Storage mites

The interest in allergy to storage mites has increased over the past few years. Storage mites feed on a variety of substances and they can be found in many different products such as grain, flour, hay and straw, but also in house dust samples. The more common genera areLepidoglyphus, Tyrophagus, Glycyphagus, Acarus andBlomia. Several species of storage mites have been shown to cause IgE-mediated sensitization among rural workers, who to a varying extent develop asthma, rhinitis or conjunctivitis when exposed to barn dust. However, a number of studies, have reported on sensitization to storage mites also among urban people, indicating that sensitization is not restricted to individuals with occupational exposure. Regarding the allergenic relationship between storage mites and house dust mites, there appears to be a limited allergenic cross-reactivity between the two species. However, both species also possess their own unique allergens. Further research on identification and characterization of storage mite allergens and their cross-reactivity is required to understand the complexity of epitopes and allergens.     

Effectiveness of benzyl benzoate in elimination of house dust mites

The effect of elimination treatment with benzyl benzoate was examined in 30 adults with asthma caused by sensitivity to house dust mites. The patients were randomised into a control and an active group, who treated their mattresses with benzyl benzoate (Acarosan^®). The study lasted 12 months and the effect of the treatment was monitored by monthly dust sampling, analyzed for major allergens fromDermatophagoides pteronyssinus andfarinae by the ELISA method and for guanine by the Acarex^® method. The clinical effect was assessed by measuring lung function, daily peak flows, symptoms and medicine consumption as well as skin prick tests, and specific IgE to mite allergens. For both groups, a significant decrease was observed in house dust mite allergens, but there was no significant difference between the groups. No considerable differences were observed in clinical parameters within or between the groups. A good correlation was observed between ELISA and Acarex^®. but the latter showed a major variation in the different classes. In conclusion. treatment of mattresses with benzyl benzoate had no effect in a group of patients with asthma due to house dust mite allergy. Regular vacuum cleaning of the bed may reduce house dust mite allergen exposure.     

Allergenic mites (Acariformes, Pyroglyphidae) in house dust

Paper is the second part of the literature review on house dust mites (including 1985). It deals with the diagnosis of the dust mite allergy, the nature of the mite allergens, distribution and population density of the mites in various premises, seasonal population dynamics and population age structure of the dermatophagoid mites, life cycle and breeding of Dermatophagoides pteronyssinus and D. farinae on different food substrates. The methods of the house dust mite control are discussed. The original data on the house dust mite distribution in Moscow is shown. A comparative estimation of the results of mite antigens in the house dust discovering by the acarological and three immunological methods are given.     

IgE reactivity to Acarus siro extract in Korean dust mite allergic patients

Although specific IgE to the storage mite Acarus siro is often detected, there are no detailed studies on IgE reactivity to A. siro in Korea. This study was undertaken to investigate the cross-reactivity to the mite species Dermatophagoides pteronyssinus, Dermatophagoides farinae, Tyrophagus putrescentiae, and A. siro in Korean mite allergic patients. Specific IgE values were determined for the four mite species and a competitive inhibition test was performed for mite extracts using the ImmunoCAP system. The IgE value to D. farinae was the highest among the four mite species tested. There was a strong correlation in the IgE value between house dust mites (D. pteronyssinus and D. farinae) and between storage mites (A. siro and T. putrescentiae). IgE reactivity to A. siro was inhibited by D. farinae and T. putrescentiae extract. Dermatophagoides farinae extract was the strongest inhibitor of IgE binding to A. siro extract, indicating that IgE reactivity to A. siro extract is a cross-reaction caused by sensitization to D. farinae. Strong IgE reactive components were observed in D. farinae and T. putrescentiae extract by SDS-PAGE and IgE immunoblotting. However, no strong IgE-binding component was observed for A. siro. Dermatophagoides farinae is the main source of mite allergens that cause sensitization in Korea. Serum IgE from some of the house dust mite-sensitized patients showed positive responses to storage mite allergens by cross-reaction. Therefore, it is necessary to pay special attention to the diagnosis of mite allergies.     

Molecular cloning and the allergenic characterization of tropomyosin from Tyrophagus putrescentiae

Storage mites have been recognized as a cause of asthma and rhinitis. Studies from several countries have shown that the IgE-mediated allergy to storage mites is of considerable importance, especially in rural populations. This study aimed to identify and characterize new allergens from Tyrophagus putrescentiae. A partial cDNA sequence encoding tropomyosin was isolated from the cDNA library by immunoscreening using anti-mouse IgG1 sera raised against T. putrescentiae whole body extract. The deduced amino acid sequence shares 64-94% identity with previously known allergenic tropomyosins. Its recombinant protein was produced by using a pET 28b expression system and purified by affinity chromatography using Ni-NTA agarose. The IgE reactivities of tropomyosins from T. putrescentiae and Dermatophagoides farinae were compared by enzyme linked immunosorbent assay (ELISA). Recombinant Tyr p 10 showed 12.5% (5/40) IgE-binding reactivity, whereas recombinant Der f 10 showed 25% (10/40) IgE-binding reactivity against the same sera from storage mite-sensitized and house dust mite-sensitized subjects. Both recombinant Tyr p 10 and Der f 10 showed little inhibition of IgE binding to T. putrescentiae crude extract by ELISA. Tropomyosin seems to contribute only a small portion of the cross-reactivity with house dust mites.     

Methods of assessment and control of house dust mites population and mite allergen exposure

The work is devoted to analysis of various methods of assessment and control of house dust mites population and mite allergens in city dwellings using own results and the literature data. Data about in-house dust mites biology and ecology, mechanisms of their migration and circulation in modern city conditions are presented. The comparison of several methods of mites number assessment and mite allergens exposure (classical acarological analysis, colorimetric method of guanine detection in house dust, immunochemical methods) has been performed and their advantages and disadvantages analyzed. As choice of adequate avoidance measures is one of the key question, various such measures (mechanical, physical and chemical) have been compared.     

Structural biology of mite allergens

Mite allergens contribute to a significant proportion of human allergic symptoms, including asthma and rhinitis. The development of therapies to treat and prevent these symptoms depends largely on our understanding of the properties of these allergens. Much effort has been devoted to determining the structure and organization of mite allergens, particularly of the house dust mites, toward understanding their activities and how they elicit immunological responses in humans. Here, we review the structural biology of the major allergens from two species of house dust mites, Dermatophagoides farinae and D. pteronyssinus, as well as allergens from a storage mite, Blomia tropicalis. The knowledge gained from the structural biology of these allergens will enable progress in producing novel, more effective treatments for mite allergies based on specific immunotherapy approaches.     

House dust mite allergens in domestic homes in Cheonan, Korea

House dust mites produce inhalant allergens of importance to allergic patients. We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea. Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home. Der p 1 and Der f 1 were measured by double monoclonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being 0.11 microgram/g (range: 0.01-4.05) and 0.14 microgram/g (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, 7.46 microgram/g (range: 0.01-262.9) and 10.2 microgram/g (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.     

The colonisation of new houses by house dust mites (Acari: Pyroglyphidae)

House dust mites,Dermatophagoides species (Acari: Pyroglyphidae), produce allergens, known for the provocation of asthma and other allergic reactions. To determine the time needed for complete colonisation of a new house by house dust mites, dust samples were collected from carpets of houses varying from 2 weeks to 2 years in age. In contrast to the expectation, no relation was found between age of the houses on the one hand and average levels of mite-allergensDer pI andDer pII and mite numbers on the other. However, presence of dogs appeared to be positively related to allergen levels. Furthermore, carpets in bedrooms appeared to contain more allergens than carpets in living-rooms. Finally, the age of the mattress was not related to allergen levels of bedroom floors.     

Clinical Significance of Skin Reactions to Mite Extracts in Children with Asthma

The mite Dermatophagoides pteronyssinus has been identified in dust from the houses of children in Birmingham suffering from asthma. Skin tests were carried out on 150 asthmatic children with extracts of D. pteronyssinus, of the related species D. farinae, of other mites found in house dust, and of crude house dust. Though positive reactions to D. pteronyssinus were obtained more frequently and were of greater size than those to the other extracts, it was considered that D. farinae is a suitable substitute for D. pteronyssinus for skin testing.In further tests on 302 asthmatic children with mite extracts and with extracts of allergens obtained commercially reactions to the former extracts were much more common than reactions to the latter.Major skin reactions (weals with diameter of 5 mm. or more) were present in 77% of children with a history of perennial asthma and house-dust sensitivity. Hence allergy to house-dust mites, particularly D. pteronyssinus, is of considerable importance in childhood asthma, and further study of the ecology and control of the mites in dust is desirable.     

Epidemiology of dust-mite-related disease

For many years it has been suggested that allergens derived from the house dust mite played a major role in the pathogenesis of asthma, eczema and some cases of allergic rhinitis. Recently, house dust mite allergens have been purified and specific immunoassays developed with which exposure to house dust mites and their allergens can be more easily determined. Using these tools, epidemiological studies have provided confirmatory evidence that not only is house dust mite exposure associated with the majority of cases of asthma in children and young adults, but that it is causally related to the development of asthma.     

Molecular and biochemical properties of storage mites (except Blomia species)

In recent years, the allergological importance of different mite species not belonging to the family Pyroglyphidae has been demonstrated. These mites, commonly named storage mites, include Lepidoglyphus destructor, Glycyphagus domesticus, Tyrophagus putrescentiae, Acarus siro, Aleuroglyphus ovatus, Suidasia medanensis and Thyreophagus entomophagus. Several allergens from these species have been purified, sequenced and cloned. Many of these allergens have shown sequence homology and a biological function similar to those previously described in Blomia tropicalis and the Dermatophagoides spp. The main allergens described in storage mites include fatty acid binding proteins, tropomysin and paramyosin homologues, apoliphorine like proteins, alfa-tubulines and other, such as group 2, 5 and 7 allergens, which definitive biological function has not been described yet. Besides the purification and characterization of allergens, the allergenicity of other species such as Acarus farris, Austroglycyphagus malaysiensis, Blomia kulagini and B. tjibodas, Cheyletus eruditus, Chortoglyphus arcuatus, Gohieria fusca, Thyreophagus entomophagus and Tyrophagus longior has been investigated. Research has also been conducted to identify allergens in parasitic mites, such as Psoroptes ovis, Sarcoptes scabiei, Varroa jacobsoni, Diplaegidia columbae and Hemisarcoptes cooremani. The allergenicity of mites present in agricultural environments has been investigated. Crossreactivity studies have also been performed to elucidate to what extent all these mites share common, or species specific epitopes. Herein we present a comprehensive review of the allergenicity of mite species which have been implicated in human respiratory and/or dermatological diseases.     

Crystal structure and some properties of a major house dust mite allergen, Derf 2

Pyroglyphid house dust mites are a major source of allergens in house dust. Mite allergens sensitize and induce asthma, rhinitis, and eczema in a large portion of patients with allergic diseases. Here, the crystal structure of a major mite allergen, Derf 2, derived from Dermatophagoides farinae was solved by single isomorphous replacement method with anomalous scattering (SIRAS) at 2.1A resolution. The present study also demonstrated that the conformation of the allergen was critical in the determination of Th1/Th2 shift based on physicochemical and immunological analyses. This indicates that rigidly folded and singly dispersed structure is essentially required for the generation of Th2 type cells by the allergen, while conformational variant protein leads to Th1 skewing, irrespective of the same amino acid sequence. This structure/function relationship may allow us to develop a novel strategy for hyposensitization therapy in patients with allergic diseases triggered by house dust mite allergens.     

尘螨过敏原的交叉反应性

尘螨是最主要的室内过敏原之一,随着社会生活的现代化,人们对室内居住环境的要求越来越高,由于环境因素而引起的一些过敏性疾病越来越受到人们的关注。本文主要综述了近几年来尘螨过敏原与其他多种螨类、软体动物（蜗牛）和甲壳类动物（虾）以及昆虫（蟑螂、衣鱼、摇蚊、石蚕蛾）等过敏原之间的交叉反应性,对临床过敏性疾病的诊断具有参考价值。     

Rapid method for the detection of storage mites in cereals: feasibility of an ELISA based approach

This paper describes the development of rapid immunodiagnostic tests for the detection of storage mite infestations in cereals and cereal products. The study's first phase (proof of concept) involved the production of a species-specific enzyme-linked immunoassay (ELISA) for the flour mite, Acarus siro (L.), a major pest of stored commodities. The specificity of this new assay was assessed against key stored product contaminants (13 species of mites of which three were predatory, five species of insects and five species of fungi) in the presence and absence of grain. The assay was species-specific (no cross-reactivity to other storage contaminants) and was unaffected by the presence of cereal antigens in the extract. In the study's second phase, species- and genera-specific ELISAs were developed for a range of key storage mite pests: the cosmopolitan food mite (Lepidoglyphus destructor), the grocers' itch mite (Glycyphagus domesticus), the grainstack mite (Tyrophagus longior), mites of the Tyrophagus and Glycyphagus generas, and all storage mites. All tests were demonstrably specific to target species or genera, with no cross-reactions observed to other storage pest contaminants or cereals. The final, validation phase, involved a comparative assessment of the species-specific A. siro and the genus-specific Tyrophagus ELISAs with the flotation technique using laboratory and field samples. Both ELISAs were quantitative (0-30 mites per 10 g wheat) and produced good comparative data with the flotation technique (A. siro r(2)=0.91, Tyrophagus spp. r(2)=0.99).     

盐城地区未成年过敏性疾病患者吸入性过敏原IgE检测结果分析

摘要 目的：通过研究分析盐城地区未成年过敏性疾病患者吸入性过敏原特异性IgE检测结果分布变化特点,为过敏性疾病预防和临床诊疗提供科学依据。方法：自2020年1月至2021年3月期间,选择430例未成年(<18岁)过敏性疾病患者,血清检测方法采用欧蒙公司生产的过敏原特异性IgE检测试剂盒。结果：430例患者中,血清过敏原IgE阳性166例(38.60%),其中尘螨和屋尘是主要的吸入性过敏原。血清IgE阳性率男性39%,女性36% (P>0.05),中学组女性阳性率（61.11 %）高于男性（45.83 %）（P<0.05）。不同年龄组间IgE阳性率有统计学差异（P<0.05）,蟑螂、尘螨、霉菌、豚草、屋尘和年龄组间有统计学差异（P<0.05）。不同临床症状与IgE阳性率有统计学差异(P<0.05),其中呼吸道过敏症状组IgE阳性率最高（48.30 %）,不同症状组间主要过敏原都是尘螨。屋尘阳性患者均合并尘螨阳性,其中70.93 %的患者表现出了呼吸道过敏症状。结论：尘螨、屋尘是盐城地区未成年过敏性疾病患者最主要的吸入性过敏原,研究血清过敏原分布,对未成年人过敏性疾病的预防、诊疗具有重要意义。     

Antigens of Ambrosia elatior (short ragweed) pollen. III. Crossed radioimmunoelectrophoresis of ragweed-allergic patients' sera with special attention to quantification of IgE responses

Short ragweed allergenic extract has been studied by means of crossed radioimmunoelectrophoresis (CRIE) with the use of sera from 37 allergic patients and the relevant control sera. In this study 22 of 52 antigens, detectable in crossed immunoelectrophoresis (CIE) against polyspecific rabbit anti-ragweed IgG, were able to bind specific human IgE to their corresponding immunoprecipitates. This binding was semiquantified by comparison with the binding of a standard serum pool. Nine antigens were identified as important allergens, including the previously isolated components, AgE, AgK, and Ra6. Certain allergens (e.g., AgE, AgK, and Ag 31) bound IgE in almost all patients' sera, whereas others showed a bimodal distribution for sera of responder and nonresponder patients. The total CRIE score was found to correlate significantly both with ragweed-specific serum IgE antibody determined by RAST (rs = 0.88; p less than 0.001) and with total IgE level (rs = 0.55; p less than 0.01). Patient's CRIE scores to AgE also correlated significantly with their specific IgE antibody to AgE measured by RIA (r = 0.47; p less than 0.01) and with skin-test sensitivity to AgE (r = 0.44; p less than 0.05). It was concluded that CRIE is well suited for identification of important ragweed allergens without the previous need for laborious isolation procedures.     

热带无爪螨体内特异性变应原定位

【目的】探讨热带无爪螨Blomia tropicalis特异性变应原在体内的定位。【方法】制作热带无爪螨石蜡切片, HE染色后光镜观察其内部形态结构。选用对尘螨过敏患者的阳性血清特异性IgE 抗体作探针,免疫组织化学染色分析其特异性抗原存在位置。【结果与结论】免疫组织化学染色可见热带无爪螨中肠、盲囊、结肠的肠壁和内容物及生殖腺等均有阳性反应。其中肠壁组织和肠腔内容物呈强阳性反应,提示肠为特异性抗原的主要存在部位。     

Sensitization of Children to Storage Mites in Kutahya, Turkey

Specific IgE against Acarus siro, Glycphagus domesticus, Tyrophagus putrescentiae, and Lepidoglyphus destructor have been investigated by ELISA in sera of 92 children. Of them, 41 were found to be specific IgE positive (≥ 0.35 IU/ml) against at least one of house dust mite species, Dermatophagoides pteronyssinus and Dermatophagoides farinae, by an immunoblot. In 65.9% of the dust mite-sensitized children, specific IgE against at least one of these mite species was found. Sensitization levels, including co-sensitization cases were found to be 35.7% against A. siro, 24.4% against T. putrescentiae, 31.7% against L. destructor, and 26.8% against G. domesticus. In non-sensitized children, dust mite sensitization level was found to be 25.5%. Breakdown of sensitization by individual species in this group was; against A. siro and T. putrescentiae at 7.8%, against L. destructor at 13.7%, and against G. domesticus at 9.8%. When all children were reckoned, 43.5% was found to be sensitized against at least one storage mite species, with sensitizations against A. siro at 18.5%, T. putrescentiae at 26.1%, L. destructor at 21.7%, and G. domesticus at 17.4%. In dust samples collected from the dwellings of children, distribution of species was found to be A. siro (17%), G. domesticus (23%), T. putrescentiae (29%), L. destructor (25%), and unidentified (6%). In Fisher''s chi-square test on SPSS program, there was a relationship between dust mite sensitization and storage mite sensitization (P < 0.05), but no meaningful relationship was found on the basis of individual mite species.     

House dust mites in Brazil--an annotated bibliography.

House dust mites have been reported to be the most important allergen in human dwellings. Several articles had already shown the presence of different mite species at homes in Brazil, being Pyroglyphidae, Glycyphagidae and Cheyletidae the most important families found. This paper is an annotated bibliography that will lead to a better knowledge of house dust mite fauna in Brazil.