Allergen extract- and component-based diagnostics in children of the ALLIANCE asthma cohort

Low type-2 immune effectors modulate atopic diseases' protective role in pancreatic cancer risk

Studies reported that atopic individuals exhibit a 36% reduced risk of developing pancreatic ductal adenocarcinoma (PDAC); however, the underlying molecular mechanisms remain unclear. This study examines the specific role of type-2 immune response in the atopy-PDAC inverse association. To endotype atopic conditions using type-2 immune effectors (i.e., eosinophils and immunoglobulin-E[IgE]) and investigate their protective effect against PDAC risk, IgE levels were measured in 688 PDAC cases and 558 controls from the PanGenEU case-control study. 'IgE-sensitization' was defined as having >100 kU/L total IgE with lab-tested sensitization to ≥1 food- or aeroallergens. Atopic conditions were determined using the European Community Respiratory Health Survey questionnaire. The UK Biobank cohort's 544 PDAC cases and 92,038 nested controls were categorized based on a threshold of 0.15 × 109 eosinophil cells/L plus self-reported atopy. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using multivariable logistic regression. Restricted cubic splines were applied to examine the nonlinear relationship between type-2 immune effectors and PDAC risk. PDAC risk was not linearly associated with type-2 immune effectors levels. Compared to low IgE-sensitized non-atopic individuals, the low IgE-sensitized atopic population had significantly reduced PDAC risk (OR = 0.56, 95% CI: 0.35-0.84). Similar trends were observed among atopic individuals with low eosinophil counts (OR = 0.67, 95% CI: 0.47-0.95). Atopic conditions were inversely associated with PDAC risk, particularly among those with low levels of type-2 immune effectors. This indicates the protective effect of atopy against PDAC risk is modulated by low type-2 immune response.

Peripheral Inflammation Featuring Eosinophilia or Neutrophilia Is Associated with the Survival and Infiltration of Eosinophils within the Tumor among Various Histological Subgroups of Patients with NSCLC

Immune activation status determines non-small cell lung cancer (NSCLC) prognosis, with reported positive/negative associations for T helper type 2 (TH2) responses, including allergen-specific IgE and eosinophils. Our study seeks to explore the potential impact of these comorbid immune responses on the survival rates of patients with NSCLC. Our retrospective study used data from the Data Warehouse of the German Center for Lung Research (DZL) and Lung Biobank at Thoraxklinik Heidelberg. We estimated the association of blood eosinophilia and neutrophilia on survival rates in an inflammatory cohort of 3143 patients with NSCLC. We also tested sensitization to food and inhalants and high-sensitivity C-reactive protein (hs-CRP) in a comorbidity cohort of 212 patients with NSCLC. Finally, we estimated the infiltration of immune-relevant cells including eosinophils, T-cells, and mast cells in a tissue inflammatory sub-cohort of 60 patients with NSCLC. Sensitization to at least one food or inhalant (sIgE) was higher in patients with adenocarcinoma (adeno-LC) than the non-adenocarcinoma (non-adeno-LC). Furthermore, hs-CRP was higher in non-adeno-LC compared with adeno-LC. Peripheral inflammation, particularly eosinophilia and neutrophilia, was associated with poor survival outcomes in NSCLC with a clear difference between histological subgroups. Finally, blood eosinophilia was paralleled by significant eosinophil infiltration into the peritumoral tissue in the lung. This study provides novel perspectives on the crucial role of peripheral inflammation, featuring eosinophilia and neutrophilia, with overall survival, underscoring distinctions between NSCLC subgroups (adeno-LC vs. non-adeno-LC). Peripheral eosinophilia enhances eosinophil infiltration into tumors. This sheds light on the complex interplay between inflammation, eosinophil infiltration, and NSCLC prognosis among various histological subtypes. Further studies are required to underscore the role of eosinophils in NSCLC among different histological subgroups and their role in shaping the tumor microenvironment.

Urinary eosinophil-derived neurotoxin is associated with reduced lung function in pediatric asthma

INTRODUCTION

Eosinophil-derived neurotoxin (EDN) is a biomarker for eosinophilic activation. Urinary (u) EDN may allow non-invasive monitoring of asthma, but clinical recommendations are lacking. We assessed the potential of uEDN as a marker of disease activity in pediatric asthma.

METHODS

We assessed urine samples of 371 children from the German ALLIANCE study cohort, from which we had: 169 preschool wheezers (<6 years), 80 asthmatics (≥6 years), and 122 healthy controls using the ImmunoCAP™ EDN Assay. Creatinine (Cr)-adjusted uEDN values were analyzed using correlations, association tests, (non) parametric statistics, multiple linear, and multivariable regression.

RESULTS

uEDN/uCr values were higher in atopic versus non-atopic preschool-aged subjects (p = .035) and associated with the sum of allergen-specific IgE in younger (r = 0.24, p = .003), and older subjects (r = 0.23, p = .043). uEDN/uCr was marginally a good determinant for atopy (p = .078, for subjects aged <6 years, and p = .058 for subjects ≥6 years). Children with the T2-high phenotype had higher uEDN/uCr (p < .001) versus T2-low-irrespective of using uEDN/uCr or blood eosinophils in combination to allergen sIgE for disease phenotyping. uEDN/uCr significantly correlated with reduced lung function among asthmatics (FEV1 z-scores: r = -0.30, p = .007, and FEV1/FVC z-scores: r = -0.24, p = .038). Using multivariable modeling, uEDN/uCr was an independent determinant of FEV1 (p = .038), and to a lesser extent, FEV1/FVC (p = .080).

CONCLUSIONS

uEDN/uCr may serve as a non-invasive biomarker for clinical features such as lung function in pediatric asthma. We highlight the utility of uEDN/uCr as a biomarker that can be easily assessed using widely available robust diagnostic immunoassays.

Analysis of risk factors for acute attacks complicated by respiratory failure in children with asthma

Objective

To describe the proportion and clinical characteristics of hospitalized children with acute asthma attacks complicated by respiratory failure and to analyze the risk factors.

Methods

This retrospective study analyzed hospital admissions of children and adolescents with acute asthma attacks between January 2016 and December 2021. Inclusion criteria were used to identify eligible cases, and demographic information and disease characteristics were collected. Patients were categorized into respiratory failure group and the other group based on the result of artery blood gas analysis. Multivariate logistic regression was utilized to investigate the risk factors associated with respiratory failure resulting from acute asthma attacks. The data were analyzed using SPSS 22.0, and significance was considered at P < 0.05.

Results

Our research involved 225 participants, with 18.7% diagnosed with respiratory failure. The respiratory failure group was found to be younger and have higher percentage of male, while birth weight, nationality, and type of residence did not differ between the two groups. In the respiratory failure group, a significant difference was observed in emergency hospitalization, ICU treatment, severe to critical attack, dyspnea and allergy history. The two groups did not differ in admission season, first asthma diagnosis, respiratory infection and comorbidity. The respiratory failure group exhibited a higher proportion of atopy-only asthma and a lower proportion of T2-high asthma. The eosinophil count, and eosinophil percentage were lower in the respiratory failure group, while neutrophil count was higher. Having a history of allergies (OR = 2.46, 95% CI: 1.08-5.59) and neutrophil count (OR = 1.10, 95% CI: 1.00-1.21) were the risk factors for respiratory failure in children with asthma. There also existed that the risk of respiratory failure increases with decreasing age of the children (OR = 0.85, 95% CI: 0.73-0.99).

Conclusion

Notably, risk factors for respiratory failure in hospitalized asthma children include age, having a history of allergies, and neutrophil count. The identification of the above factors and the implementation of timely intervention can optimize the treatment of asthma in children.

Mild allergic airways responses to an environmental mixture increase cardiovascular risk in rats

Recent epidemiological findings link asthma to adverse cardiovascular responses. Yet, the precise cardiovascular impacts of asthma have been challenging to disentangle from the potential cardiovascular effects caused by asthma medication. The purpose of this study was to determine the impacts of allergic airways disease alone on cardiovascular function in an experimental model. Female Wistar rats were intranasally sensitized and then challenged once per week for 5 weeks with saline vehicle or a mixture of environmental allergens (ragweed, house dust mite, and Aspergillus fumigatus). Ventilatory and cardiovascular function, measured using double-chamber plethysmography and implantable blood pressure (BP) telemetry and cardiovascular ultrasound, respectively, were assessed before sensitization and after single and final allergen challenge. Responses to a single 0.5 ppm ozone exposure and to the cardiac arrhythmogenic agent aconitine were also assessed after final challenge. A single allergen challenge in sensitized rats increased tidal volume and specific airways resistance in response to provocation with methacholine and increased bronchoalveolar lavage fluid (BALF) eosinophils, neutrophils, lymphocytes, cytokines interleukin (IL)-4, IL-5, IL-10, IL-1β, tumor necrosis factor-α, and keratinocyte chemoattract-growth-related oncogene characteristic of allergic airways responses. Lung responses after final allergen challenge in sensitized rats were diminished, although ozone exposure increased BALF IL-6, IL-13, IL-1 β, and interferon-γ and modified ventilatory responses only in the allergen group. Final allergen challenge also increased systolic and mean arterial BP, stroke volume, cardiac output, end-diastolic volume, sensitivity to aconitine-induced cardiac arrhythmia, and cardiac gene expression with lesser effects after a single challenge. These findings demonstrate that allergic airways responses may increase cardiovascular risk in part by altering BP and myocardial function and by causing cardiac electrical instability.

Molecular diagnosis contribution for personalized medicine

PURPOSE OF REVIEW

The purpose of the current review is to highlight the most recent findings in molecular allergy and its applicability in precision medicine for allergic patients.

RECENT FINDINGS

Molecular allergy provides useful information in areas of respiratory allergy (house dust mites, pet dander and pollen allergy), food allergy (tree nuts, peanuts, fruits and vegetables), hymenoptera venom allergy and others, in order to improve management of patients. Regional differences in sensitization profiles, assay characteristics and interpretation of molecular sensitization in relation to whole extracts and total immunoglobulin E need to be taken into account. Studies of the impact of such strategies are needed.

SUMMARY

Molecular allergy diagnosis represents a major contribution for personalized medicine. It aids in the assesment of risk prediction, disease severity, genuine/cross-reactive sensitization, and finally to apply precise management strategies.

Three patterns of sensitization to mugwort, timothy, birch and their major allergen components revealed by Latent class analysis

BACKGROUND

Mugwort, timothy, and birch are commonly spread pollen allergens across China. Although several studies have described the rates of sensitization to mugwort, timothy, and birch in China, most of them just on specific whole-allergen extracts but little was known about the co-sensitization characteristics of its allergen components. This study aimed to explore the patterns of sensitization to mugwort, timothy, birch, and their major allergen components.

METHOD

Serum specific IgE (sIgE) levels of allergen components of mugwort, timothy, birch, and cross-reactive carbohydrate determinants (CCD) were detected in 160 patients whose serum showed positive results to at least one of mugwort, timothy, and birch allergens via EUROBlotMaster system. Skin prick testing was utilized to assess the allergic reaction of grass, weed, and tree allergens. Latent class analysis was used to identify underlying patterns of sensitization to a series of allergen components and their corresponding extracts.

RESULTS

88.8% of patients with allergic rhinitis and/or asthma were positive for mugwort-sIgE, 30% for timothy-sIgE, and 32.5% for birch-sIgE. By using the LCA model, three sensitization patterns as "Mugwort, Art v 4, Bet v 2 and Phl p 12 co-sensitized", "Timothy, mugwort, and CCD co-sensitized", "Mugwort and Art v 1 co-sensitized" were revealed based on optimal statistical fit in this study. Compared with other clusters, participants in "Mugwort, Art v 4, Bet v 2 and Phl p 12 co-sensitized" pattern were associated with higher sensitization rates of common grass and tree pollens allergen. The spearman's coefficient between CCD and timothy was larger than the corresponding values of CCD with mugwort or birch.

CONCLUSION

CCD and profilin, as minor allergens in pollens, were associated with other pollen sIgE false positives presumably due to cross-reactivity. Patients sensitized with profilin had a significantly higher risk of sensitization to other pollens.

T-high asthma phenotypes across life span

RATIONALE

In adults, personalised asthma treatment targets patients with T2-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children.

OBJECTIVES

To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages.

METHODS

In the multicenter clinical ALL Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2 years (1 year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with LPS or anti-CD3/CD28.

MEASUREMENTS AND MAIN RESULTS

Based on blood eosinophil counts and allergen-specific serum IgE antibodies (sIgE), patients were categorised into four mutually exclusive phenotypes: "Atopy-only", "Eosinophils-only", "T2-high" (eosinophilia+atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2 years of follow-up. T2-high asthma in adults was associated with childhood onset suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood.

CONCLUSIONS

Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at younger age.

Atopic Status in Children with Asthma and Respiratory Allergies—Comparative Analysis of Total IgE, ImmunoCAP Phadiatop/fx5 and Euroimmun Pediatric Immunoblot

Introduction: An atopic status assessment (skin prick test or specific immunoglobulin (sIgE)) in asthmatic children is considered a milestone in identifying potential risk factors and triggers provoking loss of asthma control and asthma exacerbation. Objective: The study aims to perform a comparative analysis of different laboratory methods for a serological assessment of an atopic status in asthma and respiratory allergies in children. Material and methods: A total of 86 children were included, all of whom were diagnosed with bronchial asthma, aged from 5 to 17 years and screened for total IgE level using enzyme-linked immunosorbent assay (ELISA). In 48 randomly selected children, we performed a semi-quantitative serological in vitro assessment of the specific IgE antibodies against food and aeroallergen, using two different laboratory methods—Euroimmun Immunoblot and ImmunoCAP (Phadiatop/fx5). Results: In 70% of the children with a history of allergies, and 65.3% without clinically manifested allergies, multiscreen test ImmunoCAP Phadiatop/fx5 showed positivity and confirmed atopy. Our results showed a significant moderate to strong correlation between multiscreen ImmunoCAP Phadiatop/fx5, and Euroimmun specific IgE titers against aero-allergens—cats, mites, tree mix and food allergens—soy, wheat (р = 0.006), rice, р = 0.090), apple р = 0.007) and peanut. A sensitivity of 63% and specificity of 73.5% was observed for EUROIMMUN Pediatric (food allergens, IgE titer > 1) compared with the gold standard ImmunoCap/fx5. The mean value of total IgE is significantly higher in children with asthma and concomitant with allergic rhinitis compared to those without allergic rhinitis (mean 202.52 U/mL, IQR 102.50 (24.20–363.95) vs. 316.68, IQR 261.00 (109.20–552.50), p = 0.005). Conclusion: Establishing the spectrum of the most common respiratory and food allergens is an essential factor for maintaining asthma control, both through a strategy to avoid allergen exposure and by developing a recommendation plan. The immunoblotting technique is easily applicable in daily clinical and laboratory practice. It is also a cost-effective and reliable alternative to the “gold standard” ImmunoCAP Phadiatop/fx5 in diagnosing atopy in children.