Allergy to insect stings

Background: Bee and wasp venoms are potent allergens capable of inducing severe clinical reactions. To detect immediate-type hypersensitivity to these allergens, a rapid in vitro test was developed that relies on the upregulation of ecto-nucleotide pyrophosphatase/phosphodiesterase 3 (E-NPP3) on activated basophils. Methods: Blood basophils of 13 healthy donors and 22 patients allergic to bee or wasp venom were analyzed for E-NPP3 (CD203c) expression using monoclonal antibody 97A6. Basophils were analyzed by flow cytometry after activation with anti-IgE antibody or allergen. Venom-induced E-NPP3 upregulation on basophils was compared with diagnostic parameters, including skin tests and assessment of specific IgE. In selected samples, the increase in E-NPP3 expression on activated basophils was compared with histamine release and CD63 upregulation. Results: In 20/22 patients sensitized to wasp or bee venom, E-NPP3 expression on basophils was upregulated in response to activation by allergen or anti-IgE. The maximum increase in E-NPP3 expression (above ten times of baseline) was achieved after 15 min of stimulation with 1 µg/ml of allergen or anti-IgE antibody. Sensitized individuals who failed to upregulate E-NPP3 in response to IgE receptor cross-linking also failed to induce histamine release and CD63 upregulation. Conclusions: Flow cytometric determination of hymenoptera-venom-induced upregulation of E-NPP3 is a novel in vitro test to identify sensitized individuals.

Section: Discussionmentioning

confidence: 99%

Hymenoptera-Venom-Induced Upregulation of the Basophil Activation Marker Ecto-Nucleotide Pyrophosphatase/Phosphodiesterase 3 in Sensitized Individuals

Platz¹,

Binder²,

Marxer³

et al. 2001

“…In a normal immune response initially low-affinity IgG1 anti-PLA antibodies are detected, whereas high-affinity IgG4 anti-PLA antibodies are generated after repeated exposure [51, 52]or artificially by prolonged SIT in allergic patients [24, 52]. In contrast, individuals allergic to bee sting develop IgE anti-PLA antibodies [24, 43, 52]. …”

Section: Differential Regulation Of Specific Immune Responses By Confmentioning

confidence: 99%

“…The response to PLA provides a specially suited model to study the cellular and molecular mechanisms of specific immune response regulation in humans [24, 25, 26, 43, 44, 45, 46], reviewed in ref. 47].…”

Section: Differential Regulation Of Specific Immune Responses By Confmentioning

confidence: 99%

Regulation of Specific Immune Responses by Chemical and Structural Modifications of Allergens

Akdiş¹,

Blaser²

2000

Specific immunotherapy (SIT) is an efficient treatment of allergic diseases to defined allergens. Despite being used in clinical practice since early in this century, more rational and safer regimens are required, because SIT is faced with the risk of anaphylaxis and standardization problems of allergen-extract-based treatments. A better understanding of the pathogenesis of allergy and of the mechanisms of SIT has led to various approaches to overcome these problems. Knowledge of the influence of IgE-facilitated antigen presentation on allergen-specific Th2 responses increased the efforts to generate non-IgE-binding allergens. The current principal approach to allergen modification is to modify B cell epitopes in order to prevent IgE binding and effector cell cross-linking while preserving T cell epitopes to retain the capacity of inducing tolerance. In this way, the modified allergen will be directed to T cells by a phagocytosis/pinocytosis-mediated antigen uptake mechanism, bypassing IgE cross-linking and IgE-dependent antigen presentation. Accordingly, a differential regulation of allergen-specific T cell cytokine patterns and IgE:IgG production was demonstrated by modifications of the three-dimensional structure of allergens because of linearity in T cell epitopes and conformation dependence in B cell epitopes. In this context, chemically modified allergen extracts with low IgE-binding capacity have been developed to reduce anaphylactic side effects since the early 1980s. The progress of recombinant techniques for producing allergens and allergen derivatives has led to a dramatic improvement in the ability of developing novel vaccines for the treatment of allergy. This has enabled mutation or deletion of decisive amino acids in B cell epitopes and fractionation or oligomerization of allergens by genetic engineering as fruitful approaches to generate hypoallergenic vaccines. Moreover, non-IgE-binding short T cell epitope peptides and single-amino-acid-altered peptide ligands represent potential candidates for future SIT.

“…The obtention of VGP by electrical stimulation [25] led to improved diagnostic methods in patients with allergy to Hymenoptera venoms [2,4,5] and to a better understanding of the mechanisms involved in allergic reactions to Hyme noptera [3,26]. In addition, effective treatment modalities were developed for patients with severe anaphylactic reac tions [7,16].…”

Section: Discussionmentioning

confidence: 99%

“…The inadequacy of these reagents used for diagnosis [2,4,5] and the treatment failures [1,6,7] led to the determination of the allergenic content of this material and to immunology stud ies [3,8]. The obtention of pure venom and separation and purification of the proteins with allergenic capacity confirm early reports about the inadequacy of the whole-body mate rial extracts [1,7,9], Although expensive, pure bee venom is available for diagnostic and therapeutic purposes [3], How ever, vespid venoms available for clinical use are made by venom sac dissection [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Comparison of <i>Vespula germanica</i> Venoms Obtained from Different Sources

Sánchez

Blanca

Miranda

et al. 1994

This study was carried out to compare the allergenic potency of Vespula germanica (VG) venoms extracted by different methods and commercially available venoms from Vespula species currently used for in vivo and in vitro studies including immunotherapy. Pure VG venom was used as the reference material. Protein content and enzymatic and allergenic properties of all venoms studied were determined by dye stain reagent, hyaluronidase and phospholipase AB enzyme activities, and radioallergosorbent test inhibition studies, respectively. Radioallergosorbent test discs sensitized with commercial and pure VG venom were compared using specific IgE antibodies from subjects allergic to VG venom. The data obtained indicate that there were important differences in the allergenic potency between the Vespula species venoms employed for in vivo and/or in vitro assays, VG venom obtained by sac dissection, and pure VG venom. These results indicate that venoms from Vespula species used for in vitro and in vivo tests have a lower concentration of allergens and contain nonvenom proteins. These data should be taken into account when these vespid venoms are used for diagnostic purposes and also when evaluating immunotherapy studies.