The most common phenotypes of sensitization to inhalant allergens in childhood

Background Atopic individuals are frequently sensitized to a limited number of certain allergens, although most of them are exposed to multiple inhalant allergens in daily life. Objective We investigated the hypothesis that observed common patterns of sensitization might occur with similar frequency within two independent study populations of school-children. Methods The results were derived from skin-prick tests conducted on two large samples of children (study 1:n= 583; study 2: n= 1099) examined with the same panel of six inhalant allergens. Results In order to ensure that the comparison was uniform, the younger subpopulation of study 1 (n= 147) was compared with the sample of study 2 (n= 374). The highest frequency for monosensitization was found for sensitization to Dermatophagoides pteronyssinus (study 1: 18.4%, study 2: 20.3%), followed by monosensitization to grass pollens (study 1: 12.2%; study 2: 8.8%). Using multiple logistic regression for each specific sensitization, a significantly increased relative risk of sensitization to hazel pollens (study 1 OR 5.9; study 2 OR: 24.3) appeared to be associated with sensitization to birch pollens. The same applied to dog dander (study 1 OR: 7.3; study 2 OR: 2.6), which showed an association with sensitization to cat dander. Conclusion In summary, our data suggest that certain clusters of monosensitization and polysensitization to common inhalant allergens exist among a given population. This may well be a reflection of diversity in disposition to specific sensitization and/or antigen crossreactivity. From a practical point of view the data also might help in counselling parents of allergic children.     

Allergy to castor bean. I. Its relationship to sensitization to common inhalant allergens (atopy)

The IgE response to castor bean (Ricinus communis) was studied in 96 castor bean-allergic patients from Marseilles, France. All had positive skin tests to castor bean. The IgE response to grass, cat, dust mite, olive, and Parietaria was also measured, and a positive RAST to one or more of these allergens was taken to indicate atopic status. Castor bean-specific IgE antibodies, measured by RAST, were found in 87 (91%) of the castor bean-allergic patients, in two of 13 atopic Marseilles residents living close to the castor bean mills, in three of 42 allergic subjects who had no known contact with castor bean, and in none of a control group of 111 Marseilles blood donors. Very high levels of castor bean-specific IgE (maximum class 4 readings on the Phadebas RAST score) were found in 54 (56%) of the castor bean-allergic patients, but the level of IgE antibody to castor bean was not significantly different in atopic and nonatopic subjects. The frequency of a positive serological test (RAST) for atopy in castor bean-allergic subjects (32%) was very similar to that found in the local population (36%). These data indicate that castor bean is an extremely potent sensitizer for both atopic and nonatopic individuals. The magnitude of the specific IgE antibody response is not related to the atopic status of the patient and may be a function of the physiochemical characteristics of the allergen itself.     

Sensitization to four common inhalant allergens within 302 nuclear families

The coincidence of allergic sensitization was investigated in 302 school-aged children and their parents. Specific sensitization to four common inhalant allergens (grass and birch pollens, cat dander, Dermatophagoides pteronyssinus) was ascertained by means of skin-prick tests (SPT) carried out on the complete family unit at the beginning of a 22-month follow-up period. The same test procedure was then repeated on the children twice at 11-month intervals to provide cumulative prevalences of sensitization. A clinical history of atopy in the children (hay fever or asthma; n= 47), which was derived from an interview, is associated with sensitization (positive SPT in 89%). For three allergens (grass and birch pollens, cat dander) sensitization occurs significantly more frequently in the children of mothers who are sensitized to the same allergen (odds-ratios (ORs), 2.5–4.1). Additionally, in three of the four explanatory models related to a single antigen, maternal sensitization to one of the complementary allergens is of importance (ORs, 2.7–3.7). In contrast to this finding, none of the paternal sensitizations has statistical significance. Based on a reaction to at least one of the four allergens, the child's relative risk to be sensitized is increased in case of maternal (OR, 2.88; P= 0.001) but not of paternal (OR, 1.06; P= 0.83) sensitization. In conclusion, our data indicate that the maternal status is more predictive than that of the father with regard to the child's risk of sensitization.     

Prevalence of allergic sensitization to inhalant allergens among blood donors in Kuwait - a desert country

Kuwait is a desert country where the prevailing high temperatures, low humidity, and scant vegetation suggest a low prevalence of allergy. We evaluated the prevalence of atopic sensitization (presence of allergen-specific IgE) among young adult blood donors by screening a total of 505 subjects (male : female ratio 1.6) with mean age of 28.4 years (range 18–50 years). The Pharmacia CAP-Phadiatop® test, which detects serum IgE specific to most common airborne allergens, was used. Some of the specific sensitizing allergens were also identified by the related CAP-RAST method. Sensitization was detected in 223 of the 505 subjects (44.2%) screened. Kuwaiti nationals had a significantly higher prevalence rate (50.2%) than non-Kuwaitis (34.2%) (χ²= 8.6, P<0.003). The highest prevalence rate was found among male Kuwaitis (53.8%). The prevalence of current or previous allergic disease (subject-reported) was 20.6%. Bermuda grass, house-dust mite ( Dermatophagoides pteronyssinus ), and Chenopodium album were the most prevalent sensitizing allergens, with frequencies of 53.6%, 52.7%, and 50.9%, respectively, among the sensitized subjects (corresponding to 23.7%, 23.3%, and 22.5%, respectively) for the entire population. Sensitization increased with age, but only among the expatriates, younger Kuwaitis being as frequently sensitized as the older ones. Polysensitization was found to be common. Of the 109 CAP-RAST-positive subjects, 71 (65.1%) were sensitized to more than one allergen, and 30 of these (42.3%) were sensitized to four or more allergens. These results show that atopy is highly prevalent among young adults in Kuwait, and the higher prevalence rate among nationals than expatriates suggests the involvement of genetic or local environmental factors. The results also confirm that mite and plant pollens may be major sensitizing allergens even in a desert environment.     

Statistical analysis of IgE antibodies to the common inhalant allergens in 44,496 sera

A statistical analysis of RAST screening of 44,496 sera, submitted in 1986 and 1987 for routine diagnostic allergic examination, was performed. The sera were tested on a fixed panel of allergens, regardless of the patient's history. The association of a positive RAST with age and month of birth was studied. It was concluded that among the inhalant allergens, house-dust mite was the most frequent sensitizer for all age groups, followed by grass pollen and cat dander. Sensitization to cat dander occurred twice as often as sensitization to dog dander. Among children less than 4 years of age, a different profile of sensitization was found, indoor allergens (mites, animal danders) being more important than outdoor allergens (pollen). Furthermore, we found that children born during December-February had a slightly but significantly greater chance of becoming sensitized to grass pollen compared with children born during September and November (P less than .05). Children born during July-September had a greater chance of becoming sensitized to house dust mite compared with children born during January-March (P less than .05). Finally, it was found that children born during October-December had a greater chance of becoming sensitized to dog dander compared with children born during March-May.     

Allergic sensitization to common airborne allergens among adults in Estonia

BACKGROUND: Allergies and asthma exhibit a growing health problem in the world. Sparse data are available about the prevalence of allergic sensitization in Estonia and Eastern Europe as well. We studied the prevalence of allergic sensitization, the associations between respiratory symptoms and allergic sensitization, and the influence of age, gender, area of residence, number of siblings and other demographic attributes on allergic sensitization in the population aged 17-69 years. METHODS: We conducted a cross-sectional study with 1,346 randomly selected participants distributed in 3 geographically and culturally distinct areas of Estonia. Sensitization to 15 aeroallergens was assessed by skin prick tests. The study also included a structured interview. RESULTS: The total prevalence of allergic sensitization was 33.0%. When estimated in patients aged 20-44 years, the prevalence was 38.5%. The most common sensitizer was cockroach followed by storage mites, while sensitization to cat, dog or pollen (common sensitizers in Scandinavian countries) was low. Allergic sensitization was significantly more common in urban and suburban compared with rural areas. Storage mites were the most common sensitizers in rural areas. Living in urban or suburban areas before the age of 5 significantly increased the risk for positive skin prick tests to several allergens. CONCLUSIONS: A higher prevalence of allergic sensitization than previously believed was found. Cockroach and storage mite allergens are suggested to be included in the routine investigation panel in Estonia.     

Natural course of sensitization to food and inhalant allergens during the first 6 years of life

BACKGROUND: Specific IgE antibody responses to alimentary and environmental allergens are one of the hallmarks of atopic diseases. The knowledge of the time course of allergic sensitization during early life may facilitate measures for preventive interventions. OBJECTIVE: In a prospective birth cohort study (the Multicenter Allergy Study [MAS]) we investigated annual incidence and prevalence rates of sensitization to food and inhalant allergens during the first 6 years of life. METHODS: For 216 children of a prospective birth cohort (MAS), a complete follow-up of specific IgE measurements to 9 food and inhalant allergens was available at 1, 2, 3, 5, and 6 years of age. On the basis of these measurements, sensitization rates were estimated for the reference population of 4082 children by weighted analysis. RESULTS: Annual incidence rates of sensitization to food allergens decreased from 10% at 1 year of age to 3% at the 6 years of age. Incidences of sensitization to inhalant allergen, however, increased with age (from 1.5% at 1 year to 8% at 6 years). Point prevalences of allergic sensitization to at least 1 of the 9 tested allergens increased from 11% at 1 year up to 30% at 6 years. This increase was due to markedly increasing sensitization rates to inhalant allergens (1.5% to at least 1 inhalant allergen at 1 year and 26% at 6 years of age), whereas sensitization rates to food allergens remained stable during the first 6 years of life (10%). CONCLUSION: The earliest serologic marker for atopic immunoreactivity in infancy is the presence of IgE antibodies to egg, followed by milk. The development of sensitization to inhalant allergens occurs mostly after infancy. Beyond the third birthday annual incidence and prevalence increase markedly with age. Rates for outdoor allergens are twice those for indoor allergens.     

Epidemiology of acute asthma: IgE antibodies to common inhalant allergens as a risk factor for emergency room visits

In recent years the morbidity and mortality of asthma has increased, although the etiology is still poorly understood. Most patients with asthma suffer acute attacks that are commonly treated in hospital emergency rooms (ER). In the present study, asthma in adults was studied with acute attacks as a marker for the disease; 102 patients first observed at a university hospital ER with acute airway obstruction were compared to 118 patients observed at the same ER with any diagnosis other than shortness of breath to evaluate allergy as a risk factor for asthma in adults. Sera were assayed for IgE antibody (Ab) to dust mites, cockroach, cat dander, and grass and ragweed pollen. The results demonstrate that in adults younger than 50 years of age, the prevalence of IgE Abs was fourfold greater among subjects with asthma than among control subjects (46/67 versus 12/81; odds ratio, 10.1; 95% confidence interval, 4.9 to 20.7). The population attributable risk for the presence of IgE Ab to one of the five allergens was greater than 50%. Among individuals older than 50 years of age, the prevalence of serum IgE Abs was not significantly increased among patients with acute airway obstruction. In the whole group, the prevalence of IgE Abs to different allergens demonstrated significant seasonal and socioeconomic differences, suggesting that the associated risk is related to exposure to those allergens. The results establish that, with acute attacks of asthma as a marker for adult asthma, the presence of serum IgE Abs to common inhalant allergens is a major risk factor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Standard skin prick testing and sensitization to inhalant allergens across Europe--a survey from the GALEN network

Skin prick testing (SPT) is the standard method for diagnosing allergic sensitization but is to some extent performed differently in clinical centres across Europe. There would be advantages in harmonizing the standard panels of allergens used in different European countries, both for clinical purposes and for research, especially with increasing mobility within Europe and current trends in botany and agriculture. As well as improving diagnostic accuracy, this would allow better comparison of research findings in European allergy centres. We have compared the different SPT procedures operating in 29 allergy centres within the Global Allergy and Asthma European Network (GA(2)LEN). Standard SPT is performed similarly in all centres, e.g. using commercial extracts, evaluation after 15-20 min exposure with positive results defined as a wheal >3 mm diameter. The perennial allergens included in the standard SPT panel of inhalant allergens are largely similar (e.g. cat: pricked in all centres; dog: 26 of 29 centres and Dermatophagoides pteronyssinus: 28 of 29 centres) but the choice of pollen allergens vary considerably, reflecting different exposure and sensitization rates for regional inhalant allergens. This overview may serve as reference for the practising doctor and suggests a GA(2)LEN Pan-European core SPT panel.     

Comparison between skin prick test and serum immunoglobulin E by CAP system to inhalant allergens

Background

Skin prick tests (SPTs) and measurements of serum specific immunoglobulin E (sIgE) antibodies are the most commonly used diagnostic tools for confirming sensitization. However, disagreement between the tests has been observed.

Prediction of sensitization to flour allergens

The purpose of the present study was to investigate the factors that may contribute to the sensitization to flour in baker's apprentices, and to predict this type of sensitization with a stepwise logistic regression model. Of the total of 258 baker's apprentices, 54 (20.9%) exhibited specific IgE development against flour allergens (wheat, rye, and/or barley). Allergologic variables, such as the total IgE level and IgE specific to grass pollen, tree pollen, weed pollen, molds, and animal dander, were found to correlate strongly with the sensitization to flour. However, the correlation between the presence of other manifest allergies and the sensitization to flour was weak. The presence of shadowing of the paranasal sinuses on the radiograph (mucosal thickening, opacity, air/fluid levels, and/or polypous shadowing) correlated with flour sensitization as well as with the leukocyte and lymphocyte counts in peripheral blood. Of the lung function data, only total lung capacity (in percentage of the predicted values) weakly correlated with the sensitization to flour. We were able to predict flour sensitization with a sensitivity of 63%, a specificity of 90%, and an efficiency of 84% by using the parameters that allow for the presence or absence of IgE specific to grass pollen and tree pollen, the presence or absence of radiographic shadowing, and total lung capacity in percentage of the predicted values.     

The association of sensitization to inhalant allergens with allergy symptoms: the influence of bronchial hyperresponsiveness and blood eosinophil count

BACKGROUND: We investigated whether the association of allergy symptoms with sensitization to inhalant allergens depends on bronchial hyperresponsiveness, blood eosinophil count, or the degree and nature of sensitization. METHODS: Data on asthma and rhino-conjunctivitis symptoms were obtained from 1904 subjects from a random sample of the Dutch population, aged 20-70 years by the ECRHS questionnaire. Total IgE and specific IgE to four inhalant allergens were measured using CAP System. Bronchial hyperresponsiveness (BHR) was defined as PD20 相似文献   

Mechanisms of tolerance to inhalant allergens: the relevance of a modified Th2 response to allergens from domestic animals

Subjects can be non-allergic because (1) they are not exposed, (2) they fail to make an immune response, or (3) they make an immune response that does not include IgE antibodies (Ab). The recent observation that children raised in a house with a cat are less likely to become allergic to cat allergen than those who only get indirect exposure provides a model to investigate the factors controlling allergic responses. Many of these highly exposed children have made an IgG and IgG4 Ab response to Fel d 1 without IgE Ab, i.e., a modified Th2 response. In countries where cats are a major cause of asthma, the presence of a cat may decrease the risk of asthma. By contrast, in countries with high exposure to dust mites, cats can induce specific tolerance to Fel d 1 without influencing asthma or the IgE Ab response to dust mites. Using overlapping peptides to investigate T cell responses to Fel d 1 suggests that the structure of the molecule plays a special role in inducing the T cell responses that can control the immune response to cat allergens. This T cell response is characterized by high levels of IL-10 production, but this is not restricted to those who have made a modified Th2 response. The results suggest that there are major differences in the immune response to different allergens that profoundly affect their role in allergic disease. Dust mite and cockroach differ from cat (and rat) allergens not only in the quantity inhaled and the particles sizes but also in the biochemistry of the molecule.     

Current mite,cat, and dog allergen exposure,pet ownership,and sensitization to inhalant allergens in adults

BACKGROUND: Simultaneous exposure to more than one allergen might modify the effect of individual allergens. OBJECTIVE: The purpose of this study was to investigate the effect of current exposures to mite, cat, and dog allergen and pet ownership on sensitization in adults. METHODS: Questionnaires, skin tests, and home visits (Der p 1, Fel d 1, and Can f 1, ELISA; mattresses, living room floors) were performed in 2502 adults. Allergen exposure was treated as a continuous variable and divided into quartiles. To investigate the interaction between allergens, quartiles for 3 allergens were added, creating arbitrary combined exposure categories. RESULTS: In the univariate analysis, mite sensitization was associated with Der p 1 in mattresses (odds ratio [OR], 1.10; 95% CI, 1.01 to 1.19; P =.03) and with Can f 1 in living room floors (OR, 1.08; 95% CI, 1.00 to 1.17; P =.05). In a multivariate regression analysis, Der p 1 in mattresses remained an independent associate of mite sensitization (OR, 1.12; 95% CI, 1.02 to 1.23; P =.03) and pollen sensitization (OR, 1.23; 95% CI, 1.11 to 1.36; P =.0001). The proportion of subjects sensitized to mite increased significantly with the increasing combined exposure categories (P <.0001). The highest prevalence of sensitization to cat and dog was in the medium combined exposure categories. Cat ownership was associated with a reduced prevalence of sensitization to cats (P =.002) and a reduced prevalence of sensitization to dog (P =.003) but had no effect on sensitization to mite and pollen. CONCLUSIONS: Sensitization to dust mites increased with the increasing combined exposure. Cat ownership was associated with a lower prevalence of sensitization to cat and dog but not to mite and grass pollen.     

Skin sensitization to common allergens in Turkish wheezy children less than 3 years of age

Infants and small children with asthma are not commonly skin tested, as allergy is not considered to be a major cause of infantile asthma. The aim of this study was to determine the frequency of skin test positivity to various allergens in wheezy children less than 3 years of age. We evaluated 161 patients with infantile asthma (median age 20 months) and 100 healthy controls (median age 18 months). Infantile asthma was defined as three or more episodes of wheezing in a child less than 3 years of age, whose symptoms improved on treatment with beta-agonist and anti-inflammatory agents. All children were skin tested to house dust mites (HDM), pollens, molds, and cow milk extracts using prick technique. One hundred and eighteen (73.3%) children In the patient group tested positive to HDM, 84 (52.1%) to pollens, 37 (22.9%) to molds, and 16 (10%) to cow milk. Sensitization rates to HDM were significantly higher in the patient group than In the healthy controls. Sensitization rates to pollens were not statistically different between the two groups. There was no association between family history of atopy and frequency of sensitization to allergens in the wheezy and control groups. We concluded that skin sensitization to allergens was common In wheezy infants. The prevalence of sensitization to indoor allergens was higher than to outdoor or food allergens.     

Position paper of the EAACI: food allergy due to immunological cross‐reactions with common inhalant allergens

In older children, adolescents, and adults, a substantial part of all IgE‐mediated food allergies is caused by cross‐reacting allergenic structures shared by inhalants and foods. IgE stimulated by a cross‐reactive inhalant allergen can result in diverse patterns of allergic reactions to various foods. Local, mild, or severe systemic reactions may occur already after the first consumption of a food containing a cross‐reactive allergen. In clinical practice, clinically relevant sensitizations are elucidated by skin prick testing or by the determination of specific IgE in vitro. Component‐resolved diagnosis may help to reach a diagnosis and may predict the risk of a systemic reaction. Allergy needs to be confirmed in cases of unclear history by oral challenge tests. The therapeutic potential of allergen immunotherapy with inhalant allergens in pollen‐related food allergy is not clear, and more placebo‐controlled studies are needed. As we are facing an increasing incidence of pollen allergies, a shift in sensitization patterns and changes in nutritional habits, and the occurrence of new, so far unknown allergies due to cross‐reactions are expected.     

Specific sensitization to common allergens and pulmonary function in the European Community Respiratory Health Survey

BACKGROUND: The role of atopy in the evolution to chronic obstructive disease remains controversial. AIM: We aimed to assess the association between individual sensitization to common allergens and lung function. METHOD: We analysed data from 12,687 subjects aged 20 to 44 years, from 34 centres in 15 countries participating in the European Community Respiratory Health Survey (ECRHS). Participants performed a blood test, lung function test, methacholine challenge, and answered an administered questionnaire. The relationships between specific IgE, FEV1 and FEV1/FVC ratio were assessed for each study centre stratified by sex, followed by random effects meta-analysis. RESULTS: Asthmatics sensitized to house dust mite had a lower FEV1 (-119 mL in women and -112 mL in men) and FEV1/FVC ratio (-1.95%, and -2.48%) than asthmatics without sensitization. Asthmatics sensitized to cat had a lower FEV1 (statistically significant for women only) and a lower FEV1/FVC ratio. Asthmatic women sensitized to grass had a lower FEV1 and a lower ratio, and those sensitized to Cladosporium had a lower FEV1. A weak association was found with sensitization to cat and to Cladosporium among non-asthmatic women, which disappeared after adjusting for BHR. CONCLUSION: We conclude that atopy was related to a lower lung function, which was only apparent among asthmatics. This relationship was explained by specific sensitization to cat and to house dust mite, the latter being homogeneous across areas.