Stability of sputum inflammatory phenotypes in childhood asthma during stable and exacerbation phases

A Simulation Study of the Effect of Clinical Characteristics and Treatment Choice on Reliever Medication Use, Symptom Control and Exacerbation Risk in Moderate-Severe Asthma

INTRODUCTION

The relationship between immediate symptom control, reliever medication use and exacerbation risk on treatment response and factors that modify it have not been assessed in an integrated manner. Here we apply simulation scenarios to evaluate the effect of individual baseline characteristics on treatment response in patients with moderate-severe asthma on regular maintenance dosing monotherapy with fluticasone propionate (FP) or combination therapy with fluticasone propionate/salmeterol (FP/SAL) or budesonide/formoterol (BUD/FOR).

METHODS

Reduction in reliever medication use (puffs/24 h), change in symptom control scores (ACQ-5), and annualised exacerbation rate over 12 months were simulated in a cohort of patients with different baseline characteristics (e.g. time since diagnosis, asthma control questionnaire (ACQ-5) symptom score, smoking status, body mass index (BMI) and sex) using drug-disease models derived from large phase III/IV clinical studies.

RESULTS

Simulation scenarios show that being a smoker, having higher baseline ACQ-5 and BMI, and long asthma history is associated with increased reliever medication use (p < 0.01). This increase correlates with a higher exacerbation risk and higher ACQ-5 scores over the course of treatment, irrespective of the underlying maintenance therapy. Switching non-responders to ICS monotherapy to combination therapy after 3 months resulted in immediate reduction in reliever medication use (i.e. 1.3 vs. 1.0 puffs/24 h for FP/SAL and BUD/FOR, respectively). In addition, switching patients with ACQ-5 > 1.5 at baseline to FP/SAL resulted in 34% less exacerbations than those receiving regular dosing BUD/FOR (p < 0.01).

CONCLUSIONS

We have identified baseline characteristics of patients with moderate to severe asthma that are associated with greater reliever medication use, poor symptom control and higher exacerbation risk. Moreover, the effects of different inhaled corticosteroid (ICS)/long-acting beta agonist (LABA) combinations vary significantly when considering long-term treatment performance. These factors should be considered in clinical practice as a basis for personalised management of patients with moderate-severe asthma symptoms.

Endotypes of Paediatric Cough-Do They Exist and Finding New Techniques to Improve Clinical Outcomes

Chronic cough is a common symptom of many childhood lung conditions. Given the phenotypic heterogeneity of chronic cough, better characterization through endotyping is required to provide diagnostic certainty, precision therapies and to identify pathobiological mechanisms. This review summarizes recent endotype discoveries in airway diseases, particularly in relation to children, and describes the multi-omic approaches that are required to define endotypes. Potential biospecimens that may contribute to endotype and biomarker discoveries are also discussed. Identifying endotypes of chronic cough can likely provide personalized medicine and contribute to improved clinical outcomes for children.

Eosinophil-derived neurotoxin: An asthma exacerbation biomarker in children

Background: Asthma is a heterogeneous disease, characterized by chronic airway inflammation. Asthma exacerbations (AE) are episodes characterized by a progressive increase in symptoms of shortness of breath, cough, wheezing, or chest tightness with a decrease in lung function. There have been previous studies that examined the role of eosinophil-derived neurotoxin (EDN) in asthma, but there have been no studies of the role of EDN in children experiencing AE. Objective: In this study, we aimed to examine the association of EDN with lung function and prognosis in children admitted for severe AE. Methods: We enrolled 82 children who were admitted for severe AE at two different university hospitals in South Korea between January 2018 and December 2019. Blood tests, including white blood cell count, myeloperoxidase (MPO), total eosinophil count, EDN, C-reactive protein (CRP) level, and interleukin (IL) 4, IL-5, IL-10 values, and lung function were measured on admission and at discharge in each patient. Results: We observed significant decreases in the levels of MPO, EDN, CRP, and IL-4, with significant improvement in lung function after treatment. We then classified the subjects into two groups of different clinical phenotypes: eosinophilic asthma exacerbation (EAE) group and non-EAE group. EDN levels were higher and lung functions were lower in the EAE group. Also, we found that the EDN level was a significant biomarker useful for predicting the number of days for hospital stay. Conclusion: We found that EDN can act as a biomarker that reflects lung function, and that EDN could act as a prognostic biomarker, which demonstrated the complex role of EDN in children experiencing AE.

Airway Wall Remodeling in Childhood Asthma-A Personalized Perspective from Cell Type-Specific Biology

Airway wall remodeling is a pathology occurring in chronic inflammatory lung diseases including asthma, chronic obstructive pulmonary disease, and fibrosis. In 2017, the American Thoracic Society released a research statement highlighting the gaps in knowledge and understanding of airway wall remodeling. The four major challenges addressed in this statement were: (i) the lack of consensus to define “airway wall remodeling” in different diseases, (ii) methodologic limitations and inappropriate models, (iii) the lack of anti-remodeling therapies, and (iv) the difficulty to define endpoints and outcomes in relevant studies. This review focuses on the importance of cell-cell interaction, especially the bronchial epithelium, in asthma-associated airway wall remodeling. The pathology of “airway wall remodeling” summarizes all structural changes of the airway wall without differentiating between different pheno- or endo-types of asthma. Indicators of airway wall remodeling have been reported in childhood asthma in the absence of any sign of inflammation; thus, the initiation event remains unknown. Recent studies have implied that the interaction between the epithelium with immune cells and sub-epithelial mesenchymal cells is modified in asthma by a yet unknown epigenetic mechanism during early childhood.