Immunochemical quantitation, size distribution, and cross-reactivity of lepidoptera (moth) aeroallergens in southeastern Minnesota

Mosquito allergy: Immunological aspects and clinical management

Mosquito allergy has been conceived as the cutaneous reactions that appears during and after mosquito biting process; a perception that is supported by several scientific research. Additional data have led to conceive that other manifestations of allergic responses may occur as a cause of the exposure to somatic mosquito allergens. Two main phenotypes of mosquito allergy are identifiable: the cutaneous allergic reactions, induced by salivary allergens, and other manifestations of the allergic responses such as asthma and allergic rhino conjunctivitis that are caused by somatic allergens. The cutaneous reactions have kept the focus of attention of the scientific community. It appears as skin lesions that resembles the phenotype of papular urticaria with a defined natural history of the disease. Although these two phenotypes of mosquito allergy seem to be well differentiated in terms of the allergens that are involved and the routes of exposures, other factors such as geographical distribution, may participate. Mosquitoes have adapted to the host immune response against bites, producing immunomodulatory molecules that counteract such defensive response. The role that the immunomodulatory molecules have on the allergic immune response has not been studied yet and it is still not known if affects all mosquito allergy phenotypes. Only a few studies of allergen specific immunotherapy for cutaneous allergic reactions induced by mosquito bites have been done, and none for respiratory allergic responses. The clinical practice focuses on symptom management and avoiding mosquito bites as much as possible. Avoiding mosquitoes, using different well described methods, is still the best option to limit contact with these insects. The lack of knowledge of mosquito allergy have raised several questions that affects the clinical management of this allergic disease, from its diagnosis, prevention and immunotherapy.

Prevalence of inhaled allergen-specific IgE antibody positivity in the healthy Japanese population

BACKGROUND

Measurement of allergen-specific IgE antibodies to inhaled allergens is important for the diagnosis and risk evaluation of allergic diseases such as asthma and allergic rhinitis. This study aimed to elucidate the prevalence of allergen sensitization among the healthy population in Japan using serum samples stocked in the Japanese Red Cross for blood donation.

METHODS

Age- and gender-stratified serum samples (n = 800) from residents in Tokyo aged 20-59 years were randomly selected from the stocked serum obtained for blood donation in 2005. Total and specific IgE antibodies to 17 inhaled allergens were measured by the ImmunoCAP method. Individuals with positive (≥0.35 U_A/mL) specific IgE antibodies to at least one inhaled allergen were defined as atopic. Stocked serums from donors aged 20-29 years in Sapporo, Osaka, Fukuoka, and Okinawa (n = 200 each) were also obtained for the measurement of IgE to six common inhaled allergens, to evaluate regional differences in the rate of positivity.

RESULTS

Among residents in Tokyo, the prevalence of atopy was 78.0% and highest in men aged 20-29 years (94.0%), which decreased with age. The prevalence of specific IgE antibodies was highest for Japanese cedar pollen (66.8%), followed by cypress pollen (46.8%), Dermatophagoides pteronyssinus (38.3%), and moths (30.1%). Examination of IgE to Japanese cedar pollen, D. pteronyssinus, and moths identified 97.6% of atopic subjects in Tokyo. There were substantial regional differences in the prevalence of pollen IgE positivity.

CONCLUSIONS

This study demonstrated an extremely high prevalence of positivity in inhaled allergen-specific IgE antibodies among healthy adults in Japan.

Mosquitoes: Important Sources of Allergens in the Tropics

There are more than 3,000 mosquito species. Aedes aegypti, Ae. communis, and C. quinquefasciatus are, among others, three of the most important mosquito allergen sources in the tropics, western, and industrialized countries. Several individuals are sensitized to mosquito allergens, but the epidemiological data indicates that the frequency of sensitization markedly differs depending on the geographical region. Additionally, the geographical localization of mosquito species has been affected by global warming and some mosquito species have invaded areas where they were not previously found, at the same time as other species have been displaced. This phenomenon has repercussions in the pathogenesis and the accuracy of the diagnosis of mosquito allergy. Allergic individuals are sensitized to mosquito allergens from two origins: saliva and body allergens. Exposure to saliva allergens occurs during mosquito bite and induces cutaneous allergic reactions. Experimental and clinical data suggest that body allergens mediate different manifestations of allergic reactions such as asthma and rhinitis. The most studied mosquito species is Ae. aegypti, from which four and five allergens of the saliva and body, respectively, have been reported. Many characterized allergens are homologs to arthropod-derived allergens, which cause strong cross-reactivity at the humoral and cellular level. The generalized use of whole body Ae. communis or C. quinquefasciatus extracts complicates the diagnosis of mosquito allergy because they have low concentration of saliva allergens and may result in poor diagnosis of the affected population when other species are the primary sensitizer. This review article discusses the current knowledge about mosquito allergy, allergens, cross-reactivity, and proposals of component resolved approaches based on mixtures of purified recombinant allergens to replace saliva-based or whole-body extracts, in order to perform an accurate diagnosis of allergy induced by mosquito allergen exposure.

Respiratory sensitization to insect allergens: Species, components and clinical symptoms

Airborne insect particles have been identified as an important cause of respiratory allergies, including allergic asthma and rhinitis. In the literature, the significance of respiratory exposure to insect particles as a cause of occupational allergy has been well-documented. Indeed, many cases of occupational allergy have been reported including allergy to the larvae of flies and moths in anglers and occupationally exposed workers, to grain pests in bakers or other workers handling grains, and to crickets and/or locusts in researchers and workers in aquaculture companies. Furthermore, the prevalence of sensitization to insect allergens is considerably high among patients with asthma and/or rhinitis who are not occupationally exposed to insects, suggesting the clinical relevance of exposure to insects in indoor and outdoor environmental non-occupational settings. Exposure to cockroaches, a well-studied indoor insect, is associated with cockroach sensitization and the development and exacerbation of asthma. Booklice, another common indoor insect, were recently identified as a significant sensitizer of asthmatic patients in Japan and India, and potentially of asthma patients living in warm and humid climates around the world. Lip b 1 was identified as an allergenic protein contributing to the species-specific sensitization to booklice. Moths are considered a significant seasonal outdoor allergen and their allergens are considered to have the highest sensitization rate among Japanese patients. However, other than cockroaches, allergenic insect proteins contributing to sensitization have not been fully characterized to date.

Identification of the major allergenic proteins from silkworm moth (Bombyx mori) involved in respiratory allergic diseases

INTRODUCTION AND OBJECTIVES

Moths are a significant source of indoor and outdoor aeroallergens. High prevalence of IgE-mediated sensitization was demonstrated in a group of patients with allergic respiratory diseases. There are no studies on adult stage of these moth species allergens involved in allergic respiratory reactions - the aim of this study.

MATERIAL AND METHODS

36 participants were included in an experimental study, submitted to skin prick test with Bombyx mori wing extract and six other common allergens, as well as Western blot analysis with incubated nitrocellulose membrane impregnated with silkworm moth extract and human IgE-antibody. The participants were divided into 3 groups: 1) 21 allergic patients whose skin prick test was positive to Bombyx mori wing extract, 2) eight allergic patients whose skin prick test was positive to mite and negative to Bombyx mori extract 3) seven negative non-allergic subjects.

RESULTS

Among the 21 participants from group 1, 19 serum samples reacted to Bombyx mori extract by Western blot. All of them reacted to a protein at 80 kDa and five other proteins (66, 50, 45, 37 and 30 kDa) were identified in more than 50% of the individuals tested, considered as major allergenic proteins. Sera from seven out of eight patients sensitized to house dust mite demonstrated IgE-reactivity to Bombyx mori extract by Western blot analysis. Serum samples from healthy participants did not react at all.

CONCLUSION

Six major reactive proteins by immunoblot analysis from moth's wings sensitized patients can be potential allergens. The one at 80 kDa is the major protein, seen in all IgE-reactive patients from group 1 and in none from group 2, yet to be identified. Future studies should be conducted to better characterize these proteins.

A review on Respiratory allergy caused by insects

Hypersensitivity or allergy encompasses a wide range of immunological reactions that generally have adverse consequences involving one or many organ systems of the body. Allergens are usually glycoprotein or chemically complex low molecular weight substances. The common allergens include pollen, fungal spores, house dust mite and house dust, animal danders, drugs, foods, insect emanations, and detritus, etc. Information on the role of insects in respiratory allergy is increasing in the literature. There are about 30 million living species of insects. These insects can broadly be classified as stinging insects, biting insects and non-stinging and non-biting insects. All materials form insets namely wings, scales, saliva; dried feces and venom can cause allergic diseases, such as rhinitis, conjunctivitis, asthma and urticaria. There are wide varieties of insects such as moths, butterflies, bees, wasps, hornets, yellow jackets, flies, beetles, cockroaches, and mosquitoes. Exposure to emanations and detritus of these insects may lead to several allergies in some genetically predisposed individuals. Therefore, it is of interest to review allergies caused by various insect's stings and bites and their adverse effect on the human body.

Immunological aspects of the immune response induced by mosquito allergens

Allergies caused by mosquito bites may produce local or systemic reactions. The inhalation of mosquito allergens may also cause asthma and/or allergic rhinoconjunctivitis in sensitized individuals. The mechanisms implicated in the development of these immune responses involve IgE antibodies, different subtypes of IgG and proinflammatory cytokines as well as basophils, eosinophils and mast cells. Several allergenic components have been identified in the saliva and bodies of mosquitoes and some of these are present in different mosquito species. The most common species implicated in allergic reactions belong to the genera Aedes, Culex and Anopheles. Several Aedes aegypti allergens have been cloned and sequenced. The recombinant molecules show IgE reactivity similar to that of the native allergens, making them good candidates for the diagnosis of mosquito allergies. Allergen-specific immunotherapy with mosquito extracts induces a protective response characterized by a decreased production of IgE antibodies, increased IgG levels, a reduction in the severity of cutaneous and respiratory symptoms and the need for medication. The aims of this review are to summarize the progress made in the characterization of mosquito allergens and discuss the types of immune responses induced by mosquito bites and the inhalation of mosquito allergens in atopic individuals.

Respiratory allergy to moth: the importance of sensitization to Bombyx mori in children with asthma and rhinitis

OBJECTIVE

this study aimed to prepare a silkworm moth (Bombyx mori) antigenic extract and to perform skin prick tests with this extract in patients with allergic respiratory diseases; to evaluate serum specific immunoglobulin E (IgE) to Bombyx mori using ImmunoCAP® system and to report the frequency of positivity between the two methods and with clinical data.

METHODS

this was a cross-sectional study with 99 children and adolescents diagnosed with asthma and/or allergic rhinitis, who had skin reactivity to at least one of the six aeroallergens tested. Clinical data were evaluated: skin prick tests with Bombyx mori in-house extract, and total and specific IgE analysis using ImmunoCAP® were performed.

RESULTS

the frequency of Bombyx mori specific IgE was found to be 52.5% and 60% using the skin prick test and ImmunoCAP®, respectively. An association between a positive skin test for Bombyx mori and the presence of allergic rhinitis, atopic dermatitis, and urticaria was observed, but the same was not true for asthma or allergic conjunctivitis. There was no relation with the severity of asthma or rhinitis symptoms.

CONCLUSIONS

a high frequency of sensitization to Bombyx mori was observed in a selected population of patients with respiratory allergic diseases in the city of Curitiba, state of Paraná, Brazil. The extract prepared from the wings of this moth species is effective in demonstrating this sensitivity.

Pharaoh ant (Monomorium pharaonis): newly identified important inhalant allergens in bronchial asthma

The nonstinging house ant, Monomorium pharaonis (pharaoh ant), was recently identified as a cause of respiratory allergy. This study was performed to evaluate the extent of sensitization to pharaoh ant, and its clinical significance in asthmatic patients. We carried out skin prick tests in 318 patients with asthma. Specific IgE (sIgE) to pharaoh ant was measured by ELISA, and cross-reactivity was evaluated by ELISA inhibition tests. Bronchial provocation testing was performed using pharaoh ant extracts. Fifty-eight (18.2%) of 318 patients showed positive skin responses to pharaoh ant, and 25 (7.9%) had an isolated response to pharaoh ant. Positive skin responses to pharaoh ant were significantly higher among patients with non-atopic asthma than among those with atopic asthma (26.0% vs. 14.9%, p<0.05). There was significant correlation between sIgE level and skin responses to pharaoh ant (rho=0.552, p<0.001). The ELISA inhibition tests indicated that pharaoh ant allergens had various pattern of cross-reactivity to house dust mites and cockroaches. Bronchial provocation tests to pharaoh ant were conducted for 9 patients, and eight showed typical asthmatic reactions. In conclusion, pharaoh ant is an important source of aeroallergens, and it should be included in the skin test battery for screening the causative allergens in patients with asthma.

Insect and arachnid hypersensitivity

Insect hypersensitivity reactions can have a large number of clinical presentations. The majority of reactions are pruritic and involve the short- or sparsely haired areas of the body. Most are associated with eosinophilic infiltration into the skin, often in a perivascular pattern. The diagnosis may be based on compatible clinical signs and improvement with aggressive insect control and, in some cases, confirmation via provocative exposure. Intradermal, prick, or serum testing for allergen-specific IgE can be used to document the presence of reaginic antibodies against insect allergens. Treatments include avoidance, aggressive insect control, and symptomatic support; in some cases, immunotherapy may be useful in decreasing the severity of clinical reactions to insects.

Evaluation of four bioaerosol samplers in the outdoor environment

INTRODUCTION

A comparative evaluation of four air samplers was performed using bioaerosol collection in the outdoor environment.

METHODS

Test samplers used included a Rotorod, a Kramer-Collins suction trap, an all-glass impinger (AGI-30), and a high-volume cyclonic liquid impinger (SpinCon). All samples were analyzed microscopically for spores and pollen. The two collectors providing a liquid sample (AGI-30 and SpinCon) also were analyzed for specific allergen content by enzyme-linked immunoassay.

RESULTS

The SpinCon collected a larger number of spores than the other devices. The number of spores collected by this unit per volume of air sampled was comparable to the AGI-30. The Rotorod and Kramer-Collins collected a lower number of spores per unit of air but collected a larger number of pollen grains per volume sampled. Alternaria allergens Alt a I and GP70 were collected by both liquid impingers; however, the SpinCon collected more Alt a I and the AGI-30 collected more GP70.

CONCLUSIONS

The SpinCon is a device that is capable of efficiently sampling a high volume of air and concentrating it in a form that can be analyzed for the presence of spores and fungal allergens. It is less useful for collecting intact pollen grains. Pollen allergen quantitation has not yet been performed on the SpinCon effluent.

Role of insects as inhalant allergens in bronchial asthma with special reference to the clinical characteristics of patients

The whole body extracts (WBEs) of 13 common insects from Delhi, namely Musca domestica (house fly); Sitophilus oryzae (rice weevil); Callosobrochous maculatus (pulse beetle); Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti (mosquitoes); Blattella germanica and Periplaneta americana (cockroaches: male, female and nymph); Spodoptera litura and Heliothis armigera (moths), were prepared to evaluate their allergenic significance in patients with allergic bronchial asthma. Intradermal (ID) tests were performed with these WBEs on 75 patients with bronchial asthma and 20 healthy non-allergic volunteers. An ID test was considered positive when the weal diameter was more than twice that of phosphate-buffered saline control and at least 6 mm in size and an erythema of more than 15 mm. In the patients 27.7% of the ID tests performed were total positive (1+ to 4+) as compared to 7.1% in the controls. Ten point two per cent of ID responses were markedly positive in asthmatics (2+ to 4+) as against none in controls. Of the 13 bronchial provocation tests (BPTs) performed on patients giving positive cutaneous responses, eight (61.5%) were positive. Similarly, RASTs were positive in 87.5% of the limited sera tested from the patients with positive ID responses. The patients with a positive family history of allergic disorders gave higher percentages of positive ID responses as compared to the asthmatics with no family history. Similarly, the ID positivity was significantly higher in patients with associated allergic diseases like allergic rhinitis as compared to the patients with bronchial asthma alone. Interestingly, we observed significantly higher ID response to insects in seasonal asthmatics.(ABSTRACT TRUNCATED AT 250 WORDS)