Inflammatory markers as exacerbation risk factors after asthma therapy switch from inhaled steroids to montelukast

Mild asthma is not mild: risk factors and predictive biomarkers for severe acute exacerbations and progression in mild asthma

INTRODUCTION

Asthma is a common chronic respiratory disease characterized by chronic airway inflammation, airway hyperresponsiveness, reversible airflow limitation, and airway remodeling. Mild asthma is the most common type of asthma, but it is the most neglected. Sometimes mild asthma can lead to acute severe exacerbations or even death.

AREAS COVERED

This article reviews the epidemiology, risk factors, and possible predictors of acute severe exacerbations and disease progression in mild asthma to improve the understanding of mild asthma and its severe acute exacerbations and progression.

EXPERT OPINION

There is a necessity to improve asthma patient categorization and redefine mild asthma's concept to heighten patient and physician attention. Identifying mild asthma patients that are highly vulnerable to severe acute exacerbations and researching the mechanisms are future prioritizations.

PI3Kδ inhibition prevents IL33, ILC2s and inflammatory eosinophils in persistent airway inflammation

Background

Phosphoinositide-3-kinase-delta (PI3Kδ) inhibition is a promising therapeutic approach for inflammatory conditions due to its role in leucocyte proliferation, migration and activation. However, the effect of PI3Kδ inhibition on group 2 innate lymphoid cells (ILC2s) and inflammatory eosinophils remains unknown. Using a murine model exhibiting persistent airway inflammation we sought to understand the effect of PI3Kδ inhibition, montelukast and anti-IL5 antibody treatment on IL33 expression, group-2-innate lymphoid cells, inflammatory eosinophils, and goblet cell metaplasia.

Results

Mice were sensitised to house dust mite and after allowing inflammation to resolve, were re-challenged with house dust mite to re-initiate airway inflammation. ILC2s were found to persist in the airways following house dust mite sensitisation and after re-challenge their numbers increased further along with accumulation of inflammatory eosinophils. In contrast to montelukast or anti-IL5 antibody treatment, PI3Kδ inhibition ablated IL33 expression and prevented group-2-innate lymphoid cell accumulation. Only PI3Kδ inhibition and IL5 neutralization reduced the infiltration of inflammatory eosinophils. Moreover, PI3Kδ inhibition reduced goblet cell metaplasia.

Conclusions

Hence, we show that PI3Kδ inhibition dampens allergic inflammatory responses by ablating key cell types and cytokines involved in T-helper-2-driven inflammatory responses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00461-5.

Methodology for determining the correlation of the clinical efficacy of therapy with the addition of a drug (for example, anti-asthma therapy in children)

Introduction: In the recent years, much attention has been paid to the use of leukotriene receptor antagonists (LTRA) in the treatment of bronchial asthma (BA). It has been even proposed to use them as alternatives to hormone therapy. Yet, there are studies demonstrating the advantage of montelukast as similar to placebo. The objective was to create a methodology for determining the correlation of the clinical efficacy of therapy with the addition of a drug (on example, clinical efficacy of montelukast in an anti-asthmatic therapy in pediatric patients).

Materials and methods: The data on prescribed regimens was retrospectively extracted from the inpatient records of 608 BA patients admitted to hospital in 2014–2015. Mathematical evaluation was based on the risk factor concept.

Results and discussion: The absolute efficacies (AEs) was estimated to be 91.85% (95% CI 90.15–93.55%) in the exposed group; the attributable efficacy (AtE) was found to be 17.00% (95% CI 10.91–23.09%); the relative efficacy (RE) was found to be 1.23 (95% CI 0.21–2.24); and the population attributable efficacy (PAtE) was found to be 7.55% (95% CI 2.49–12.61%).

Conclusions: The AtE, RE, and PAtE were statistically significant. The RE was found to be 1.23. However, the lower limit of its 95% CI (0.21–2.24) was less than 1, indicating that the increase in clinical efficacy was not found to be statistically significant. In the studied sample positive outcome rates were 91.85% (95% CI 90.15–93.55%) in the exposed group and 74.85% (95% CI 72.49–77.21%) in the comparator group. He presented methodology for determining the correlation of the clinical efficacy of the pharmacotherapy regimen with the addition of a drug can be successfully applied in the future.

Eosinophilic airway inflammation is a main feature of unstable asthma in adolescents

BACKGROUND

Stability of asthma is a clinical phenotype of the disease based on long-term evaluation of control of asthma symptoms and its exacerbations. A relationship between airway inflammation and clinical classification of asthma based on stability criterion has not been well studied.

OBJECTIVES

The purpose of our study was to analyze the inflammation profile of stable and unstable asthma in adolescents treated with moderate and high doses of inhaled corticosteroids.

METHODS

139 young asthmatics of 16.8 (3.25) years were classified in the stable group (N = 72) and unstable group (N = 67) after a 3-month prospective observation. Inflammatory markers including cytogram of the induced sputum (IS), fractional exhaled nitric oxide (FeNO) and bronchial hyperresponsiveness (BHR) following provocation with hypertonic saline and exercises, as well as clinical and spirometric parameters in both groups were compared.

RESULTS

75% of patients with unstable asthma revealed elevated percentage of eosinophils in the induced sputum (>2.5%), and mean values were significantly higher in comparison with stable asthma: 2.0 (0,5-4,2) vs 5,5 (2,6-11,3), p < 0,001. Bronchial hyperresponsiveness was markedly higher in unstable asthma, especially in asthma with eosinophilic profile; statistically significant differences also related to functional pulmonary tests. In multivariate analysis, asthma instability was significantly associated with sEos (p = 0.005), BHR (p = 0.001) but not FeNO (p = 0.24).

CONCLUSION (AND CLINICAL RELEVANCE)

Eosinophilic inflammation, relatively resistant to high doses of inhaled corticosteroids, is a dominant type of inflammation in unstable asthma in adolescents. Asthma instability is also associated with higher bronchial hyperresponsiveness and lower spirometric parameters. In the light of the new studies and progress in biological methods of therapy of eosinophilic inflammation, unstable asthma, especially in case of severe course, requires extended diagnostics with determination of inflammatory phenotype.

Effect of the leukotriene receptor antagonist montelukast on orthodontic tooth movement

Asthma is a chronic inflammatory disease, and its prevalence is relatively high among children. Optimal management of asthma often requires long-term pharmacotherapy; however, the effects of these medications on orthodontic treatment is uncertain. We evaluated the effects of the leukotriene LTD₄ receptor antagonist montelukast on orthodontic tooth movement in an animal model. Eight mongrel dogs were given montelukast for periods up to 4 weeks. An orthodontic force of 150-200 g was applied to move the second and fourth premolars toward the site of the extracted third premolar. The distance between premolars was measured at baseline and at weeks 1, 2, and 4. Histological examination with hematoxylin-eosin staining was used to evaluate osteoclast activity. A slight delay in orthodontic movement and decreased osteoclast activity were observed in the montelukast-treated group, as compared with untreated controls. However, the differences were not statistically significant (P > 0.05). Our findings suggest that montelukast use will not interfere with orthodontic treatment of asthma patients. However, these findings require confirmation in clinical studies.

Cysteinyl leukotriene receptor 1 antagonism prevents experimental abdominal aortic aneurysm

Cysteinyl-leukotrienes (cys-LTs) are lipid mediators involved in human inflammatory diseases, in particular asthma. We have previously identified cys-LTs in tissue specimens of human abdominal aortic aneurysm (AAA) and linked these mediators to increased metalloproteinase activity. Here we show in vivo that antagonism of the CysLT1 receptor by montelukast, an established antiasthma drug, protects against aneurysm in three mouse models of AAA at doses comparable to human medical practice. Together, these data support the role of cys-LTs in AAA and indicate a new potential therapeutic approach for treatment of this clinically silent and highly lethal disease.

Cysteinyl-leukotrienes (cys-LTs) are 5-lipoxygenase-derived lipid mediators involved in the pathogenesis and progression of inflammatory disorders, in particular asthma. We have previously found evidence linking these mediators to increased levels of proteolytic enzymes in tissue specimens of human abdominal aortic aneurysm (AAA). Here we show that antagonism of the CysLT1 receptor by montelukast, an established antiasthma drug, protects against a strong aorta dilatation (>50% increase = aneurysm) in a mouse model of CaCl₂-induced AAA at a dose comparable to human medical practice. Analysis of tissue extracts revealed that montelukast reduces the levels of matrix metalloproteinase-9 (MMP-9) and macrophage inflammatory protein-1α (MIP-1α) in the aortic wall. Furthermore, aneurysm progression was specifically mediated through CysLT1 signaling since a selective CysLT2 antagonist was without effect. A significantly reduced vessel dilatation is also observed when treatment with montelukast is started days after aneurysm induction, suggesting that the drug not only prevents but also stops and possibly reverts an already ongoing degenerative process. Moreover, montelukast reduced the incidence of aortic rupture and attenuated the AAA development in two additional independent models, i.e., angiotensin II- and porcine pancreatic elastase-induced AAA, respectively. Our results indicate that cys-LTs are involved in the pathogenesis of AAA and that antagonism of the CysLT1 receptor is a promising strategy for preventive and therapeutic treatment of this clinically silent and highly lethal disease.