Vulnerability to acid reflux of the airway epithelium in severe asthma

A systematic review and meta-analysis exploring the bidirectional association between asthma and gastroesophageal reflux disease in children

Background: Asthma is the most prevalent chronic respiratory disease in children, and gastroesophageal reflux disease (GERD) is one of its extraesophageal complications of asthma. Both conditions are commonly observed in pediatric outpatient clinics, but the causality between them in children is still debated. Therefore, we conducted a systematic review and meta-analysis to evaluate the bidirectional association between asthma and GERD in children. Methods: We systematically reviewed original studies published from January 2000 to February 2024 by searching the data bases. We also performed manual retrieval and screening to identify studies that met the inclusion criteria. The quality of the final included studies was evaluated by using the Newcastle-Ottawa Scale, and outcome measures were extracted. Results: We identified nine eligible studies, which included 304,399 children of different ages from seven countries. Overall, the risk of developing GERD in children with asthma (odds ratio [OR] 2.16 [95% confidence interval [CI], 1.6-2.91) was higher than the risk of developing asthma in children with GERD (OR 1.55 [95% CI, 1.32-1.82]). Conclusion: Based on the available studies, it can be concluded that asthma and GERD are mutually aggravating factors in children, presenting a bidirectional association. However, the risk of developing GERD in children with asthma is higher to some extent. More large-scale and high-quality prospective cohort studies are needed in the future to provide richer evidence and more research opportunities.

Shared genetic architecture between gastro-esophageal reflux disease, asthma, and allergic diseases

The aim is to investigate the evidence for shared genetic architecture between each of asthma, allergic rhinitis and eczema with gastro-esophageal reflux disease (GERD). Structural equation models (SEM) and polygenic risk score (PRS) analyses are applied to three Swedish twin cohorts (n = 46,582) and reveal a modest genetic correlation between GERD and asthma of 0.18 and bidirectional PRS and phenotypic associations ranging between OR 1.09-1.14 and no correlations for eczema and allergic rhinitis. Linkage disequilibrium score regression is applied to summary statistics of recently published GERD and asthma/allergic disease genome wide association studies and reveals a genetic correlation of 0.48 for asthma and GERD, and Genomic SEM supports a single latent factor. A gene-/gene-set analysis using MAGMA reveals six pleiotropic genes (two at 12q13.2) associated with asthma and GERD. This study provides evidence that there is a common genetic architecture unique to asthma and GERD that may explain comorbidity and requires further investigation.

Elevated Saliva Pepsin Concentration as a Risk Factor for Asthma in Children with Allergic Rhinitis: A Preliminary Study

Objective

This study aimed to explore whether saliva pepsin concentration (SPC) could be regarded as a risk factor for the occurrence and unfavorable control of asthma in children with allergic rhinitis.

Methods

A prospective study was conducted on a group of 20 consecutive children newly diagnosed with allergic rhinitis and asthma (referred to as the asthma group). All these children underwent fractional exhaled nitric oxide (FeNO) measurement, lung function tests, and assessment of asthma control using the 7-item Childhood Asthma Control Test (C-ACT) score. Simultaneously, a control group consisting of 20 children with simple allergic rhinitis, matched for baseline characteristics, was included. SPC measurement was performed in the two groups.

Results

The SPC value was significantly higher in the asthma group than that in the control group (165.0 ± 82.8 ng/mL vs 68.4 ± 34.5 ng/mL) (P < 0.001). In the asthma group, SPC was independently associated with FeNO, the ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC), and forced expiratory flow at 50% and 75% of FVC (FEF50 and FEF75) (all P < 0.05). The severity of nasal symptoms evaluated by the visual analogue scale (N-VAS) was independently associated with FEF75, the maximal mid-expiratory flow (MMEF), and C-ACT score (P < 0.05).

Conclusion

Direct pepsin exposure and uncontrolled nasal symptoms may play crucial roles in the pathogenesis and progression of childhood allergic asthma. The SPC value can be considered as a risk factor for asthma in children with allergic rhinitis.

Mepolizumab in Patients With Severe Asthma and Comorbidities: 1-Year REALITI-A Analysis

BACKGROUND

Severe asthma is complex; comorbidities may influence disease outcomes.

OBJECTIVE

To assess mepolizumab effectiveness in patients with severe asthma and comorbidities.

METHODS

REALITI-A was a 2-year international, prospective study enrolling adults with asthma newly prescribed mepolizumab (100 mg subcutaneously) at physician's discretion. This post hoc analysis assessed 1-year outcomes stratified by comorbidities at enrollment: chronic rhinosinusitis with nasal polyps (CRSwNP), gastroesophageal reflux disease (GERD), depression/anxiety, and chronic obstructive pulmonary disease (COPD). Outcomes included the rate of clinically significant asthma exacerbations (CSEs; requiring systemic corticosteroids and/or hospital/emergency room admission) between the 12 months pre- and post-mepolizumab treatment and changes from baseline in daily maintenance oral corticosteroid dose (mo 12), Asthma Control Questionnaire-5 score (mo 12) and forced expiratory volume in 1 second (FEV1; mo 9-12).

RESULTS

At enrollment (n = 822), 321 of 822 (39%), 309 of 801 (39%), 203 of 785 (26%), and 81 of 808 (10%) patients had comorbid CRSwNP, GERD, depression/anxiety, and COPD, respectively. Post- versus pre-treatment across all comorbidity subgroups: the rate of CSEs decreased by 63% or more; among 298 (39%) patients on maintenance oral corticosteroids at baseline, median dose decreased by 50% or more; Asthma Control Questionnaire-5 score decreased by 0.63 or more points; FEV1 increased by 74 mL or more. Patients with versus without CRSwNP had the greatest improvements (eg, rate of CSEs decreased by 75%). Patients without GERD, depression/anxiety, or COPD had greater improvements than those with the respective comorbidities, except for FEV1 in patients with COPD.

CONCLUSIONS

Mepolizumab improved disease outcomes in patients with severe asthma irrespective of comorbidities, with additional benefit for patients with CRSwNP.

Management of comorbidities in difficult and severe asthma

Difficult-to-treat and severe asthma are challenging clinical entities. In the face of suboptimal asthma control, the temptation for clinicians is to reflexively escalate asthma-directed therapy, including increasing exposure to corticosteroids and commencement of costly but potent biologic therapies. However, asthma control is objectively and subjectively assessed based on measurable parameters (such as exacerbations or variability in pulmonary physiology), symptoms and patient histories. Crucially, these features can be confounded by common untreated comorbidities, affecting clinicians' assessment of asthma treatment efficacy.

Characterization and cluster analyses of elderly asthma in comparison with nonelderly patients with asthma in Japan

BACKGROUND

Asthma is a heterogeneous disease with multiple phenotypes that are useful in precision medicine. As the population ages, the elderly asthma (EA, aged ≥ 65 years) population is growing, and EA is now a major health problem worldwide.

OBJECTIVE

To characterize EA and identify its phenotypes.

METHODS

In adult patients with asthma (aged ≥ 18 years) who had been diagnosed with having asthma at least 1 year before study enrollment, 1925 were included in the NHOM-Asthma (registered in UMIN-CTR; UMIN000027776), and the data were used for this study, JFGE-Asthma (registered in UMIN-CTR; UMIN000036912). Data from EA and non-EA (NEA) groups were compared, and Ward's minimum-variance hierarchical clustering method and principal component analysis were performed.

RESULTS

EA was characterized by older asthma onset, longer asthma duration and smoking history, more comorbidities, lower pulmonary function, less atopic, lower adherence, and more hospital admissions because of asthma. In contrast, the number of eosinophils, total immunoglobulin E level, oral corticosteroid use, and asthma control questionnaire scores were equivalent between EA and NEA. There were 3 distinct phenotypes in EA, which are as follows: EA1: youngest, late onset, short duration, mild; EA2: early onset, long duration, atopic, low lung function, moderate; and EA3: oldest, eosinophilic, overweight, low lung function, most severe. The classification factors of the EA phenotypes included the age of onset and asthma control questionnaire-6. Similarities were observed between EA and NEA phenotypes after principal component analysis.

CONCLUSION

The EA in Japan may be unique because of the population's high longevity. Characterization of EA phenotypes from the present cohort indicated the need for distinct precision medicine for EA.

TRIAL REGISTRATION

JFGE-Asthma registered in UMIN-CTR (https://www.umin.ac.jp/ctr/); UMIN000036912.