%, n = 18). Five years’ of VIT was declared by 71% (n = 22). Before the termination of treatment, more than half of the centres (58%, n = 18) performed sIgE and almost half (42%, n = 13) performed skin tests. To confirm VIT efficacy, few centres (26%, n = 8) conducted the sting challenge. About half of centres provided the patients with an adrenalin auto-injector both at the time of initial diagnostics and at the end of treatment. More than half (55%, n = 17) used antihistamines in all patients. Almost half (45%, n = 14) declared to stop treatment with β-blockers and almost one fourth (23%, n = 7) discontinued angiotensin-converting-enzyme inhibitors.

Conclusions

In the most important procedures, there is a very high compliance with the guidelines. In the areas where the guidelines are not precise, we observed a large spread of results.

Current Advances in Immunological Studies on the Vespidae Venom Antigen 5: Therapeutic and Prophylaxis to Hypersensitivity Responses

Although systemic reactions caused by allergenic proteins present in venoms affect a small part of the world population, Hymenoptera stings are among the main causes of immediate hypersensitivity responses, with risk of anaphylactic shock. In the attempt to obtain therapeutic treatments and prophylaxis to hypersensitivity responses, interest in the molecular characterization of these allergens has grown in the scientific community due to the promising results obtained in immunological and clinical studies. The present review provides an update on the knowledge regarding the immune response and the therapeutic potential of Antigen 5 derived from Hymenoptera venom. The results confirm that the identification and topology of epitopes, associated with molecular regions that interact with antibodies, are crucial to the improvement of hypersensitivity diagnostic methods.

Characterization of the honeybee venom proteins C1q-like protein and PVF1 and their allergenic potential

Honeybee (Apis mellifera) venom (HBV) represents an ideal model to study the role of particular venom components in allergic reactions in sensitized individuals as well as in the eusociality of Hymenoptera species. The aim of this study was to further characterize the HBV components C1q-like protein (C1q) and PDGF/VEGF-like factor 1 (PVF1). C1q and PVF1 were produced as recombinant proteins in insect cells. Their allergenic properties were examined by determining the level of specific IgE antibodies in the sera of HBV-allergic patients (n = 26) as well as by their capacity to activate patients' basophils (n = 11). Moreover, the transcript heterogeneity of PVF1 was analyzed. It could be demonstrated that at least three PVF1 variants are present in the venom gland, which all result from alternative splicing of one transcript. Additionally, recombinant C1q and PVF1 from Spodoptera frugiperda insect cells exhibited specific IgE reactivity with approximately 38.5% of sera of HBV-allergic patients. Interestingly, both proteins were unable to activate basophils of the patients, questioning their role in the context of clinically relevant sensitization. Recombinant C1q and PVF1 can build the basis for a deeper understanding of the molecular mechanisms of Hymenoptera venoms. Moreover, the conflicting results between IgE sensitization and lack of basophil activation, might in the future contribute to the identification of factors that determine the allergenic potential of proteins.

The high molecular weight dipeptidyl peptidase IV Pol d 3 is a major allergen of Polistes dominula venom

Hymenoptera venom allergy can cause severe anaphylaxis in untreated patients. Polistes dominula is an important elicitor of venom allergy in Southern Europe as well as in the United States. Due to its increased spreading to more moderate climate zones, Polistes venom allergy is likely to gain importance also in these areas. So far, only few allergens of Polistes dominula venom were identified as basis for component-resolved diagnostics. Therefore, this study aimed to broaden the available panel of important Polistes venom allergens. The 100 kDa allergen Pol d 3 was identified by mass spectrometry and found to be a dipeptidyl peptidase IV. Recombinantly produced Pol d 3 exhibited sIgE-reactivity with approximately 66% of Polistes venom-sensitized patients. Moreover, its clinical relevance was supported by the potent activation of basophils from allergic patients. Cross-reactivity with the dipeptidyl peptidases IV from honeybee and yellow jacket venom suggests the presence of exclusive as well as conserved IgE epitopes. The obtained data suggest a pivotal role of Pol d 3 as sensitizing component of Polistes venom, thus supporting its status as a major allergen of clinical relevance. Therefore, Pol d 3 might become a key element for proper diagnosis of Polistes venom allergy.