Mite allergen exposure, sensitisation and clinical symptoms in Valdivia, Chile.

One hundred consecutive asthmatic paediatric patients were evaluated and skin tested with a battery of skin prick test reagents, including 8 different standardized house dust mite extracts. Asthma severity was graded according to the Global Initiative for Asthma (GINA) document in mild persistent (52 patients), moderate persistent (39) and severe persistent (9). Sixty patients had asthma and allergic rhinitis, 12 asthma and eczema, and 8 asthma, allergic rhinitis and eczema. The patient population was divided into 2 different socioeconomic groups (50 patients per group) based on a standardized, validated questionnaire. A dust sample was collected with an adapted vacuum cleaner from the mattress of each patient and analysed for Der p 1, Der f 1 and Der p 2 allergen content using monoclonal antibodies. Eighty patients were skin test positive to at least one mite species. All positive skin test patients were positive to Dermatophagoides pteronyssinus, 99% to D. farinae, 92% to Euroglyphus maynei, 80% to Lepidoglyphus destructor, 73% to Tyrophagus putrescientae, 72% to Blomia tropicalis; 70% to Acarus siro and 68% to Chortoglyphus arcuatus. All patients with severe persistent asthma had a positive skin test to mites, 85% in the moderate group, and 73% in the mild group (p < 0.01). 95% of patients with asthma and allergic rhinitis had a positive skin test to mites, 92% of patients with asthma and eczema and 100% of patients with asthma, allergic rhinitis and eczema; (p < 0.01). Mean Der p 1, Der f 1 and Der p 2 allergen concentrations were 18.3, 0.6 and 5.6 microg/g of mattress dust, respectively. Mean Der p 1 allergen levels in the middle-low socioeconomic group were significantly higher than in the middle high group (p < 0.01). There is a high rate of allergic sensitisation among pediatric asthmatic patients in Chile. More than one species are implicated, although sensitisation and exposure to D. pteronyssinus predominates. Mite allergic patients are exposed to high mite allergen concentrations, exceeding previously established risk levels for sensitisation and symptoms.     

First report on sensitization to allergens of a house dust mite, Suidasia pontifica (Acari: Saproglyphidae).

A species of house dust mite, Suidasia pontifica, was recently shown to produce allergens affecting man. The species may be as important as other allergen producing mite in sensitization and causing allergic symptoms in Malaysians. Surveys conducted demonstrated that 80% of the houses surveyed were positive for this mite with densities ranged from 2 to 50 mites per gram of dust. Colonies of the species has been successfully established and materials from those colonies have been used to produce extracts for studies on sensitization to the mites. A total of 85 suspected allergic rhinitis patients were tested and 74.1% demonstrated positive reactions. Extract of this mite should be considered for routine diagnostic testing and possible immunotherapy.     

Mite allergen levels and acarologic analysis in house dust samples in Uberaba, Brazil.

Mite allergen exposure has been widely related to sensitization and development of allergic diseases. This study intended to evaluate the degree of allergen exposure in Uberaba, Brazil, through the measurements of Der f 1 and Der p 1 allergen levels associated with the acarologic analysis in house dust samples. A total of 240 dust samples were collected from 60 houses through vacuuming sofas and bedding, during the months of March and July 2000. Indoor temperature and relative humidity were also measured. Mites were counted and identified under light microscopy and allergen levels were measured by two-site monoclonal antibody ELISAs. The major mite family was Pyroglyphidae (39.4%), having D. pteronyssinus as the most frequent species (15.6%), followed by D. farinae (12.3%) and E. maynei (7.9%). The family Glycyphagidae was less commonly found (4.8%), with Blomia tropicalis (4.4%) as its majoritary member. The highest levels of Der f 1 and Der p 1 allergens were found in bedding samples in March (31.7 and 0.9 microg/g of dust, respectively), with Der f 1 levels significantly higher than Der p 1 (p < 0.0001). There was a significant positive correlation between the mite number and allergen levels. These results indicate that Dermatophagoides sp are the most frequent mites in our region followed by E. maynei. Therefore, the knowledge of the local mite fauna would improve the means of investigating the association between allergen exposure and sensitization, allowing the addition of new mite extracts in diagnostic tests.     

Indoor Allergens and Microbial Bio-Contaminants in Homes of Asthmatic Children in Central Taiwan

Indoor allergens and microbial bio-contaminants play a significant role in asthma symptoms. The aim of the study was to determine levels of house dust mite allergens, bacterial endotoxin, and fungal beta-glucan in homes of 120 asthmatic children in central Taiwan. Dust samples from 120 mattresses (67 double-sided) were analyzed for house dust mite allergens (Der p 1, Der f 1, and Blo t 5), endotoxin, and beta-glucan. Pillows (n = 118) were analyzed for house dust mite allergens only. Kitchen dust samples were analyzed for the cockroach allergen, Bla g 1. Blo t 5 was detected in 9.3% pillows and 82.2% mattresses, Der p 1 in 95.8% pillows and 93.2% mattresses, and Der f 1 in 82.2% pillows and 83.1% mattresses. Geometric mean levels (95% confidence interval) of endotoxin and beta-glucan in mattresses were 108.4 Eu/mg (81.4–144.2) and 25.2 μg/g (22.7–28.0), respectively. House dust mite allergens and endotoxin levels were significantly lower on the bamboo side of 67 mattresses, compared to the inner sprung mattress side. Geometric mean of kitchen Bla g 1 was 0.61 U/g (95% CI: 0.43–0.85). Given the presence of Der p 1, Der f 1 and Blo t 5 in central Taiwan, it is advised to measure allergens of all three house dust mite species to obtain a true index of allergen exposure. Bamboo sides of mattresses had significantly lower house dust mite allergens and endotoxin levels.     

哮喘患儿家庭内尘螨变应原含量分布特征及其影响因素

目的经动态监测北京地区尘螨变应性哮喘患儿家庭内尘螨变应原含量,获得尘螨变应原含量在螨种、室内区域和季节性分布特征及其影响因素。方法选取2011年3月至2012年1月在北京儿童医院哮喘门诊就诊的48例尘螨变应性哮喘患儿,男34例,女14例,年龄3～14岁,平均年龄8岁4个月。在春、夏、秋、冬各季动态收集家庭内床垫、枕头、沙发、卧室及客厅地板的灰尘样本,采用统一问卷调查患儿家居环境。采用酶联免疫吸附试验测定以上灰尘样本中户尘螨变应原第一组分（Der P1）和粉尘螨变应原第一组分（Der f1）的含量。结果家庭内Der f1平均含量为0．13μg/g,显著高于DerP1平均含量0．02μg/g,差异具有统计学意义（P〈0．05）。室内区域尘螨变应原含量分布显示,床垫、枕头及沙发灰尘样本中Der f1含量分别为0．69、0．42和0．22μg／g,显著高于卧室地板和客厅地板灰尘样本Der f1含量（分别为0．07和0．07μg／g）;床垫、枕头和沙发DerP1含量分别为0．03、0．02和0．02μg／g,显著高于客厅及卧室地板灰尘样本DerP1含量（分别为0．02和0．02μg／g）。比较各区域各季节尘螨含量变化,结果显示从床垫来源的Der f1含量在冬季显著高于夏季（分别为0．98和0．36μ/g）,从卧室及客厅地板来源的Der f1含量在冬季（分别为0．09和0．08μg／g）显著高于春季（分别为0．06和0．06μg／g）,从床垫来源的Der P1含量在冬季显著高于秋季（分别为0．04和0．02μg／g）,从沙发来源的Der P1含量在冬季显著高于夏季（分别为0．02和0．02μg／g）,以上结果差异均具有统计学意义。夏、秋、冬季尘螨含量与相对湿度呈正相关关系,秋、冬季尘螨含量与温度呈负相关关系。家居环境有霉斑、家庭成员有吸烟者、家长陪伴患儿就寝可能是造成室内尘螨含量较高（≥2μg／g）的危险因素。结论北京地区尘螨变应性哮喘患儿家庭环境中尘螨以Der f1为主,床垫、枕头及沙发区域是Der f1和Der p1的主要来源,以冬季尘螨暴露含量最高。温湿度对尘螨含量的影响受到季节影响。家居环境中造成室内尘螨含量较高的可能危险因素包括霉斑、家庭成员有吸烟者、家长陪伴患儿就寝。     

Monthly variation of Dermatophagoides allergens and its influence on respiratory allergy in a high altitude environment (Quito, 2800 m a.s.l. in Andean Ecuador)

BackgroundSeasonal variation of Dermatophagoides allergens and its influence in allergic respiratory airway diseases has not been investigated in Andean cities. The objective of this study was to evaluate those parameters in a city located in the Andean mountains.MethodsDer p1 and Der f1 were measured in dust samples from mattresses in 13 houses in Quito (2800 m above sea level). Samples were collected monthly from August 2004 to July 2005. Patients presenting to a local outpatient allergy clinic with asthma and rhinitis and isolated allergy to Dermatophagoides were analysed to determine if a correlation existed between seasonal Der allergen levels and the number of patients presenting with allergies.ResultsHigh levels of dust mites and humidity were observed throughout the year. The highest geometrical mean values of allergens were detected in April (Der p1, 10.15 μg/g) and May (Der f1, 13.03 μg/g), whilst the lowest levels were detected in August (Der p1, 4.26 μg/g), and September (Der f1, 1.4 μg/g). Of the 361 patients examined, 182 were allergic to Dermatophagoides, (45.6% asthmatics, 97.8% rhinitics, and 43.4% with both diseases). Patient presentation spiked in August, and from February to May. However, there was not a significant correlation between mite allergen concentrations and humidity or the number of patients presenting with allergies.ConclusionsDust samples from mattresses in Quito revealed high concentrations of Der p1 and Der f1. We observed a trend towards increased presentation of asthmatic and rhinitic patients in the months with highest levels of allergens.     

北京地区尘螨过敏患者家庭螨类调查

目的调查北京地区尘螨过敏患者家庭螨类种类和比例,为北京地区尘螨防治提供理论依据。方法以北京协和医院就诊的38例北京地区尘螨过敏患者为研究对象,于2008年12月至2010年1月人户吸尘采集其所在家庭室内尘土样本,采用漂浮法收集尘土中的螨,分离制片,显微镜下分类计数并绘图。结果 38个家庭共采集样本345份,螨检出率为64.6%;经分离鉴定得出蜱螨亚纲3目12科15属22种,其中丝泊尘螨为我国致敏螨类一新纪录种;昆虫纲啮虫目1科1属2种。在分析的1798个标本中,主要致敏螨种前3位的依次为粉尘螨(62.46%),户尘螨(21.47%)和丝泊螨(5.28%)。对不同采集地点的调查结果表明,平房(91.1%)样本阳性率高于楼房(59.5%)。对不同生活环境螨密度的数据分析表明,枕头的平均螨密度最高,达到282只螨/克尘土,其次为床褥(120只螨/克尘土)和沙发(115只螨/克尘土)。平均螨密度在9至10月达最高峰,5至7月和12月至次年1月也出现2个高峰,3月和11月密度最低。结论本研究首次发现并报道了北京地区存在的丝泊尘螨,亦属于亚洲首次报道。北京地区室内优势螨种为粉尘螨,其次为屋尘螨和丝泊尘螨,平均螨密度在9至10月达最高峰。     

Pyroglyphid mites, xerophilic fungi and allergenic activity in dust from hospital mattresses

Dust from mattresses of different composition and age was analysed for mites, xerophilic fungi and allergenic activity. The mites of the genus Demodex were the most abundant (58.2 per cent). Also pyroglyphid mites occurred commonly (36.6 per cent). Pyroglyphid mites were present in small numbers (mean: 1 specimen/0.2 g of dust) in 12 out of the 17 older polyester-foam mattresses. The 11 cotton-horsechair mattresses and the newly used polyester-foam mattresses (three tested) were without them. The dust from the cotton-horsehair mattresses had a significantly higher allergenic activity than from those of polyester-foam. Xerophilic fungi were isolated in three out of 31 mattresses. The species isolated belonged to the genus Aspergillus and Eurotium. E. repens occurred most frequently. Disinfection of mattresses was suggested to have a negative influence on the occurrence of mites and fungi.     

House dust mites in the city of Lima, Peru.

Since mites are the most common house dust allergens, knowledge about the species most prevalent in a region is important for diagnostic and specific immunotherapy purposes. In order to establish the prevalence of house dust mites in different city districts, 100 house dust samples were collected from different parts of Lima. Lima is a city of tropical climate located along the coast of the Pacific Ocean. The relative air humidity is 80-90% and the various districts studied are located at altitudes ranging from 37-355 meters. The mite Blomia tropicalis was the organism most frequently detected, being present in 59% of the house dust samples. Dermatophagoides pteronyssinus occupied second place (15.9%), followed by Chortoglyphus arcuatus and Tyrophagus putrescentiae. These four mites, taken together, represented more than 90% of the mites detected. No specimen of the species Dermatophagoides farinae was detected. We conclude that B. tropicalis and D. pteronyssinus are the most common house dust mites in Lima. Considering the high prevalence of B. tropicalis in Lima and the fact that its cross-reactivity with antigens of the mites of the family Pyroglyphidae is minimal, we conclude that sensitization to this mite should be investigated separately in allergic patients living in Lima.     

上海市居室尘螨变应原浓度初步检测

目的检测上海市居室尘螨变应原浓度。方法应用层析介质及蛋白质沉淀技术从螨代谢分泌物中分离、纯化粉尘螨变应原Dff F3及国际公认的变应原Der fⅢ,经临床检测和放射性变应原吸附实验(RAST)鉴定其变应原性。制备抗Dff F3和Der fⅢIgG,从室内收集尘埃,分离尘螨抗原,夹心ELISA测定尘螨变应原Dff F3和Der fⅢ浓度。结果Dff F3和Der fⅢ呈现强致变应性,均能与尘螨过敏哮喘患者血清IgE结合。检测200份家庭尘埃样品尘螨变应原,结果显示,Dff F3浓度>10μg/g的家庭占57.0%,2~10μg/g的家庭占29.5%,<2μg/g的家庭占13.5%。Der fⅢ浓度>10μg/g的家庭占53.5%,2～10μg/g的家庭占32.0%,<2μg/g的家庭占14.5%。结论上海市部分居室尘螨变应原浓度偏高。粉尘螨Dff F3有较强的变应原性。     

海南变态反应性疾病患儿对屋尘螨/粉尘螨和仓储螨的特异性IgE

目的探讨海南变态反应性疾病患儿对尘螨和仓储螨的特异性IgE水平。方法对海南变态反应性疾病患儿进行13种常见变应原皮肤点刺和7种螨的体外特异性IgE检测。结果 121例患儿中对屋尘螨和粉尘螨的皮肤点刺阳性率为100%,而对热带无爪螨的阳性率为85.8%。7种螨的体外特异性IgE依次为屋尘螨99.2%、粉尘螨95.0%、热带无爪螨87.6%、家嗜甜螨79.7%、害嗜鳞螨67.8%、腐食酪螨59.5%和粗脚粉螨52.9%。对仓储螨过敏的患儿同时都对屋尘螨和热带无爪螨过敏,并且IgE水平更高。除热带无爪螨外,其他仓储螨的特异性IgE有很好的相关性。结论除屋尘螨和粉尘螨外,热带无爪螨也是海南地区的重要致敏原,其他仓储螨亦有可能引起慢性变态反应性疾病。     

空气净化器降低室内尘螨过敏原含量及其免疫反应性的实验研究

目的 检测开启空气净化器前后室内空气中粉尘螨主要过敏原的含量,探讨粉尘螨经空气净化器不同作用时间后对其抗原免疫反应性的影响。方法 实验分组采样:(1)不开空调和空气净化器;(2)开空调、不开空气净化器;(3)同时开空调和空气净化器;(4)开空气净化器、不开空调。用粉尘采样器分别采集室内空气中尘螨过敏原Der f1和Der f2,运用ELISA方法检测4种环境条件下空气中Der f1、Der f2的含量;通过ELISA和免疫印迹方法检测空气净化器作用不同时间(24 h、48 h和72 h)后粉尘螨过敏原免疫反应性的变化。结果 20个取样房间在开空调之后室内尘螨过敏原的含量都会增高,而在使用空气净化器后,不管是在空调开启或者关闭的情况下室内空气中Der f1和Der f2都会降低(P<0.01);粉尘螨在空气净化器等离子和静电高压场强作用下,死亡的粉尘螨其免疫反应性均较活螨显著降低(P<0.01),免疫组化显示其免疫反应性有所降低。结论 本实验使用空气净化器能够显著降低室内空气中的尘螨过敏原Der f1、Der f2的浓度,并且通过空气净化器作用后,死亡的粉尘螨免疫反应性显著降低,提示使用空气净化器对过敏性疾病(如哮喘和过敏性鼻炎)具有重要的预防和干预作用。     

Evaluation of the level of house dust mite allergens,Der p 1 and Der f 1 in Iranian homes,a nationwide study

BackgroundExposure to house dust mites (HDMs) is a major risk factor for the development of allergic symptoms. HDMs are worldwide in distribution. Assessing these allergens in each area is a critical step in evaluating the risk of sensitisation and controlling allergic symptoms. The aim of the present study was to evaluate the level of major HDMs, Der p 1 and Der f 1, in various parts of Iran.MethodsIn 2009, 257 dust samples were obtained from living rooms’ carpets in seven cities throughout Iran with different geoclimatic conditions. The level of Der p 1 and Der f 1 was measured by commercial ELISA.ResultsDetectable level of Der p 1 and Der f 1 levels were only found in Gorgan and Sari, two cities near the Caspian Sea with moderate temperatures and high relative humidity. In both of these cities, Der f 1 was more frequent than Der p 1 (100% vs. 85%) and was found to be at a higher level than Der p 1 (geometric mean 3128 vs. 439 ng/g dust, P < 0.001).ConclusionThe results of this study confirm that house dust mites in Iran are restricted to the Caspian Sea coastal areas, and in other parts, due to seasonal variations of temperature and humidity mites are not able to grow well and therefore are not an important risk factor for sensitisation and respiratory allergies.     

Mite allergens

There is an increasing awareness of the health implications of mite sensitivity, as it is closely related to asthma. Mite allergy constitutes a complex worldwide problem, with sanitary and economical implications. Not only are mite species present in house dust, producing potent allergens, but other, less studied species are also responsible for significant allergic reactions in occupational settings. In this review, we focus on the growing number of mite species that are implicated in allergic cutaneous and respiratory diseases in humans. Mite allergy is not restricted only to the human “indoor” environment, because numerous reports clearly demonstrate that many species that can induce sensitization and symptoms are encountered in occupational settings. An important component of allergy research is the evaluation of the allergenic cross-reactivity to verify to what extent different mite species have unique, species-specific, or cross-reactive allergens. The results of these investigations have important clinical consequences for the diagnosis and treatment of allergic diseases. Internationally standardized mite extracts are needed to compare sensitization rates around the world and clearly establish risk factors associated with sensitization and asthma. In spite of recent controversial results, a significant reduction in the exposure to mite allergens continues to be an important challenge and one of the main goals in the treatment of mite-induced respiratory symptoms. In many cases, this reduction must be achieved in the workplace as well as in the home environment.     

Concentration en allergènes majeurs d’acariens du groupe 1 dans la moquette : comparaison entre des chambres à coucher et des bureaux

Several studies have demonstrated the role of domestic exposure to mite in mite allergic patients. However, only one limited study have measured mite exposure at work in offices. The aim of our study was to compare group 1 mite allergen levels in carpets of offices and bedrooms. Thirty bedrooms and 27 offices were randomly selected. Dust samples were performed according to the international recommendations. Mite allergens were measured using ELISA based assay. A dramatic difference was found in group 1 mite allergen levels between bedrooms (mean: 18.4 μg/g) and offices (mean: 0.32 μg/g). We conclude that mite exposure in offices does not seem to be at risk for atopic and non atopic workers.     

Dynamics of the number of house dust mites and the accumulation of groups 1 and 2 allergens in simple periodic cultures

Dynamics of the number and biomass of D. pteronyssinus and D. farinae and the concentration of major significant mite allergens of groups 1 and 2 were studied in simple periodic cultures. The experiments provided evidence for that there is a positive relationship between the concentration of mite allergens Der p I, Der p II, Der f I, Der f II and the number of mites D. pteronyssinus and D. farinae, as evidenced by both correlation coefficients and curves. The same relationship was seen while examining the number of mites and the exposure of mite allergens in house dust. The findings suggest that the concentration of major mite allergens of Groups 1 and 2 in addition to the number/biomass of mites are one of the most important criteria for the maturity of the culture. The cultures of D. pteronyssinus and D. farinae mature no later than on day 29 of the onset of cultivation, as shown by the maximum concentrations of Der p I, Der p II, Der f I, Der f II and mite biomass, achieved in this period.     

尘螨Ⅰ类变应原所致过敏性哮喘治疗的研究进展

尘螨是引起哮喘等过敏性疾病的主要气传变应原之一,其变应原种类繁多,尘螨Ⅰ类变应原是主要的致敏成分之一。本文就尘螨Ⅰ类变应原引起的螨性过敏性哮喘的发病机制、治疗及其研究进展做一综述。     

Respiratory symptoms in relation to indoor exposure to mite and cat allergens and endotoxins. Indoor Factors and Genetics in Asthma (INGA) Study Group.

The authors investigated the relationship between respiratory symptoms in adults and exposure to mite and cat allergens, the role of endotoxins in house dust, the effects of mixtures of several allergens, and interactions between allergen exposure and allergic sensitization. Within a nested case-control study, 405 subjects aged 25-50 yrs from two German cities answered a standardized questionnaire. Allergen-specific immunoglobulin-E was measured. Dust samples were taken from the subjects' homes to determine exposure to mite (Dermatophagoides pteronyssinus antigen 1 Der p 1) and (D. farinae antigen 1 Der f l) and cat (cat antigen d1 Fel d 1) allergen and endotoxin content in settled house dust. Exposure to Der f 1 and Der p 1 plus Der f 1 >10 microg x g(-1) of mattress dust, respectively, increased the risk of wheeze and breathlessness (odds ratios (OR): 4.04, 95% confidence interval (CI): 1.53-10.64, OR: 2.78, 95% CI: 1.06-7.28). Fel d 1 >8 microg x g(-1) was positively associated with cough at night (OR: 2.74, 95%, CI: 1.22-.17), noteworthy also in the nonsensitized subjects. Subjects exposed to elevated concentrations of more than one allergen had an up to seven-fold increase in the risk of respiratory symptoms, compared to nonexposed subjects. Sensitized subjects exposed to elevated concentrations of Der f 1 or Fel d 1 were found to have the highest risk of asthma attacks and respiratory symptoms. No statistically significant association was found between exposure to endotoxins and respiratory health. Indoor exposure to Dermatophagoides farinae antigen 1 and cat antigen d1 is a risk factor for respiratory symptoms in adults, and for cat antigen d 1 even in nonsensitized subjects. The risk is increased if subjects are exposed to a mixture of allergens or if they are sensitized in addition to high exposure.     

Correlation of environmental mite levels and the symptoms of allergic rhinitis regarding the efficacy of preventive education

Allergic rhinitis is still a commonly investigated disease all over the world. Allergens are usually in the nature of glycoprotein or protein which interact with antibodies resulting in the formation of specific Ig E in the body 1. It is presumed that some environmental factors play an important role in their clinics. In allergic rhinitis, symptoms usually occur after the interaction of nasal mucosa with allergens. Allergens may be indoors, outdoors or in both environments. House-dust contains most of the indoor allergens. Mites are the most egregious allergen in house dust. D. pteronyssinus is commonly seen in European countries, D. farinae is mostly seen in North America. House-dust mites play an important role in allergic sensitization of individuals in Turkey. Perennial allergic rhinitis is a common chronic disorder that results most frequently from sensitivity to house-dust mites. National and international guidelines for the management of allergic rhinitis recommend that house and dust mite avoidance measures be considered for all patients with house-dust mite provoked rhinitis. Symptoms of allergic rhinitis are related to the environmental mite level in which patients live. The aim of this study is to show the relationship between mite levels and symptoms of allergic rhinitis diagnosed patients and the change of mite levels in the environment after appropriate education.