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Allergens in Hymenoptera venom. XXI. Cross-reactivity and multiple reactivity between fire ant venom and bee and wasp venoms.

The relationships between fire ant venom and bee and wasp venoms were explored by studying sera from five groups of subjects. Group 1 included adults not allergic to any venoms and who were not exposed to fire ants. Group 2 included adults with fire ant exposure who were not allergic to venoms. Group 3 included patients with recent systemic reactions to fire ant venom. Group 4 included patients allergic to bee and vespid venoms with no fire ant exposure. Last, group 5 included patients allergic to bee and vespid venoms with fire ant exposure. None of the serum samples from group 1 was RAST reactive to fire ant venom, but 24% of those from group 2 were fire ant positive, as were 100% of those from group 3, 51% of those from group 4, and 87% of those from group 5. The RAST-positive patients in groups 2 and 5 were also skin test positive. RAST inhibition studies demonstrated cross-reactivity in some cases and multiple reactivity in others. The serum samples were further investigated via nondenaturing electrophoretic immunoblot studies and RAST with highly purified allergens. Serum samples from group 4 reacted to a single band on immunoblots and with only one of the four purified allergens from fire ant venom (Solenopsis invicta I, or Sol i I). Serum samples from groups 2, 3, and 5 showed various patterns of allergen reactivity. All serum samples from patients allergic to fire ant venom who also reacted to bee and/or vespid venoms by RAST contained IgE antibodies binding to Sol i I.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Allergens in Hymenoptera venoms. IV. Comparison of venom and venom sac extracts.

Honeybee venom sac extract is compared with pure venom. All five known allergens of venom are present in venom sac extract. Enzyme analyses indicate that the sac extracts contain 11% to 16% venom. At least 10 additional components, several of which are proteins, are present in venom sac extract. Radioallergosorbent test (RAST) studies of yellow jacket venom and venom sac extract yielded a correlation of r = 0.94, with only some weakly reactive sera positive to only one preparation. A few sera were substantially more reactive with venom sac extract. Venom sac extracts appear to be suitable for in vitro diagnostic use, but the extraneous proteins and peptides may make them less suitable than pure venoms for use in immunotherapy.

Acid Phosphatase↗

Allergens in hymenoptera venoms. X. Vespid venoms versus venom sac extracts: comparison by two-dimensional polyacrylamide gel electrophoresis.

Vespid venoms were compared to venom sac extracts by two-dimensional polyacrylamide gel electrophoresis using non-equilibrium pH gradient electrophoresis in the first dimension and sodium dodecyl sulfate electrophoresis in the second. The gels were stained with silver. Fresh venoms from four species, Vespula maculifrons, Polistes fuscatus fuscatus, P. metricus and P. exclamans, were compared with commercially available venom sac extracts from the same species. In each case the venom sac extract contained all of the proteins detected in the fresh venom plus numerous additional proteins which are probably sac components. Yellow jacket and bee (Apis mellifera) proteins were extracted from the gels and tested for IgE binding activity using pooled sera from RAST-positive individuals. Significant IgE binding activity was found for the five known bee allergens and for the major yellow jacket venom proteins. Fresh pure vespid venoms contain a relatively small number of major protein subunits. Venom sac extracts contain the same components plus many other proteins not found in the pure venoms.

Allergens↗

Double sensitization to honeybee and wasp venom: immunotherapy with one or with both venoms? Value of FEIA inhibition for the identification of the cross-reacting ige antibodies in double-sensitized patients to honeybee and wasp venom.

BACKGROUND: Double sensitization to honeybee (Apis mellifera) and wasp venom (Vespula spp.) as determined by skin test and measurement of specific IgE is common in hymenoptera sting allergy. Double-sensitized patients have either distinct antibodies for each venom or cross-reacting antibodies that recognize similar or identical epitopes in both venoms. Unfortunately, patients often fail to identify the stinging insect which makes it difficult to distinguish cross-reactors from non cross-reactors. However, for economic reasons as well as for the benefit of the patients, it would be useful to identify complete cross-reactors. METHODS: In this study we investigated 24 double-sensitized patients who were candidates for venom immunotherapy. Homologous and heterologous FEIA inhibition was carried out with honeybee (Apis mellifera) and wasp venom (Vespula spp.) preparations from two different providers. The inhibitor concentrations were ranging from 0 to 100 microg protein/ml. RESULTS: Sera of 4 patients were completely cross-reacting for one venom (3 honeybee, 1 wasp), 8 patients were partially cross-reacting and 10 patients were not cross-reacting. Two patients were excluded from the study due to insufficient homologous inhibition. Data from specific IgE measurements, skin test, and clinical history were not useful for the identification of cross-reacting patients. CONCLUSION: FEIA inhibition is easy to perform and useful for the identification of patients with complete cross-reactivity. In these patients immunotherapy might be restricted to one venom which is beneficial for the patient and cost-effective.

Adolescent↗

Allergens in hymenoptera venom. VI. Cross reactivity of human IgE antibodies to the three vespid venoms and between vespid and paper wasp venoms.

A substantial degree of immunologic cross-reactivity is demonstrated among yellow jacket (YJV), yellow hornet (YHV) and white-faced hornet (WFHV) venoms and between the vespid venoms and paper wasp venom (PWV) by RAST inhibition studies of individual sera from allergic patients. Cross-reactivity is shown to be complete, partial or absent in various cases. In many cases RAST inhibition studies are able to demonstrate the primary sensitivity. Specificity by RAST inhibition did not always agree with specificity by quantitative RAST. A variety of patterns of cross-reaction are shown to exist between the pairs of venoms studied. There is no general pattern of cross-reactivity among the vespids or between vespid and paper wasp. Some cross-reactivity appears to result from multiple stings by different insects.

Allergens↗

Sub-class of IgG anti-bee venom antibody produced during bee venom immunotherapy and its relationship to long-term protection from bee stings and following termination of venom immunotherapy.

The IgG sub-class antibody response to bee venom in the four sub-classes was investigated in ten patients during and after venom immunotherapy. All patients tolerated a bee sting challenge 1, 2 and 3 years after the start of treatment as well as 1 and 2 years after treatment was stopped. Anti-phospholipase A2 (PLA2) antibodies were of IgG1 and IgG4 sub-class and rose early in treatment, IgG1 anti-PLA2 fell to pre-treatment levels after 3 years in contrast to IgG4 anti-PLA2 levels, which remained high during maintenance therapy and declined relatively little in the 2 years after the termination of treatment. This data shows that IgG4 antibodies are maintained in the absence of monthly maintenance injections and suggests that they may provide long lasting clinical protection from insect stings.

Adolescent↗

Characterization of venom (Duvernoy's secretion) from twelve species of colubrid snakes and partial sequence of four venom proteins.

R.E. Hill and S.P. Mackessy. Characterization of venom (Duvernoy's secretion) from twelve species of colubrid snakes and partial sequence of four venom proteins. Toxicon XX, xx-yy, 2000. - Venomous colubrids, which include more than 700 snake species worldwide, represent a vast potential source of novel biological compounds. The present study characterized venom (Duvernoy's gland secretion) collected from twelve species of opisthoglyphous (rear-fanged) colubrid snakes, an extremely diverse assemblage of non-venomous to highly venomous snakes. Most venoms displayed proteolytic activity (casein), though activity levels varied considerably. Low phosphodiesterase activity was detected in several venoms (Amphiesma stolata, Diadophis punctatus, Heterodon nasicus kennerlyi, H. n. nasicus and Thamnophis elegans vagrans), and acetylcholinesterase was found in Boiga irregularis saliva and venom, but no venoms displayed hyaluronidase, thrombin-like or kallikrein-like activities. High phospholipase A(2) (PLA(2)) activity was found in Trimorphodon biscutatus lambda venom, and moderate levels were detected in Boiga dendrophila and D. p. regalis venoms as well as B. dendrophila and H. n. nasicus salivas. Non-reducing SDS-PAGE revealed 7-20 protein bands (3.5 to over 200 kD, depending on species) for all venoms analyzed, and electrophoretic profiles of venoms were typically quite distinct from saliva profiles. Components from A. stolata, Hydrodynastes gigas, Tantilla nigriceps and T. e. vagrans venoms showed protease activity when run on gelatin zymogram gels. N-terminal protein sequences for three 26 kD venom components of three species (H. gigas, H. torquata, T. biscutatus) and one 3.5 kD component (T. nigriceps) were also obtained, and the 3.5 kD peptide showed apparent sequence homology with human vascular endothelial growth factor; these data represent the first sequences of colubrid venom components. Protease, phosphodiesterase and PLA(2) activities are also common to elapid and viperid snake venoms, but it is apparent that numerous other (as yet undescribed) components make up the majority of colubrid venom proteins. The complex nature of venoms produced by most species surveyed, and the high levels of protease or phospholipase A(2) activity of some venoms, suggest that many colubrids could become an important source of human health concern as encounters with these snakes increase.

Acetylcholinesterase↗

Comparison of the allergenicity and antigenicity of Polistes venom and other vespid venoms.

The crossantigenicity of Polistes venom with other vespid venoms was examined with rabbit and human antisera. Venom preparations from various Polistes species were obtained by electrical stimulation of individual insects and venom sac dissection. Rabbit antibodies were raised to the venom (P. apachus) and venom sac extract (P. exclamans). Human antisera were obtained from patients allergic to Polistes and other vespid venoms. The venom appeared to be more potent than the venom sac preparations in reactions with rabbit IgG and human IgE antibodies. Among the Polistes species, P. exclamans, P. instablis, and P. apachus venoms showed several lines of precipitation with rabbit antisera, and P. annularis and P. fuscatus venoms only one line, suggesting quantitative or qualitative antigenic differences. In RAST analysis, most sera reacted equally to all Polistes species but occasional exceptions were noted, again suggesting differences in venom allergens. P. exclamans-coupled discs gave the most consistent results. In gel diffusion experiments, there was no crossreactivity between Polistes and yellow jacket venoms and only limited crossreactivity between Polistes and hornet venoms. Patients sensitive to Polistes venom showed varying degrees of reactivity to yellow jacket and hornet venoms in RAST analysis. Patients sensitive to other vespid venoms also showed varying degrees os sensitivity to Polistes venom. Polistes venom appears to contain a genus-unique antigen (allergen). In addition, there appear to be some crossreacting antigens in Polistes and other vespid venoms but to a much lesser degree than found previously in the analysis of the relationship of yellow jacket and hornet venoms.

Allergens↗

Evidence for heterogeneous forms of the snake venom metalloproteinase jararhagin: a factor contributing to snake venom variability.

The reprolysin subfamily of metalloproteinases includes snake venom metalloproteinases (SVMP) and mammalian disintegrin/metalloproteinase. These proteins are synthesized as zymogens and undergo proteolytic processing resulting in a variety of multifunctional proteins. Jararhagin is a P-III SVMP isolated from the venom of Bothrops jararaca. In crude venom, two forms of jararhagin are typically found, full-length jararhagin and jararhagin-C, a proteolytically processed form of jararhagin that is composed of the disintegrin-like and cysteine-rich domains of jararhagin. To better understand the structural and mechanistic bases for these forms of jararhagin in the venom of B. jararaca and the source of venom complexity in general, we have examined the jararhagin forms isolated from venom and the autolysis of isolated jararhagin under the conditions of varying pH, calcium ion concentration, and reducing agents. From our results, jararhagin isolated from venom appears as two forms: a predominant form that is stable to in vitro autolysis and a minor form that is susceptible to autolysis under a variety of conditions including alkaline pH, low calcium ion concentrations, or reducing agent. The autolysis site for production of jararhagin-C from isolated jararhagin was different from that observed for jararhagin-C as isolated from crude venom. Taken together, these data lead us to the conclusion that during the biosynthesis of jararhagin in the venom gland at least three forms are present: one form which is rapidly processed to give rise to jararhagin-C, one form which is resistant to processing in the venom and autolysis in vitro, and one minor form which is susceptible to autolysis under conditions that promote destabilization of its structure. The presence of these different forms of jararhagin contributes to greater structural and functional complexity of the venom and may be a common feature among all snake venoms. The biological and biochemical features in the venom gland responsible for these jararhagin isoforms are currently under investigation.

Amino Acid Sequence↗

In vitro analysis of venom from the wasp Nasonia vitripennis: susceptibility of different cell lines and venom-induced changes in plasma membrane permeability.

The lethal effects of crude venom prepared from the ectoparasitic wasp Nasonia vitripennis were examined with cultured cells from six insect and two vertebrate species. Venom caused cells from Sarcophaga peregrina (NIH SaPe4), Drosophila melanogaster (CRL 1963), Trichoplusia ni (TN-368 and BTI-TN-5B1-4), Spodoptera frugiperda (SF-21AE), and Lymantria dispar (IPL-Ldfbc1) to round up, swell, and eventually die. Despite similar sensitivities and overlapping LC50 values [0.0004-0.0015 venom reservoir equivalents (VRE)/microl], profound differences were noted at the onset of cytotoxicity among the six insect cell lines: over 80% of the NIH SaPe4 and SF21AE cells were nonviable within 1 h after addition of an LC99 dose of venom, whereas the other cells required a 5-10-fold longer incubation period to produce mortality approaching 100%. In contrast, cells from the grass frog, Rana pipiens (ICR-2A), and goldfish, Carassius auratus (CAR), showed little sensitivity to the venom: six venom reservoir equivalents were needed to induce 50% mortality in ICR-2A cells [50% lethal concentration (LC50) = 0.067 VRE/microl), and 9 VRE did not yield sufficient mortality in CAR cells for us to calculate an LC50. All susceptible cells showed similar responses when incubated with wasp venom: retraction of cytoplasmic extensions (when present), blebbing of the plasma membrane, swelling of the plasma and nuclear membranes, condensation of nuclear material, and eventual cell death attributed to lysis. The rate of swelling and lysis in NIH SaPe4 and BTI-TN-5B1-4 cells exposed to venom appeared to be dependent on the diffusion potential of extracellular solutes (Na+ = choline > sucrose > or = raffinose > K+), which is consistent with a colloid-osmotic lysis mechanism of cell death. When T. ni cells were cotreated with venom and the K+ channel blocker 4-aminopyridine, cell swelling and lysis increased with increasing drug concentration. In contrast, cells from S. peregrina were protected from the effects of the venom when treated in a similar manner. Addition of certain divalent cations (Zn+2 and Ca+2) to the extracellular media 1 h postvenom incubation rescued both BTI-TN-5B1-4 and NIH SaPe4 cells, suggesting that protection was gained from closure of open pores rather than prevention of pore formation. Venom from N. vitripennis displayed no hemolytic activity toward sheep erythrocytes, supporting the view that venom intoxication is not by a nondiscriminate mechanism. A possible mode of action of the venom is discussed.

4-Aminopyridine↗

[Characterization of the biological activities of the 'yellow' and 'white' venoms from Crotalus durissus ruruima compared with the Crotalus durissus terrificus venom. Neutralizing activity of Crotalus durissus ruruima antivenins].

The biological activities of 'yellow' and 'white' venom of a rattlesnake Crotalus durissus ruruima Hoge, 1965, found in the savanna-like vegetation (cerrado) of northern Brazil (Roraima) and Venezuela have been studied, and compared to the reference Crotalus durissus terrificus venom. The lethal activity of venoms depended on the inoculation route. The most toxic venom was the white one. The venoms of C. d. terrificus and the yellow of C. d. ruruima had similar lethalities. The yellow venom of C. d. ruruima showed a caseinolytic activity three times higher than that obtained with either the venom of C. d. terrificus or the white one of the C. d. ruruima. Hemorrhagic and necrotic activities were found only in the yellow venom. White and yellow venoms from C. d. ruruima showed a similar action on fibrinogen; this thrombin-like action was greater with C. d. terrificus venom. On histopathological sections local and pulmonary hemorrhage was found only with the yellow venom, but myonecrotic activity was observed with both venoms of C. d. ruruima. Among all antivenoms studied, the anti-bothropic-crotalic was the best at neutralizing hemorrhagic and hemolytic activities. These results suggest that antivenom bothropic-crotalic should be used in the treatment of patients with snakebite by C. d. ruruima: besides its neutralization on lethal activity, it also neutralizes the hemorrhagic activity present in some venoms.

Animals↗

Effects of CD80 and CD86 on cytokine production in patients with wasp-venom allergy who receive venom immunotherapy.

Several studies have provided evidence that activation of antigen-specific T cells requires interactions between CD28 on T cells and its ligands, CD80 and CD86, on antigen-presenting cells (APCs). However, the effects of CD80 and CD86 on cytokine production in patients with Hymenoptera venom allergy who receive venom immunotherapy remain unclear. We examined the effects of CD80 and CD86 on Th1- and Th2-cytokine production before and after venom immunotherapy in patients with wasp-venom allergy. Peripheral blood mononuclear cells (PBMCs) were isolated from patients with wasp-venom allergy before and after three months of venom immunotherapy. CD4+ T cells and monocytes were isolated as APCs from PBMCs and were cocultured with wasp venom in the presence of anti-CD80 or -CD86 blocking antibodies. Interleukin (IL)-4, IL-10, and interferon (IFN)-gamma were measured by enzyme-linked immunosorbent assay. The expression of CD80 and CD86 on CD14+ PBMCs was detected by fluorescence-activated cell-sorter analysis. The expression of CD86, but not that of CD80, on CD14+ PBMCs cocultured with venom increased after three months of venom immunotherapy, but not before venom immunotherapy. Blockade of CD86 reduced IL-10 production after three months of venom immunotherapy. IL-10 production promoted by CD86 costimulation may be involved in the mechanism of venom immunotherapy in patients with venom allergy.

Antigens, CD↗

Detection of Loxosceles species venom in dermal lesions: a comparison of 4 venom recovery methods.

STUDY OBJECTIVE: Loxosceles species spider envenomations may produce necrotic, disfiguring dermal inflammatory lesions resembling neutrophilic dermatoses. With definitive treatment options lacking, clinicians are reluctant to obtain invasive biopsy specimens for diagnostic analysis. We compared less invasive venom collection methods and determined the time limit after inoculation for feasible venom recovery in an animal model. METHODS: Nine New Zealand rabbits were randomized to 1 of 3 groups (n=3). Groups 1 and 2 were inoculated intradermally with 3 microg of L reclusa venom at 5 inoculation sites per rabbit. Albumin (3 microg) was injected intradermally in each rabbit as a negative control. Hair (group 1) and aspirate samples (group 2) were collected (1 time per site) over a 1-week period after inoculation. Group 3 was inoculated with 3 microg of Loxosceles species venom on 1 flank and 3 microg of albumin on the opposite flank. Daily serum specimens were collected over a 7-day period. On day 7, dermal punch biopsy specimens were taken from the venom and control inoculation sites. Hair, aspirate, biopsy, and serum specimens were assayed for venom by using an enzyme-linked immunosorbent assay. A generalized linear model was fit with the generalized estimating equation method to estimate the mean differences between groups. RESULTS: Venom was detected in hair, aspirate, and biopsy specimens on all days of the study period. Hair samples yielded venom recovery on day 1 (median 0.062 ng/100 microL; mean difference 0.054 ng/100 microL; 95% confidence interval [CI] 0.048 to 0.059) through day 7 (median 0.020 ng/100 microL; mean difference 0.020 ng/100 microL; 95% CI 0.013 to 0.027). Aspirates were positive for venom recovery on day 1 (median 0.275 ng/100 microL; mean difference 0.231 ng/100 microL; 95% CI 0.192 to 0.271) through day 7 (median 0.0 ng/100 microL; mean difference 0.032 ng/100 microL; 95% CI -0.18 to 0.078). The highest venom yield was from the biopsy specimens (median 1.75 ng/100 microL; mean difference 0.041 ng/100 microL; 95% CI 0.033 to 0.027). Venom was undetectable in all serum samples. CONCLUSION: Loxosceles species venom is detectable in hair, aspirate, and dermal biopsy specimens at least 7 days after venom inoculation and undetectable in serum by using the rabbit model.

Animals↗

Analysis of differing patterns of cross-reactivity of honeybee and yellow jacket venom-specific IgE: use of purified venom fractions.

Prior studies of sera from insect sting-allergic patients have analyzed the relationship of coexisting honeybee venom- and yellow jacket venom-specific IgE. Radioallergosorbent (RAST)-inhibition tests with these venoms revealed four different patterns of activity. In this present study, purified fractions prepared from these venoms were used to analyze these varying patterns. The hyaluronidases of yellow jacket venom and honeybee venom showed extensive cross-reaction. The phospholipases from these venoms showed minimal cross-reactivity; antigen 5 was restricted to yellow jacket venom. There was a high molecular weight component in yellow jacket venom with immunologic properties similar to honeybee venom acid phosphatase. Sera from individual patients showed quantitative and qualitative differences in the reactions to the major components of both venoms. The differences in the RAST-inhibition patterns in patients with elevated levels of both honeybee venom- and yellow jacket venom-specific IgE are accounted for by these differences as well as by differences in the cross-reactivity between the individual components.

Animals↗

Late onset reactions following venom immunotherapy and venom skin tests.

This report describes patients who had late onset reactions following venom immunotherapy and venom skin tests. Six adult patients had symptoms of fatigue, malaise, fever, headache, and joint ache, starting four to six hours after venom immunotherapy and lasting up to four days. Two of the patients had prolonged reactions at or adjacent to the skin test sites. All of these patients had a history of venom anaphylaxis; four had severe cardiovascular symptoms. All received yellow jacket venom immunotherapy and four honeybee venom immunotherapy. In four patients, the reactions occurred following small venom doses, 0.1 to 2 micrograms. Two patients reacted after maintenance doses of 50 micrograms. There was no relationship to the serum IgE or IgG antibody titers. All but one patient had serum venom-specific IgE but the titers covered a wide range. Serum venom-specific IgG was present in four patients. There was no response in lymphocyte culture to bee venom stimulation in two patients. Two of these patients stopped venom immunotherapy; one had reached the maintenance dose. In three patients, prophylactic parenteral steroids have ameliorated the reactions. After a temporary dose reduction, the sixth patient is now asymptomatic. A seventh patient developed asthma, 12 hours following a maintenance dose of 50 micrograms of yellow jacket venom. Concomitant steroid administration has effectively prevented the reaction. Another patient, a 6-year-old boy, developed fever, edema of the face and lips, erythema of the leg, and a large, tender right inguinal node eight hours following venom skin tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

Classification of myonecrosis induced by snake venoms: venoms from the prairie rattlesnake (Crotalus viridis viridis), western diamondback rattlesnake (Crotalus atrox) and the Indian cobra (Naja naja naja).

The pathogenesis of myonecrosis induced by three different snake venoms was studied by light microscopic examination of skeletal muscle tissue taken at time periods ranging from 0.25 hr to 4 weeks after an intramuscular injection of the venom into mice. It was possible to identify different types of myonecrosis based on the abnormal morphologic states of the damaged cells. The types of myonecrosis observed correlated with the types of components present in the venom injected. Venoms containing direct acting toxins such as myotoxin a or phospholipase A2 induced specific types of myonecrosis. Also, venoms containing hemorrhagic toxins produced a type of myonecrosis similar to that induced by pure hemorrhagic toxins. The pathogenesis of each type of myonecrosis could be divided into the same four phases based on the pathologic states of the affected cells and the time after injection. During the 'early phase' (0.25-3 hr) affected muscle cells were in several different pathologic states reflecting the types of components present in the venom injected. During the 'intermediate phase' (6-24 hr) the pathologic state of the damaged cells had changed and depending on the venom new states might be present. By the 'late phase' (48-96 hr) all damaged cells have reached a common pathologic state of necrosis. The 'final phase' (1-4 weeks) is characterized by regeneration (partial or complete) of muscle cells. Although the number of different types of myonecrosis depended on the type of venom injected, i.e. Naja naja naja venom produced only two different types whereas Crotalus atrox venom produced at least four different types, cells of each tpe of myonecrosis progressed through the same four phases. In studies of the myotoxicity of snake venoms it is important to examine tissues taken during the early and intermediate phases to obtain accurate and useful information on the types of myonecrosis caused by the venom.

Animals↗

Identification by immunoblot of venom glycoproteins displaying immunoglobulin E-binding N-glycans as cross-reactive allergens in honeybee and yellow jacket venom.

BACKGROUND: IgE antibodies against carbohydrate epitopes have been identified recently as a major cause of in vitro double positivity to honeybee (HB) and vespid venom in patients with stinging-insect allergy. As these antibodies possibly have low clinical relevance they may be misleading in the diagnosis of venom allergy. OBJECTIVE: To confirm the role of carbohydrate epitopes in double positivity and to locate the responsible glycoallergens in HB and yellow jacket (YJ) venom by western blot. METHODS: Immunoblot inhibition using HB venom, YJ venom and two glycoprotein sources displaying 1-3-fucosylated N-glycans (i.e. oilseed rape (OSR) pollen, and the synthetic neo-glycoprotein fucosylated/xylosylated N-glycans from bromelain coupled to bovine serum albumin (MUXF-BSA)) as inhibitors were performed with sera from 15 double-positive patients with stinging-insect allergy. Additionally, reactivity with blotted hymenoptera venoms of a carbohydrate-specific rabbit antiserum against OSR pollen was investigated. RESULTS: Major venom glycoallergens binding with carbohydrate-specific human IgE and rabbit IgG were detected in HB venom at 42 (hyaluronidase (HYA)), 46, 65 and 95 kDa, and in YJ venom at 38 and 43 kDa (HYA). Antibody binding to these allergens was completely lost after periodate treatment. Glycans of HB phospholipase were bound by patients' IgE only after protein denaturation. In 10 of the 15 patients the reactivity was with the second venom because of carbohydrates alone. The high-molecular-weight glycoallergens identified in HB venom probably correspond to similar proteins described earlier, including allergens B and C. The 38-kDa YJ allergen might represent a homologue of V mac 3. CONCLUSIONS: The data confirm the proposed role of carbohydrate-specific IgE in double positivity to HB and YJ venom and shed new light on some previously described minor hymenoptera allergens of uncertain clinical significance. The consideration of carbohydrate-specific IgE may allow to discriminate between patients with potentially relevant and patients with non-relevant double sensitization.

Adolescent↗