Insect Allergens Research Articles

Intradermal reactivity to various insect and arachnid allergens among dogs from the southeastern United States

Objective To compare cutaneous reactivity to insect and arachnid allergens in clinically normal (control) and allergic dogs in the southeastern United States. Design Prospective, controlled study. Animals 26 clinically normal dogs and 82 allergic dogs from the southeastern United States. Procedure Intradermal skin testing with various dilutions of 13 insect and arachnid allergens was performed on control dogs to establish skin threshold concentrations (ie, concentrations to which < 25% of the dogs had positive reactions). These established threshold concentrations were then used to test allergic dogs for reactivity. Prevalence of single and multiple insect and arachnid reactions were determined. Results Flea allergen was the only allergen that caused a significantly higher prevalence of positive reactions in allergic dogs than in control dogs. Clinical Implications Flea hypersensitivity is the most important arthropod hypersensitivity in dogs. The importance of reactivity to insect and arachnid allergens other than flea allergen can be determined only when prevalence of positive reactivity has been determined in an appropriate regional control group of dogs. (J Am Vet Med Assoc 1996;209:1431–1434)

Anaphylaxis to the ingestion and inhalation of Tenebrio molitor (mealworm) and Zophobas morio (superworm).

It has been well documented, worldwide, that inhalation and/or contact with airborne particulate insect products has resulted in sensitivity to insect proteins and is manifested by such common entities as dermatitis, conjunctivitis, rhinitis, and asthma. However, the deliberate ingestion of a variety of insects (undertaken to prove their edibility and nutrient value) resulted in subsequent sensitization of some individuals. Such an outcome has not previously been reported in the literature. The objective was to document the anaphylactic reaction to the purposeful ingestion of mealworm in an individual known to be sensitized to the inhalation of beetle larvae. We used the occasion of the Centennial Celebration of The New York Entomological Society to expose members and guests of the Society to the ingestion of various insects. The subjects of the study consisted of: 1) Three members were adversely affected; 2) One individual with Baker's asthma; and 3) A number of controls with no known hypersensitivity to insect products. The investigation was undertaken by food challenges, inhalation challenges, skin testing to the individual insect allergens, a) Tenebrio molitor (TM), b) Zophobas morio (ZM), c) Blattella germanica (BG), skin testing to common indoors and outdoor allergens, and direct bind ELISA and ELISA inhibition. One individual manifesting hypersensitivity both by ingestion and inhalation to mealworm was identified. This sensitivity was documented clinically as well as by objective testing.

Role of complex asparagine-linked glycans in the allergenicity of plant glycoproteins.

Many plant proteins, particularly those found in foods and pollen, are known to act as sensitizing agents in humans upon repeated exposure. Among the cereal flour proteins involved in asthmatic reactions, those members of the alpha-amylase inhibitor family which are glycosylated, polypeptides, BMAI-1, BTAI-CMb*, and WTAI-CM16* are particularly reactive both in vivo and in vitro. We show here that these major glycoprotein allergens carry a single asparagine-linked complex glycan that contains both beta 1-->2 xylose and alpha 1-->3 fucose. Evidence is presented that the xylosyl residue and, to a lesser extent, the fucosyl residue are key IgE-binding epitopes and largely responsible for the allergenicity of these and unrelated proteins from plants and insects. Our results suggest that the involvement of xylose- and fucose-containing complex glycans in allergenic responses may have been underestimated previously; these glycans provide a structural basis to help explain the cross-reactivities often observed between pollen, vegetable food, and insect allergens.

Honey allergy is rare in patients sensitive to pollens

We challenged in a double-blind manner 46 pollen-allergic patients with 30 g of honey and another 32 patients with a placebo (30 g of syrup). Minor, mostly subjective, symptoms were seen in or reported by 26% of those challenged with honey and 41% of those challenged with placebo. In no case could the symptoms with certainty be related to the challenge. Eight commercially available honeys were examined for allergen activity by RAST inhibition and immunospot methods. Both pollen and insect allergen activity was found in all honeys, and they could cause allergic reactions. However, no serious or even obvious reaction occurred in pollen-allergic patients challenged with honey.

Mite and Insect Allergens

This paper aims to present to colleagues as broad a picture as possible within the confines of a reasonable length information about the range of mites and insects known to cause allergy problems. In addition it provides a reference list, and may stimulate thoughts about possible causes for unresolved clinical problems.

Epitope mapping with peptides of Chit I component III and immunomodulation of the Chit immune response

Background: Hemoglobins of the Diptera family are known as aggressive inhalant allergens. Methods: The whole sequence of the insect allergen Chi t I component III was studied for T-cell epitope activity in cell cultures of 15 sensitized patients with a panel of 17 overlapping synthetic peptides and 12 peptides obtained by tryptic cleavage. Results: All but one of the peptides tested were found to be immunogenic. The nonstimulatory sequence 102–109 and two other tryptic peptides (69–90 and 110–135) were used in inhibition experiments. The Chi t I-induced proliferation was downregulated by all tested peptides when compared with stimulation with Chi t I alone. Conclusions: Because stimulation with phytohemagglutinin or tetanus toxoid was not influenced by the above-mentioned peptides, this mechanism seems to be specific for the antigen. Specific immunomodulation with nonstimulating peptides may offer new therapy approaches.

Humoral immune response to the insect allergen Chi t I in aquarists and fish‐food factory workers

Our examination of 225 subjects who had been exposed to the insect allergen Chi t I involved the degree of allergen exposure, the exposure-associated symptoms, and their relationship to the presence of specific IgE and IgG antibodies as well as sensitization to ubiquitous allergens. It could be shown that specific IgE antibodies found in 34% of these subjects were closely associated with symptoms (P < 0.01), whereas no relationship between IgG antibodies and complaints could be observed. Conjunctivitis (63%) and rhinitis (62%) were predominant, followed by asthma (45%) and urticaria (37%). Antibody levels of patients suffering from asthma were highest. In addition, symptoms were associated with the degree of exposure. While nearly all IgE-sensitized subjects of the medium-, high-, and very high-exposure group were symptomatic, only 57% of the sensitized individuals of the low-exposure group reported complaints. Furthermore, specific IgE antibodies were most frequently present in the groups with medium (46%) and high (54.5%) exposure, whereas IgG antibodies predominated in individuals with very high exposure (69.1%). In the low-exposure group, most subjects (73.6%) had neither IgE nor IgG antibodies. In addition, within Chi t I sensitized subjects, sensitization to common allergens and elevated total IgE levels were more frequently present than within non-Chi t I sensitized individuals, indicating a predisposition to allergy.

Validity of skin testing for the diagnosis of food allergy in dogs

One hundred suspected allergic dogs were skin-tested with 9 food extracts, in addition to other inhalant and insect allergens. Forty-eight of the dogs had +2 or greater intradermal reactions to 1 or more food extracts at concentration of 1,000 protein nitrogen units/ml. Thirty of the food extract-positive dogs were fed a restrictive hypoallergenic diet. Of these 30 dogs, 3 improved, then allergy signs worsened when they were challenge-exposed with the original diet. Fifty-two dogs did not have skin test reactivity to any of the 9 food extracts. Of these 52 dogs, 35 were fed a restrictive diet. Six improved, then allergy signs worsened when dogs were challenge-exposed with the original diet. Skin-testing with selected allergenic food extracts was not useful in identifying food-sensitive dogs.

Validity of skin testing for diagnosis of food allergy in dogs

Summary One hundred suspected allergic dogs were skin-tested with 9 food extracts, in addition to other inhalant and insect allergens. Forty-eight of the dogs had +2 or greater intradermal reactions to 1 or more food extracts at concentration of 1,000 protein nitrogen units/ml. Thirty of the food extract-positive dogs were fed a restrictive hypoallergenic diet. Of these 30 dogs, 3 improved, then allergy signs worsened when they were challenge-exposed with the original diet. Fifty-two dogs did not have skin test reactivity to any of the 9 food extracts. Of these 52 dogs, 35 were fed a restrictive diet. Six improved, then allergy signs worsened when dogs were challenge-exposed with the original diet. Skin-testing with selected allergenic food extracts was not useful in identifying food-sensitive dogs.

IgE-Mediated Skin Reaction Among Asthmatic Children in Riyadh

Fifty-five asthmatic children aged 6-13 years attending a pediatric allergy clinic were skin tested with a panel of 35 inhalant commercial allergens. The allergen extracts were grouped into pollen including trees, grasses and weeds, fungal spores, insect, animal and other indoor allergens. Thirty-five (63.6%) of the asthmatic children had one or more positive skin reactions. Reactions were most common, and strongest to the indoor and animal panel and to pollens. Fungal reactions were less common and weaker. This represents a lower proportion of skin test-positive asthmatic children than other Western countries. This might relate either to the presence of asthma without atopy, lack of exposure to potential allergens, or lack of appropriate antigens relevant to the disease in the skin test panel.

Histamine Release from Human Basophils by the Insect Allergen Chi t I

Hemoglobins of the Diptera species Chironomus thummi thummi (Chi t I) are potent inhalant allergens. Chi t I-specific histamine release was measured by a new radioimmunoassay in whole human blood taken from 20 sensitized patients, 11 exposed nonsensitized probands, and 11 nonexposed controls. The sensitized patients, who all had positive skin tests and radioallergosorbent test results with Chi t I, showed a significantly higher histamine release than the two other groups. However, within the patient group, the percentage of released histamine did not correlate with the intensity of the skin test response or the concentration of Chi t I-specific IgE antibodies. Our results demonstrate that this method is a sensitive and specific in vitro test for evaluation of IgE-mediated sensitization.

Immunochemical Demonstration of Red Oak Pollen Aeroallergens outside the Oak Pollination Season

Abstract Airborne red oak (Quercus rubra) allergens were collected with volumetric air samplers during 1983–1985 and quantitated immunochemically using red oak pollen proteins adsorbed to plastic microtiter plates and pooled IgE-containing sera from seven oak-sensitive persons. Peak levels of allergen occurred in late April to early May and coincided with peak oak pollen counts from Rotoslide collections. However, additional peaks of oak allergenic activity were measured during July through early October, at times when oak pollen was not airborne. Most of the allergen was in particles smaller than 5 microns even during the pollination period. These peaks coincided with changes in wind from the usual northwest direction to a southernly direction. Among 19 other tree, grass, weed, mold, or insect allergens tested, only birch, and, to a lesser extent, willow, cross-reacted with red oak. We postulate that bits of decaying leaves, male catkins during the summer and early fall and other plant particles become airborne during changes in wind direction and velocity. Because other allergens, such as ragweed, Alternaria, grass and insects, are also abundant in late summer and fall, it will be very difficult to determine the degree to which this oak allergen contributes to late summer hay fever and asthma.

Cross-reactivity of IgE antibodies to caddis fly with arthropoda and mollusca

We investigated the possibility that subjects with IgE antibodies to an inhalant insect allergen, such as caddis fly, might also have antibodies to cross-reacting carbohydrate determinants (CCDs). IgE antibodies to cross-reacting allergens in caddis flies, mussels, oysters, shrimps, crabs, honeybee, and yellow jacket venoms were determined by RAST, RAST inhibition, and immunoblot studies with sera from three different sources: (1) sera of patients with well-defined inhalant atopy to caddis fly, (2) sera with IgE anti-CCD antibodies from subjects without known exposure to caddis fly, and (3) hyperimmune antisera with IgG anti-CCD antibodies raised as a result of immunization of rabbits with grass-pollen extract, buckwheat glycoprotein, or with honeybee venom. Sera from groups 2 and 3 reacted with Sepharose-coupled caddis fly extract in a RAST-type assay and elicited virtually identical patterns on immunoblots of caddis fly extract separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas the sera from group 1 atopic patients did not react with CCD-rich material. However, indications for other types of cross-reacting antibodies were detected. The IgE antibodies of one of the patients studied (who was allergic not only to caddis fly but also to shellfish) were found to detect a cross-reacting homologous protein in extracts of mussel, oyster, shrimp, crab, honeybee, and yellow jacket venom. Preliminary results suggest that this cross-reacting 13 kd protein, the most prominent caddis fly allergen, is an invertebrate hemoglobin (erythrocruorin)-like molecule. These studies suggest the possibility that patients sensitized by exposure to caddis fly antigens could develop allergic reactions during their first exposure to shellfish or to their first bee sting.

Aeroallergens in dairy barns near Cooperstown, New York and Rochester, Minnesota.

We sampled atmospheric barn air using a volumetric air sampler in ten barns near Cooperstown, NY and six barns near Rochester, MN, and, with radioimmunoassays, measured allergens of Aspergillus fumigatus, Thermoactinomyces vulgaris, Micropolyspori faeni, short ragweed, rye grass group I pollen, Alternaria (Alt-1), Dermatophagoides sp. Lepidoglyphus destructor, common insect allergen, mouse urine, rat urine, and cattle epithelium. The most abundant allergen present was A. fumigatus followed by L. destructor. This study provides initial data on barn aerobiology and demonstrates for the first time the abundance of L. destructor allergens in North American dairy barns. More comprehensive study of barns, poultry houses, confinement houses for swine, and other agricultural environments from various geographic locations is needed to define the allergen levels to which millions of farm workers are exposed each day. While most of the allergens were expected, the presence of airborne allergens reactive with antisera to Dermatophagoides suggests indirectly that substantial amounts of pyroglyphid mites are present in some barns.

Allergens of the imported fire ant

A whole body extact (WBE) was prepared by saline extraction of ground imported fire ants (IFA). A serum pool from rabbits immunized with the WBE elicited 31 precipitates on crossed immunoelectrophoresis. Crossed radioimmunoelectrophoresis was performed with sera from 26 RAST IFA-positive subjects, 24 of whom were known for clinical hypersensitivity to IFA and two subjects, known to be hypersensitive to yellow jacket. Radiostaining was obtained to 14 precipitates, some of which were judged to be partially identical. Thus, six apparently different allergen groups could be identified. Two of these fulfilled arbitrary criteria of major allergens. Three of the IFA WBE allergens were easily identified in crossed immunoelectrophoresis of a commercially obtained IFA-venom preparation. Sodium dodecyl sulfate-poly acrylamide gel electrophoresis of the IFA WBE demonstrated protein bands with molecular weight ranging from 10,000 to 200,000 daltons. An immunoblotting technique with nitrocellulose paper strips revealed binding of human IgE from hypersensitive subjects to four different bands (either single bands or clusters of proteins of similar molecular weight) with molecular weights ranging from 13,000 to 42,000 daltons. It is a notable finding that these insect allergens thus were of a similar size as important aeroallergens.

Epitope mapping of major insect allergens (chironomid hemoglobins) with monoclonal antibodies

Monoclonal antibodies (m ABs) were raised against the physically and chemically well-defined insect allergen, component CTT III from Chironomus thummi thummi (CTT) hemoglobin. With these m ABs, we observed epitopes present in as many different hemoglobin (Hb) molecules from the widespread insect family Chironomidae as possible. These Hbs were identified as important allergens in previous studies. Twenty m ABs from seven different clones were tested for specificity against the CTT Hbs III, IIIa, IV, and I to X, as well as against Hbs from 14 other chironomid species; m ABs 1 to 3 were found to be specific for an epitope that was expressed on the CTT III component as well as in Hbs from three other species. m ABs 5 to 7 and 15 recognized an epitope expressed in CTT III, CTT IIIa, CTT IV, and in Hbs from 13 other species. m ABs 8 to 14 and 16 to 20 demonstrated heteroclitic behavior, that is, they bound CTT IIIa better than the immunogen CTT III. Reactivity of m AB 6 with a clinically relevant epitope was demonstrated by up to 15% inhibition of antibody binding by human IgE from sensitized patients. Our results demonstrate that clinically relevant allergenic epitopes can be localized on different molecules with m ABs. This could be important in the development of immunotherapy protocols with highly purified or fragmented allergens.

Allergy to insects in Japan: III. High frequency of IgE antibody responses to insects (moth, butterfly, caddis fly, and chironomid) in patients with bronchial asthma and immunochemical quantitation of the insect-related airborne particles smaller than 10 μm in diameter

After recognizing that moth, butterfly, caddis fly, and chironomid were the insects predominantly found in our environment, reaginic sensitivities to these insects in patients with asthma were investigated with extracts of silkworm wing for the detection of moth and/or butterfly allergy, caddis fly wing for caddis fly allergy, and chironomid whole body for chironomid allergy. At least 50% of 56 randomly selected patients with asthma had positive intracutaneous reactions to these insect extracts, and at least 80% of the skin reaction positive patients had specific IgE antibodies. An immunochemical assay of these insect-related aeroallergens in the dust collected 18.6 m above ground revealed the presence in the air of insect-related particles <10 μm in diameter with two peaks a year, one in the spring (silkworm wing, 3.18 ng protein equivalent to that of the crude extract per cubic meter of air; caddis fly wing, 3.08 ng/m 3; and chironomid whole body, 5.21 ng/m 3) and one in the autumn (silkworm wing, 8.24 ng/m 3; caddis fly wing, 4.74 ng/m 3; and chironomid whole body, 18.19 ng/m 3). Although we have no idea whether or not such peak values are enough to cause asthmatic symptoms, seasonal fluctuations of specific IgE antibodies to these insects appeared to be similar to those of atmospheric insect allergens measured by this method. These findings suggest that insects are widespread and common inhalant allergens.

Allergy to biting insects.

Allergic reactions to biting insects mediated by IgE antibodies are generally considered to be relatively uncommon. There are only a handful of convincing reports in the literature of reactions to bites of mosquitoes and fleas. A small number of cases of allergy to bites of other flies have been reported as well as 2 cases of bedbug allergy. The biting insect that was most commonly cited as causing the allergic reactions reported in the literature and in the Registry of Reactions to Insect Bites run by the Committee on Insect Allergy of the American Academy of Allergy and Immunology was the kissing bug (Triatoma spp, also called reduviid bug and cone-nose bug). 1 Two recent studies performed in a community that contained prime habitat for Triatoma demonstrated a prevalence of IgE antibodies against Triatoma protracta in 6.7% of the population studied. 2 In the same population 3.3% demonstrated IgE antibodies to honeybee and/or yellow jacket venom. 3 Most of the literature on biting insect allergy consists of case reports or summaries of uncontrolled clinical experiences, so that it is very difficult to evaluate critically. There are, however, classic studies of bite reactions in animals by Feinberg et al, 4 and modern scientific investigation of true allergy to flea bites in dogs is now being initiated. 5 In this review we will examine the following: how saliva (oral secretion) antigens can be obtained from biting insects; the normal spectrum of reactions to insect bites; a critical evaluation of reports of allergy to bites from various types of insects; biting insect allergens, the relationship to stinging insect allergy; and the treatment and prevention of reactions.

Dermal reactivity to histamine, serotonin and bradykinin in relation to allergic skin reactions of the horse.

The reactivity of horse skin to intradermal inoculation of histamine, serotonin and bradykinin was investigated, and the resulting reactions compared with those produced in the same horses by a 1% whole-body extract of Culicoides. Both histamine and bradykinin produced large reactions, but there was no significant correlation between the dermal responsiveness to insect allergen and either histamine or bradykinin. Two anti-histamine drugs (promethazine hydrochloride and tripelennamine hydrochloride) were effective in reducing the reaction produced by the insect extract.

Inhalant allergy following occupational exposure to blowflies

An allergic reaction, provoked by exposure to the blowfly Lucilia cuprina and shown to be IgE-mediated, occurred in a subject employed in an entomological research laboratory. The subject's serum, and sera from three other asthmatic patients with IgE antibodies to blowfly extracts, also reacted with extracts from the screw-worm fly (Chrysomya bezziana). Results suggested that antigens from the two species share immunological cross-reactivity. Cross-reactions also exist between the different developmental stages of both species. Allergic reactions to inhaled insect allergens may not be uncommon in the Australian community.