Pattern Of Allergic Sensitization Research Articles

Patterns of allergic sensitization in adults with severe asthma: the ATLAS non-interventional study

Objectives Severe asthma is heterogeneous, with childhood-onset asthma believed more likely to be allergic, whereas adult-onset asthma is considered typically non-allergic. However, the allergic diagnosis is typically by exclusion: if patients do not react to an allergen panel, which is not standardized and often limited to few allergens, they are considered non-allergic. The overall aim of the ATLAS study was to characterize the sensitization to allergens in severe asthma (independent of phenotype). Methods Single-visit, cross-sectional, non-interventional study in adults with severe asthma. Analyses were conducted for total and specific immunoglobulin E against 53 allergens, overall and in subgroups, including age at asthma onset (<20 [childhood-onset] and >40 years of age). Results Among 1010 recruited patients, 28.4% reported childhood-onset asthma and 33.6% onset >40 years of age. After excluding patients receiving omalizumab/anti-IL5 therapy, 27.6% were not sensitized to any tested allergens, whereas 19.1% were sensitized to >10 allergens. All allergens triggered sensitization in some patients. Baseline characteristics in the two onset subgroups were similar; 23.2% with childhood-onset asthma were not sensitized to any allergen, compared to 32.0% with onset >40 years of age. Conclusion When a broad panel of allergens is used for sensitization testing, as many as three quarters of patients with severe asthma display sensitivity to at least one allergen, with substantial overlaps in all characteristics between the two age-at-onset subgroups. All of the tested allergens triggered a response in at least some patients, emphasizing the importance of including a broad range of allergens in any testing panel.

Patterns of allergic sensitization and factors associated with emergence of sensitization in the rural tropics early in the life course: findings of an Ecuadorian birth cohort.

Introduction: There are limited data on emergence of allergic sensitization (or atopy) during childhood in tropical regions.Methods: We followed a birth cohort of 2,404 newborns to 8 years in tropical Ecuador and collected: risk factor data by maternal questionnaires periodically from birth; atopy was measured by skin prick test reactivity (SPT) to aeroallergens in parents, and aeroallergens and food allergens in children at 2, 3, 5, and 8 years; and stool samples for soil-transmitted helminths (STH) from children periodically to 8 years and from parents and household members at the time of recruitment of cohort children. Data on risk factors were measured either at birth or repeatedly (time-varying) from birth to 8 years. Longitudinal repeated-measures analyses were done using generalized estimating equations to estimate the age-dependent risk of positive SPT (SPT+) to any allergen or mite during early childhood.Results: SPT+ to any allergen was present in 29.0% of fathers and 24.8% of mothers, and in cohort children increased with age, initially to mite but later to cockroach, reaching 14.8% to any allergen (10.7% mite and 5.3% cockroach) at 8 years. Maternal SPT+, particularly presence of polysensitization (OR 2.04, 95% CI 1.49–2.77) significantly increased the risk of SPT+ during childhood, while household overcrowding at birth decreased the risk (OR 0.84, 95% CI 0.72–0.98). For mite sensitization, maternal polysensitization increased (OR 2.14, 95% CI 1.40–3.27) but rural residence (OR 0.69, 95% CI 0.50–0.94) and birth order (3rd−4th vs. 1st−2nd: OR 0.71, 95% CI 0.52–0.98) decreased the risk. Time-varying exposures to agricultural activities (OR 0.77, 95% CI 0.60–0.98) and STH parasites (OR 0.70, 95% CI 0.64–0.91) during childhood decreased while anthelmintics increased the childhood risk (OR 1.47, 95% CI 1.05–2.05) of mite sensitization.Conclusion: Our data show the emergence of allergic sensitization, primarily to mite and cockroach allergens, during childhood in tropical Ecuador. A role for both antenatal and post-natal factors acting as potential determinants of SPT+ emergence was observed.

Extract and molecular-based early infant sensitization and associated factors-A PreventADALL study.

More knowledge about sensitization patterns in early infancy, including impact of molecular allergology, is needed to help predict future allergy development more accurately. We aimed to determine the prevalence and patterns of allergic sensitization at 3months of age, and explore possible associated factors. From the Scandinavian antenatally recruited PreventADALL mother-child cohort, we included 1110 3-month infants with available serum. Sensitization was defined as s-IgE of ≥0.1kUA /L by Phadiatop Infant® (ThermoFisher Scientific) including birch, cat, grass, dog, milk, egg, peanut and wheat. Further ImmunoCAP analyses to ovomucoid, casein, Ara h 1-3, omega-5-gliadin were performed in food extract s-IgE-positive children. Maternal sensitization was defined as s-IgE≥0.35kUA /L to Phadiatop® (inhalant allergen mix) and/or Fx5 (food allergen mix) at 18-week pregnancy. Overall 79 (7.3%) infants had specific sensitization, many with low s-IgE-levels (IQR 0.16-0.81kUA /L), with 78 being sensitized to food extract allergens; 41 to egg, 27 to milk, 10 to peanut, and 25 to wheat. A total of 62/78 were further analysed, 18 (29%) had s-IgE to ovomucoid, casein, Ara h 1-3 and/or omega-5-gliadin. Eight infants (0.7%) were sensitized to inhalant allergens. Maternal sensitization to food allergens was associated with infant sensitization, odds ratio 3.64 (95% CI 1.53-8.68). Already at 3months of age, 7% were sensitized to food, mostly without detectable s-IgE to food allergen molecules, and <1% to inhalant allergens. Maternal food sensitization was associated with infants' sensitization.

Pattern of allergic sensitization in chronic rhinitis: A 19-year retrospective study.

The pattern of allergic sensitization provides data for physicians to take appropriate care of allergic patients. To analyze the long-term pattern of allergen skin prick test (SPT) sensitization at a single tertiary care hospital in Thailand. Medical records of adult rhinitis patients during 1998 to 2017 were reviewed. Inclusion criteria were chronic rhinitis with positive SPT to at least one aeroallergen in the test panel. Outcome measures were SPT results, clinical symptoms, and their effect on patient quality of life (QoL). Descriptive statistics were used to demonstrate the pattern of sensitization. Multivariate linear regression was used to identify association between evaluated factors and patient QoL. Six thousand five hundred and seventeen adult patients were included in this study. Mean age was 36.4 & 13.8 years. A majority of patients (59.4%) had positive SPT, and 83.7% of those had polysensitization. Dermatophagoides pteronyssinus and sedge were the most common indoor (54.8%) and outdoor allergens (37.7%), respectively. Compared among the various periods of data collection over a 19-year period, there was no major change in the pattern of sensitization. Considering the most recent data from 2013-2017, the prevalence of sensitization increased from 66.8% to 73.7% (p < 0.001). Clinical symptoms, except sneezing and allergen sensitization, affect QoL of chronic rhinitis patients (p < 0.001). House dust mite and sedge are the most common indoor and outdoor allergens. There was no major change in the pattern of sensitization. Almost all allergic symptoms significantly affect QoL.

Allergic sensitization pattern of patients in Brazil

ObjectiveAllergic sensitization is one of the key components for the development of allergies. Polysensitization seems to be related to the persistence and severity of allergic diseases. Furthermore, allergic sensitization has a predictive role in the development of allergies. The aim of this study was to characterize the pattern of sensitization of atopic patients treated at different pediatric allergy referral centers in Brazil. MethodsA nation-wide transversal multicenter study collected data on patients attended in Brazil. Peripheral blood samples were collected to determine the serum levels of allergen-specific IgE. If allergen-specific IgE was higher than 0.1 kUA/L, the following specific components were quantified. ResultsA total of 470 individuals were enrolled in the study. Mite sensitization was the most frequent kind in all participants. A high frequency of sensitization to furry animals and grasses featured in the respiratory allergies. Regarding components, there was a predominance of sensitization to Der p 1 and Der p 2. It has been verified that having a food allergy, atopic dermatitis, or multimorbidity are risk factors for the development of more severe allergic disease. ConclusionStudies on the pattern of allergic sensitization to a specific population offer tools for the more effectual prevention, diagnosis, and treatment of allergic diseases. Sensitization to dust mites house was the most prevalent in the evaluated sample. High rates of sensitization to furry animals also stand out. Patients with food allergy, atopic dermatitis, or multimorbidity appear to be at greater risk for developing more severe allergic diseases.

Recent changing pattern of aeroallergen sensitization in children with allergic diseases: A single center study

Purpose: Allergic diseases have been increasing worldwide over the past few decades. Allergic sensitization is a pivotal risk factor for the development of allergic diseases. The purpose of this study was to examine changes in allergic sensitization patterns of aero allergens over the last 10 years in children with respiratory allergic diseases. Methods: We retrospectively reviewed the medical records of 12,848 children under the age of 18 years who received skin prick tests (n=3,852) or serum specific IgE tests (n=8,996) to evaluate sensitization from 2007 to 2016 in a single center, Seoul, Korea. Results: Sensitization rate to house dust mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus) reached a plateau in preschool (28.3%-32.8%) and schoolchildren (45.8%-47.2%). Sensitization rate to animal dander (cat and dog) was increasing from 8.4% to 12.5% in preschool children and from 10.3% to 18.6% in schoolchildren (trend P<0.001 each). In preschool children, tree (birch, oak, and alder; from 3.5% to 6.4%), grass (timothy; from 0.8% to 6.5%), weed (ragweed and mugwort; from 2.8% to 6.9%) pol lens and mold (Alternaria; from 2.5% to 6.0%) were also in similar increasing pattern (trend P=0.001, P<0.001, P=0.003, and P<0.001, respectively). Additionally, tree (from 9.0% to 15.2%), grass (from 2.6% to 5.2%) pollens were also in increasing pattern in schoolchildren (trend P<0.001 and P=0.024, respectively). Conclusion: Over the past 10 years, sensitization patterns of aeroallergen have been changing in Korean children with allergic dis eases. We should pay attention to the changing patterns of allergic sensitization to educate and prevent the allergic disease. (Allergy Asthma Respir Dis 2019;7:186-191)

Sensitization profiles to hazelnut allergens across the United States

BackgroundMeasurement of IgE antibody to hazelnut components can aid in the prediction of allergic responses to the food. ObjectiveTo investigate the association between patient demographics (age, location) and patterns of allergic sensitization to hazelnut components across the United States and to investigate the degree of correlation between hazelnut sensitization with sensitization to other tree nuts, peanuts, and their components. MethodsSerum samples from 10,503 individuals with hazelnut extract specific IgE (sIgE) levels of 0.35 kUA/L or higher were analyzed for IgE antibodies to Cor a 1, 8, 9, and 14 by ImmunoCAP. A subset of these patients were analyzed for IgE antibodies to peanut, walnut, and cashew nut IgE along with associated components. ResultsAmong hazelnut sensitized individuals, children (<3 years old) were predominantly sensitized to Cor a 9 and Cor a 14. Conversely, Cor a 1 sIgE sensitization was much higher in adults than children, especially in the Northeastern United States. Cor a 8 sensitization was relatively constant (near 10%) across all ages. Cosensitization of hazelnut with other tree nuts and peanuts was related to correlation of IgE concentrations of individual component families. ConclusionWe conclude that sensitization to individual hazelnut components is highly dependent on age and/or geographic location. Component correlations suggest that cosensitization to hazelnut and walnut may be caused by their pathogenesis-related protein 10 allergens, nonspecific lipid transfer proteins, or seed storage proteins, whereas hazelnut and peanut cosensitization is more often caused by cross-reactivity of pathogenesis-related protein 10 (Cor a 1 and Ara h 8) and nonspecific lipid transfer proteins (Cor a 8 and Ara h 9).

Joint Clustering With Correlated Variables

ABSTRACTTraditional clustering methods focus on grouping subjects or (dependent) variables assuming independence between the variables. Clusters formed through these approaches can potentially lack homogeneity. This article proposes a joint clustering method by which both variables and subjects are clustered. In each joint cluster (in general composed of a subset of variables and a subset of subjects), there exists a unique association between dependent variables and covariates of interest. To this end, a Bayesian method is designed, in which a semi-parametric model is used to evaluate any unknown relationships between possibly correlated variables and covariates of interest, and a Dirichlet process is used to cluster subjects. Compared to existing clustering techniques, the major novelty of the method exists in its ability to improve the homogeneity of clusters, along with the ability to take the correlations between variables into account. Via simulations, we examine the performance and efficiency of the proposed method. Applying the method to cluster allergens and subjects based on the association of wheal size in reaction to allergens with age, we found that a certain pattern of allergic sensitization to a set of allergens has a potential to reduce the occurrence of asthma.

Patterns of allergic sensitization and atopic dermatitis from 1 to 3 years: Effects on allergic diseases.

While allergic sensitization and atopic dermatitis (AD) are known to increase the risk for allergic diseases, the impact of different temporal and clinical patterns of sensitization and AD is less well defined. We investigated patterns of sensitization and AD from early infancy to age 3, and the differential risk of developing allergic diseases within each pattern in a general cohort. Children (n = 2629) from the Canadian Healthy Infant Longitudinal Development (CHILD) Study underwent skin prick tests and were assessed clinically for AD at ages 1 and 3 years. We applied an unsupervised latent class analysis (LCA) to the following 5 factors at these ages: AD, food sensitization, inhalant sensitization, poly-sensitization to foods and poly-sensitization to inhalants. The risks for developing asthma, allergic rhinitis and food allergy at 3 years were evaluated for each identified group. Five distinct classes were revealed by LCA: healthy (81.8%), atopic dermatitis (7.6%), inhalant sensitization (3.5%), transient sensitization (4.1%) and persistent sensitization (3.2%). Using healthy children as the baseline, children in the "atopic dermatitis" group had the next lowest risk for all allergic outcomes at 3 years; those in the "inhalant sensitization" group had the highest risk for allergic rhinitis; children in the "transient sensitization" group were at an increased risk for food allergy; while children in the "persistent sensitization" group had the highest risk for all allergic diseases. There is substantial heterogeneity among allergen-sensitized children. Researchers and clinicians need to be aware of the non-specificity associated with labelling children simply as "atopic" and "non-atopic" without considering the timing of their atopic history, type of sensitization and AD status. Children with AD who were poly-sensitized to foods at an early age appear to be at greatest risk of developing other allergic diseases.

Allergic sensitization patterns identified through latent class analysis among children with and without asthma

BackgroundSpecific patterns of allergic sensitization to common allergens may provide relevant clinical insight into asthma risk. ObjectiveTo identify patterns of allergic sensitization based on multiple individual allergens and link these to current and persistent asthma using baseline and 3-year follow-up data. MethodsChildren 7 to 8 years old with (n = 196) and without (n = 136) asthma from the New York City Neighborhood Asthma and Allergy Study were studied. IgE against a panel of 112 antigens was measured using the ISAC multiplex panel array. Latent class analysis (LCA) was used to identify patterns of allergic sensitization among the 26 most common allergens against which children had measurable IgE. The association between patterns of allergic sensitization and risk of asthma and other allergic diseases was examined. ResultsLCA identified 4 patterns of allergic sensitization as follows: low risk of sensitization (prevalence of 53% in children with asthma and 76% in children without asthma), indoor (prevalence of 23% in children with asthma and 15% in children without asthma), pollen and indoor group 1 (prevalence of 16% in children with asthma and 5% in children without asthma), and pollen and indoor group 2 (prevalence of 9% in children with asthma and 4% in children without asthma). Compared with the low risk of sensitization pattern, children belonging to the 3 sensitized patterns had significantly higher risk of asthma at ages 7 to 8 years and 3 years later, with the highest risk for children in the pollen and indoor group 1 pattern. ConclusionsLCA facilitates the study of sensitization profiles to a large number of common allergens. Analyzing patterns of allergic sensitization from multiple allergens reveals additional relevant associations with asthma than the study of a single allergen or total IgE.

The Prevalence and Patterns of Allergic Sensitization in Isparta, Turkey

The Prevalence and Patterns of Allergic Sensitization in Isparta, Turkey

Patterns of Allergic Sensitization in High IgE Syndromes.

Dramatic elevations in the serum IgE level are seen both in polygenic allergic diseases such as atopic dermatitis and food allergy, and in a growing list of monogenic primary immune deficiencies (PIDs). Although the IgE produced in patients with PID has generally been considered to be driven by dysregulated IL-4 production and thus lack antigen specificity, in fact allergen-specific IgE can be detected by skin and serum testing in many of these patients. However, perhaps not surprisingly given the distinct immunologic pathways involved, the patterns of allergic disease and atopic sensitization vary widely between syndromes, leading to strikingly different clinical phenotypes.

The Editor takes a closer look at some of this month's articles

The Editor takes a closer look at some of this month's articles

Prevalence of allergic sensitization in the United States: Results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006

Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005-2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population. We investigated clustering, sociodemographic, and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization. Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Participants aged 1 year or older (n = 9440) were tested for serum specific IgEs (sIgEs) to inhalant and food allergens; participants 6 years or older were tested for 19 sIgEs, and children aged 1 to 5 years were tested for 9 sIgEs. Serum samples were analyzed by using the ImmunoCAP System. Information on demographics and participants' characteristics was collected by means of questionnaire. Of the study population aged 6 years and older, 44.6% had detectable sIgEs, whereas 36.2% of children aged 1 to 5 years were sensitized to 1 or more allergens. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling young age, male sex, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization. The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs based on sociodemographic and regional factors. Biological cross-reactivity might be an important but not the sole contributor to the clustering of allergen-specific IgEs.

Sensitization to airborne allergens among adults and its impact on allergic symptoms: a population survey in northern Vietnam

BackgroundThe knowledge about allergic sensitization and its relationship with clinical symptoms and diseases among adults in South-East Asia is poor. The aim of this study was to investigate the prevalence and pattern of allergic sensitization and the association with asthma and allergic rhinitis in adults in urban and rural Vietnam.MethodsAmong 5,782 responders to a questionnaire survey in northern Vietnam, a random sample was invited to a clinical follow-up and 684 (46%) participated. The methods included a structured interview using a modified GA2LEN study questionnaire on symptoms and possible determinants for diseases. Skin prick test (SPT) with ten common airborne indoor and outdoor allergens, lung function test, and methacholine test was performed among subjects ≤60 years of age.ResultsIn total, one third of subjects had a positive SPT reaction to at least one allergen, 36.9% of men and 31.0% of women (n.s.). The most common sensitizer was the storage mite B. tropicalis (men 27.7%; women 18.7%) followed by house dust mite D. pteronyssinus (men 16.5%; women 10.6%), and D. farinae (men 15.3%; women 6.3%), and cockroach (men 16.5%; women 10.2%). Sensitization to all major allergens were significantly more common among men and among subjects ≤45 years compared with women and subjects >45 years, respectively. The prevalence of sensitization to animals, pollen and molds were low. The majority of cockroach-sensitized subjects were also sensitized to mites. Sensitization to any allergen and all major allergens were significantly associated with rhinitis, but not with asthma. However, bronchial hyper-reactivity was significantly associated with increasing number of positive SPTs (p = 0.047).ConclusionsAmong adults in northern Vietnam sensitization to mite and cockroach most common in both rural and urban areas. The dominant sensitizer was the storage mite B. tropicalis, which should be included in future studies and also in clinical practice, owing to its association with clinical symptoms. As in the Western world allergic sensitization was associated with rhinitis and bronchial hyper-reactivity. The lack of association with asthma in South-East Asia needs to be studied further.

Specific patterns of allergic sensitization in early childhood and asthma &amp; rhinitis risk

Specific patterns of allergic sensitization as well as quantification of the in vitro IgE response in early life may provide relevant clinical insight into future rhinitis and asthma risk. To define relationships among established sensitization to particular aeroallergens, quantitative analyses of allergen-specific IgE levels, pet exposure and sensitization, and asthma and rhinitis risk. Children at high-risk for the development of asthma and allergic diseases were enrolled at birth into the Childhood Origins of ASThma (COAST) study. Allergen-specific IgE was assessed at ages 1, 3, 6, and 9years by fluoroenzyme immunoassay (Unicap(®) 100; Pharmacia Diagnostics). Current asthma and rhinitis were diagnosed at age 6 and 8years. Sensitization to dog was strongly associated with increased asthma risk (P<0.0001). Sensitization to perennial compared with seasonal allergens was more strongly associated with asthma risk, while sensitization to seasonal allergens was more closely associated with rhinitis risk. Increased levels of specific IgE to perennial allergens were associated with an increased asthma risk (P=0.05), while any detectable level of IgE to seasonal allergens was associated with increased rhinitis risk (P=0.0009). While dog and cat sensitization were both independently associated with increased asthma and rhinitis risk, dog exposure at birth was associated with a reduced risk of asthma, regardless of dog sensitization status during the first 6years of life (P=0.05). Analysing specific patterns of an individual's allergic sensitization profile reveals additional relevant associations with asthma and rhinitis risk as opposed to the information gained from characterizing an individual as 'atopic' by the presence of any demonstrable sensitization alone. Furthermore, protective mechanisms of dog exposure with regards to asthma risk appear to be unrelated to the prevention of sensitization.

The allergic sensitization in infants with atopic eczema from different countries

No study has compared allergic sensitization patterns in infants with atopic eczema from different countries. The aim of this study was to investigate the patterns of allergic sensitization in a cohort of infants with atopic eczema participating in a multicentre, international study. Two thousand one hundred and eighty-four infants (mean age 17.6 months) with atopic eczema from allergic families were screened in 94 centres in 12 countries to participate in a randomized trial for the early prevention of asthma. Clinical history, Severity Scoring of Atopic Dermatitis Index, measurements for total serum IgE and specific IgE antibodies to eight food and inhalant allergens were entered into a database before randomization to treatment. A history of type of feeding in the first weeks of life and exposure to animals was recorded. A total of 52.9% of the infants had raised total IgE, and 55.5% were sensitized to at least one allergen. There was a wide difference in the total IgE values and in the sensitization rates to foods and aeroallergens among infants from different countries. The highest prevalence rates of allergen-sensitized infants were found in Australia (83%), the UK (79%) and Italy (76%). Infants from Belgium and Poland consistently had the lowest sensitization rates. In each country, a characteristic pattern of sensitization was found for aeroallergens (house dust mite > cat > grass pollen > Alternaria), but not for food allergens. In infants with atopic eczema, there is a wide variation in the pattern of allergic sensitization between countries, and data from one country are not necessarily generalizable to other countries.

Determinants of Aeroallergen-specific IgE in a New York Birth Cohort of Puerto Rican Children

RationaleCompared with other Latino groups, Puerto Rican children have a high prevalence of asthma and differing patterns of allergic sensitization.MethodsWith an inner-city birth cohort of 274 New York City-born Puerto Rican children selected on maternal history of atopy/asthma settled dust levels of cockroach, mouse, cat, and dust mite allergen and the development of specific IgE against these four aeroallergens are being measured. To date, we have allergen-specific IgE for 82 children who have reached age 4 and their mothers.ResultsBy age 4, 23% of the children were seroatopic (i.e. ≥0.35 IU/ml to any of the measured aeroallergen), specifically sensitized to cockroaches (7%), mice (7%), cats (10%), and dust mites (10%). Children had greater odds of seroatopy when mothers were sensitized to dust mites (OR = 4.0 [1.3-12.1]) or cats (OR = 3.3 [1.1-9.7]). Neither maternal cockroach nor mouse sensitization was significantly associated with children's seroatopy. Allergen concentrations in dust were not significantly associated with children's seroatopy. Nonetheless, none of the 12 children who were born into a home with cats developed IgE to any of the aeroallergens as compared with 27% seroatopy among those who were not born in a home with a cat.ConclusionsPuerto Rican children whose mothers are sensitized to dust mites or cats have greater odds of developing IgE specific for at least one of the tested indoor allergens. Cat ownership appeared to be inversely associated with sensitization at this age. Further study of this cohort will examine how socio-cultural factors influence allergic sensitization. RationaleCompared with other Latino groups, Puerto Rican children have a high prevalence of asthma and differing patterns of allergic sensitization. Compared with other Latino groups, Puerto Rican children have a high prevalence of asthma and differing patterns of allergic sensitization. MethodsWith an inner-city birth cohort of 274 New York City-born Puerto Rican children selected on maternal history of atopy/asthma settled dust levels of cockroach, mouse, cat, and dust mite allergen and the development of specific IgE against these four aeroallergens are being measured. To date, we have allergen-specific IgE for 82 children who have reached age 4 and their mothers. With an inner-city birth cohort of 274 New York City-born Puerto Rican children selected on maternal history of atopy/asthma settled dust levels of cockroach, mouse, cat, and dust mite allergen and the development of specific IgE against these four aeroallergens are being measured. To date, we have allergen-specific IgE for 82 children who have reached age 4 and their mothers. ResultsBy age 4, 23% of the children were seroatopic (i.e. ≥0.35 IU/ml to any of the measured aeroallergen), specifically sensitized to cockroaches (7%), mice (7%), cats (10%), and dust mites (10%). Children had greater odds of seroatopy when mothers were sensitized to dust mites (OR = 4.0 [1.3-12.1]) or cats (OR = 3.3 [1.1-9.7]). Neither maternal cockroach nor mouse sensitization was significantly associated with children's seroatopy. Allergen concentrations in dust were not significantly associated with children's seroatopy. Nonetheless, none of the 12 children who were born into a home with cats developed IgE to any of the aeroallergens as compared with 27% seroatopy among those who were not born in a home with a cat. By age 4, 23% of the children were seroatopic (i.e. ≥0.35 IU/ml to any of the measured aeroallergen), specifically sensitized to cockroaches (7%), mice (7%), cats (10%), and dust mites (10%). Children had greater odds of seroatopy when mothers were sensitized to dust mites (OR = 4.0 [1.3-12.1]) or cats (OR = 3.3 [1.1-9.7]). Neither maternal cockroach nor mouse sensitization was significantly associated with children's seroatopy. Allergen concentrations in dust were not significantly associated with children's seroatopy. Nonetheless, none of the 12 children who were born into a home with cats developed IgE to any of the aeroallergens as compared with 27% seroatopy among those who were not born in a home with a cat. ConclusionsPuerto Rican children whose mothers are sensitized to dust mites or cats have greater odds of developing IgE specific for at least one of the tested indoor allergens. Cat ownership appeared to be inversely associated with sensitization at this age. Further study of this cohort will examine how socio-cultural factors influence allergic sensitization. Puerto Rican children whose mothers are sensitized to dust mites or cats have greater odds of developing IgE specific for at least one of the tested indoor allergens. Cat ownership appeared to be inversely associated with sensitization at this age. Further study of this cohort will examine how socio-cultural factors influence allergic sensitization.

Aeroallergen sensitization correlates with PC 20 and exhaled nitric oxide in subjects with mild-to-moderate asthma

Aeroallergen sensitization in adult asthmatic patients from a wide geographic area has not been correlated with patients' characteristics, markers of airways inflammation, and lung function. We assessed data obtained from the Asthma Clinical Research Network trials to determine the relationship of aeroallergen sensitization to age, sex, ethnicity, and markers of inflammation and airways function. Skin testing (14 epicutaneous) was performed on 1338 subjects with objectively diagnosed mild-to-moderate asthma from 11 Asthma Clinical Research Network studies. Skin testing used identical techniques and a quality assurance program to ensure uniformity across centers. Ninety-five percent of the subjects had at least 1 positive skin test response. Of these, 14% had positive reactions to 1 or 2 allergens and 81% had positive reactions to 3 or more allergens, and 2% of subjects reacted only to seasonal allergens, 26% only to perennial allergens, and 67% to both. Increasing IgE and exhaled nitric oxide values, decreasing PC(20) values, and minority ethnicity significantly correlated with the number of positive skin test responses. Subjects with late-onset asthma were less likely to be sensitized; nonetheless, 89% of subjects older than 60 years had positive responses. Ninety-five percent of patients with mild-to-moderate asthma might have an allergic component. Age does not significantly affect aeroallergen sensitization, but the pattern of allergic sensitization varies with ethnicity and geography. Measures used to characterize asthma, such as IgE, exhaled nitric oxide, and PC(20) values, are correlated with aeroallergen sensitization.

Prevalence of allergy, patterns of allergic sensitization and allergy risk factors in rural and urban children

We aimed to compare the prevalence of allergic diseases and sensitization in children living in urban and rural areas and to identify potential risk/protection factors associated with allergy. School children 12-16 years old, from urban community (n = 201) and rural area (n = 203) were recruited. The data obtained by questionnaire were referred to doctors' diagnosis, skin prick tests (SPTs), and serum specific and total IgE assessment. The prevalence of allergic diseases in urban children was significantly higher as compared with rural children [asthma 16.42%vs 1.97% (P < 0.001) allergic rhinitis 38.81%vs 10.84% (P < 0.001)]. Positive SPTs to at least one allergen was found in 63.7% of urban and 22.7% rural children (P < 0.001). Significantly higher percentage of allergic rural than urban children were monosensitized or sensitized to 2-4 allergens, but almost a fourfold higher percentage of allergic urban children was found to be sensitized to five or more allergens (P < 0.0001). The history of frequent upper respiratory factor (URT) infections, antibiotic therapy, tonsiltectomy/adenoidectomy were positively associated with development of atopy and sensitization. Our findings confirm that residence of rural area is associated with a significant lower prevalence of allergic sensitization and symptoms in school children. Several risk and protective factors related to environment and style of life could be identified in both environments.