Association of asthma with serum IgE levels and skin-test reactivity to allergens

Changes in symptoms of asthma and rhinitis by sensitization status over ten years in a cohort of young Chilean adults

Background

We investigated the net changes in prevalence of symptoms of asthma and rhinitis over 10 years in a cohort of young by baseline sensitization status.

Methods

One thousand one hundred ninety three Chilean adults subjects aged 22–28 living in a semi-rural area of central Chile answered a lifestyle and the European Community Respiratory Health Survey (ECRHS) questionnaires. Bronchial hyper-responsiveness (BHR) and skin prick test (SPT) to eight allergens were measured at baseline in 2001. Ten years later, 772 participants completed the questionnaires again. Estimates of adjusted net changes in prevalence of symptoms by sensitization status at baseline and association between sensitization status at baseline and respiratory symptoms ten years later were assessed.

Results

A quarter of the participants were sensitized to at least one allergen in 2001. Prevalence of wheeze had a net change per year of −0.37 % (95 % Confidence Interval −0.71 to 0.02 %; p = 0.067). Self-reported nasal allergies in the last 12 months increased by 0.83 % per year (95 % CI 0.49 to 1.17 %; p < 0.001). Those sensitized to either cat fur (OR 1.76; CI 1.01 to 3.05), cockroach, (OR 2.09; 1.13 to 3.86) blend of grass and pollens (1.78; 95 % CI 1.08 to 2.92), or weeds (OR 1.77; 95 % CI 1.01 to 3.12) in 2001 were more likely to have wheeze in the last 12 months 10 years later.

Conclusion

Symptoms of asthma remained stable or slightly changed over 10 years in adults, whilst rhinitis and nasal allergies greatly increased. Being sensitized to at least one allergen is a risk factor for persistent symptoms of asthma and rhinitis, but not for determining net changes of symptoms over time. The underlying causes for the contrasting trends between asthma and nasal allergy are unknown.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0273-6) contains supplementary material, which is available to authorized users.

Mast cells and their activation in lung disease

Mast cells and their activation contribute to lung health via innate and adaptive immune responses to respiratory pathogens. They are also involved in the normal response to tissue injury. However, mast cells are involved in disease processes characterized by inflammation and remodeling of tissue structure. In these diseases mast cells are often inappropriately and chronically activated. There is evidence for activation of mast cells contributing to the pathophysiology of asthma, pulmonary fibrosis, and pulmonary hypertension. They may also play a role in chronic obstructive pulmonary disease, acute respiratory distress syndrome, and lung cancer. The diverse mechanisms through which mast cells sense and interact with the external and internal microenvironment account for their role in these diseases. Newly discovered mechanisms of redistribution and interaction between mast cells, airway structural cells, and other inflammatory cells may offer novel therapeutic targets in these disease processes.

Patient stratification and the unmet need in asthma

Asthma is often described as an inflammatory disease of the lungs and in most patients symptomatic treatment with bronchodilators or inhaled corticosteroids is sufficient to control disease. Unfortunately there are a proportion of patients who fail to achieve control despite treatment with the best current treatment. These severe asthma patients have been considered a homogeneous group of patients that represent the unmet therapeutic need in asthma. Many novel therapies have been tested in unselected asthma patients and the effects have often been disappointing, particularly for the highly specific monoclonal antibody-based drugs such as anti-IL-13 and anti-IL-5. More recently, it has become clear that asthma is a syndrome with many different disease drivers. Clinical trials of anti-IL-13 and anti-IL-5 have focused on biomarker-defined patient groups and these trials have driven the clinical progression of these drugs. Work on asthma phenotyping indicates that there is a group of asthma patients where T helper cell type 2 (Th2) cytokines and inflammation predominate and these type 2 high (T2-high) patients can be defined by biomarkers and response to therapies targeting this type of immunity, including anti-IL-5 and anti-IL-13. However, there is still a subset of T2-low patients that do not respond to these new therapies. This T2-low group will represent the new unmet medical need now that the T2-high-targeting therapies have made it to the market. This review will examine the current thinking on patient stratification in asthma and the identification of the T2-high subset. It will also look at the T2-low patients and examine what may be the drivers of disease in these patients.

Particularities of allergy in the Tropics

Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

Humoral immune factors and asthma among American Indian children: a case-control study

Background

Asthma is recognized as intimately related to immunologic factors and inflammation, although there are likely multiple phenotypes and pathophysiologic pathways. Biomarkers of inflammation may shed light on causal factors and have potential clinical utility. Individual and population genetic factors are correlated with risk for asthma and improved understanding of these contributions could improve treatment and prevention of this serious condition.

Methods

A population-based sample of 108 children with clinically defined asthma and 216 control children were recruited from a small community in the northern plains of the United States. A complete blood count, high sensitivity C-reactive protein, total IgE and specific antibodies to 5 common airborne antigens (CAA), in addition to basic demographic and anthropomorphic data were obtained. Logistic regression was primarily used to determine the association between these humoral factors and risk of asthma.

Results

The body mass index (BMI) of those with asthma and their total leukocyte counts, percentage of eosinophils, and levels of total IgE were all greater than corresponding control values in univariate analysis. The presence of detectable, specific IgE antibodies to five common airborne antigens was more likely among cases compared with controls. In multivariate analysis, total IgE was independently associated with asthma; but not after inclusion of a cumulative measure of specific IgE sensitization.

Conclusion

Many previously reported associations between anthropomorphic and immune factors and increased risk of asthma appear to be also present in this American Indian population. In this community, asthma is strongly associated with sensitization to CAA.

[Biomarkers in asthma]

Identifying new biomarkers in asthma is attractive but requires assessing their relevance and their reliability to clinical practice. Beyond fashion, the improvement in identification of new candidate biomarkers benefited of scientific and biologic progresses, biobanks and platforms robustly backed on longitudinal cohorts and registries. Paradoxically, the main issue is now to stress up the good question, in other words to correctly characterize the unmet needs in asthma that might benefit of a biomarker. Chronicity, variability, weakness of diagnostic tools and the heterogeneity of the disease are features of asthma claiming for identifying new biomarkers. Unmet needs in asthma encompass areas such as diagnosis, prognosis, management and follow-up, therapeutic guidance and phenotypic/endotypic identification. FEV1 is an available biomarker largely tested in asthma worth in most of these areas. Albeit, mandatory features required for a new biomarker to emerge, pro/con debates on those already existing and currently used methods for identifying new ones are worth explorations. We reviewed and summarized the current literature focusing biomarkers in asthma.

Four-year follow-up in children with moderate/severe uncontrolled asthma after withdrawal of a 1-year omalizumab treatment

PURPOSE OF REVIEW

Allergic asthma, which is the most frequent asthma phenotype, is mainly a chronic inflammatory disease characterized by elevated serum IgE levels and specific-IgE against common allergens. A significant group of asthmatic children have uncontrolled moderate/severe symptoms despite the use of medium/high doses of inhaled corticosteroids (ICS) in combination with another controller. Asthma guidelines suggest omalizumab as an add-on therapy in these children and recent evidence has shown the efficacy and safety of this mAb against IgE.

RECENT FINDINGS

Asthma cannot be cured and current available treatments are unable to modify the natural course of the disease. Recent studies have shown positive effects of omalizumab in reducing airway inflammation and remodelling. Herein, a 4-year follow-up of a group of children with moderate/severe uncontrolled asthma taking part in a randomized double blind placebo control with omalizumab is shown. After discontinuation of anti-IgE, children were followed up for 4 years. During the first 3 years of follow-up, they were completely free of asthma symptoms without any need of ICS or rescue medication.

SUMMARY

The new evidence published and the clinical observation described herein generate the hypothesis that treatment with omalizumab could potentially modify the natural course of asthma. However, further studies are needed.

Anti-Ascaris immunoglobulin E associated with bronchial hyper-reactivity in 9-year-old rural Bangladeshi children

BACKGROUND

Studies have addressed the immunomodulatory effects of helminths and their protective effects upon asthma. However, anti-Ascaris IgE has been reported to be associated with an increased risk of asthma symptoms. We examined the association between serum levels of anti-Ascaris IgE and bronchial hyper-responsiveness (BHR) in children living in rural Bangladesh.

METHODS

Serum anti-Ascaris IgE level was measured and the BHR test done in 158 children aged 9 years selected randomly from a general population of 1705 in the Matlab Health and Demographic Surveillance Area of the International Centre for Diarrhoeal Disease Research, Bangladesh. We investigated wheezing symptoms using a questionnaire from the International Study of Asthma and Allergies in Childhood. BHR tests were successfully done on 152 children (108 'current wheezers'; 44 'never-wheezers'). We examined the association between anti-Ascaris IgE level and wheezing and BHR using multiple logistic regression analyses.

RESULTS

Of 108 current-wheezers, 59 were BHR-positive; of 44 never-wheezers, 32 were BHR-negative. Mean anti-Ascaris IgE levels were significantly higher (12.51 UA/ml; 95% confidence interval (CI), 9.21-17.00) in children with current wheezing with BHR-positive than in those of never-wheezers with BHR-negative (3.89; 2.65-5.70; t test, p < 0.001). A BHR-positive test was independently associated with anti-Ascaris IgE levels with an odds ratio (OR) = 7.30 [95% CI, 2.28-23.33], p = 0.001 when adjusted for total IgE, anti-Dermatophagoides pteronyssinus IgE, pneumonia history, parental asthma, Trichuris infection, forced expiratory volume in one second, eosinophilic leukocyte count, and sex.

CONCLUSIONS

Anti-Ascaris IgE level is associated with an increased risk of BHR among 9-year-old rural Bangladeshi children.

House dust mite-specific IgA2 is associated with protection against eczema in allergic patients

Upon inhalation, house dust mite (HDM) allergens are deposited at the nasal and oral mucosa, where IgA is produced abundantly. IgA subclasses have been linked to protection against respiratory allergy previously. It is currently not known whether and how the human IgA subclasses IgA1 and IgA2 contribute to the clinical status of house dust mite-allergic patients. Saliva and serum samples were collected, and HDM-specific, IgE, IgG4, IgA1 and IgA2 levels were determined. HDM-specific levels of IgA in serum were similar to levels measured in nonallergic controls, but HDM-specific levels of IgA2 in saliva were decreased in allergic subjects. HDM-allergic patients who suffered from rhinitis and eczema showed a significant decrease in IgA2-levels compared to patients who suffered from rhinitis only. Taken together, our findings indicate that HDM-specific IgA2, but not IgA1, levels in serum and saliva are reduced in HDM-allergic patients suffering from eczema.

A General and Robust Framework for Secondary Traits Analysis

Case-control designs are commonly employed in genetic association studies. In addition to the case-control status, data on secondary traits are often collected. Directly regressing secondary traits on genetic variants from a case-control sample often leads to biased estimation. Several statistical methods have been proposed to address this issue. The inverse probability weighting (IPW) approach and the semiparametric maximum-likelihood (SPML) approach are the most commonly used. A new weighted estimating equation (WEE) approach is proposed to provide unbiased estimation of genetic associations with secondary traits, by combining observed and counterfactual outcomes. Compared to the existing approaches, WEE is more robust against biased sampling and disease model misspecification. We conducted simulations to evaluate the performance of the WEE under various models and sampling schemes. The WEE demonstrated robustness in all scenarios investigated, had appropriate type I error, and was as powerful or more powerful than the IPW and SPML approaches. We applied the WEE to an asthma case-control study to estimate the associations between the thymic stromal lymphopoietin gene and two secondary traits: overweight status and serum IgE level. The WEE identified two SNPs associated with overweight in logistic regression, three SNPs associated with serum IgE levels in linear regression, and an additional four SNPs that were missed in linear regression to be associated with the 75th quantile of IgE in quantile regression. The WEE approach provides a general and robust secondary analysis framework, which complements the existing approaches and should serve as a valuable tool for identifying new associations with secondary traits.

Parallel reductions of IgE and exhaled nitric oxide after optimized anti-inflammatory asthma treatment

Immunoglobulin E (IgE) is crucial for the development of airway inflammation in atopic asthma, and inhibition of IgE using monoclonal antibodies is now part of asthma therapy. However, the impact of ordinary anti-inflammatory treatment on IgE is unclear. The aim of this study was to investigate if optimization of treatment with inhaled corticosteroid (ICS) and leukotriene-receptor antagonist (LTRA) according to symptoms or exhaled nitric oxide (F_ENO) levels over a one-year period affects IgE concentrations. Altogether, 158 relatively well-controlled but multi-sensitized asthmatics (age 18-65 years), with ongoing ICS treatment at baseline, were included in this post hoc analysis of data from a randomized, controlled trial on F_ENO-guided asthma therapy. Asthma control and quality of life (Juniper ACQ and mAQLQ), F_ENO, and serum IgE were measured at baseline and after one year. Concentrations of IgE antibodies to six common perennial aeroallergens were summed up (perennial IgE). We found that perennial and total IgE decreased by 10.2% and 16.0% (P < .001 both comparisons). This was not related to allergen exposure, whereas the total use of ICS and LTRA during the year correlated with the reduction in perennial IgE (P = .030 and P = .013). The decrease in perennial and total IgE correlated significantly with the reduction in F_ENO (P < .003 and P < .001), and with improvements in ACQ and mAQLQ scores (P < 0.05, all comparisons). We conclude that one year of optimization of treatment with ICS and LTRA in patients with persistent atopic asthma resulted in significant decreases in total IgE and IgE antibodies; these decreases correlated with a reduction in F_ENO and improvements in asthma control and quality of life. Thus, IgE is reduced by ordinary asthma controller medications and the effect on IgE seems to be clinically important.

Challenges and Current Efforts in the Development of Biomarkers for Chronic Inflammatory and Remodeling Conditions of the Lungs

This review discusses biomarkers that are being researched for their usefulness to phenotype chronic inflammatory lung diseases that cause remodeling of the lung's architecture. The review focuses on asthma, chronic obstructive pulmonary disease (COPD), and pulmonary hypertension. Bio-markers of environmental exposure and specific classes of biomarkers (noncoding RNA, metabolism, vitamin, coagulation, and microbiome related) are also discussed. Examples of biomarkers that are in clinical use, biomarkers that are under development, and biomarkers that are still in the research phase are discussed. We chose to present examples of the research in biomarker development by diseases, because asthma, COPD, and pulmonary hypertension are distinct entities, although they clearly share processes of inflammation and remodeling.

Anti-asthmatic effects of oxymatrine in a mouse model of allergic asthma through regulating CD40 signaling

The aim of the study was to investigate the anti-asthmatic effects of oxymatrine (OXY) and the possible underlying mechanisms. The mouse asthma model was established by ovalbumin (OVA) intraperitoneal injection. A total of fifty mice were randomly assigned to five groups: control, OVA, OVA + dexamethasone (Dex, 2 mg · kg(-1)), and OVA + OXY (40 mg · kg(-1)), and OVA + OXY (80 mg · kg(-1)), respectively. Histological studies were conducted by the hematoxylin and eosin (HE) staining, the levels of interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13, and IgE were evaluated by enzyme-linked immunosorbent assay (ELISA), and the protein level of CD40 was analyzed by Western blotting. OXY inhibited OVA-induced increases in eosinophil count; the levels of IL-4, IL-5, IgE, and IL-13 were recovered. It also substantially inhibited OVA-induced eosinophilia in lung tissues and the expression of CD40 protein. These findings suggest that OXY may effectively ameliorate the progression of asthma and could be explored as a possible therapy for patients with allergic asthma.

Comparison and clinical utility evaluation of four multiple allergen simultaneous tests including two newly introduced fully automated analyzers

Background

We compared the diagnostic performances of two newly introduced fully automated multiple allergen simultaneous tests (MAST) analyzers with two conventional MAST assays.

Methods

The serum samples from a total of 53 and 104 patients were tested for food panels and inhalant panels, respectively, in four analyzers including AdvanSure AlloScreen (LG Life Science, Korea), AdvanSure Allostation Smart II (LG Life Science), PROTIA Allergy-Q (ProteomeTech, Korea), and RIDA Allergy Screen (R-Biopharm, Germany). We compared not only the total agreement percentages but also positive propensities among four analyzers.

Results

Evaluation of AdvanSure Allostation Smart II as upgraded version of AdvanSure AlloScreen revealed good concordance with total agreement percentages of 93.0% and 92.2% in food and inhalant panel, respectively. Comparisons of AdvanSure Allostation Smart II or PROTIA Allergy-Q with RIDA Allergy Screen also showed good concordance performance with positive propensities of two new analyzers for common allergens (Dermatophagoides farina and Dermatophagoides pteronyssinus). The changes of cut-off level resulted in various total agreement percentage fluctuations among allergens by different analyzers, although current cut-off level of class 2 appeared to be generally suitable.

Conclusions

AdvanSure Allostation Smart II and PROTIA Allergy-Q presented favorable agreement performances with RIDA Allergy Screen, although positive propensities were noticed in common allergens.

•

Two new multiple allergen simultaneous tests (MAST) analyzers are evaluated.

•

AdvanSure Smart II and PROTIA presented favorable agreement performance with RIDA.

•

Positive propensity of new assays for D. farina and D. pteronyssinus was noticed.

•

The changes of cut-off level resulted in total agreement percentage fluctuations.

Influence of Omalizumab on Allergen-Specific IgE in Patients with Adult Asthma

BACKGROUND

Omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, inhibits the binding of circulating IgE to mast cells and basophils, resulting in fewer episodes of airway inflammation, asthma symptoms and exacerbations in patients with severe allergic asthma. Treatment of patients with asthma using omalizumab increases serum total IgE (tIgE) levels. However, little is known about the influence of omalizumab on allergen-specific IgE (sIgE).

METHODS

tIgE and sIgE in 47 adult patients with severe asthma were measured with a fluorescent enzyme immunoassay (ImmunoCAP-FEIA) before and after omalizumab treatment.

RESULTS

Treatment with omalizumab increased tIgE and sIgE levels. The increases in sIgE by class category after omalizumab treatment were positively correlated with baseline sIgE positivity before treatment. The mean changes in sIgE levels after omalizumab treatment were also correlated with baseline sIgE levels before treatment. The mean changes in tIgE levels were positively correlated with the mean changes in IgE levels against Dermatophagoides pteronyssinus, crude house dust, Japanese cedar and moth. Omalizumab markedly influenced the negative-to-positive seroconversion rate for IgE against Japanese cedar (30.8%), Candida (29.0%) and moth (28.0%). Finally, all patients with negative-to-positive seroconversion for Japanese cedar-specific IgE had cedar pollinosis before beginning omalizumab treatment.

CONCLUSIONS

The changes in sIgE levels after omalizumab treatment may be dependent on the baseline sIgE levels. Our data may indicate the presence of undetectable but functional sIgE.

Case-control study evaluating competing risk factors for angioedema in a high-risk population

OBJECTIVES/HYPOTHESIS

Black race is a risk factor for angioedema. The primary aim was to examine the relationship between race-ethnicity and risk factors for angioedema.

STUDY DESIGN

Using a retrospective case-control study design, data was extracted with the Clinical Looking Glass utility, a data collection and management tool that captures data from electronic medical record systems within the Montefiore Healthcare System. Cases were emergency department (ED) visits with primary or secondary International Classification of Diseases, Ninth Revision, code diagnoses of angioedema in adults aged ≥ 18 years from January 2008 to December 2013 at three Montefiore centers in Bronx, New York. Controls were a random sampling of adult ED visits during the same period.

METHODS

In primary analyses, angiotensin-converting enzyme inhibitor (ACE-I) and black race were evaluated for synergy. The influence of different risk factors in the development of angioedema was evaluated using logistic regression models. Finally, race-ethnicity was further explored by evaluating for effect modification by stratification of models by race-ethnicity categories.

RESULTS

There were 1,247 cases and 6,500 controls randomly selected from a larger control pool. ACE-I use (odds ratio [OR] 3.70, 95% confidence interval [CI] 2.98, 4.60), hypertension (OR 1.88, 95% CI 1.55, 2.29), and black race (OR 2.25, 95% CI 1.86, 2.72) were the strongest risk factors. ACE-I use and black race were not synergistic (OR 1.10, 95% CI 0.80, 1.51). Race-ethnicity was an effect modifier for certain risk factors.

CONCLUSION

Race-ethnicity acts as an effect modifier for particular angioedema risk factors. The two strongest risk factors, ACE-I use and black race, were not synergistic.

LEVEL OF EVIDENCE

3b. Laryngoscope, 126:1823-1830, 2016.

Asthma phenotypes and IgE responses

The discovery of IgE represented a major breakthrough in allergy and asthma research, whereas the clinical interest given to IgE in asthma has been blurred until the arrival of anti-IgE biotherapy. Novel facets of the complex link between IgE and asthma have been highlighted by the effect of this treatment and by basic research. In parallel, asthma phenotyping recently evolved to the concept of endotypes, relying on identified/suspected pathobiological mechanisms to phenotype patients, but has not yet clearly positioned IgE among biomarkers of asthma.In this review, we first summarise recent knowledge about the regulation of IgE production and its main receptor, FcεRI. In addition to allergens acting as classical IgE inducers, viral infections as well as air pollution may trigger the IgE pathway, notably resetting the threshold of IgE sensitivity by regulating FcεRI expression. We then analyse the place of IgE in different asthma endo/phenotypes and discuss the potential interest of IgE among biomarkers in asthma.

Evolving Concepts of Asthma

Our understanding of asthma has evolved over time from a singular disease to a complex of various phenotypes, with varied natural histories, physiologies, and responses to treatment. Early therapies treated most patients with asthma similarly, with bronchodilators and corticosteroids, but these therapies had varying degrees of success. Similarly, despite initial studies that identified an underlying type 2 inflammation in the airways of patients with asthma, biologic therapies targeted toward these type 2 pathways were unsuccessful in all patients. These observations led to increased interest in phenotyping asthma. Clinical approaches, both biased and later unbiased/statistical approaches to large asthma patient cohorts, identified a variety of patient characteristics, but they also consistently identified the importance of age of onset of disease and the presence of eosinophils in determining clinically relevant phenotypes. These paralleled molecular approaches to phenotyping that developed an understanding that not all patients share a type 2 inflammatory pattern. Using biomarkers to select patients with type 2 inflammation, repeated trials of biologics directed toward type 2 cytokine pathways saw newfound success, confirming the importance of phenotyping in asthma. Further research is needed to clarify additional clinical and molecular phenotypes, validate predictive biomarkers, and identify new areas for possible interventions.

Specific allergen immunotherapy attenuates allergic airway inflammation in a rat model of Alstonia scholaris pollen induced airway allergy

Pollen grains are well established to be an important cause of respiratory allergy. Current pharmacologic therapies for allergic asthma do not cure the disease. Allergen specific immunotherapy is the only treatment method which re-directs the immune system away from allergic response leading to a long lasting effect. The mechanism by which immunotherapy achieves this goal is an area of active research world-wide. The present experimental study was designed to develop an experimental model of allergic lung inflammation based on a relevant human allergen, Alstonia scholaris pollen, and to establish the immunological and cellular features of specific allergen immunotherapy using this same pollen extract. Our results revealed that Alstonia scholaris pollen sensitization and challenge causes eosinophilic airway inflammation with mucin hypersecretion. This is associated with increased total IgE, increased expression of FcɛRI on lung mast cells and increased levels of IL-4, IL-5 & IL-13 as confirmed by ELISA, in-situ immunofluorescence and FACS assay. Allergen specific immunotherapy reduced airway inflammation and also decreased total IgE level, FcɛRI expression, IL-4, IL-5 & IL-13 levels. It was further noted that the reduction of these levels was more by intra-nasal route than by intra-peritoneal route. Thus we present a novel animal model of Alstonia scholaris pollen allergic disease and specific allergen immunotherapy which will pave the way towards the development of better treatment modalities.

The gender, age and risk factor distribution differs in self-reported allergic and non-allergic rhinitis: a cross-sectional population-based study

Background

Few population-based studies have assessed the prevalence and the risk factors of non-allergic rhinitis (NAR) in comparison to allergic rhinitis (AR). Moreover, epidemiologic data on rhinitis in the elderly subjects and in southern Europe are scarce.

Objective

This study aimed at estimating the prevalence and at comparing the risk factor distribution of AR and NAR in a general population sample aged 20–84 years in Italy.

Methods

A questionnaire on respiratory symptoms and risk factors was administered to random samples of the Italian population aged 20–44 (n = 10,494) 45–64 (n = 2167) and 65–84 (n = 1030) in the frame of the Gene Environment Interactions in Respiratory Diseases (GEIRD) study. Current AR and NAR were defined according to the self-reported presence of nasal allergies or of nasal symptoms without a cold or the flu.

Results

NAR showed a significant descending pattern in females from 12.0 % (95 % CI 11.1, 13.1) in the 20–44 year age class, to 7.5 % (5.4, 10.3) in the 65–84 year age class (p = 0.0009), and a roughly stable pattern in males, from 10.2 % (9.3, 11.2) to 11.1 % (8.4, 13.9) (p = 0.5261). AR decreased from 26.6 % (25.7, 27.6) in 20–44 years age class to 15.6 % (13.3, 18.0) in the 65–84 years age class (p < 0.0001), without gender difference. Subjects living near industrial plants and ex- and current smokers had a higher risk of NAR. Current smokers had a lower risk and subjects living in a Mediterranean climate a higher risk of AR.

Conclusion

AR and NAR are fairly distinct conditions, as they have a different age, gender and risk factor distribution.

Interleukin-21-Producing CD4(+) T Cells Promote Type 2 Immunity to House Dust Mites

Asthma is a T helper 2 (Th2)-cell-mediated disease; however, recent findings implicate Th17 and innate lymphoid cells also in regulating airway inflammation. Herein, we have demonstrated profound interleukin-21 (IL-21) production after house dust mite (HDM)-driven asthma by using T cell receptor (TCR) transgenic mice reactive to Dermatophagoides pteronyssinus 1 and an IL-21GFP reporter mouse. IL-21-producing cells in the mediastinal lymph node (mLN) bore characteristics of T follicular helper (Tfh) cells, whereas IL-21(+) cells in the lung did not express CXCR5 (a chemokine receptor expressed by Tfh cells) and were distinct from effector Th2 or Th17 cells. Il21r(-/-) mice developed reduced type 2 responses and the IL-21 receptor (IL-21R) enhanced Th2 cell function in a cell-intrinsic manner. Finally, administration of recombinant IL-21 and IL-25 synergistically promoted airway eosinophilia primarily via effects on CD4(+) lymphocytes. This highlights an important Th2-cell-amplifying function of IL-21-producing CD4(+) T cells in allergic airway inflammation.

Asthma severity, not asthma control, is worse in atopic compared with nonatopic adolescents with asthma

BACKGROUND

The effects of atopic and nonatopic asthma phenotypes on asthma morbidity are unclear. Moreover, asthma morbidity in patients without atopy might be mediated by immunoglobulin E (IgE).

OBJECTIVE

To determine differences in morbidity in patients with asthma with and without atopy in a population of inner-city adolescents with asthma and to assess the impact of total IgE (tIgE) in this population.

METHODS

Data were obtained from 546 inner-city adolescents in the Asthma Control Evaluation study. A positive skin prick test reaction to 14 aeroallergens and specific IgE to 5 aeroallergens determined atopic status. High (≥75th percentile) and low (≤25th percentile) tIgE levels were categorized. Asthma control (Asthma Control Test) and asthma severity (Composite Asthma Severity Index [CASI]) were measured at multiple time points over 1 year. Fractional exhaled nitric oxide (FeNO) and measurements of morbidity also were collected. Multivariable and repeated measures analyses modeled the relation between atopic status and morbidity.

RESULTS

Baseline CASI scores increased 0.90 point (P < .05) and FeNO increased 0.85 natural logarithmic unit (P < .001) in participants with vs without atopy. Repeated measures analyses showed consistent results. Participants without atopy and increased tIgE had FeNO 0.73 natural log unit higher (P < .01) than low tIgE and a nonsignificant increase in CASI. The CASI score and FeNO levels were higher for high than for low tIgE in participants with atopy.

CONCLUSION

In this population, participants with atopic asthma had worse asthma severity and higher FeNO compared with those with nonatopic asthma, but no difference in control. In all participants, higher tIgE indicated worse severity and higher FeNO. In this population, asthma severity and FeNO might be mediated by IgE in the 2 asthma phenotypes.

Distinguishing benign from pathologic TH2 immunity in atopic children

BACKGROUND

Although most children with asthma and rhinitis are sensitized to aeroallergens, only a minority of sensitized children are symptomatic, implying the underlying operation of efficient anti-inflammatory control mechanisms.

OBJECTIVE

We sought to identify endogenous control mechanisms that attenuate expression of IgE-associated responsiveness to aeroallergens in sensitized children.

METHODS

In 3 independent population samples we analyzed relationships between aeroallergen-specific IgE and corresponding allergen-specific IgG (sIgG) and associated immunophenotypes in atopic children and susceptibility to asthma and rhinitis, focusing on responses to house dust mite and grass.

RESULTS

Among mite-sensitized children across all populations and at different ages, house dust mite-specific IgG/IgE ratios (but not IgG4/IgE ratios) were significantly lower in children with asthma compared with ratios in those without asthma and lowest among the most severely symptomatic. This finding was mirrored by relationships between rhinitis and antibody responses to grass. Depending on age/allergen specificity, 20% to 40% of children with allergen-specific IgE (sIgE) of 0.35 kU/L or greater had negative skin test responses, and these children also expressed the high sIgG/sIgE immunophenotype. sIgG1 from these children inhibited allergen-induced IgE-dependent basophil activation in a dose-dependent fashion. Profiling of aeroallergen-specific CD4(+) TH memory responses revealed positive associations between sIgG/sIgE ratios and IL-10-dependent gene signatures and significantly higher IL-10/TH2 cytokine (protein) ratios among nonsymptomatic children.

CONCLUSION

In addition to its role in blocking TH2 effector activation in the late-phase allergic response, IL-10 is a known IgG1 switch factor. We posit that its production during allergen-induced memory responses contributes significantly to attenuation of inflammation through promoting IgG1-mediated damping of the FcεRI-dependent acute-phase reaction. sIgG1/sIgE balance might represent a readily accessible therapeutic target for asthma/rhinitis control.

Management of the patient with eosinophilic asthma: a new era begins

Now that it is generally accepted that asthma is a heterogeneous condition, phenotyping of asthma patients has become a mandatory part of the diagnostic workup of all patients who do not respond satisfactorily to standard therapy with inhaled corticosteroids. Late-onset eosinophilic asthma is currently one of the most well-defined asthma phenotypes and seems to have a different underlying pathobiology to classical childhood-onset, allergic asthma. Patients with this phenotype can be identified in the clinic by typical symptoms (few allergies and dyspnoea on exertion), typical lung function abnormalities (“fixed” airflow obstruction, reduced forced vital capacity and increased residual volume), typical comorbidities (nasal polyposis) and a good response to systemic corticosteroids. The definitive diagnosis is based on evidence of eosinophilia in bronchial biopsies or induced sputum, which can be estimated with reasonable accuracy by eosinophilia in peripheral blood. Until recently, patients with eosinophilic asthma had a very poor quality of life and many suffered from frequent severe exacerbations or were dependent on oral corticosteroids. Now, for the first time, novel biologicals targeting the eosinophil have become available that have been shown to be able to provide full control of this type of refractory asthma, and to become a safe and efficacious substitute for oral corticosteroids.

Late-onset eosinophilic asthma has a distinct clinical and functional profile with treatment implicationshttp://ow.ly/MH7AH

Primary Care of the Patient with Asthma

Obstructive lung disease includes asthma and chronic obstructive pulmonary disease (COPD). Because a previous issue of Medical Clinics of North America (2012;96[4]) was devoted to COPD, this article focuses on asthma in adults, and addresses some topics about COPD not addressed previously. Asthma is a heterogeneous disease marked by variable airflow obstruction and bronchial hyperreactivity. Onset is most common in early childhood, although many people develop asthma later in life. Adult-onset asthma presents a particular challenge in the primary care clinic because of incomplete understanding of the disorder, underreporting of symptoms, underdiagnosis, inadequate treatment, and high rate of comorbidity.

Urinary leukotriene E4 levels in atopic and non-atopic preschool children with recurrent episodic (viral) wheezing: a potential marker?

Backround: Reliable biological markers for the differentiation of asthma phenotypes in preschool children with wheezing are lacking. The purpose of the study is to assess the relationship of urinary Leukotriene E4 (U-LTE4) to particular asthma phenotypes in preschool children with recurrent episodic (viral) wheezing following upper respiratory tract infections with or without atopic predisposition.

METHODS

Ninety-six preschool patients with recurrent episodic wheezing participated, 52 atopic and 44 non-atopic, during exacerbation and in remission. Exacerbation was defined on clinical basis (wheeze in the presence of coryzal symptoms). Atopy was determined by specific serum IgE measurement and skin-prick testing. U-LTE4 was determined by enzyme immunoassay. Thirty-six age-matched, non-asthmatic, non-atopic children served as controls.

RESULTS

During exacerbation, U-LTE4 was significantly higher in all children with recurrent episodic wheezing in comparison to A: Remission: 642.20 ± 268 versus 399.45 ± 204, p value <0.001 and B:

CONTROLS

642.20 ± 268 versus 271.39 ± 83, p value <0.001. Atopic patients demonstrated significantly higher levels of U-LTE4 compared to non-atopic, both during exacerbation 872.13 ± 246 versus 613.15 ± 150, p value = 0.0013 and during remission 507.59 ± 182 versus 283.59 ± 160, p value <0.001. During remission, a highly significant difference of U-LTE4 was found when controls were compared to atopic patients: 271.39 ± 83 versus 507.59 ± 182, p value = 0.002 but not when compared to non-atopic ones: 271.39 ± 83 versus 283.59 ± 160, p value = 0.432.

CONCLUSION

U-LTE4 is strongly associated with the acute wheeze episode in preschool children, more so in atopics. Increased basal levels of U-LTE4 occur only in atopics. This suggests a potential role of U-LTE4 as a marker of atopic, virus-induced asthma in preschool children.

Allergic Respiratory Inflammation and Remodeling

Asthma and rhinitis are inflammatory diseases of the respiratory tract. Respiratory inflammation of the adaptive and innate immune system is the focus of this review, and chronic inflammation is not limited to the respiratory tissue. The inflammatory response, which consists of phagocytes, eosinophils, mast cells, and lymphocytes, spreads along the respiratory tract, leading to tissue damage. Mast cells and eosinophils are commonly recognized for their detrimental role in allergic reactions on activation through the high- and low-affinity receptors for IgE FcɛRI. These cells rapidly produce and secrete many of the mediators responsible for the typical symptoms of asthma and rhinitis. However, increasing amount of evidence demonstrate that mast cells and leukocytes have vital roles in host defense against pathogenesis. Histological methods are used to study leukocytes and receptor expression pattern in different respiratory tract compartments. The overall aim of this review was to understand the relationship between upper and lower respiratory tract inflammation and remodeling in patients with allergic and non-allergic asthma and rhinitis. In conclusion, this review discusses the relationship between the upper and lower airway in respiratory disease and focuses on the effect of respiratory processes on laryngeal inflammation, remodeling, function, and symptoms; however, they also have a central role in the initiation of the allergic immune response. Our findings suggest that there are differences that contribute to the development of immunopathological mechanisms of these clinically distinct forms of asthma, rhinitis, and chronic obstructive pulmonary disease.

Gene-Environment Interactions in Asthma: Genetic and Epigenetic Effects

Over the past three decades, a large number of genetic studies have been aimed at finding genetic variants associated with the risk of asthma, applying various genetic and genomic approaches including linkage analysis, candidate gene polymorphism studies, and genome-wide association studies (GWAS). However, contrary to general expectation, even single nucleotide polymorphisms (SNPs) discovered by GWAS failed to fully explain the heritability of asthma. Thus, application of rare allele polymorphisms in well defined phenotypes and clarification of environmental factors have been suggested to overcome the problem of 'missing' heritability. Such factors include allergens, cigarette smoke, air pollutants, and infectious agents during pre- and post-natal periods. The first and simplest interaction between a gene and the environment is a candidate interaction of both a well known gene and environmental factor in a direct physical or chemical interaction such as between CD14 and endotoxin or between HLA and allergens. Several GWAS have found environmental interactions with occupational asthma, aspirin exacerbated respiratory disease, tobacco smoke-related airway dysfunction, and farm-related atopic diseases. As one of the mechanisms behind gene-environment interaction is epigenetics, a few studies on DNA CpG methylation have been reported on subphenotypes of asthma, pitching the exciting idea that it may be possible to intervene at the junction between the genome and the environment. Epigenetic studies are starting to include data from clinical samples, which will make them another powerful tool for re-search on gene-environment interactions in asthma.

Effects of Egg White Consumption on Immune Modulation in a Mouse Model of Trimellitic Anhydride-induced Allergy

Egg allergy has been shown to be the most common food allergy in children with atopic dermatitis. Allergic reactions to proteins derived from egg white (EW) are more common than those derived from egg yolk. Ovomucoid, ovalbumin, ovotransferrin, and lysozyme have been identified as major allergens in EW. This study was conducted to evaluate the effect of EW on immune modulation in an induced allergy mouse model. A total of 50 five-week-old BALB/c male mice were treated with trimellitic anhydride (TMA) for three weeks to induce allergy-like symptoms. The TMA-treated mice were rested for one week and then divided into five groups and fed 0, 10, 50, and 100 mg/d EW for four weeks. All EW consumption groups showed no significant increase or decrease in the populations of white blood cells; however, a significant increase in B-lymphocyte activity was observed in the fourth week. Furthermore, EW consumption did not influence serum immunoglobulin G and immunoglobulin E levels. Taken together, these data demonstrate that the consumption of EW by TMA-treated mice did not increase allergic parameters such as serum IgE level, but enhanced the lymphocyte activities against pathogens. Therefore, this study suggests that the consumption of EW promotes Th2 immune modulation, and EW could be an excellent candidate for maintaining health.

Omalizumab for severe asthma: efficacy beyond the atopic patient?

Several years ago, omalizumab became commercially available for the treatment of severe asthma. It remains the only monoclonal antibody to be marketed for this purpose. Since then, many studies have been published endorsing its efficacy and effectiveness. Concomitantly, evidence of an overlap between atopic and non-atopic severe asthma has emerged. However, there also appears to be some disagreement regarding the value of omalizumab in the management of non-atopic disease, as some studies have failed to show any benefit in these patients. The recent literature has also sought to identify appropriate prognostic biomarkers for the use of omalizumab, other than immunoglobulin (IgE) levels. This article briefly summarizes the evolution of asthma treatment, the pathophysiology of the condition, and the method of action of omalizumab. The author describes the controlled and uncontrolled studies (also named "real-life studies") published in adult and pediatric populations in different countries and expresses his view on the current place of the drug in the management of severe allergic asthma. He offers a personal perspective on the recent evidence for the use of omalizumab in non-atopic patients, highlighting the implications for current clinical practice and the gaps in our knowledge. The author justifies his belief that omalizumab is not only an IgE-blocking drug and should be considered as a disease-modifying therapy because of its multiple effects on different biologic pathways. Finally, some areas for future research are indicated.

Invariant Natural Killer T Cells Play a Role in Chemotaxis, Complement Activation and Mucus Production in a Mouse Model of Airway Hyperreactivity and Inflammation

CD1d-restricted invariant natural killer T (iNKT) cells play a critical role in the induction of airway hyperreactivity (AHR). After intranasal alpha-galactosylceramide (α-GalCer) administration, bronchoalveolar lavage fluid (BALF) proteins from mouse lung were resolved by two-dimensional differential gel electrophoresis (2D-DIGE), and identified by tandem mass spectroscopy. A lack of iNKT cells prevented the development of airway responses including AHR, neutrophilia and the production of the proinflammatory cytokines in lungs. Differentially abundant proteins in the BALF proteome of α-GalCer-treated wild type mice included lungkine (CXCL15), pulmonary surfactant-associated protein D (SFTPD), calcium-activated chloride channel regulator 1 (CLCA1), fragments of complement 3, chitinase 3-like proteins 1 (CH3LI) and 3 (CH3L3) and neutrophil gelatinase-associated lipocalin (NGAL). These proteins may contribute to iNKT regulated AHR via several mechanisms: altering leukocyte chemotaxis, increasing airway mucus production and possibly via complement activation.

Analysis of asthma patients for cryptococcal seroreactivity in an urban German area

Cryptococcus neoformans is an opportunistic fungal pathogen that causes lung inflammation and meningoencephalitis in immunocompromised patients but is also able to asymptomatically infect immunocompetent individuals. C. neoformans is found ubiquitously especially in urban areas where it is spread by pigeons, and fungal exposure may predispose for asthma development already at an early age, as soon as confronted with pigeon droppings. In the study presented here, we investigated the presence of specific immunoglobulin G (IgG) against C. neoformans in sera from patients suffering from asthma in comparison to a healthy control cohort, accrued from the Leipzig Research Centre for Civilization Diseases (LIFE). For serological analysis we developed a flow cytometry (FACS) based assay specific for an acapsular strain of C. neoformans to comprehensively analyze different cryptococcal serotypes. Compared with the non-asthmatic cohort, asthmatics exhibited, as expected, an elevated level of total serum immunoglobulin E (IgE), whereas the IgG seroreactivity against C. neoformans was not significantly different among the two groups (P = .118). Nevertheless, there was a trend toward increased Cryptococcus-specific IgG antibodies in the serum of asthmatics. Additionally, in male asthmatics an increased IgG-mediated seroreactivity compared to female asthmatics was found. This points to a higher prevalence of subclinical C. neoformans infection in male asthmatics and may support the hypothesis of C. neoformans as a risk factor for the development of asthma in urban areas.

Mast cells in airway diseases and interstitial lung disease

Mast cells are major effector cells of inflammation and there is strong evidence that mast cells play a significant role in asthma pathophysiology. There is also a growing body of evidence that mast cells contribute to other inflammatory and fibrotic lung diseases such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. This review discusses the role that mast cells play in airway diseases and highlights how mast cell microlocalisation within specific lung compartments and their cellular interactions are likely to be critical for their effector function in disease.

An Exploratory Pilot Study of Genetic Marker for IgE-Mediated Allergic Diseases with Expressions of FcεR1α and Cε

The high affinity immunoglobulin E (IgE) receptor-FcεR1 is mainly expressed on the surface of effector cells. Cross-linking of IgE Abs bound to FcεR1 by multi-valent antigens can induce the activation of these cells and the secretion of inflammatory mediators. Since FcεR1 plays a central role in the induction and maintenance of allergic responses, this study aimed to investigate the association of FcεR1 with the allergic phenotype of Cε expression and cytokine and histamine release from peripheral leukocytes. Peripheral leukocytes from 67 allergic and 50 non-allergic subjects were used for genotyping analysis. Peripheral mononuclear cells (PBMCs) were used for Cε expression and ELISpot analysis, while polymorphonuclear cells (PMNs) were used for histamine release. The association between genotype polymorphism of the FcεR1α promoter region (rs2427827 and rs2251746) and allergic features of Cε expression and histamine were analyzed, and their effects on leukocytes function were compared with wild type. The genotype polymorphisms of FcεR1α promoter region with CT and TT in rs2427827 and TC in rs2251746 were significantly higher in allergic patients than in non-allergic controls. Patients with single nucleotide polymorphism (SNP) of FcεR1α promoter region had high levels of total IgE, mite-specific Der p 2 (Group 2 allergen of Dermatophagoides pteronyssinus)-specific IgE and IgE secretion B cells. The mRNA expression of FcεR1α was significantly increased after Der p2 stimulation in PBMCs with SNPs of the FcεR1α promoter region. Despite the increased Cε mRNA expression in PBMCs and histamine release from PMNs and the up-regulated mRNA expression of interleukin (IL)-6 and IL-8 secretions after Der p2 stimulation, there was no statistically significant difference between SNPs of the FcεR1α promoter region and the wild type. SNPs of FcεR1α promoter region were associated with IgE expression, IgE producing B cells, and increased Der p2-induced FcεR1α mRNA expression. These SNPs may be used as a disease marker for IgE-mediated allergic inflammation caused by Dermatophagoides pteronyssinus.

Rationale for specific allergen testing of patients with asthma in the clinical pulmonary office setting

Asthma is a chronic inflammatory disease that affects an estimated 25 million people in the United States. In 70% to 90% of cases, asthma is associated with IgE-mediated mechanisms, which have proved central to allergen-induced inflammation in preclinical and clinical models. The importance of IgE levels in patients with moderate to severe asthma has been confirmed in randomized controlled studies with a targeted IgE blocker. Advances in laboratory methods to detect and quantify allergen-specific IgE antibodies have allowed for a quick-and-easy diagnosis of allergic IgE-mediated sensitivities in the office. Pulmonologists tend to order in vitro tests to measure allergen-specific IgE rather than to perform allergen skin testing, which is seen as the purview of allergists. This article reviews the importance of allergen testing in patients with asthma—whether by skin testing or by in vitro methods—and highlights the advantages, limitations, and interpretation of results derived from each method. Additionally, this article includes suggested documentation and administrative details for physician reporting in the office setting.

Gene expression in relation to exhaled nitric oxide identifies novel asthma phenotypes with unique biomolecular pathways

RATIONALE

Although asthma is recognized as a heterogeneous disease associated with clinical phenotypes, the molecular basis of these phenotypes remains poorly understood. Although genomic studies have successfully broadened our understanding in diseases such as cancer, they have not been widely used in asthma studies.

OBJECTIVES

To link gene expression patterns to clinical asthma phenotypes.

METHODS

We used a microarray platform to analyze bronchial airway epithelial cell gene expression in relation to the asthma biomarker fractional exhaled nitric oxide (FeNO) in 155 subjects with asthma and healthy control subjects from the Severe Asthma Research Program (SARP).

MEASUREMENTS AND MAIN RESULTS

We first identified a diverse set of 549 genes whose expression correlated with FeNO. We used k-means to cluster the patient samples according to the expression of these genes, identifying five asthma clusters/phenotypes with distinct clinical, physiological, cellular, and gene transcription characteristics-termed "subject clusters" (SCs). To then investigate differences in gene expression between SCs, a total of 1,384 genes were identified that highly differentiated the SCs at an unadjusted P value < 10(-6). Hierarchical clustering of these 1,384 genes identified nine gene clusters or "biclusters," whose coexpression suggested biological characteristics unique to each SC. Although genes related to type 2 inflammation were present, novel pathways, including those related to neuronal function, WNT pathways, and actin cytoskeleton, were noted.

CONCLUSIONS

These findings show that bronchial epithelial cell gene expression, as related to the asthma biomarker FeNO, can identify distinct asthma phenotypes, while also suggesting the presence of underlying novel gene pathways relevant to these phenotypes.

Urinary LTE4 levels as a diagnostic marker for IgE-mediated asthma in preschool children: a birth cohort study

Objectives

Leukotrienes play a central pathophysiological role in allergic asthma. The aim of this study was to investigate the utility of measuring urinary leukotriene E₄ (LTE₄) levels in the diagnosis of atopic diseases in early childhood.

Methods

Children aged 0 through 4 years from a birth cohort in the Prediction of Allergies in Taiwanese Children (PATCH) study were enrolled. Urinary LTE₄ levels were measured and its association between total serum IgE levels, allergen-specific IgE sensitization and atopic diseases were assessed.

Results

A total of 182 children were regular followed up at clinics for a four-year follow-up period. Urinary LTE₄ levels appeared to be elevated in children with total serum IgE levels exceeding 100 kU/L, allergen-specific IgE sensitization after 2 years of age. Elevation of urinary LTE₄ levels (≥500 pg/mg of creatinine) significantly discriminated high serum total IgE levels (≥100 kU/L) at age 2 (P = 0.027). A higher level of total serum IgE or urinary LTE₄ was significantly associated with the risk of developing allergic rhinitis and asthma at age 3. A significantly higher urinary LTE₄ level was found in children with a combination of IgE sensitization and asthma at age 4.

Conclusions

Urinary LTE₄ levels appear to be highly associated with IgE sensitization and its related allergic airway diseases after age 2. The measurement of urinary LTE₄ (≥500 pg/mg of creatinine) could not only be a non-invasive method for atopic predisposition but also potentially provide a strategy for the diagnosis and management of asthma in preschool children.

Polymorphisms of endotoxin pathway and endotoxin exposure: in vitro IgE synthesis and replication in a birth cohort

BACKGROUND

Genetic variants in endotoxin signaling pathway are important in modulating the effect of environmental endotoxin on asthma and atopic phenotypes. Our objective was to determine the single nucleotide polymorphisms (SNPs) in the endotoxin signaling pathway that may influence in vitro IgE synthesis and to investigate the relationship between these variants and endotoxin exposure in relation to the development of asthma and atopy in a birth cohort.

METHODS

Peripheral blood mononuclear cells from 45 children with asthma were stimulated with 2 and 200 ng/ml lipopolysaccharide in vitro and IgE was measured in the culture supernatants. Children were genotyped for 121 SNPs from 30 genes in the endotoxin signaling pathway. Variants with a dose-response IgE production in relation to lipopolysaccharide (LPS) were selected for replication in a population-based birth cohort, in which we investigated the interaction between these SNPs and endotoxin exposure in relation to airway hyper-responsiveness, wheeze, and atopic sensitization.

RESULTS

Twenty-one SNPs in nine genes (CD14, TLR4, IRF3, TRAF-6, TIRAP, TRIF, IKK-1, ST-2, SOCS1) were found to modulate the effect of endotoxin on in vitro IgE synthesis, with six displaying high linkage disequilibrium. Of the remaining 15 SNPs, for seven we found significant relationships between genotype and endotoxin exposure in the genetic association study in relation to symptomatic airway hyper-responsiveness (CD14-rs2915863 and rs2569191, TRIF-rs4807000), current wheeze (ST-2-rs17639215, IKK-1-rs2230804, and TRIF-rs4807000), and atopy (CD14-rs2915863 and rs2569192, TRAF-6-rs5030411, and IKK-1-rs2230804).

CONCLUSIONS

Variants in the endotoxin signaling pathway are important determinants of asthma and atopy. The genotype effect is a function of the environmental endotoxin exposure.

Longitudinal increase in total IgE levels in patients with adult asthma: an association with poor asthma control

Background

Immunoglobulin (Ig) E is well-known to play a critical role in allergic diseases. We investigated the association between longitudinal change in total IgE level and the asthma control in patients with adult asthma.

Methods

For this retrospective study, 154 patients with asthma aged 21–82 years were recruited from the allergy and pulmonary units of the Showa University Hospital. Data on longitudinal changes in IgE over the preceding 10 years were collected and logarithmically transformed. Associations between longitudinal change in IgE and clinical characteristics including asthma control test (ACT) score, asthma control, pulmonary function test, and antigen specific IgE, were assessed.

Results

Patients with increased IgE tended to have significantly higher mean age, more episodes of acute exacerbation within a year, lower ACT scores, and used oral corticosteroids more frequently than those with decreased or unchanged IgE. The prevalence of uncontrolled asthma was higher in patients with increased IgE than in those with decreased or unchanged IgE. Mean %FEV₁ and FEV_1% were lower in patients with increased IgE than in those with decreased or unchanged IgE. Moreover, the prevalence of Aspergillus-specific IgE was higher in patients with increased IgE than in those with decreased or unchanged IgE.

Conclusions

These data suggest that a longitudinal increase in total IgE is associated with both poor asthma control and Aspergillus-specific IgE in patients with adult asthma.

Increased frequency of dual-positive TH2/TH17 cells in bronchoalveolar lavage fluid characterizes a population of patients with severe asthma

BACKGROUND

TH2 cells can further differentiate into dual-positive TH2/TH17 cells. The presence of dual-positive TH2/TH17 cells in the airways and their effect on asthma severity are unknown.

OBJECTIVE

We sought to study dual-positive TH2/TH17 cells in bronchoalveolar lavage (BAL) fluid from asthmatic patients, examine their response to glucocorticoids, and define their relevance for disease severity.

METHODS

Bronchoscopy and lavage were performed in 52 asthmatic patients and 25 disease control subjects. TH2 and TH2/TH17 cells were analyzed by using multicolor flow cytometry and confocal immunofluorescence microscopy. Cytokines were assayed by means of ELISA.

RESULTS

Dual-positive TH2/TH17 cells were present at a higher frequency in BAL fluid from asthmatic patients compared with numbers seen in disease control subjects. High-level IL-4 production was typically accompanied by high-level IL-17 production and coexpression of GATA3 and retinoic acid receptor-related orphan receptor γt. Increased presence of TH2/TH17 cells was associated with increased IL-17 production in lavage fluid. TH2/TH17 cell counts and IL-17 production correlated with PC20 for methacholine, eosinophil counts, and FEV1. TH2/TH17 cells, unlike TH2 cells, were resistant to dexamethasone-induced cell death. They expressed higher levels of mitogen-activated protein-extracellular signal-regulated kinase kinase 1, a molecule that induces glucocorticoid resistance. On the basis of the dominance of BAL fluid TH2 or TH2/TH17 cells, we identified 3 subgroups of asthma: TH2(predominant), TH2/TH17(predominant), and TH2/TH17(low). The TH2/TH17(predominant) subgroup manifested the most severe form of asthma, whereas the TH2/TH17(low) subgroup had the mildest asthma.

CONCLUSION

Asthma is associated with a higher frequency of dual-positive TH2/TH17 cells in BAL fluid. The TH2/TH17(predominant) subgroup of asthmatic patients manifested glucocorticoid resistance in vitro. They also had the greatest airway obstruction and hyperreactivity compared with the TH2(predominant) and TH2/TH17(low) subgroups.

Effects of Egg White Consumption on Allergy, Immune Modulation, and Blood Cholesterol Levels in BALB/c Mice

We previously demonstrated that water-soluble egg yolk extract is not related to elevation of serum immunoglobulin E, which can initiate allergic reactions; however, it increases the level of high density lipoprotein (HDL)-cholesterol and the activity of B lymphocytes. In this study, egg white (EW) was fed to BALB/c mice to determine its influence on growth efficiency, immune modulation, and changes in serum lipid levels. A total of 50 five-wk-old BALB/c male mice were divided into 5 groups, 4 of which were fed 0, 10, 50, or 100 mg/d EW for 4 wk. Mice with an uptake of 10, 50 and 100 mg/d EW showed no significant changes in daily weight gain, feed efficiency rate, or populations of white blood cells. However, the activities of both B and T lymphocytes were significantly increased in all three EW groups at the final week of treatment. Interestingly, serum levels immunoglobulin E were not altered by EW consumption, but the IgG level was significantly increased in the 100 mg/d EW group. Serum lipid profile analyses showed no significant changes in total cholesterol, HDL, low density lipoprotein, or triglyceride levels by EW consumption. Taken together, these data demonstrate that consumption of EW promotes immune cell activities and the upregulation of serum IgG levels. However, we found no changes in serum lipid profiles and IgE levels. Therefore, our study suggests that consumption of EW might not be related to the risk of food allergy, but could be an excellent candidate for the maintenance of physiological homeostasis.

Elucidation of pathways driving asthma pathogenesis: development of a systems-level analytic strategy

Asthma is a genetically complex, chronic lung disease defined clinically as episodic airflow limitation and breathlessness that is at least partially reversible, either spontaneously or in response to therapy. Whereas asthma was rare in the late 1800s and early 1900s, the marked increase in its incidence and prevalence since the 1960s points to substantial gene × environment interactions occurring over a period of years, but these interactions are very poorly understood (1-6). It is widely believed that the majority of asthma begins during childhood and manifests first as intermittent wheeze. However, wheeze is also very common in infancy and only a subset of wheezy children progress to persistent asthma for reasons that are largely obscure. Here, we review the current literature regarding causal pathways leading to early asthma development and chronicity. Given the complex interactions of many risk factors over time eventually leading to apparently multiple asthma phenotypes, we suggest that deeply phenotyped cohort studies combined with sophisticated network models will be required to derive the next generation of biological and clinical insights in asthma pathogenesis.

Sensitization to food and inhalant allergens in relation to atopic diseases in early childhood: a birth cohort study

Objectives

A correct interpretation of sensitization to common allergens is critical in determining susceptibility to allergic diseases. The aim of this study was to investigate the patterns of sensitization to food and inhalant allergens, and their relation to the development of atopic diseases in early childhood.

Methods

Children aged 0 through 4 years from a birth cohort in the Prediction of Allergies in Taiwanese Children (PATCH) study were enrolled. Specific IgE antibody against food and inhalant allergens were measured and their association between total serum IgE levels and atopic diseases were assessed.

Results

A total of 182 children were regular followed up at clinics for a four-year follow-up period. The prevalence of food allergen sensitization increased markedly after 6 months of age, reaching up to 47% at 1.5 years of age and then declined significantly to 10% in parallel with a considerable increase in the prevalence of sensitization to inhalant allergens up to 25% at age 4. Food allergen sensitization appeared to be mainly associated with the elevation of serum total IgE levels before age 2. A combined sensitization to food and inhalant allergens had an additive effect on serum IgE levels after age 2, and was significantly associated with the risk of developing atopic diseases at age 4.

Conclusions

Sensitization to food occurs early in life, in parallel with the rising prevalence of sensitization to inhalant allergens at older age. A combined sensitization to food and inhalant allergens not only has an additive increase in serum IgE antibody production but also increases the risk of developing allergic respiratory diseases in early childhood.

Risk factors for and pre-medications to prevent cetuximab-induced infusion reactions in patients with squamous cell carcinoma of the head and neck

OBJECTIVES

Cetuximab, a chimeric monoclonal antibody, is the only targeted therapy approved for squamous cell carcinoma of the head and neck (SCCHN). Infusion reactions (IRs) occur in 6-18% of patients pre-medicated with diphenhydramine. Evidence for clinical risk factors for IRs is limited and the benefit of additional pre-medication to prevent IRs is unclear.

MATERIALS AND METHODS

A retrospective, single institution study of 243 SCCHN patients treated with cetuximab to evaluate potential risk factors for IRs and to assess the efficacy of additional pre-medications (nebulized albuterol and intravenous (IV) corticosteroids and/or H2-blockers) to decrease the risk of IR.

RESULTS

IR (grades 1-4) and high grade (grades 3-4 only) IR occurred in 47 (19.3%) and 16 (6.6%) patients, respectively. Multivariate analysis identified Caucasian race (OR7.11, p=0.003), medication allergy (OR3.74, p=0.002), and blood eosinophils >3% (OR2.75, p=0.01) independently increased the risk of IR; Caucasian race (OR5.57, p=0.007) and medication allergy (OR4.10, p=0.0007) increased the risk of high grade IR. IR (grades 1-4) and high grade IR occurred in 31.8% and 22.7% pre-medicated with diphenhydramine alone. Univariate analysis identified albuterol, famotidine, and corticosteroids decreased the risk of high grade IR. Furthermore, there was a significant difference between the possible combinations of the pre-medications and the risk of high grade IR by Fisher Exact test (p=0.003) whereby the combination of albuterol, famotidine and corticosteroids was effective in preventing high grade IR. Thirty (64%) of the 47 patients who developed an IR were re-challenged and did not experience a recurrence of an IR.

CONCLUSION

These data may be used to identify patients at higher risk for cetuximab-induced IR who may be advised to not receive cetuximab or who may benefit from additional pre-medications to decrease the risk of a high grade IR.

Influence of MILR1 promoter polymorphism on expression levels and the phenotype of atopy

The recently identified cell surface immunoreceptor MILR1 (mast cell immunoglobulin-like receptor 1; synonyms, Allergin-1) has been shown to suppress immunoglobulin E (IgE)-mediated, mast cell-dependent responses in both mice and humans. We performed a mutation search of MILR1 together with a genetic association study to determine whether polymorphisms in MILR1 are associated with atopy in human. Mutation screening of MILR1 was performed using DNA from 146 unrelated Japanese. Genotyping of the identified polymorphisms was done with 1505 individuals from the general Japanese adult population. Atopy, as defined by positive responses for specific IgEs against at least one of the 26 common allergens, was evaluated using MAST-26. Five polymorphisms (rs6504230, c.-170_-166delAGGAA, rs8071835, rs143526766 and rs12936887) and two rare missense variants (Val273Ala and Leu311Val) were identified by mutation screening. The C allele of rs6504230 had protective effects against atopy (P=0.002). A luciferase reporter assay using the promoter region of MILR1 revealed that the C allele of rs6504230 was associated with increased expression of MILR1, which was in accordance with the results of expression quantitative trait loci analysis using human leukocytes. Our data indicates that the rs6504230 polymorphism affects MILR1 expression levels in humans, leading to a susceptibility to producing specific IgE antibodies against common allergens.

Novel diagnostic approaches and biological therapeutics for intrinsic asthma

Intrinsic asthma has been considered as a specific disease entity for a long time, although many controversies have emerged in relation to this concept. Of note, not finding specific allergen sensitization in an asthmatic patient neither excludes an allergic component nor the essential role that immunoglobulin E may play in asthma. The diagnostic approach should be similar in any patient suspected to have asthma. The atopic status is one among many other questions. Omalizumab, the only monoclonal anti-immunoglobulin E antibody commercialized for asthma, should be tried in patients with uncontrolled severe asthma independent of their atopic status.

Inhaled environmental allergens and toxicants as determinants of the asthma phenotype

The driving environmental factors behind the development of the asthma phenotype remain incompletely studied and understood. Here, we present an overview of inhaled allergic/atopic and mainly nonallergic/nonatopic or toxicant shapers of the asthma phenotype, which are present in both the indoor and outdoor environment around us. The inhaled allergic/atopic factors include fungus, mold, animal dander, cockroach, dust mites, and pollen; these allergic triggers and shapers of the asthma phenotype are considered in the context of their ability to drive the immunologic IgE response and potentially induce interactions between the innate and adaptive immune responses, with special emphasis on the NADPH-dependent reactive oxygen-species-associated mechanism of pollen-associated allergy induction. The inhaled nonallergic/nonatopic, toxicant factors include gaseous and volatile agents, such as sulfur dioxide, ozone, acrolein, and butadiene, as well as particulate agents, such as rubber tire breakdown particles, and diesel exhaust particles. These toxicants are reviewed in terms of their relevant chemical characteristics and hazard potential, ability to induce airway dysfunction, and potential for driving the asthma phenotype. Special emphasis is placed on their interactive nature with other triggers and drivers, with regard to driving the asthma phenotype. Overall, both allergic and nonallergic environmental factors can interact to acutely exacerbate the asthma phenotype; some may also promote its development over prolonged periods of untreated exposure, or possibly indirectly through effects on the genome. Further therapeutic considerations should be given to these environmental factors when determining the best course of personalized medicine for individuals with asthma.