Allergen-specific IgE Levels Research Articles

Preterm birth reduces the incidence of atopy in adulthood

Immunologic pathways are primed in early life. Preterm birth can influence this process and thereby affect whether a person will have atopy later in life. Previous studies on the effects of preterm birth on atopy in adulthood have been inconclusive and limited to children or subjects born moderately preterm. Our aim was to compare the incidence of atopy among young adults who were born preterm and at very low birth weight (≤ 1500 g) with that of term-born young adults (control subjects). The study comprised 166 adults who were born preterm and at very low birth weight and 172 control subjects, all of whom were from the Helsinki Study of Very Low Birth Weight Adults. We assessed atopic predisposition at ages 18 to 27 years using skin prick tests for 6 common aeroallergens and measurements of serum concentrations of total IgE and 3 types of allergen-specific (cat, birch, and timothy) IgE. We asked the subjects whether they had been given a diagnosis of asthma or allergic rhinitis or had atopic eczema and analyzed data by using logistic or linear regression, adjusting for potential confounding factors. The risk for having at least 1 positive reaction on a skin prick test was reduced (adjusted odds ratio, 0.43; 95% CI, 0.23-0.79, P = .007), and the concentration of cat-specific IgE was less (25% less; 95% CI, 43% to 2.3% less; P = .033) in sera from very-low-birth-weight subjects compared with that seen in sera from control subjects. Within the very-low-birth-weight group, those born at an earlier gestational age were less likely to have positive skin prick test reactions (adjusted odds ratio for 1 week, 0.82; 95% CI, 0.68-0.98, P = .029) and less likely to have high levels of allergen-specific IgE. Cumulative incidences of atopic disease were similar between adults of very low birth weight and control subjects. Young adults born prematurely and at very low birth weight have a lower incidence of atopy than adults who were born full term. This finding supports the hypothesis that the risk for atopy is determined during early stages of development.

Vitamin D levels and food and environmental allergies in the United States: Results from the National Health and Nutrition Examination Survey 2005-2006

Previous research supports a possible link between low vitamin D levels and atopic disease. However, the association between low vitamin D levels and total and allergen-specific IgE levels has not been studied. We sought to test the association between serum 25-hydroxyvitamin D (25[OH]D) deficiency (<15 ng/mL) and insufficiency (15-29 ng/mL) and allergic sensitization measured by serum IgE levels in a US nationally representative sample of 3136 children and adolescents and 3454 adults in the National Health and Nutrition Examination Survey 2005-2006. The association of 25(OH)D deficiency with 17 different allergens was assessed after adjustment for potential confounders, including age; sex; race/ethnicity; obesity, low socioeconomic status; frequency of milk intake; daily hours spent watching television, playing videogames, or using a computer; serum cotinine levels; and vitamin D supplement use. In children and adolescents allergic sensitization to 11 of 17 allergens was more common in those with 25(OH)D deficiency. Compared with sufficient vitamin D levels of greater than 30 ng/mL, after multivariate adjustment, 25(OH)D levels of less than 15 ng/mL were associated with peanut (odds ratio [OR], 2.39; 95% CI, 1.29-4.45), ragweed (OR, 1.83; 95% CI, 1.20-2.80), and oak (OR, 4.75; 95% CI, 1.53-4.94) allergies (P<.01 for all). Eight other allergens were associated with 25(OH)D deficiency, with P values of less than .05 but greater than .01. There were no consistent associations seen between 25(OH)D levels and allergic sensitization in adults. Vitamin D deficiency is associated with higher levels of IgE sensitization in children and adolescents. Further research is needed to confirm these findings.

Allergy-related outcomes in relation to serum IgE: results from the National Health and Nutrition Examination Survey 2005-2006.

The National Health and Nutrition Examination Survey (NHANES) 2005-2006 was the first population-based study to investigate levels of serum total and allergen-specific IgE in the general US population. We estimated the prevalence of allergy-related outcomes and examined relationships between serum IgE levels and these outcomes in a representative sample of the US population. Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Study subjects aged 6 years and older (n= 8086) had blood taken for measurement of total IgE and 19 specific IgE levels against common aeroallergens, including Alternaria alternata, Aspergillus fumigatus, Bermuda grass, birch, oak, ragweed, Russian thistle, rye grass, cat dander, cockroach, dog dander, dust mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus), mouse and rat urine proteins, and selected foods (egg white, cow's milk, peanut, and shrimp). Serum samples were analyzed for total and allergen-specific IgE by using the Pharmacia CAP System. Information on allergy-related outcomes and demographics was collected by questionnaire. In NHANES 2005-2006, 6.6% reported current hay fever, and 23.5% had current allergies. Allergy-related outcomes increased with increasing total IgE levels (adjusted odds ratios for a 10-fold increase in total IgE level of 1.86 [95% CI, 1.44-2.41] for hay fever and 1.64 [95% CI, 1.41-1.91] for allergies). Increased levels of plant-, pet-, and mold-specific IgE contributed independently to allergy-related symptoms. The greatest increase in odds was observed for hay fever and plant-specific IgE (adjusted odds ratio, 4.75; 95% CI, 3.83-5.88). In the US population self-reported allergy symptoms are most consistently associated with increased levels of plant-, pet-, and mold-specific IgE.

Effects of aqueous extract of Echinodorus grandiflorus on the immune response in ovalbumin-induced pulmonary allergy

Asthma is a disease characterized by intermittent obstruction of the airways and chronic inflammation that affects approximately 300 million people worldwide. The immune response in asthma is predominantly T(H)2, with high levels of total and allergen-specific IgE and bronchial eosinophilia. Asthma treatment is aimed at controlling the disease, and the drugs used currently have systemic adverse effects and generally are not effective in difficult-to-control cases. To investigate the effect of aqueous extract of Echinodorus grandiflorus, a plant used in folk medicine for its diuretic and anti-inflammatory properties, in a model of pulmonary allergy. BALB/c mice were intraperitoneally sensitized and nasally challenged with ovalbumin. Aqueous extract and dexamethasone treatments (0.1 mL/d per mouse) were initiated on day 32 and concluded on day 40. Eight hours after the last challenge evaluations, of serum, bronchoalveolar lavage, and lung tissue were performed. Oral treatment with the extract markedly reduced the number of total cells and eosinophils in bronchoalveolar lavage. The eosinophil peroxidase activity in lung tissue, the levels of ovalbumin-specific IgE in serum, the levels of CCL11, and the gene expression of interleukin 4 and interleukin 13 in lung tissue were also lower after treatment. These results suggest that the aqueous extract of E grandiflorus is able to modulate allergic pulmonary inflammation and may be useful as a potential therapeutic agent for asthma.

High allergen‐specific serum immunoglobulin E levels in nonatopic West Highland white terriers

Human and canine atopic dermatitis (AD) share an association with IgE specific to environmental allergens, but few studies have evaluated serum allergen-specific IgE in nonatopic dogs. This study compared serum allergen-specific IgE levels in 30 atopic and 18 nonatopic West Highland white terriers. Atopic dermatitis was confirmed using standard criteria. Nonatopic dogs were over 5 years of age and had no clinical signs or history of AD. Serum allergen-specific IgE levels were measured with Allercept(®) IgE ELISAs using a 48-allergen Australian panel. Positive reactions were defined as ≥150 ELISA absorbance units. Intradermal tests were performed in 16 atopic dogs, either at the time of or at various times prior to serum collection. In atopic dogs, the most common positive ELISA and intradermal test results were to Dermatophagoides farinae (11 of 30 dogs), but there were no statistically significant correlations between results from the two methods for any allergen. In nonatopic dogs, multiple high-positive ELISA reactions were reported to 45 of 48 allergens, most commonly D. farinae and Tyrophagus putrescentiae (17 of 18 dogs each). Positive ELISA results in nonatopic dogs were statistically significantly higher than those in atopic dogs for 44 of 48 allergens, including two allergens (D. farinae and Dermatophagoides pteronyssinus) commonly regarded as significant in canine AD. In conclusion, positive allergen-specific IgE ELISAs were not specific for canine AD, and high allergen-specific IgE levels were seen in nonatopic dogs. The clinical significance of this and whether it characterizes a protective phenotype is unclear.

Fruit and vegetable consumption in relation to allergy: Disease-related modification of consumption?

Previous largely cross-sectional studies suggest that fruit and vegetable consumption reduces the risk of allergic disease in children, but results are conflicting. To investigate the association between current fruit or vegetable intake and allergic disease in 8-year-old Swedish children, and to evaluate the potential effect of disease-related modification of consumption. Cross-sectional data were obtained from a Swedish birth cohort study. Information on fruit and vegetable consumption as well as symptoms and diagnoses of allergic diseases was obtained by parental questionnaires at the 8-year follow-up. Allergen-specific IgE levels against food and inhalant allergens were obtained from blood samples collected at age 8 years. In total, 2447 children were included. Data were analyzed with logistic regression. An inverse relation was observed between total fruit consumption and rhinitis (odds ratio, highest vs lowest quartile, 0.62; 95% CI, 0.45-0.86; P for trend, .002), whereas no association was observed for total vegetable intake. In analyses of individual foods, intake of apples/pears and carrots was inversely associated with rhinitis, asthma, and atopic sensitization. Fifty percent of the children with rhinitis were sensitized against birch pollen, which may cross-react with apples and carrots. After exclusion of children who reported food-related allergic symptoms, most of the observed inverse associations moved toward the null and became nonsignificant. We confirm the inverse associations between fruit intake and allergic disease in children observed in earlier studies. However, our data also indicate that disease-related modification of consumption contributed to this association.

Guidelines for the Diagnosis and Management of Food Allergy in the United States: Summary of the NIAID-Sponsored Expert Panel Report

Guidelines for the Diagnosis and Management of Food Allergy in the United States: Summary of the NIAID-Sponsored Expert Panel Report

Asthma cases in childhood attributed to atopy in tropical area in Brazil

This study aimed to explore the association between asthma and atopy in a cohort of children living in a large urban center in Brazil. Atopy was defined by the presence of allergen-specific IgE in serum or by a positive skin prick test. In a sample of 1 445 Brazilian children, the association between the prevalence of asthma, skin prick test positivity, and allergen-specific IgE in serum was investigated. The prevalence of asthma was 22.6%. The presence of serum allergen-specific IgE was frequent in asthmatics and nonasthmatics, and the prevalence of asthma increased only with levels of allergen-specific IgE > 3.5 kilounits/L. The proportion of asthma attributable to atopy was estimated to be 24.5% when atopy was defined by the presence of allergen-specific IgE. With a given level of specific IgE, no association between skin test reactivity and asthma was observed. Skin prick tests were less sensitive than specific IgE for detection of atopy. Most asthma cases in an urban underprivileged setting in Brazil were not attributable to atopy. This observation has important implications for understanding the risk factors for the asthma epidemic in Latin America.

Tolerability and clinical efficacy of oral immunotherapy with house dust mites in a model of canine atopic dermatitis: a pilot study

Atopic dermatitis (AD) is a chronic, life-long disease. In humans, immunotherapy (IT) is the only treatment that can alter the course of AD. Oral IT is appealing owing to the ease of administration and the potential for increased compliance. The purposes of this study were to investigate the tolerability, clinical efficacy and effects on allergen-specific IgE of oral IT using a canine AD model. Thirteen atopic beagles sensitized to house dust mites (HDMs) were randomly divided into two groups. One group received daily oral doses of HDMs while the other group received vehicle only for 7 months. The investigator evaluating the dogs was blinded to the allocation of treatments. Prior to and after 2 and 7 months of IT, dogs were challenged daily with HDMs for 3 days concurrently, and clinical signs were scored using a modified Canine Atopic Dermatitis Extent and Severity Index (CADESI). Prior to and at completion of oral IT, serum was collected for measurement of allergen-specific IgE. Oral IT was well tolerated, and no adverse effects were noted. Analysis of variance showed no significant effect of time, group and group × time interaction for CADESI scores. In addition, there were no significant differences in allergen-specific IgE levels. In conclusion, it appears that oral administration of HDMs is well tolerated in these atopic beagles but that this protocol was not sufficient to induce clinical improvement. Further, longer-term studies will be necessary to explore the potential of oral IT in veterinary medicine.

854 Allergen Specific Ige and Total Ige Levels in Preschool Children with Acute Urticaria

Background and aim: The common causes of acute urticaria are viral respiratory infection, foods allergens and medications. The aim was to identify the contribution of foods, viral infections and drugs to induce acute urticaria in relation to specific and total IgE levels. Methods: The authors present a prospective study included preschool aged children admited in pediatric clinic for acute urticaria over a 2-year period. The diagnosis of acute urticaria is based on personal medical history and clinical manifestations. Allergen-specific IgE levels were measured for a panel of 11 foods (cow's milk. egg white, whole egg, codfish, peanut, hazelnut, soy, cereal mix, wheat, tomato, citrus mix) and drug (penicillinum). The measurement of specific IgE using serologic assays RAST/EAST (EAST class qualitative range 0-4). Total IgE levels of >100 kUI/L were considered positive. Results: 38 preschool children with acute urticaria were included in the study. 28 children (73.6%) had respiratory infection associated with antibiotics intake. The duration of urticaria was 5.80+/-;2.40 days. Foods ingestion were considered responsible for urticaria in 10 cases (26.4%). The levels of specific IgE were correlated with acute urticaria for eggs (1-4), cow's milk (2-3), peanuts (2-4), codfish (2-4), soybeant (2-4), wheat (1-3), cereal mix (2-4), citrus mix (1-4), tomato (2-3). Total IgE level was elevated in 24 cases. Conclusions: Infections, foods, drugs induced acute urticaria in children. The correlation of total and specific IgE levels and symptoms was determined. The results indicate that children with higher total IgE and specific IgE levels have a major risk of recurrent urticaria.

Identification of the Mhc Region as an Asthma Susceptibility Locus in Recombinant Congenic Mice

Mouse models of allergic asthma are characterized by airway hyperreactivity (AHR), Th2-driven eosinophilic airway inflammation, high allergen-specific IgE (anti-OVA IgE) levels in serum, and airway remodeling. Because asthma susceptibility has a strong genetic component, we aimed to identify new asthma susceptibility genes in the mouse by analyzing the asthma phenotypes of the Leishmania major resistant (lmr) recombinant congenic (RC) strains. The lmr RC strains are derived from C57BL/6 and BALB/c intercrosses and carry congenic loci on chromosome 17 (lmr1) and 9 (lmr2) in both backgrounds. Whereas the lmr2 locus on chromosome 9 contributes to a small background-specific effect on anti-OVA IgE and AHR, the lmr1 locus on chromosome 17 mediates a strong effect on Th2-driven eosinophilic airway inflammation and background-specific effects on anti-OVA IgE and AHR. The lmr1 locus contains almost 600 polymorphic genes. To narrow down this number of candidate genes, we performed genome-wide transcriptional profiling on lung tissue from C.lmr1 RC mice and BALB/c control mice. We identified a small number of differentially expressed genes located within the congenic fragment, including a number of Mhc genes, polymorphic between BALB/c and C57Bl/6. The analysis of asthma phenotypes in the C.B10-H2b RC strain, carrying the C57Bl/6 haplotype of the Mhc locus in a BALB/c genetic background, reveals a strikingly similar asthma phenotype compared with C.lmr1, indicating that the differentially expressed genes located within the C.B10-H2b congenic fragment are the most likely candidate genes to contribute to the reduced asthma phenotypes associated with the C57Bl/6 allele of lmr1.

Evaluation of airway reactivity and immune characteristics as risk factors for wheezing early in life

Childhood asthma is most often characterized by recurrent wheezing, airway hyperreactivity, and atopy; however, our understanding of these relationships from early in life remains unclear. Respiratory tract illnesses and atopic sensitization early in life might produce an interaction between innate and acquired immune responses, leading to airway inflammation and heightened airway reactivity. We hypothesized that premorbid airway reactivity and immunologic characteristics of infants without prior episodes of wheezing would be associated with subsequent wheezing during a 1-year follow-up. One hundred sixteen infants with chronic dermatitis were enrolled before episodes of wheezing. Airway reactivity, allergen-specific IgE levels, cytokine production by stimulated PBMCs, and percentages of dendritic cells were measured on entry, and airway reactivity was reassessed at the 1-year follow-up. Linear regression models were used to evaluate a predictor's effect on continuous outcomes. Milk sensitization, egg sensitization, or both were associated with heightened airway reactivity before wheezing and after the onset of wheezing; however, these factors were not associated with an increased risk of wheezing. There was an interaction between initial airway reactivity and wheezing as a determinant of airway reactivity at follow-up. In addition, cytokine production by stimulated PBMCs was a risk factor for wheezing, whereas increased percentages of conventional dendritic cells were protective against wheezing. Our data in a selected cohort of infants support a model with multiple risk factors for subsequent wheezing that are independent of initial airway reactivity; however, the causative factors that produce wheezing very early in life might contribute to heightened airway reactivity.

Immunoglobulin Production Pattern in Allergic and Non-Allergic Subjects

Allergic rhinitis (AR) is characterized by Th2 polarized immune response, such as increased IL-4 and reduced IFN-γ production, and by a functional defect of T regulatory cells. This impaired immune response profile influences the pattern of immunoglobulin (Ig) production in allergic patients. However, no studies have compared the pattern of inhalant allergen-specific Ig classes between allergic patients and normal subjects. The aim of this study is to therefore investigate the allergen-specific IgE, IgG, IgG4, and IgA serum level pattern in a group of patients with pollen allergy and in non-allergic healthy subjects. One hundred and two allergic patients (evaluated both out of and in the pollen season) were enrolled. In addition, 50 healthy non-allergic subjects were recruited during the whole year. Serum allergen-specific IgE, IgG, IgG4, and IgA for Parietaria, grasses, and birch were quantitatively determined by the ImmunoCAP System method. Allergen-specific IgE, IgG, IgG4, and IgA serum levels were significantly different for each tested allergen (p=0.0001 for each class) among groups. Allergic patients, mainly during pollen season, showed the highest IgG, IgG4, and IgA levels. The present study therefore provides the preliminary evidence that Ig production pattern toward inhalant allergens may depend on the specificity of the allergenic response both in non-allergic subjects and allergic patients Allergic patients do not show a defect of IgG and IgA classes. In addition, this study is the first that quantitatively evaluates the Ig classes. However, further studies should include non-allergic subjects evaluated both during and out of the pollen season.

Diagnosis of cow milk allergy in the gut, never an easy task

The paper by Lins et al. 1 is an important study because it highlights several key features of cow milk protein allergy. The investigators identified 66 patients who had adverse reactions to cow’s milk protein by history. These included a variety of cutaneous, gastrointestinal, and systemic complaints. Total and allergen specific serum immunoglobulin IgE levels were measured including casein, beta lactoglobulin and alpha lactalbumin. Patients were instructed to follow a cow’s milk free diet for at least 2 weeks using a soy protein based formula. After symptoms remitted, an in-hospital cow’s milk protein challenge was performed and weekly follow-up visits were continued for 4 consecutive weeks following the in-hospital challenge, during which time patients continued to consume cow milk. About half of the patients did not have a positive reaction to cow’s milk protein. In those who did, a delayed reaction was common, occurring in 77% of those testing positive. Patients relapsed as late as the third week on cow milk protein. Specific IgE levels of two subfractions of cow’s milk protein were elevated in only a very small percentage of patients testing positive by challenge. The obvious conclusion of the paper is that many children in whom symptoms are thought to be related to cow’s milk protein allergy probably have another cause for their symptoms. Other not so obvious but equally important conclusions to be remembered from the study include the observation that most cow’s milk protein allergy in infancy and early childhood is not IgE mediated. This form of allergy is characterized by delayed hypersensitivity as is nicely illustrated by the relapse in symptoms rather late in the course of challenge, up to 3 weeks. Therefore,

A critical balance between allergen-specific IGE levels and taste preference during food aversion

A critical balance between allergen-specific IGE levels and taste preference during food aversion

Physico-chemical and clinico-immunologic studies on the allergenic significance of Aspergillus tamarii, a common airborne fungus

Aspergillus-derived inhalant allergens play an important role in the etiology of allergic respiratory diseases. In the present study, we investigated the allergenic potential of Aspergillus tamarii, quantified its airborne content, identified its major/minor allergens, evaluated heterogeneity of patients’ IgE response to its allergens and cross-reactivity of its allergens with other Aspergillus allergens. Skin prick tests with A tamarii extract were performed on 300 patients of bronchial asthma/allergic rhinitis and 20 healthy volunteers. Sixty-six patients (22%) elicited positive cutaneous reactions to A tamarii extract. Only one of the 20 non-allergic healthy volunteer showed a mild positive cutaneous reaction. Allergen-specific IgE levels increased with increase in patients’ cutaneous response (0% in negative to 100% in 3+/4+). The skin positivity and allergen-specific IgE levels were significantly higher in patients compared to healthy volunteers ( P > 0.05). However, no differences were found for these two parameters among patients of bronchial asthma, allergic rhinitis and bronchial asthma with allergic rhinitis. The airborne A tamarii allergen content was highest in February and October. A tamarii extract revealed at least 22 proteins (13.3–120 kDa). Seventeen of these proteins bound patients’ IgE with six being major allergens (13.3, 23, 25, 34, 39.5, 43 kDa). Three major allergens (13.3, 34, 43 kDa) were found to cross-react with A flavus and one (34 kDa) with A niger. Our results revealed that A tamarii allergen(s) are present in the air, which might serve as important inhalant allergens in IgE-mediated allergic respiratory diseases.

Indoor pet exposure and the outcomes of total IgE and sensitization at age 18 years

Early-life exposure to household pets has been shown to be protective against allergic sensitization in childhood. We sought to evaluate the association between early-life pet exposure and allergic sensitization at age 18 years. Teenagers who had been enrolled in the Detroit Childhood Allergy Study birth cohort in 1987-1989 were contacted at age 18 years. Serum total and allergen-specific IgE levels to 7 common allergens (dust mite, cat, dog, ragweed, Timothy grass, Alternaria species, and peanut; atopy was defined as any specific IgE level > or =0.35 kU/L) were measured at age 18 years. Annual interview data from childhood were used to determine indoor dog and cat (> or =50% of their time in the home) exposure during early life. Exposure was considered in various ways: first year, cumulative lifetime, and age groups, as well as multiple pets. Dog or cat exposure in the first year of life was not associated with atopy (relative risk, 0.97; 95% CI, 0.83-1.12). Those living with pets in the first year and atopic at 18 years had lower total IgE levels. Neither cumulative exposure nor exposure at a particular age was strongly and consistently associated with either outcome. Although not statistically significant, there was a pattern of decreased odds of sensitization among those with 2 or more pets versus no pets in the first year of life. Early-life pet exposure can be associated with lower total IgE levels among atopic subjects but is not strongly associated with decreased likelihood of sensitization to common allergens at age 18 years.

Anti‐Asthma Simplified Herbal Medicine Intervention‐induced long‐lasting tolerance to allergen exposure in an asthma model is interferon‐γ, but not transforming growth factor‐β dependent

SummaryBackground Chronic allergic asthma is the result of a T‐helper type 2 (Th2)‐biased immune status. Current asthma therapies control symptoms in some patients, but a long‐lasting therapy has not been established. Anti‐Asthma Simplified Herbal Medicine Intervention (ASHMI™), a Chinese herbal formula improved symptoms and lung function, and reduced Th2 responses in a controlled trial of patients with persistent moderate to severe asthma.Objective We evaluated the persistence of ASHMI™ beneficial effects following therapy in a murine model of chronic asthma and the immunological mechanisms underlying such effects.Methods BALB/c mice sensitized intraperitoneally with ovalbumin (OVA) received 3 weekly intratracheal OVA challenges to induce airway hyper‐reactivity (AHR) and inflammation (OVA mice). Additionally, OVA mice were treated with ASHMI™ (OVA/ASHMI™) or water (OVA/sham) for 4 weeks, and then challenged immediately and 8 weeks post‐therapy. In other experiments, OVA mice received ASHMI™ treatment with concomitant neutralization of IFN‐γ or TGF‐β. Effects on airway responses, cytokine‐ and OVA‐specific IgE levels were determined 8 weeks post‐therapy.Results Before treatment, OVA mice exhibited AHR and pulmonary eosinophilic inflammation following OVA challenge, which was almost completely resolved immediately after completing treatment with ASHMI™ and did not re‐occur following OVA re‐challenge up to 8 weeks post‐therapy. Decreased allergen‐specific IgE and Th2 cytokine levels, and increased IFN‐γ levels also persisted at least 8 weeks post‐therapy. ASHMI™ effects were eliminated by the neutralization of IFN‐γ, but not TGF‐β, during therapy.Conclusion ASHMI™ induced long‐lasting post‐therapy tolerance to antigen‐induced inflammation and AHR. IFN‐γ is a critical factor in ASHMI™ effects. Cite this as: K. Srivastava, T. Zhang, N. Yang, H. Sampson and X. M. Li, Clinical &amp; Experimental Allergy, 2010 (40) 1678–1688.

Allergen‐specific IgE as a biomarker of exposure plus sensitization in inner‐city adolescents with asthma

Relationships among allergen-specific IgE levels, allergen exposure and asthma severity are poorly understood since sensitization has previously been evaluated as a dichotomous, rather than continuous characteristic. Five hundred and forty-six inner-city adolescents enrolled in the Asthma Control Evaluation study underwent exhaled nitric oxide (FE(NO)) measurement, lung function testing, and completion of a questionnaire. Allergen-specific IgE levels and blood eosinophils were quantified. Dust samples were collected from the participants' bedrooms for quantification of allergen concentrations. Participants were followed for 12 months and clinical outcomes were tracked. Among sensitized participants, allergen-specific IgE levels were correlated with the corresponding settled dust allergen levels for cockroach, dust mite, and mouse (r = 0.38, 0.34, 0.19, respectively; P < 0.0001 for cockroach and dust mite and P = 0.03 for mouse), but not cat (r = -0.02, P = 0.71). Higher cockroach-, mite-, mouse-, and cat-specific IgE levels were associated with higher FE(NO) concentrations, poorer lung function, and higher blood eosinophils. Higher cat, dust mite, and mouse allergen-specific IgE levels were also associated with an increasing risk of exacerbations or hospitalization. Allergen-specific IgE levels were correlated with allergen exposure among sensitized participants, except for cat. Allergen-specific IgE levels were also associated with more severe asthma across a range of clinical and biologic markers. Adjusting for exposure did not provide additional predictive value, suggesting that higher allergen-specific IgE levels may be indicative of both higher exposure and a greater degree of sensitization, which in turn may result in greater asthma severity.

Anti-allergic potential of oligomannose-coated liposome-entrapped Cry j 1 as immunotherapy for Japanese cedar pollinosis in mice

Administration of oligomannose-coated liposomes (OMLs) in mice can induce Th1 immune responses against antigens entrapped in the OMLs. In the present study, we investigated the anti-allergic effect of treatment with oligomannose-coated liposomes (OMLs) with entrapped Cry j 1, a major allergen of Japanese cedar pollen (Cry j 1/OMLs), in Balb/c mice sensitized with Cry j 1. Pretreatment of unsensitized mice with Cry j 1/OMLs repressed the elevation of total and allergen-specific IgE levels in sera elicited in response to subsequent sensitization with Cry j 1. Cry j 1-specific IgG1 in sera also decreased in Cry j 1/OML-treated mice, while the levels of Cry j 1-specific IgG2a in these mice significantly increased after sensitization with Cry j 1. In addition, Cry j 1/OML-treated mice showed high IFN-γ production from spleen cells and low IL-4/IFN-γ and IL-5/IFN-γ ratios in response to in vitro stimulation with Cry j 1. These results indicate that allergen-specific Th1 immune responses predominate over Th2 responses and control IgE elevation in Cry j 1/OML-treated mice. The anti-allergic effect of Cry j 1/OML determined by suppression of serum IgE levels was also observed in Cry j 1-presensitized mice after challenge with antigen. Thus, Cry j 1/OMLs may be useful for immunotherapeutic control of allergic reactions to Japanese cedar pollinosis.