From preschool wheezing to asthma: Immunological determinants

Asthma represents a chronic respiratory disease affecting millions of children worldwide. The transition from preschool wheezing to school-age asthma involves a multifaceted interplay of various factors, including immunological aspects in early childhood. These factors include complex cellular interactions among different immune cell subsets, induction of pro-inflammatory mediators and the molecular impact of environmental factors like allergens or viral infections on the developing immune system. Furthermore, the activation of specific genes and signalling pathways during this early phase plays a pivotal role in the manifestation of symptoms and subsequent development of asthma. Early identification of the propensity or risk for asthma development, for example by allergen sensitisation and viral infections during this critical period, is crucial for understanding the transition from wheeze to asthma. Favourable immune regulation during a critical 'window of opportunity' in early childhood can induce persistent changes in immune cell behaviour. In this context, trained immunity, including memory function of innate immune cells, has significant implications for understanding immune responses, potentially shaping long-term immunological outcomes based on early-life environmental exposures. Exploration of these underlying immune mechanisms that drive disease progression will provide valuable insights to understand childhood asthma development. This will be instrumental to develop preventive strategies at different stages of disease development for (i) inhibiting progression from wheeze to asthma or (ii) reducing disease severity and (iii) uncovering novel therapeutic strategies and contributing to more tailored and effective treatments for childhood asthma. In the long term, this shall empower healthcare professionals to develop evidence-based interventions that reduce the burden of asthma for children, families and society overall.

A Delphi consensus on diagnosis, management, and treatment with allergen immunotherapy of polysensitized children in Spain: CAPP study, Part 1

BACKGROUND

The study aimed to evaluate the level of agreement between specialists in pediatric allergology regarding the diagnosis and indications for pollen allergen immunotherapy (AIT) of polysensitized children in Spain.

MATERIALS AND METHODS

A Delphi study was performed using an online survey designed by a committee of pediatric AIT experts: 46 and 44 panelists participated in rounds 1 and 2, respectively. In round 1, 204 statements on 8 dimensions were evaluated (Diagnosis; Therapeutic management; Pollens - Part I; Mites; Moulds; Animals; Hymenoptera venom; and Mixtures - Part II). A total of 148 statements were finally accepted after round 2. Panel members rated their level of agreement with assessments on a 9-point Likert scale based on acceptance by ≥ 66.7% of them.

RESULTS

According to the results, the polysensitization determination in allergic patients is confirmed by clinical history, skin prick test, total and specific IgE, and molecular diagnostics. Clinical assessments are recommended for the AIT effectiveness evaluation. Follow-ups should be performed 6 months after AIT initiation. According to experts, pollens are the most representative allergens in allergic rhinitis but AIT is more effective in bronchial asthma treatment. The IgE levels are positively related to the intensity of the symptomatology and the efficacy of Grass AIT. In pollen mixtures, a maximum mixture of three AIT allergens is established between Grass, Olive, and Cupressaceae. Mixing pollen from Platanus acerifolia and Parietaria is not recommended.

CONCLUSIONS

This study provides, where evidence is lacking, current expert-based opinions on clinical decision-making for managing pollen AIT in polysensitized children.

Molecular sensitisation patterns to aeroallergens in a Mediterranean paediatric population and their clinical implications

BACKGROUND

Environmental exposures, climate change, and lifestyle factors are key contributors to respiratory allergies. Understanding the connection between allergen exposure and the development of allergic diseases in early life is essential for identifying sensitization patterns and optimizing diagnostic and therapeutic strategies.

OBJECTIVE

This study aims to characterize the allergic sensitization profile in a Mediterranean paediatric population using a component-resolved diagnosis (CRD) approach. Specifically, we analyse the prevalence and serodominance of aeroallergens, examine age-related sensitization patterns, and assess their implications for personalized allergen immunotherapy. Additionally, we highlight the need to incorporate the identified molecular allergens into standardized allergenic extracts to improve diagnostic accuracy and immunotherapy efficacy.

METHODS

We conducted an observational, cross-sectional study including paediatric patients (0-15 years) diagnosed with allergic rhinitis, with or without asthma. Patients were classified according to disease severity following international guidelines. Skin prick tests were performed using standardized extracts, and specific IgE levels were determined with the multiplex assay Allergy Explorer 2 (ALEX2-MADX).

RESULTS

A total of 47 patients were included (mean age: 7.5 years). Sensitization to house dust mites (HDM) was the most prevalent (74.5%), followed by pollen (57.4%) and animal epithelia (44.6%). The most frequently recognized allergens were Der p 23 (59.57%) for HDM, Ole e 1 (36.17%) for olive pollen, and Fel d 1 (27.7%) for cat epithelium. The highest IgE levels were observed in children aged 6-10 years. Polysensitization was present in 66% of patients, with frequent co-recognition of allergens from different sources. The findings emphasize the need to ensure that allergenic extracts used in diagnosis and immunotherapy contain relevant molecular components to enhance treatment precision.

CONCLUSION

A detailed molecular characterization of allergic sensitization in paediatric patients provides valuable insights into aeroallergen exposure and its clinical implications. Our findings reinforce the importance of incorporating relevant molecular allergens into standardized diagnostic and therapeutic extracts to optimize patient management and improve the efficacy of allergen-specific immunotherapy.

Polysensitisation is associated with more severe symptoms: The reality of patients with allergy

BACKGROUND

Studying the sensitisation profiles of patients with allergies allows for a deeper understanding of the disease which may facilitate the selection of the best-personalised allergen immunotherapy. This observational, cross-sectional, multicentre study aimed to demonstrate the heterogeneity of the German population with allergies by analysing specific immunoglobulin E (sIgE) patterns towards aeroallergens and exploring the relationship between sensitisation and clinical symptoms.

METHODS

In total, 500 patients with allergies from different regions of Germany were recruited based on their case histories, clinical allergic symptoms and skin prick test data for aeroallergens. Serum samples were analysed using ImmunoCAP assays to determine sIgE levels for 33 allergenic sources and 43 molecular allergens.

RESULTS

Most patients (81%) were polysensitised. Betula verrucosa pollen was the most common cause of sensitisation (59%), followed by Phleum pratense (58%) and Dermatophagoides pteronyssinus (44%). The highest prevalence rates of molecular allergens were observed for Bet v 1 (84%) from birch pollen, Phl p 1 from grass pollen (82%), Der p 2 (69%) from mites and Fel d 1 (69%) from cat. Polysensitisation was significantly associated with the presence of asthma and the severity of rhinitis symptoms.

CONCLUSIONS

Our findings show a high rate of polysensitisation and emphasise the importance of molecular diagnosis for more precise and comprehensive insights into sensitisation patterns and their association with clinical symptoms. These data may help improve personalised diagnosis and immunotherapy adapted to the needs of individual patients in the region.