Longitudinal eosinophil-derived neurotoxin measurements and asthma development in preschool wheezers

Rhinovirus-induced wheeze was associated with asthma development in predisposed children

AIM

This study explored whether early-life factors, such as rhinovirus-induced wheeze and allergic sensitisation, were related to asthma at 11 years of age.

METHODS

We focused on 107 children aged 6-48 months, who attended the paediatric emergency department at Astrid Lindgren's Children's Hospital in Stockholm, Sweden, with acute wheeze in 2008-2012. They also attended follow-up visits at 11 years of age and were compared with 46 age-matched healthy controls. Odds ratios (OR) with 95% confidence intervals (CI) were calculated with logistic regression.

RESULTS

We found that 62.6% of the acute wheeze cases had asthma at 11 years of age. Rhinoviruses at inclusion were the only common airway viruses associated with an increased asthma risk (OR 2.4, 95% CI 1.02-5.6). Other increased risks were parental heredity for asthma and/or allergies (adjusted OR 3.4, 95% CI 1.1-9.9) and allergic sensitisation at 2 years of age (adjusted OR 3.0, 95% CI 1.02-8.7). The highest prevalence of asthma was when children had both rhinovirus-induced wheeze at inclusion and allergic sensitisation at 7 years of age.

CONCLUSION

Our findings highlight the importance of hereditary factors and allergic sensitisation on the development of asthma and suggest that rhinoviruses are associated with asthma development in predisposed children.

A systematic review and meta-analysis on absolute eosinophil counts and the risk of asthma in preschool children with wheezing: An EAACI Task Force Report

Preschool children with wheezing disorders pose diagnostic and therapeutic challenges and consume substantial healthcare resources. Peripheral eosinophil blood count (EBC) has been proposed as a potential indicator for future asthma development. This review by the European Academy of Allergy and Clinical Immunology (EAACI) Preschool Wheeze Task Force aimed to provide systematic evidence for the association between increased EBC and the risk of future asthma, as well as to identify potential cutoff values. In February 2023, a search of PubMed, EMBASE, and Cochrane Library databases was conducted to identify studies comparing EBCs in preschool children with wheezing who continued to wheeze later in life and those who did not. Included observational studies focused on children aged <6 years with a wheezing disorder, assessment of their EBCs, and subsequent asthma status. No language or publication date restrictions were applied. Among the initial 3394 studies screened, 10 were included in the final analysis, involving 1225 patients. The data from these studies demonstrated that high EBC in preschool children with wheezing is associated with future asthma development, with odds ratios of 1.90 (95% CI: 0.45-7.98, p = .38), 2.87 (95% CI: 1.38-5.95, p < .05), and 3.38 (95% CI: 1.72-6.64, p < .05) for cutoff values in the <300, 300-449, and ≥450 cells/μL ranges, respectively. Defining a specific cutoff point for an elevated EBC lacks consistency, but children with EBC >300 cells/μL are at increased risk of asthma. However, further research is needed due to the limitations of the included studies. Future investigations are necessary to fully elucidate the discussed association.

Eosinophil-derived neurotoxin levels in early childhood and association with preschool asthma - A prospective observational study

INTRODUCTION

Eosinophil-derived neurotoxin (EDN) is related to childhood asthma, while normal values are lacking. We aimed to document serum EDN levels at 1 and 3 years in general and in non-atopic children, and explore if EDN levels differed by sex or were associated with preschool asthma at 3 years.

METHODS

From the PreventADALL birth cohort, we included 1233 children with EDN analysed using ImmunoCAP at 1 and/or 3 years. Non-atopic children had no history of wheeze, asthma, allergic sensitization or atopic dermatitis. Preschool asthma was defined as having ≥3 episodes of bronchial obstruction between 2 and 3 years, plus doctor diagnosed asthma and/or asthma medication use by 3 years. The upper limit of normal (ULN) of EDN was defined as the 95th percentile. With Youden Index we calculated EDN cut-off levels for risk of preschool asthma.

RESULTS

The overall median (ULN) EDN levels were 27.4 (121) μg/L at 1 year (n = 787), and 20.1 (87.8) μg/L at 3 years (n = 857). Non-atopic children had EDN levels of 24.0 (107) μg/L at 1 year (n = 147), and 17.3 (84.6) μg/L at 3 years (n = 173). EDN levels were higher in boys compared to girls; 32.0 (133) versus 24.5 (97.0) μg/L at 1 year, and 20.9 (96.3) versus 19.0 (72.4) μg/L at 3 years. Preschool asthma was observed in 109/892 (12.2%) children. Higher EDN levels at 1 (>26.7 μg/L) and 3 (≥20.5 μg/L) years were associated with preschool asthma; adjusted OR (95% CI) 2.20 (1.09, 4.41) and 4.68 (2.29, 9.55), respectively.

CONCLUSION AND CLINICAL RELEVANCE

We report EDN values in early childhood, demonstrating higher levels at 1 compared to 3 years and in boys compared to girls at both ages. Higher EDN levels at both ages were associated with preschool asthma. However, EDN cut-off levels for preschool asthma were overall lower than the ULN of non-atopic children, limiting translation into clinical practice.

Allergic sensitisation and type-2 inflammation is associated with new-onset and persistent allergic disease

BACKGROUND

Allergic disease is common. The aim of this study was to look at the change in asthma and rhinitis over time and to characterise factors contributing to remission and persistence of disease.

METHODS

This cohort study included 255 individuals with or without asthma and or rhinitis that participated in a population survey and a follow-up 10 years later. The participants were tested for allergic sensitisation, total IgE, multiplex allergen component analysis and type-2 inflammatory markers: exhaled nitric oxide (FE NO), eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN).

RESULTS

Of the 132 healthy individuals, 112 remained healthy, 16 developed rhinitis, 4 asthma and rhinitis over the 10 years. Out of 82 subjects with rhinitis, 26 went into remission, 53 remained unchanged and 3 developed asthma in addition to rhinitis. None of the 41 participants with asthma and rhinitis went into remission. Subjects with persistent rhinitis and asthma had higher levels of total IgE (odds ratio [OR] 95% confidence interval [CI]: 6.16 [3.05-12.5]) at baseline and after 10 years, and FE NO and ECP at baseline (OR per log unit increase, 95% CI 5.21 [1.20-22.7] and 6.32 [1.52-26.4], respectively), compared with those that remained healthy. Subjects with persistent rhinitis were more likely to be sensitised to grass pollen and had higher total IgE levels than those that went into remission. Individuals with persistent asthma were more likely to be sensitised to tree pollen and furry animals than those with only persistent rhinitis (OR 95% CI: 3.50 [1.29-9.49] and 6.73 [2.00-22.6], respectively).

CONCLUSION

IgE sensitisation and total IgE levels are associated with the persistence of rhinitis and asthma. Participants with persistent allergic disease had higher levels of allergen sensitisation and type 2 inflammation markers at baseline than those who remained healthy.

Clinical Potential of Eosinophil-Derived Neurotoxin in Asthma Management

The assessment and management of patients with asthma is challenging because of the complexity of the underlying inflammatory mechanisms and heterogeneity of their clinical presentation. Optimizing disease management requires therapy individualization that should rely on reliable biomarkers to unravel the phenotypes and endotypes of asthma. The secretory activity and turnover of eosinophils, as assessed by measuring eosinophil-derived proteins, may provide an accurate and complementary tool that mirrors the eosinophil activation status. Emerging evidence suggests that eosinophil-derived neurotoxin has considerable potential as a precision medicine biomarker. In this review, we explore the suitability of eosinophil-derived neurotoxin as a biomarker in asthma management, with particular emphasis on its clinical significance in the management of both pediatric and adult populations.