Insect allergy. A comparative study including case histories and immunological parameters

Insect Sting Reactions and Specific IgE to Venom and Major Allergens in a General Population

BACKGROUND

Insect sting reactions are frequently reported, but population studies documenting the frequency and the relation to IgE-sensitization and serum tryptase are scarce.

METHODS

Questionnaire data and results from measurements of specific IgE against venom, major allergens and cross-reacting carbohydrate determinants (CCDs) were collected from 2,090 adult participants in a cross-sectional survey.

RESULTS

13% of the population reported symptoms of sting reactions and about half were systemic in nature. In all, 15% were sensitized to venom but only 31% of these had reacted to stings and only 38% of those with reactions had IgE to venom. In addition, 12% with IgE to venom were double-sensitized (DS), i.e. to both bee and wasp venom. Among DS IgE to major venom allergens, rApi m 1, rVes v 1 and rVes v 5 were negative and of no help in 31%, but 59% could be identified as likely sensitized to bee or wasp. IgE to CCDs occurred in only 0.7%, but 80% of these were DS. Finally, 36% with IgE to CCDs had had symptoms, mostly local. Serum tryptase was not associated with a history of sting reactions.

CONCLUSIONS

In a temperate climate, self-reported insect sting reactions and sensitization to venom are frequent, but in most cases, these are not seen in the same individual. In DS individuals, measurements of IgE to major allergens can be helpful in some but not all cases and additional analyses are needed. IgE to CCDs may have some clinical relevance.

Novel and viable acetylcholinesterase target site for developing effective and environmentally safe insecticides

Insect pests are responsible for human suffering and financial losses worldwide. New and environmentally safe insecticides are urgently needed to cope with these serious problems. Resistance to current insecticides has resulted in a resurgence of insect pests, and growing concerns about insecticide toxicity to humans discourage the use of insecticides for pest control. The small market for insecticides has hampered insecticide development; however, advances in genomics and structural genomics offer new opportunities to develop insecticides that are less dependent on the insecticide market. This review summarizes the literature data that support the hypothesis that an insect-specific cysteine residue located at the opening of the acetylcholinesterase active site is a promising target site for developing new insecticides with reduced off-target toxicity and low propensity for insect resistance. These data are used to discuss the differences between targeting the insect-specific cysteine residue and targeting the ubiquitous catalytic serine residue of acetylcholinesterase from the perspective of reducing off-target toxicity and insect resistance. Also discussed is the prospect of developing cysteine-targeting anticholinesterases as effective and environmentally safe insecticides for control of disease vectors, crop damage, and residential insect pests within the financial confines of the present insecticide market.

Insect-specific irreversible inhibitors of acetylcholinesterase in pests including the bed bug, the eastern yellowjacket, German and American cockroaches, and the confused flour beetle

Insecticides directed against acetylcholinesterase (AChE) are facing increased resistance among target species as well as increasing concerns for human toxicity. The result has been a resurgence of disease vectors, insects destructive to agriculture, and residential pests. We previously reported a free cysteine (Cys) residue at the entrance to the AChE active site in some insects but not higher vertebrates. We also reported Cys-targeting methanethiosulfonate molecules (AMTSn), which, under conditions that spared human AChE, caused total irreversible inhibition of aphid AChE, 95% inhibition of AChE from the malaria vector mosquito (Anopheles gambia), and >80% inhibition of activity from the yellow fever mosquito (Aedes aegypti) and northern house mosquito (Culex pipiens). We now find the same compounds inhibit AChE from cockroaches (Blattella germanica and Periplaneta americana), the flour beetle (Tribolium confusum), the multi-colored Asian ladybird beetle (Harmonia axyridis), the bed bug (Cimex lectularius), and a wasp (Vespula maculifrons), with IC(50) values of approximately 1-11muM. Our results support further study of Cys-targeting inhibitors as conceptually novel insecticides that may be free of resistance in a range of insect pests and disease vectors and, compared with current compounds, should demonstrate much lower toxicity to mammals, birds, and fish.

A proteomic study of the major allergens from yellow jacket venoms

The venoms of stinging insects belong to the most dangerous allergen sources and can cause fatal anaphylactic reactions. Reliable prediction of a patient's risk to anaphylactic reactions is vital, and diagnosis requires the knowledge of the relevant allergens. Recently, a new hyaluronidase -like glycoprotein from Vespula vulgaris (Ves v 2b) was identified. This led us to investigate hyaluronidases and also other major allergens from V. germanica and four additional Vespula species. By MALDI-Q-TOF-MS, the new hyaluronidase-like protein was shown to be the major component of the 43-kDa band in all Vespula species studied. LC-ESI-Q-TOF-MS/MS sequencing of Ves g 2a and Ves g 2b facilitated the cloning of their cDNA. Ves v 2b and Ves g 2b turned out to be essentially identical on protein level. Whereas the less abundant "a" form displayed enzymatic activity, the new "b" homologue did not. This is probably caused by amino acid exchanges in the active site, and it raises questions about the physiological role of this protein. Sequence comparisons by MS/MS of antigen 5 and phospholipases from V. vulgaris, germanica, maculifrons, pensylvanica, flavopilosa and squamosa revealed the latter as a taxonomic outlier and led to the discovery of several not previously reported amino acid differences.

Systemic reactions to wasp sting: is the clinical pattern related to age, sex and atopy?

BACKGROUND

The aim of this study was to analyze the frequency of clinical features and the severity of systemic reactions to wasp stings, and to establish their relationship with mean age, sex, and atopy.

METHODS

We studied 115 patients who suffered an anaphylactic reaction to wasp sting and showed specific IgE to venoms from Vespula and/or Polistes. In all patients, age, sex and personal history of atopy were registered. Cutaneous, respiratory, cardiovascular and gastrointestinal involvement during the course of the reaction was investigated. Each patient was assigned a severity grade according to a simple two-grade classification based on Müller's criteria. Bivariable analysis was performed to analyze the associations among mean age, sex and atopy and the symptoms and severity of the reaction.

RESULTS

The mean age was 40.2 years. There were 60 males (52.2 %) and 55 females (47.8 %). Twenty-six patients (22.6 %) were atopic. The percentages of involved systems were as follows: skin 90.4 %, respiratory 54.8 %, cardiovascular 33.9 %, and gastrointestinal 21.7 %. Reactions were mild in 40.8 %, and severe in 59.1 %. The mean age was higher in patients without cutaneous symptoms (p < 0.05). Cardiovascular involvement was more frequent in males (p < 0.05). No other significant differences were found.

CONCLUSION

The symptoms of systemic reactions to wasp venom most frequently involved the skin, while reactions without cutaneous involvement were more frequent in older patients. Cardiovascular involvement was more common in males. The clinical pattern was not determined by atopy and the variables studied were not related to severity.

Lack of Correlation between Severity of Clinical Symptoms, Skin Test Reactivity, and Radioallergosorbent Test Results in Venom-Allergic Patients

Purpose

To retrospectively examine the relation between skin test reactivity, venom-specific immunoglobulin E (IgE) antibody levels, and severity of clinical reaction in patients with insect venom allergy.

Method

Thirty-six patients (including 15 females) who presented with a history of allergic reactions to insect stings were assessed. The mean age at the time of the reactions was 33.4 ± 15.1 years (range, 4-76 years), and patients were evaluated 43.6 ± 90 months (range, 1-300 months) after the reactions. Clinical reactions were scored according to severity, from 1 (cutaneous manifestations only) to 3 (anaphylaxis with shock). These scores were compared to scores for skin test reactivity (0 to 5, indicating the log increase in sensitivity from 1 μg/mL to 0.0001 μg/mL) and radioallergosorbent test (RAST) levels (0 to 4, indicating venom-specific IgE levels, from undetectable to >17.5 kilounits of antigen per litre [kUA/L]).

Results

No correlation was found between skin test reactivity (Spearman's coefficient = 0.15, p = .377) or RAST level (Spearman's coefficient = 0.32, p = .061) and the severity of reaction. Skin test and RAST scores both differed significantly from clinical severity (p < .05), but there was a significant correlation between skin test reactivity and RAST score (p = .042). There was no correlation between skin test reactivity and time since reaction (Spearman's coefficient = 0.18, p = .294) nor between RAST and time since reaction (r = 0.1353, p = .438). Elimination of patients tested more than 12 months after their reaction still produced no correlation between skin test reactivity (p = .681) or RAST score (p = .183) and the severity of the clinical reaction.

Conclusion

In venom-allergic patients (in contrast to reported findings in cases of inhalant IgE-mediated allergy), there appears to be no significant correlation between the degree of skin test reactivity or levels of venom-specific IgE (determined by RAST) and the severity of the clinical reaction.

Prevention and treatment of hymenoptera venom allergy: guidelines for clinical practice

Based on the knowledge of the living conditions and habitat of social Aculeatae a series of recommendations have been formulated which can potentially greatly minimize the risk of field re-sting. After a systemic sting reaction, patients should be referred to an allergy specialist for evaluation of their allergy, and if necessary venom immunotherapy (VIT). An emergency medical kit should be supplied, its use clearly demonstrated and repeatedly practised until perfected. This should be done under the supervision of a doctor or a trained nurse. Epinephrine by intramuscular injection is regarded as the treatment of choice for acute anaphylaxis. H1-antihistamines alone or in combination with corticosteroids may be effective in mild to moderate reactions confined to the skin and may support the value of treatment with epinephrine in full-blown anaphylaxis. Up to 75% of the patients with a history of systemic anaphylactic sting reaction develop systemic symptoms once again when re-stung. Venom immunotherapy is a highly effective treatment for individuals with a history of systemic reaction and who have specific IgE to venom allergens. The efficacy of VIT in yellow jacket venom allergic patients has been demonstrated also by assessing health-related quality of life. If both skin tests and serum venom specific IgE turn negative, VIT may be stopped after 3 years. After VIT lasting 3-5 years, most patients with mild to moderate anaphylactic symptoms remain protected following discontinuation of VIT even with positive skin tests. Longer term or lifelong treatment should be considered in high-risk patients. Because of the small but relevant risk of re-sting reactions, in these patients, emergency kits, including epinephrine auto-injectors, should be discussed with every patient when stopping VIT.

Diagnosis of Hymenoptera venom allergy

The purpose of diagnostic procedure is to classify a sting reaction by history, identify the underlying pathogenetic mechanism, and identify the offending insect. Diagnosis of Hymenoptera venom allergy thus forms the basis for the treatment. In the central and northern Europe vespid (mainly Vespula spp.) and honeybee stings are the most prevalent, whereas in the Mediterranean area stings from Polistes and Vespula are more frequent than honeybee stings; bumblebee stings are rare throughout Europe and more of an occupational hazard. Several major allergens, usually glycoproteins with a molecular weight of 10-50 kDa, have been identified in venoms of bees, vespids. and ants. The sequences and structures of the majority of venom allergens have been determined and several have been expressed in recombinant form. A particular problem in the field of cross-reactivity are specific immunoglobulin E (IgE) antibodies directed against carbohydrate epitopes, which may induce multiple positive test results (skin test, in vitro tests) of still unknown clinical significance. Venom hypersensitivity may be mediated by immunologic mechanisms (IgE-mediated or non-IgE-mediated venom allergy) but also by nonimmunologic mechanisms. Reactions to Hymenoptera stings are classified into normal local reactions, large local reactions, systemic toxic reactions, systemic anaphylactic reactions, and unusual reactions. For most venom-allergic patients an anaphylactic reaction after a sting is very traumatic event, resulting in an altered health-related quality of life. Risk factors influencing the outcome of an anaphylactic reaction include the time interval between stings, the number of stings, the severity of the preceding reaction, age, cardiovascular diseases and drug intake, insect type, elevated serum tryptase, and mastocytosis. Diagnostic tests should be carried out in all patients with a history of a systemic sting reaction to detect sensitization. They are not recommended in subjects with a history of large local reaction or no history of a systemic reaction. Testing comprises skin tests with Hymenoptera venoms and analysis of the serum for Hymenoptera venom-specific IgE. Stepwise skin testing with incremental venom concentrations is recommended. If diagnostic tests are negative they should be repeated several weeks later. Serum tryptase should be analyzed in patients with a history of a severe sting reaction.

Anafilaxia por picadura de himenóptero: estudio de 113 casos

BACKGROUND AND OBJECTIVE

The purpose of this study was to describe the clinical and epidemiological features of anaphylactic reactions to hymenoptera stings, with a case-history analysis according to severity.

PATIENTS AND METHOD

We conducted an observational descriptive study of patients aged between 10 and 80 years who suffered a systemic reaction after hymenoptera sting. All of them showed specific serum IgE to venoms from Apis, Vespula and/or Polistes. A questionnaire including history of atopy, past reactions and characteristics of the reaction, was performed by individual interview. Anaphylactic reactions were classified into two levels of severity according to Müller's classification. An analysis of independence was carried out in order to relate each level with several factors: age, gender, atopy, type of previous reactions, area of sting and time sequence.

RESULTS

113 patients were included (63 male; mean age [standard deviation]: 40.1 [15.9] years). Reactions were accounted for bee venom in 10.6% of patients, and wasp in 89.4%. Specific IgE was positive to Vespula in 91.9% of subjects, Polistes in 71.4%, and Apis in 28.7%. Furthermore, 50.4% were sensitive to both Vespula and Polistes. Personal history of atopy was found in 20.3%. Among the 106 patients who reminded previous stings, local large reactions were referred by 35.9% and systemic reactions by 16.5%. Upper limb was the most frequent area of sting (38.9%). Most common symptoms were: pruritus (77.8%), hives (57.5%), edema (54.8%), erythema (52.2%), dizziness (51.3%) and dyspnea (49.5%). Severe reactions occurred in 65.5% of patients. Age, gender, atopy, type of previous reactions, area of sting and restoration time were not significantly associated with severity. Time elapsed to first symptom was proportionally shorter in severe cases (p < 0.05).

CONCLUSIONS

There is a high frequency of hypersensitivity to wasp venom (Vespula) in the studied population. Except for immediacy, severity-associated data could not be established.

The CD63 basophil activation test in Hymenoptera venom allergy: a prospective study

BACKGROUND

The basophil activation test (BAT), which relies on flow cytometric quantitation of the allergen-induced up-regulation of the granule-associated marker CD63 in peripheral blood basophils, has been suggested to be a useful approach in detecting responsiveness to allergens. The purpose of this study was to establish the usefulness of the BAT with regard to the clinical history and current diagnostic tools in Hymenoptera venom allergy using a prospective study design.

METHODS

Fifty-seven consecutive patients allergic to Hymenoptera venom as defined by a systemic reaction after an insect sting, and 30 age- and sex-matched control subjects with a negative history were included. The degree and nature of sensitization was confirmed by skin testing, specific immunoglobulin E (IgE), serum tryptase levels and BAT. In the nonallergic control group only analysis of specific IgE and BAT were performed. Correlation of BAT, skin test and specific IgE, respectively, with the clinical history in the allergic group was termed as sensitivity and in the control group as specificity.

RESULTS

Twenty one of 23 (91.3%) bee venom allergic patients and 29 of 34 (85.3%) patients allergic to wasp and hornet venom tested positive in BAT. The overall sensitivity of BAT, specific IgE and skin tests were 87.7, 91.2 and 93.0%, respectively. The overall specificities were 86.7% for BAT and 66.7% for specific IgE. No correlation between the severity of clinical symptoms and the magnitude of basophil activation was observed.

CONCLUSION

The BAT seems to be an appropriate method to identify patients allergic to bee or wasp venom with a comparable sensitivity to standard diagnostic regimens. The higher specificity of BAT as compared with specific IgE makes this test a useful tool in the diagnosis of Hymenoptera venom allergy.

Glucocorticoids enhance interleukin-4 production to neo-antigen (hyaluronidase) in children immunocompromised with cytostatic drugs

Immunoglobulin E (IgE)-mediated immediate-type allergic reactions to hyaluronidase have been observed in children with central nervous system (CNS) tumors. Glucocorticoids, used as therapy for brain edema, are discussed controversially as T helper 2 (Th2) stimulatory factors. In this study we investigated the role of glucocorticoids on a Th2 cytokine-promoting effect in children with CNS tumors. Peripheral blood mononuclear cells (PBMCs) from: 29 children suffering from malignant brain tumors, of whom 23 received short-term glucocorticoid treatment (for 3-4 days) during the course of chemotherapy; 18 children with nephrotic syndrome or renal transplantation receiving long-term glucocorticoid treatment; and 13 healthy children, were incubated with phytohemagglutinin (PHA) and/or anti-CD28 monoclonal antibody (mAb) and, in a second approach, with hyaluronidase. The concentrations of Th cell-mediated cytokines - interleukin (IL)-4, IL-10, and interferon-gamma (IFN-gamma) - were measured in supernatants. The IL-4 production of PBMCs incubated with PHA/anti-CD28 mAb from children with repeated co-administration of glucocorticoids, hyaluronidase, and cytostatic drugs (median: 249.9 pg/ml; range: 234.4-261.7) was significantly higher (p < 0.0001) than IL-4 production of PBMC from children of all the other groups (median: 86.18; range: 16.0-212.5). There was no significant difference in the levels of IL-10 and IFN-gamma within the groups. PBMCs stimulated only with hyaluronidase failed to produce detectable levels of cytokines. The results of this study indicate that repeated co-administration of glucocorticoids and hyaluronidase (a neo-antigen) enhance IL-4 production in vitro and thus may induce the production of specific IgE antibodies in children immunocompromised with cytostatic drugs. Hyaluronidase itself does not stimulate in vitro IL-4 synthesis in PBMCs of children receiving cytostatic drugs.

IgE and T-cell responses to high-molecular weight allergens from bee venom

BACKGROUND

Bee venom contains multiple allergens with a wide distribution of molecular weight. In contrast with conventional bee venom desensitization, peptide or recombinant allergen immunotherapy may have to take into account patients' individual patterns of humoral or cellular response.

OBJECTIVE

To study immunoglobulin (Ig)E and T-cell responses to high-molecular weight bee venom allergens >/= 50 kDa.

METHODS

Bee venom proteins were separated by size exclusion chromatography and fractions were characterized by one and two-dimensional gel electrophoresis. IgE antibody binding to bee venom fractions was analysed by immunoblotting and T-cell responses by proliferation assay.

RESULTS

Among 38 bee venom-hypersensitive patients, IgE recognition pattern of bee venom allergens varied greatly. IgE bound mainly to phospholipase A2 and furthermore to several proteins >/= 50 kDa (50, 54, 69, 84 and 94 kDa). N-terminal sequences of these proteins showed no homology with known proteins. In addition, peripheral mononuclear cells from patients as well as from nonatopic donors strongly proliferated in response to those proteins.

CONCLUSIONS

Although present in low amounts, high-molecular weight allergens from bee venom elicit strong IgE and T-cell responses, and may need to be considered as clinically relevant. Therefore, the development of peptide or recombinant protein-based immunotherapy for bee venom allergy may require careful characterization of such allergens.

The frequency and clinical significance of specific IgE to both wasp (Vespula) and honey-bee (Apis) venoms in the same patient

BACKGROUND

Changeover from Phadebas RAST to Pharmacia AutoCAP increased double-positivity to both honey-bee and common wasp (vespula) venom in our patients.

OBJECTIVE

We examined the frequency of IgE double-positivity, its clinical relevance and utility in investigating potentially allergic patients.

METHODS

One hundred and eighty-two patients with hymenoptera allergy were tested using RAST (n = 51) and AutoCAP (n = 131) assays over 4 years. Patients had a history of reactions to vespulae (22), honey-bee (10) and unidentified hymenoptera (vespinae) (7).

RESULTS

After changing from RAST to AutoCAP double-positivity increased from 10 (5/ 51) to 30% (39/131) (P < 0.01). RAST and CAP assays gave similar median class results (vespula = 3, honey-bee = 2). Thirty-six CAP patients had systemic reactions of Mueller grade II and above. In vespula-allergic double-positive subjects, high CAP classes (> or = class 3) to honey-bee were common (30%). In 25% the CAP classes were equal. In honey-bee-allergic subjects, all vespula venom CAP IgE was low titre (class 1 or 2) and 20% were equal for both venoms. In 43% of vespinae-allergic patients the CAP class was equal to both (class 2 and 3). In contrast, intradermal skin test double-positivity was uncommon. Double-negative skin test results were common in the CAP double-positive population (22% of honey-bee-allergic, 13% of vespula-allergic and 43% of vespinae-allergic patients). Vespula allergic patients have higher bee-venom IgE than vice versa. Twenty-seven per cent of CAP double-positive patients (representing 8% of all venom allergic patients tested over this period) had equal class IgE to both venoms which was not helpful in diagnosis. Combination of skin testing and CAP is unhelpful in only 5/37 (14%) of patients with double-positive serology.

CONCLUSION

If used in isolation CAP may be misleading, especially if only one venom is tested. Identification of the causative venom must utilize both clinical history and skin testing in these double-positive patients, and challenge testing if indicated.

Clinical symptoms and immunologic reactivity to bee and wasp stings in beekeepers

We compared the history of sting reactions with venom skin prick test (SPT) and CAP RAST reactions in beekeepers in order to assess the value of structured questions and symptom backgrounds. The study population consisted of 102 beekeepers, who were 25-75 years of age. Bee and wasp venom SPT was performed with concentrations of 10, 100, and 300 micrograms/ml. The CAP Phadiatop test was used in the screening of IgE antibodies against common inhalant allergens. Forty-two beekeepers had never experienced large local or systemic reactions after a bee sting. Of the 31 subjects with a history of systemic reactions, 13 had experienced these during the previous year. A significant difference (P < 0.01) between systemic reactors and nonreactors was found in bee venom CAP and SPT (300 micrograms/ml). However, due to considerable overlap, these tests are unable to discriminate between allergic and nonallergic beekeepers. Both bee venom SPT (300 micrograms/ml) and CAP tests were positive in 65% of systemic reactors and in 34% of nonreactors (P = 0.008). Venom SPT (300 micrograms/ml) correlated significantly with CAP for both venoms. No correlation was observed between venom allergy and atopy. Clinically, the most practical concentration for evaluating bee and wasp venom sensitization by SPT proved to be 300 micrograms/ml.

Yellow jacket allergy. Comparison of skin prick tests and intradermal tests with three different yellow jacket venom extracts

The aim of the present study was to compare yellow jacket venom extracts from two different companies and to compare skin prick test (SPT) with intradermal test (IDT). IDT and SPT with yellow jacket venom (ALK and Pharmacia Reless) were performed on 54 yellow jacket allergic patients and 44 symptom-free volunteers. Venom was diluted to 300, 100, 10 and 1 microgram/ml for SPT and 10(0), 10(-1), 10(-2), 10(-3) and 10(-4) micrograms/ml for IDT, according to the manufacturers' instructions. Skin tests were performed on both forearms. Both extracts showed approximately the same relationship between sensitivity and specificity, but the Pharmacia Reless yellow jacket venom extract showed a 5-10 fold higher biological activity in both SPT and IDT. Thus yellow jacket venoms of ALK and Pharmacia Reless are not comparable in allergen activity at the same venom concentrations. Using extracts from the same company, SPT and IDT were comparable with regard to sensitivity and specificity at an allergen concentration 1000 times higher for SPT than for IDT.

Reactions to argasid tick bites by island residents on the Great Barrier Reef

OBJECTIVE

To attribute a cause and quantify allergic-like symptoms observed among island residents.

DESIGN

Skin prick tests and intradermal injections with ultraviolet-irradiated, filtered (0.22 microns) whole-body homogenates of the soft tick, Ornithodoros capensis, were used to reproduce experimentally the symptoms observed.

SETTING

Heron Island, Great Barrier Reef, Australia.

PARTICIPANTS

Island residents were designated as such after having spent more than 1 month on the island during the summer seabird breeding season.

INTERVENTIONS

Control measures were instigated using a residual insecticide, delta-methrin, sprayed inside sleeping quarters.

MAIN OUTCOME MEASURES

Acaricide spraying reduced (X2 = 4.42; P less than 0.05) the number of island residents complaining of having been bitten by ticks, yet was considered an inefficient control measure as 67% reported being attacked by ticks after spraying.

RESULTS

Among 97 island residents, elevated total IgE levels were associated with reaction to tick bite in 11 cases (X2 = 27.17; P less than 0.001), but were not of reliable diagnostic value. Symptoms included intense pruritus, blistering (a major feature), erythema, weeping lesions, lymphangitis, dull ache, rheumatic pain and general lassitude, and intense discomfort. Sera from two of four volunteers with known reactions to O. capensis and one of four others with reactions to the Australian paralysis tick, Ixodes holocyclus, cross-reacted with antigens from a total of four of six biting/stinging and non-biting arthropods (radioallergosorbent tests).

CONCLUSIONS

Symptoms associated with reactions to tick bite peaked in severity at 35-40 hours and thus the response was most likely delayed type IV hypersensitivity.

A comparison of two RAST methods and skin prick testing in the diagnosis of wasp venom allergy

With the aim of evaluating the correlation between skin prick test and two radioallergosorbent tests (RAST) using paper (P-RAST) and Al(OH)3 (Al-RAST) as sorbent materials, 45 consecutive patients known to have been stung by wasp within 6 months were examined. Four patients had a normal reaction, four a large local reaction and 37 a systemic reaction. We found a good correlation between a systemic reaction and a positive P-RAST. Fifty-one per cent of patients with a systemic reaction had a negative Al-RAST, whereas only 8% had a negative P-RAST. Eight per cent of patients with a systemic reaction had a negative SPT. In the eight patients without a systemic reaction, the same patient reacted positively in Al-RAST and P-RAST.

Allergy to venom from bee or wasp: the relation between clinical and immunological reactions to insect stings

Sixty-three patients, applying to the casualty ward after a bee or wasp sting, were tested. On the day of admission, and 4 weeks later, blood was sampled to measure specific IgE and IgG against bee and wasp venom and total IgE. Four weeks after the insect sting, all patients were examined with skin-prick test (1, 10 and 100 micrograms/ml), and intracutaneous test (0.05 ml of extract 1.0 microgram/ml). The amount of venom-specific IgE and IgG increased significantly during the 4-week period, venom-specific IgE was most pronounced in patients experiencing the most severe clinical reactions. However, no significant correlations were found between the results of the immunological tests carried out 4 weeks after the insect sting and the clinical reaction upon the insect sting.

Immunotherapy with Hymenoptera venoms. Position paper of the Working Group on Immunotherapy of the European Academy of Allergy and Clinical Immunology

Immunotherapy with Hymenoptera venoms is widely used throughout the world and is accepted as an effective treatment for most patients with Hymenoptera venom allergy. There are, however, still some unresolved problems with this form of treatment. At present there is no definite test which makes it possible to identify patients at risk - and thus candidates for immunotherapy - unequivocally. On the basis of prospective studies on the natural history of Hymenoptera allergy, venom immunotherapy is indicated in adults with severe systemic anaphylaxis. It is usually not necessary in patients with large local reactions only. Children with mild systemic reactions, e.g. urticaria, will need immunotherapy only in case of repeated reactions and/or a high risk of re-exposure. The selection of venoms for immunotherapy may lead to some confusion owing to common antigenic determinants shared by venoms of various Hymenoptera species. Many different regimens for immunotherapy have been proposed. At present, the three main are: rush, stepwise or clustered and classical. The maintenance dose of 100 micrograms usually protects from life-threatening reactions. However, in some patients 200 micrograms are necessary for complete protection. The usual interval between maintenance injections is 4 to 6 weeks. In many patients a strong increase of venom specific serum IgG-antibodies usually parallels clinical protection induced by venom immunotherapy, although many exceptions have been reported. Allergic side effects of venom immunotherapy are not rare, especially with honey bee venom and during the initial phase of dose increase. The question of the duration of venom immunotherapy is handled differently: although some authors recommend treatment for life, most suggest treating patients until skin tests and RAST become negative.

Insect allergy. Predictive value of diagnostic tests: a three-year follow-up study

One hundred and six adults with various reactions to yellow jacket (YJ), honey bee (HB) or unidentified insects (UI) were tested for allergy to insect venoms. For various reasons none received immunotherapy. Individuals completed questionnaires annually for three consecutive years and described sting reactions within the previous season. Ninety subjects completed all the questionnaires and 77 of these were re-tested at the end of the period. Nine out of 25 patients reacted with a systemic reaction when re-stung. High IgE and low IgG venom-specific antibody levels indicated an unfavourable prognosis, since eight of 11 individuals who initially presented venom-specific IgE greater than RAST class 2 and venom-specific IgG below detection limit had systemic reactions at re-sting. No such reactions occurred in subjects with no specific IgE and only one out of six with specific IgE as well as IgG reacted systematically. Skin prick tests (SPT) of less than 3mm with YJ venom 1,000 micrograms/ml excluded later systemic symptoms to stings, whereas larger skin reactions gave an equal chance of systemic or local reactions at re-sting. In individuals not stung by UI, YJ and/or HB the decline in venom-specific IgG and IgE was significant, median values ranging from 41% to 75% over the 3-year period. The decline was unaffected by the type of sting reaction prior to the initial test. SPT results did not change significantly. The findings are relevant when testing patients several years after their last insect sting and the results might indicate that the antibody decline is accompanied by a decrease in clinical sensitivity.

Immunotherapy with yellow jacket venom. A comparative study including three different extracts, one adsorbed to aluminium hydroxide and two unmodified

Thirty-two patients with previous systemic allergic reaction to yellow jacket stings were randomly allocated to three groups receiving immunotherapy with different preparations of yellow jacket venom: 1) extract adsorbed to aluminium hydroxide (Alutard-SQ), 2) Pharmalgen extract or 3) non-adsorbed extract from Allergologisk Laboratorium (ALK aq.). Regular examinations showed a decrease in skin prick test size in nearly all patients. Specific IgE-antibody (RAST and CRIE scores) showed a similar, but not significant tendency to decrease in all three groups. Specific IgG-antibody increased considerably in the Alutard group only; after 2 years, however, no difference could be detected between the three groups. During dose increase, patients treated with ALK aq. generally had smaller local reactions to injections than those treated with Pharmalgen. Few systemic reactions occurred in all three groups. Nineteen patients treated for 2 1/2-3 1/2 years were challenged in-hospital with stings from yellow jackets. No systemic and only minor local reactions occurred. Consequently, with the dose regimens applied all three extracts seem effective even though no common changes in either specific IgE or IgG could be demonstrated.