Alzheimer's Incidence and Prevalence with and without Asthma: A Medicare cohort study

BACKGROUND

International data suggest that asthma, like other inflammatory diseases, might increase Alzheimer's disease (AD) risk.

OBJECTIVE

To explore risk pathways and future mitigation strategies by comparing diagnostic claims-based AD incidence and prevalence among US patients with asthma to non-asthma patients.

METHODS

This cohort study included a national Medicare 20% random sample 2013-2015. Adult patients with >12 months continuous Medicare with asthma were compared to non-asthma subjects overall and as matched. Asthma was defined by one inpatient or two outpatient codes for asthma. The main outcomes were two-year incident or prevalent AD defined as any codes for ICD-9 331.0 or ICD-10 G30.0, G30.1, G30.8, G30.9.

RESULTS

Among 5,460,732 total beneficiaries, 678,730 patients were identified with baseline asthma and more often identified as Black or Hispanic, were Medicaid eligible, or resided in a highly disadvantaged neighborhood than those without asthma. Two-year incidence of AD was 1.4% with asthma vs 1.1% without; prevalence was 7.8% vs 5.4% (both p=<0.001). Per 100,000 patients over two years, 303 more incident AD diagnoses occurred in asthma, with 2,425 more prevalent cases (p<0.001). Multivariable models showed asthma had greater odds of two-year AD incidence [AOR 1.33 (1.29-1.36); matched 1.2 (1.17-1.24)] and prevalence [AOR 1.48 (1.47-1.50); matched 1.25 (1.22-1.27)).

CONCLUSION

Asthma was associated with 20-33% increased two-year incidence and 25-48% increased prevalence of claims-based Alzheimer's disease in this nationally representative US sample. Future research should investigate risk pathways of underlying comorbidities and social determinants, as well as whether there are potential asthma treatments that may preserve brain health.

Targeting Asthma Remission as the Next Therapeutic Step Toward Improving Disease Control

The long-term goal of asthma management is to achieve disease control, comprising the assessment of 2 main domains: (1) symptom control and (2) future risk of adverse outcomes. Decades of progress in asthma management have correlated with increasingly ambitious disease control targets. Moreover, the introduction of precision medicines, such as biologics, has further expanded the limits of what can be achieved in terms of disease control. It is now believed that clinical remission, a term rarely associated with asthma, may be an achievable treatment goal. An expert framework published in 2020 took the first step toward developing a commonly accepted definition of clinical remission in asthma. However, there remains a widespread discussion about the clinical parameters and thresholds that should be included in a standardized definition of clinical remission. This review aims to discuss on-treatment clinical remission as an aspirational outcome in asthma management, drawing on experiences from other chronic diseases where remission has long been a goal. We also highlight the integral role of shared decision-making between patients and health care professionals and the need for a common understanding of the individual patient journey to remission as foundational elements in reducing disease burden and improving outcomes for patients with asthma.

Dupilumab reduces exacerbations independent of changes in biomarkers in moderate-to-severe asthma

BACKGROUND

Changes from baseline in fractional exhaled nitric oxide (FeNO) and blood eosinophil count (Eos) may be related to efficacy outcomes in dupilumab-treated patients with moderate-to-severe asthma.

OBJECTIVE

This post-hoc analysis investigated biomarker changes in placebo- and dupilumab-treated patients with uncontrolled moderate-to-severe asthma enrolled in QUEST (NCT02414854).

METHODS

Spline analyses of annualized severe exacerbation rate (AER) and change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 second (FEV1) at Week 52 were performed as a function of fold-change in FeNO at Week 52, and maximum fold-change in Eos over Week 0-12 (also change from baseline in pre-bronchodilator FEV1 at Week 12).

RESULTS

The combined placebo and dupilumab groups comprised 638 and 1264 patients, respectively. FeNO levels declined rapidly by Week 2 then gradually to Week 52 in patients treated with dupilumab vs placebo; Eos counts, after initially increasing with dupilumab, declined slightly from baseline in both treatment groups. AER during QUEST showed no significant association with change in biomarkers in either treatment group. Change from baseline in pre-bronchodilator FEV1 at Week 52 was inversely associated with fold-change in FeNO in both groups, with significant difference between the dupilumab and placebo curves (P = .014) and was positively associated with fold-change in Eos in both groups (P = .022).

CONCLUSION

Relative changes in FeNO and Eos were not associated with AER, regardless of treatment arm. However, changes in both biomarkers showed predictive value for lung function improvement; for FeNO this was specific to the dupilumab treatment arm.

Activated sputum eosinophils associated with exacerbations in children on mepolizumab

BACKGROUND

MUPPITS-2 was a randomized, placebo-controlled clinical trial that demonstrated mepolizumab (anti-IL-5) reduced exacerbations and blood and airway eosinophils in urban children with severe eosinophilic asthma. Despite this reduction in eosinophilia, exacerbation risk persisted in certain patients treated with mepolizumab. This raises the possibility that subpopulations of airway eosinophils exist that contribute to breakthrough exacerbations.

OBJECTIVE

We aimed to determine the effect of mepolizumab on airway eosinophils in childhood asthma.

METHODS

Sputum samples were obtained from 53 MUPPITS-2 participants. Airway eosinophils were characterized using mass cytometry and grouped into subpopulations using unsupervised clustering analyses of 38 surface and intracellular markers. Differences in frequency and immunophenotype of sputum eosinophil subpopulations were assessed based on treatment arm and frequency of exacerbations.

RESULTS

Median sputum eosinophils were significantly lower among participants treated with mepolizumab compared with placebo (58% lower, 0.35% difference [95% CI 0.01, 0.74], P = .04). Clustering analysis identified 3 subpopulations of sputum eosinophils with varied expression of CD62L. CD62Lint and CD62Lhi eosinophils exhibited significantly elevated activation marker and eosinophil peroxidase expression, respectively. In mepolizumab-treated participants, CD62Lint and CD62Lhi eosinophils were more abundant in participants who experienced exacerbations than in those who did not (100% higher for CD62Lint, 0.04% difference [95% CI 0.0, 0.13], P = .04; 93% higher for CD62Lhi, 0.21% difference [95% CI 0.0, 0.77], P = .04).

CONCLUSIONS

Children with eosinophilic asthma treated with mepolizumab had significantly lower sputum eosinophils. However, CD62Lint and CD62Lhi eosinophils were significantly elevated in children on mepolizumab who had exacerbations, suggesting that eosinophil subpopulations exist that contribute to exacerbations despite anti-IL-5 treatment.

Gene-based association study of rare variants in children of diverse ancestries implicates TNFRSF21 in the development of allergic asthma

BACKGROUND

Most genetic studies of asthma and allergy have focused on common variation in individuals primarily of European ancestry. Studying the role of rare variation in quantitative phenotypes and in asthma phenotypes in populations of diverse ancestries can provide additional, important insights into the development of these traits.

OBJECTIVE

We sought to examine the contribution of rare variants to different asthma- or allergy-associated quantitative traits in children with diverse ancestries and explore their role in asthma phenotypes.

METHODS

We examined whole-genome sequencing data from children participants in longitudinal studies of asthma (n = 1035; parent-identified as 67% Black and 25% Hispanic) to identify rare variants (minor allele frequency < 0.01). We assigned variants to genes and tested for associations using an omnibus variant-set test between each of 24,902 genes and 8 asthma-associated quantitative traits. On combining our results with external data on predicted gene expression in humans and mouse knockout studies, we identified 3 candidate genes. A burden of rare variants in each gene and in a combined 3-gene score was tested for its associations with clinical phenotypes of asthma. Finally, published single-cell gene expression data in lower airway mucosal cells after allergen challenge were used to assess transcriptional responses to allergen.

RESULTS

Rare variants in USF1 were significantly associated with blood neutrophil count (P = 2.18 × 10-7); rare variants in TNFRSF21 with total IgE (P = 6.47 × 10-6) and PIK3R6 with eosinophil count (P = 4.10 × 10-5) reached suggestive significance. These 3 findings were supported by independent data from human and mouse studies. A burden of rare variants in TNFRSF21 and in a 3-gene score was associated with allergy-related phenotypes in cohorts of children with mild and severe asthma. Furthermore, TNFRSF21 was significantly upregulated in bronchial basal epithelial cells from adults with allergic asthma but not in adults with allergies (but not asthma) after allergen challenge.

CONCLUSIONS

We report novel associations between rare variants in genes and allergic and inflammatory phenotypes in children with diverse ancestries, highlighting TNFRSF21 as contributing to the development of allergic asthma.

Resting state functional connectivity changes following mindfulness-based stress reduction predict improvements in disease control for patients with asthma

BACKGROUND

The staggering morbidity associated with chronic inflammatory diseases can be reduced by psychological interventions, including Mindfulness-Based Stress Reduction (MBSR). Proposed mechanisms for MBSR's beneficial effects include changes in salience network function. Salience network perturbations are also associated with chronic inflammation, including airway inflammation in asthma, a chronic inflammatory disease affecting approximately 10% of the population. However, no studies have examined whether MBSR-related improvements in disease control are related to changes in salience network function.

METHODS

Adults with asthma were randomized to 8 weeks of MBSR or a waitlist control group. Resting state functional connectivity was measured using fMRI before randomization, immediately post-intervention, and 4 months post-intervention. Using key salience network regions as seeds, we calculated group differences in change in functional connectivity over time and examined whether functional connectivity changes were associated with increased mindfulness, improved asthma control, and decreased inflammatory biomarkers.

RESULTS

The MBSR group showed greater increases in functional connectivity between salience network regions relative to the waitlist group. Improvements in asthma control correlated with increased functional connectivity between the salience network and regions important for attention control and emotion regulation. Improvements in inflammatory biomarkers were related to decreased functional connectivity between the salience network and other networks.

CONCLUSIONS

Increased resting salience network coherence and connectivity with networks that subserve attention and emotion regulation may contribute to the benefits of MBSR for patients with asthma. Understanding the neural underpinnings of MBSR-related benefits in patients is a critical step towards optimizing brain-targeted interventions for chronic inflammatory disease management.

Molecular pathways underlying lung-brain axis signaling in asthma: Relevance for psychopathology and neuroinflammation

BACKGROUND

Accumulating evidence indicates that asthma has systemic effects and affects brain function. Although airway inflammation is proposed to initiate afferent communications with the brain, the signaling pathways have not been established.

OBJECTIVE

We sought to identify the cellular and molecular pathways involved in afferent lung-brain communication during airway inflammation in asthma.

METHODS

In 23 adults with mild asthma, segmental bronchial provocation with allergen (SBP-Ag) was used to provoke airway inflammation and retrieve bronchoalveolar lavage fluid for targeted protein analysis and RNA sequencing to determine gene expression profiles. Neural responses to emotional cues in nodes of the salience network were assessed with functional magnetic resonance imaging at baseline and 48 hours after SBP-Ag.

RESULTS

Cell deconvolution and gene coexpression network analysis identified 11 cell-associated gene modules that changed in response to SBP-Ag. SBP-Ag increased bronchoalveolar lavage eosinophils and expression of an eosinophil-associated module enriched for genes related to TH17-type inflammation (eg, IL17A), as well as cell proliferation in lung and brain (eg, NOTCH1, VEGFA, and LIF). Increased expression of genes in this module, as well as several TH17-type inflammation-related proteins, was associated with an increase from baseline in salience network reactivity.

CONCLUSIONS

Our results identify a specific inflammatory pathway linking asthma-related airway inflammation and emotion-related neural function. Systemically, TH17-type inflammation has been implicated in both depression and neuroinflammation, with impacts on long-term brain health. Thus, our data emphasize that inflammation in the lung in asthma may have profound effects outside of the lung that may be targetable with novel therapeutic approaches.

Safety and Efficacy of Dexpramipexole in Eosinophilic Asthma (EXHALE): A randomized controlled trial

BACKGROUND

There is a need for new and effective oral asthma therapies. Dexpramipexole, an oral eosinophil-lowering drug, has not previously been studied in asthma.

OBJECTIVE

We sought to evaluate the safety and efficacy of dexpramipexole in lowering blood and airway eosinophilia in subjects with eosinophilic asthma.

METHODS

We performed a randomized, double-blind, placebo-controlled proof-of-concept trial in adults with inadequately controlled moderate to severe asthma and blood absolute eosinophil count (AEC) greater than or equal to 300/μL. Subjects were randomly assigned (1:1:1:1) to dexpramipexole 37.5, 75, or 150 mg BID (twice-daily) or placebo. The primary end point was the relative change in AEC from baseline to week 12. Prebronchodilator FEV1 week-12 change from baseline was a key secondary end point. Nasal eosinophil peroxidase was an exploratory end point.

RESULTS

A total of 103 subjects were randomly assigned to dexpramipexole 37.5 mg BID (N = 22), 75 mg BID (N = 26), 150 mg BID (N = 28), or placebo (N = 27). Dexpramipexole significantly reduced placebo-corrected AEC week-12 ratio to baseline, in both the 150-mg BID (ratio, 0.23; 95% CI, 0.12-0.43; P < .0001) and the 75-mg BID (ratio, 0.34; 95% CI, 0.18-0.65; P = .0014) dose groups, corresponding to 77% and 66% reductions, respectively. Dexpramipexole reduced the exploratory end point of nasal eosinophil peroxidase week-12 ratio to baseline in the 150-mg BID (median, 0.11; P = .020) and the 75-mg BID (median, 0.17; P = .021) groups. Placebo-corrected FEV1 increases were observed starting at week 4 (nonsignificant). Dexpramipexole displayed a favorable safety profile.

CONCLUSIONS

Dexpramipexole demonstrated effective eosinophil lowering and was well tolerated. Additional larger clinical trials are needed to understand the clinical efficacy of dexpramipexole in asthma.

Dupilumab efficacy in high sleep disturbance management among patients with type 2 asthma

BACKGROUND

Patients with asthma often experience sleep disturbances. We assessed the 5-item Asthma Control Questionnaire (ACQ-5) score ≥2.5 as a useful threshold to identify patients with moderate-to-severe type 2 asthma and high sleep disturbance (HSD) and investigated dupilumab efficacy on clinical and sleep-related outcomes among patients with HSD.

METHODS

QUEST (NCT02414854) data were used in this post hoc analysis. A composite endpoint from validated patient-reported outcomes was developed to identify patients with HSD using sleep-related items from the ACQ-5, Asthma-Related Quality-of-Life Questionnaire, Rhino-Conjunctivitis Quality-of-Life Questionnaire, and Sino-Nasal Outcome Test-22. Impairment in at least 1 item was considered an indication of HSD. Change from baseline to Week 52 in nighttime symptoms, ACQ-5 score, lung function, annualized severe exacerbation rates (AER), and short-acting β-agonists use during treatment was used to assess dupilumab efficacy.

RESULTS

In type 2 asthma patients, 64% had HSD at baseline; of those with ACQ-5 ≥2.5 at baseline, 82% had HSD. In this population, dupilumab reduced nighttime symptoms and ACQ-5 score by 0.31 and 0.56 points, respectively, by Week 52 versus placebo, and led to a 66% reduction in AER during QUEST and 0.34 L improvement in pre-bronchodilator (pre-BD) forced expiratory volume in 1 s (FEV1) at Week 52.

CONCLUSION

A majority of patients with moderate-to-severe type 2 asthma with ACQ-5 ≥2.5 at baseline had HSD. Dupilumab reduced nighttime symptoms and exacerbations, and improved lung function, overall asthma control, and quality of life. Further studies are needed to confirm the association between ACQ-5 score ≥2.5 and higher sleep disturbance rates.

Efficacy of dupilumab in patients with uncontrolled, moderate-to-severe asthma with fungal sensitization

BACKGROUND

Fungal sensitization (FS) exacerbates asthma in patients who have elevated type 2 inflammatory response. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin (IL)-4 and IL-13, key and central drivers of type 2 inflammation in multiple diseases.

OBJECTIVE

This post hoc analysis, funded by the manufacturers of dupilumab, was conducted to assess dupilumab efficacy in patients from the phase 3 LIBERTY ASTHMA QUEST trial (NCT02414854) and TRAVERSE open-label extension (NCT02134028) study who had uncontrolled, moderate-to-severe asthma with type 2 inflammatory phenotype (defined as blood eosinophil count ≥150 cells/μL or FeNO ≥25 ppb) and with FS (defined as IgE specific to Alternaria alternata, Aspergillus fumigatus or Cladosporium herbarum >0.35 IU/mL).

METHODS

We evaluated annualized rate of severe exacerbations (AER), change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 s (FEV1 ), asthma control (per 5-item Asthma Control Questionnaire [ACQ-5]) and biomarker levels (blood eosinophil count, fractional exhaled nitric oxide [FeNO], total IgE, fungal-specific IgEs, thymus and activation-regulated chemokine [TARC] and eotaxin-3).

RESULTS

Dupilumab vs. placebo reduced AER, improved pre-BD FEV1 and asthma control (ACQ-5), and reduced serum IgE levels, blood eosinophil count, TARC, eotaxin-3 and FeNO in patients both with and without FS after 52 weeks of treatment in QUEST. Reductions in asthma exacerbation rates and improvements in all other variables were sustained over the TRAVERSE open-label extension study.

CONCLUSION

Dupilumab demonstrated efficacy during prolonged treatment in patients with uncontrolled, moderate-to-severe asthma with FS.

The Unified Airway Hypothesis: Evidence From Specific Intervention With Anti-IL-5 Biologic Therapy

The unified airway hypothesis proposes that upper and lower airway diseases reflect a single pathological process manifesting in different locations within the airway. Functional, epidemiological, and pathological evidence has supported this well-established hypothesis for some time. However, literature on the pathobiologic roles/therapeutic targeting of eosinophils and IL-5 in upper and lower airway diseases (including asthma, chronic rhinosinusitis with nasal polyps [CRSwNP], and nonsteroidal anti-inflammatory drug-exacerbated respiratory disease) has recently emerged. This narrative review revisits the unified airway hypothesis by searching the scientific literature for recent learnings and clinical trial/real-world data that provide a novel perspective on its relevance for clinicians. According to the available literature, eosinophils and IL-5 have important pathophysiological roles in both the upper and lower airways, although the impact of eosinophils and IL-5 may vary in asthma and CRSwNP. Some differential effects of anti-IL-5 and anti-IL-5-receptor therapies in CRSwNP have been observed, requiring further investigation. However, pharmaceutical targeting of eosinophils and IL-5 in patients with upper, lower, and comorbid upper and lower airway inflammation has led to clinical benefit, supporting the hypothesis that these are linked conditions manifesting in different locations. Consideration of this approach may improve patient care and aid clinical decision making.

Rhinoviruses A and C elicit long-lasting antibody responses with limited cross-neutralization

Rhinoviruses (RVs) can cause severe wheezing illnesses in young children and patients with asthma. Vaccine development has been hampered by the multitude of RV types with little information about cross-neutralization. We previously showed that neutralizing antibody (nAb) responses to RV-C are detected twofold to threefold more often than those to RV-A throughout childhood. Based on those findings, we hypothesized that RV-C infections are more likely to induce either cross-neutralizing or longer-lasting antibody responses compared with RV-A infections. We pooled RV diagnostic data from multiple studies of children with respiratory illnesses and compared the expected versus observed frequencies of sequential infections with RV-A or RV-C types using log-linear regression models. We tested longitudinally collected plasma samples from children to compare the duration of RV-A versus RV-C nAb responses. Our models identified limited reciprocal cross-neutralizing relationships for RV-A (A12-A75, A12-A78, A20-A78, and A75-A78) and only one for RV-C (C2-C40). Serologic analysis using reference mouse sera and banked human plasma samples confirmed that C40 infections induced nAb responses with modest heterotypic activity against RV-C2. Mixed-effects regression modeling of longitudinal human plasma samples collected from ages 2 to 18 years demonstrated that RV-A and RV-C illnesses induced nAb responses of similar duration. These results indicate that both RV-A and RV-C nAb responses have only modest cross-reactivity that is limited to genetically similar types. Contrary to our initial hypothesis, RV-C species may include even fewer cross-neutralizing types than RV-A, whereas the duration of nAb responses during childhood is similar between the two species. The modest heterotypic responses suggest that RV vaccines must have a broad representation of prevalent types.

Impact of asthma on the brain: evidence from diffusion MRI, CSF biomarkers and cognitive decline

Chronic systemic inflammation increases the risk of neurodegeneration, but the mechanisms remain unclear. Part of the challenge in reaching a nuanced understanding is the presence of multiple risk factors that interact to potentiate adverse consequences. To address modifiable risk factors and mitigate downstream effects, it is necessary, although difficult, to tease apart the contribution of an individual risk factor by accounting for concurrent factors such as advanced age, cardiovascular risk, and genetic predisposition. Using a case-control design, we investigated the influence of asthma, a highly prevalent chronic inflammatory disease of the airways, on brain health in participants recruited to the Wisconsin Alzheimer's Disease Research Center (31 asthma patients, 186 non-asthma controls, aged 45-90 years, 62.2% female, 92.2% cognitively unimpaired), a sample enriched for parental history of Alzheimer's disease. Asthma status was determined using detailed prescription information. We employed multi-shell diffusion weighted imaging scans and the three-compartment neurite orientation dispersion and density imaging model to assess white and gray matter microstructure. We used cerebrospinal fluid biomarkers to examine evidence of Alzheimer's disease pathology, glial activation, neuroinflammation and neurodegeneration. We evaluated cognitive changes over time using a preclinical Alzheimer cognitive composite. Using permutation analysis of linear models, we examined the moderating influence of asthma on relationships between diffusion imaging metrics, CSF biomarkers, and cognitive decline, controlling for age, sex, and cognitive status. We ran additional models controlling for cardiovascular risk and genetic risk of Alzheimer's disease, defined as a carrier of at least one apolipoprotein E (APOE) ε4 allele. Relative to controls, greater Alzheimer's disease pathology (lower amyloid-β42/amyloid-β40, higher phosphorylated-tau-181) and synaptic degeneration (neurogranin) biomarker concentrations were associated with more adverse white matter metrics (e.g. lower neurite density, higher mean diffusivity) in patients with asthma. Higher concentrations of the pleiotropic cytokine IL-6 and the glial marker S100B were associated with more salubrious white matter metrics in asthma, but not in controls. The adverse effects of age on white matter integrity were accelerated in asthma. Finally, we found evidence that in asthma, relative to controls, deterioration in white and gray matter microstructure was associated with accelerated cognitive decline. Taken together, our findings suggest that asthma accelerates white and gray matter microstructural changes associated with aging and increasing neuropathology, that in turn, are associated with more rapid cognitive decline. Effective asthma control, on the other hand, may be protective and slow progression of cognitive symptoms.

Dupilumab Improves Long-term Outcomes in Patients With Uncontrolled, Moderate-to-Severe GINA-Based Type 2 Asthma, Irrespective of Allergic Status

BACKGROUND

Previous research has shown greater efficacy of dupilumab in patients with uncontrolled asthma and type 2 inflammation. We analyzed dupilumab's efficacy in patients from TRAVERSE study with or without evidence of allergic asthma and type 2 inflammation per current GINA guidelines (≥150 eosinophils/μL or FeNO ≥20 ppb).

METHODS

All patients aged ≥12 years who rolled over from the placebo-controlled QUEST study (NCT02414854) to TRAVERSE (NCT02134028) received add-on dupilumab 300mg every two weeks for up to 96 weeks. We assessed annualized severe asthma exacerbation rates (AERs) and changes from parent study baseline (PSBL) in pre-bronchodilator FEV₁ and 5-item asthma control questionnaire (ACQ-5) score in patients with moderate-to-severe type 2 asthma with and without evidence of allergic asthma at PSBL.

RESULTS

In TRAVERSE, dupilumab consistently reduced AER across all subgroups. By Week 96, dupilumab increased pre-bronchodilator FEV₁ from PSBL by 0.35-0.41L in patients receiving placebo during QUEST (placebo/dupilumab) and 0.34-0.44L in those receiving dupilumab during QUEST (dupilumab/dupilumab) with an allergic phenotype at baseline. In patients without evidence of allergic asthma, pre-bronchodilator FEV₁ improved by 0.38-0.41L and 0.33-0.37L, respectively. By Week 48, ACQ-5 scores decreased from PSBL by 1.63-1.69 (placebo/dupilumab) and 1.74-1.81 (dupilumab/dupilumab) points across subgroups with allergic asthma, and 1.75-1.83 (placebo/dupilumab) and 1.78-1.86 (dupilumab/dupilumab) in those without.

CONCLUSIONS

Long-term treatment with dupilumab reduced exacerbation rates, and improved lung function and asthma control in patients with asthma with type 2 inflammation as per current GINA guidance and irrespective of evidence of allergic asthma.

Consequences of severe asthma exacerbations

PURPOSE OF REVIEW

Asthma exacerbations are major factors in asthma morbidity and also have long-term consequences.

RECENT FINDINGS

Asthma is characterized by an accelerated and progressive loss of lung function. Recent evidence has pointed to the frequency of exacerbations as being a significant contributor to a loss of lung function in asthma.

SUMMARY

A consequence of asthma exacerbations is a greater loss of lung function. Airway inflammation is central to asthma severity and susceptibility for exacerbations. Evidence suggests that the increase in airway inflammation during an asthma exacerbation further compromised lung function. Treatment of severe asthma with Type (T)-2 directed biologics significantly prevents the frequency of exacerbations in severe asthma. Early indications also suggest that prevention of exacerbations by biologics may reduce a loss in lung function from exacerbations.

323 Onset of atopic comorbidities relative to atopic dermatitis diagnosis in a real-world setting using an Israeli claims database

Patients with atopic dermatitis (AD) are more likely than the general population to have other type 2 associated conditions, for example, asthma, allergic rhinitis (AR) and food allergy (FA).1,2 Classically, the atopic march is thought to begin with AD and progresses to FA, asthma and AR,1,2 but this may be an oversimplification. This study aimed to describe the epidemiology of type 2 associated conditions included in the atopic march among patients newly diagnosed with AD in a large healthcare provider database in Israel. This retrospective cohort study was performed using the Maccabi Healthcare Services database in Israel, which includes over 2.5 million members. Based on the International Classification of Diseases, 9th revision (ICD-9) diagnosis codes, patients with diagnosed AD during 2000–2019 were identified. The earliest AD diagnosis was defined as the index date and patients had to have been enrolled for ≥12 months pre-index to exclude prevalent AD. Diagnosis data were obtained during 1998–2020 to describe the cumulative prevalence of asthma, AR and FA pre- and post-AD diagnosis (−1, 0, 1, 5, 10 and 20 years) using Kaplan–Meier analysis among patients aged &lt;3, 3–5, 6–11, 12–17 and ≥18 years at AD diagnosis. The study included 243,687 patients (51.6% female) with AD. The median (interquartile range) age at AD diagnosis was 4.3 (1.1–22.8) years, with 43.9% and 72.7% of patients diagnosed before age 3 and 18 years, respectively. At AD diagnosis, 28.1% had a prior/concurrent diagnosis of asthma/AR/FA (asthma: 17.1%, AR: 12.8%, FA: 3.4%). Among patients diagnosed with AD at age &lt;3 years, 16.2% had been diagnosed with asthma/AR/FA by/at the time of their AD diagnosis (asthma: 10.6%, AR: 2.2%, FA: 4.9%). In this youngest age group, the cumulative prevalences of asthma/AR/FA were 28.8%, 42.7%, 49.6% and 59.6% within 1, 5, 10 and 20 years post-AD diagnosis. Among patients diagnosed with AD in adulthood, 37.7% had been diagnosed with asthma/AR/FA by/at the time they were diagnosed with AD (asthma: 16.5%, AR: 29.7%, FA: 0.8%). It this oldest age group, the cumulative prevalences of asthma/AR/FA were 40.3%, 46.1%, 50.9% and 57.6% within 1, 5, 10 and 20 years post-AD diagnosis. The results of this real-world analysis are consistent with previous evidence that AD is primarily a childhood-onset disease. The sharpest increase in type 2 associated conditions was seen in the 5 years post-AD diagnosis among patients diagnosed with AD at age &lt;3 years. Most adults newly diagnosed with AD who developed another type 2 associated condition had already done so prior to AD diagnosis, although it is possible that earlier AD diagnoses were not captured. Regardless of age at AD diagnosis, nearly 60% of patients with AD were estimated to have ≥1 of asthma/AR/FA within 20 years of their AD diagnosis.

Associations between outdoor air pollutants and non-viral asthma exacerbations and airway inflammatory responses in children and adolescents living in urban areas in the USA: a retrospective secondary analysis

BACKGROUND

Asthma prevalence and severity have markedly increased with urbanisation, and children in low-income urban centres have among the greatest asthma morbidity. Outdoor air pollution has been associated with adverse respiratory effects in children with asthma. However, the mechanisms by which air pollution exposure exacerbates asthma, and how these mechanisms compare with exacerbations induced by respiratory viruses, are poorly understood. We aimed to investigate the associations between regional air pollutant concentrations, respiratory illnesses, lung function, and upper airway transcriptional signatures in children with asthma, with particular focus on asthma exacerbations occurring in the absence of respiratory virus.

METHODS

We performed a retrospective analysis of data from the MUPPITS1 cohort and validated our findings in the ICATA cohort. The MUPPITS1 cohort recruited 208 children aged 6-17 years living in urban areas across nine US cities with exacerbation-prone asthma between Oct 7, 2015, and Oct 18, 2016, and monitored them during reported respiratory illnesses. The last MUPPITS1 study visit occurred on Jan 6, 2017. The ICATA cohort recruited 419 participants aged 6-20 years with persistent allergic asthma living in urban sites across eight US cities between Oct 23, 2006, and March 25, 2008, and the last study visit occurred on Dec 30, 2009. We included participants from the MUPPITS1 cohort who reported a respiratory illness at some point during the follow-up and participants from the ICATA cohort who had nasal samples collected during respiratory illness or at a scheduled visit. We used air quality index values and air pollutant concentrations for PM2·5, PM10, O3, NO2, SO2, CO, and Pb from the US Environmental Protection Agency spanning the years of both cohorts, and matched values and concentrations to each illness for each participant. We investigated the associations between regional air pollutant concentrations and respiratory illnesses and asthma exacerbations, pulmonary function, and upper airway transcriptional signatures by use of a combination of generalised additive models, case crossover analyses, and generalised linear mixed-effects models.

FINDINGS

Of the 208 participants from the MUPPITS1 cohort and 419 participants from the ICATA cohort, 168 participants in the MUPPITS1 cohort (98 male participants and 70 female participants) and 189 participants in the ICATA cohort (115 male participants and 74 female participants) were included in our analysis. We identified that increased air quality index values, driven predominantly by increased PM2·5 and O3 concentrations, were significantly associated with asthma exacerbations and decreases in pulmonary function that occurred in the absence of a provoking viral infection. Moreover, individual pollutants were significantly associated with altered gene expression in coordinated inflammatory pathways, including PM2·5 with increased epithelial induction of tissue kallikreins, mucus hypersecretion, and barrier functions and O3 with increased type-2 inflammation.

INTERPRETATION

Our findings suggest that air pollution is an important independent risk factor for asthma exacerbations in children living in urban areas and is potentially linked to exacerbations through specific inflammatory pathways in the airway. Further investigation of these potential mechanistic pathways could inform asthma prevention and management approaches.

FUNDING

National Institutes of Health, National Institute of Allergy and Infectious Diseases.

Multi-omic association study identifies DNA methylation-mediated genotype and smoking exposure effects on lung function in children living in urban settings

Impaired lung function in early life is associated with the subsequent development of chronic respiratory disease. Most genetic associations with lung function have been identified in adults of European descent and therefore may not represent those most relevant to pediatric populations and populations of different ancestries. In this study, we performed genome-wide association analyses of lung function in a multiethnic cohort of children (n = 1,035) living in low-income urban neighborhoods. We identified one novel locus at the TDRD9 gene in chromosome 14q32.33 associated with percent predicted forced expiratory volume in one second (FEV1) (p = 2.4x10-9; βz = -0.31, 95% CI = -0.41- -0.21). Mendelian randomization and mediation analyses revealed that this genetic effect on FEV1 was partially mediated by DNA methylation levels at this locus in airway epithelial cells, which were also associated with environmental tobacco smoke exposure (p = 0.015). Promoter-enhancer interactions in airway epithelial cells revealed chromatin interaction loops between FEV1-associated variants in TDRD9 and the promoter region of the PPP1R13B gene, a stimulator of p53-mediated apoptosis. Expression of PPP1R13B in airway epithelial cells was significantly associated the FEV1 risk alleles (p = 1.3x10-5; β = 0.12, 95% CI = 0.06-0.17). These combined results highlight a potential novel mechanism for reduced lung function in urban youth resulting from both genetics and smoking exposure.

Asthma Management in Adults

Management of asthma in adults has advanced in the past 10 years. Central to these advances has been further clarification of type (T) 2 mechanisms of airway inflammation and utilization of T2 biomarkers, that is, eosinophils and fractional exhaled nitric oxide. In addition, epithelial cells are emerging as significant contributors to inflammation through generation of alarmins to initiate local injury as well as downstream pathways. Five new biologics, mepolizumab, benralizumab, reslizumab, dupilumab, and tezepelumab, were approved to join omalizumab and revolutionize severe asthma treatment. These biologics significantly prevent exacerbations to spare systemic corticosteroids use and their side effects. Guidelines attest to the effectiveness of inhaled corticosteroids/long-acting β-agonists (formoterol) for both maintenance and rescue therapy. Focused updates to the Expert Panel Report addressed limited but specific questions relevant to asthma control. Future guidelines should include phenotype/endotype-directed therapeutics to gain more precision-directed treatment.

Dupilumab Efficacy in Patients with Uncontrolled Moderate-to-Severe Type 2 Asthma Regardless of Perennial Aeroallergen Sensitization

Purpose

Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukins-4/-13, key and central drivers of type 2 (T2) inflammation in multiple diseases. In phase 3 QUEST (NCT02414854), dupilumab vs placebo significantly reduced asthma exacerbation rates (AER) and improved pre-bronchodilator forced expiratory volume in 1 second (FEV₁) in patients with uncontrolled, moderate-to-severe asthma, with greater effects in patients with elevated T2 biomarkers (≥150 eosinophils/µL or fractional exhaled nitric oxide [FeNO] ≥25 parts per billion). Overall safety was consistent with the known dupilumab safety profile. This post hoc analysis assessed dupilumab efficacy in QUEST patients with T2 asthma with evidence of an allergic phenotype (baseline serum IgE ≥30 IU/mL and aeroallergen-specific IgE ≥0.35 IU/mL) by number of aeroallergen sensitizations: 1, 2, 3, or ≥4. Non-sensitized patients (serum total IgE <30 IU/mL without evidence of allergic phenotype) were also assessed.

Patients and Methods

Endpoints were annualized AER, change from baseline in pre-bronchodilator FEV₁ and asthma control (5-item Asthma Control Questionnaire [ACQ-5]), and FeNO and serum total IgE levels over the 52-week treatment period.

Results

In all subgroups by number of allergens sensitized, dupilumab vs placebo reduced AER by 35-67% and improved both pre-bronchodilator FEV₁ at Week 12 (least squares mean differences: 0.10-0.26 L across subgroups) and ACQ-5 score at Week 52 (-0.26 to -0.43). Dupilumab significantly reduced FeNO and total IgE levels at Week 52 compared with placebo. Similar results were observed in non-sensitized patients.

Conclusion

Dupilumab improved clinical outcomes and reduced biomarker levels in patients with uncontrolled, moderate-to-severe T2 asthma irrespective of allergen sensitization status or number.

Clinical Trial Registration

ClinicalTrials.gov Identifier: NCT02414854.

Asthma exacerbations: the Achilles heel of asthma care

Asthma exacerbations significantly impact millions of patients worldwide to pose large disease burdens on affected patients, families, and health-care systems. Although numerous environmental factors cause asthma exacerbations, viral respiratory infections are the principal triggers. Advances in the pathophysiology of asthma have elucidated dysregulated protective immune responses and upregulated inflammation that create susceptibility and risks for exacerbation. Biologics for the treatment of severe asthma reduce rates of exacerbations and identify specific pathways of inflammation that contribute to altered pathophysiology, novel therapeutic targets, and informative biomarkers. Major steps to prevent exacerbations include the identification of molecular pathways whose blockage will prevent asthma attacks safely, predictably, and effectively.

Dupilumab Is Effective in Patients With Moderate-to-Severe Uncontrolled GINA-Defined Type 2 Asthma Irrespective of an Allergic Asthma Phenotype

BACKGROUND

The Global Initiative for Asthma report recommends consideration of add-on biologics for patients with type 2 inflammation (blood eosinophils ≥150 cells/μL, fractional exhaled nitric oxide [Feno] ≥20 parts per billion or allergic asthma) whose asthma cannot be controlled by high-dose inhaled corticosteroids. In QUEST (NCT02414854), add-on dupilumab versus placebo was efficacious in patients with uncontrolled, moderate to severe asthma, including those with eosinophils greater than or equal to 150 cells/μL and/or Feno greater than or equal to 25 parts per billion.

OBJECTIVE

To assess dupilumab efficacy in patients with a type 2 phenotype in the presence or absence of allergic asthma phenotype.

METHODS

Patients aged 12 years or older received add-on dupilumab 200/300 mg versus matched placebo every 2 weeks for 52 weeks. Allergic asthma phenotype was defined as baseline serum total IgE greater than or equal to 30 IU/mL and 1 or more perennial aeroallergen-specific IgE level greater than or equal to 0.35 kU/L. Annualized rate of severe asthma exacerbations and changes from study baseline in prebronchodilator and postbronchodilator FEV₁ were evaluated in patients with allergic and nonallergic phenotype with baseline blood eosinophils greater than or equal to 150 cells/μL and/or Feno greater than or equal to 20 parts per billion.

RESULTS

Of 1902 patients in QUEST, 83.3% had eosinophils and/or Feno above Global Initiative for Asthma thresholds; 56.9% had evidence for allergic asthma. Dupilumab significantly reduced the rate of severe asthma exacerbations in patients with (48.8%) and without (64.0%) evidence of allergic asthma and improved prebronchodilator and postbronchodilator FEV₁ in patients with elevated type 2 biomarkers, irrespective of whether they showed evidence of an allergic asthma phenotype.

CONCLUSIONS

In patients with type 2 biomarkers over Global Initiative for Asthma thresholds, dupilumab significantly reduced exacerbations and improved lung function. Efficacy was not impacted by allergic status.

Clinically relevant effects of Mindfulness-Based Stress Reduction in individuals with asthma

Background

Psychological distress and comorbid psychopathology contribute to exacerbation risk in patients with asthma. Thus, interventions designed to reduce stress and improve emotion regulation, such as Mindfulness-Based Stress Reduction (MBSR), may augment standard care. Few studies have addressed this question and a paucity of data exists to determine the ability of MBSR to impact clinical outcomes in asthma.

Methods

This randomized controlled trial investigated effects of MBSR training on asthma control and airway inflammation, in relation to psychological symptoms, in adults with asthma. Participants were randomized to an 8-week MBSR training (n = 35) or wait-list control group (n = 34). Clinically relevant asthma assessments, including Asthma Control Questionnaire and inflammatory biomarkers, were collected at baseline and six approximately-monthly follow-ups. Self-reported mindfulness, distress, depression, and anxiety symptoms were assessed at baseline, post-intervention, and study completion. Chronic stress level was determined at baseline only.

Results

Asthma control improved significantly in individuals randomized to MBSR, relative to wait-list controls (p = .01; effect size d = 0.76), which was maintained at 4mo post-intervention. 32% of MBSR participants achieved a clinically significant improvement, based on the ACQ6 Minimally Important Difference, relative to 12% of wait-list participants. Moreover, MBSR-related improvement in asthma control was associated with a reduction in distress (p = .043) and the intervention was most efficacious for those with the highest baseline depressive symptoms (p = .023). Importantly, MBSR also reduced levels of exhaled nitric oxide, a biomarker of airway inflammation, relative to wait-list controls (p < .05).

Conclusion

Supporting and extending extant evidence of mind-body relationships in asthma and the benefits of stress reduction for these patients, this is, to the best of our knowledge, the first RCT to demonstrate that training in MBSR improves clinically relevant asthma outcomes. MBSR may thus be a valuable addition to optimal asthma management, particularly for those with comorbid psychopathology.

Clinical trial registration

NCT02157766.

Adherence and Persistence to Single-Inhaler Versus Multiple-Inhaler Triple Therapy for Asthma Management

BACKGROUND

Treatment guidelines recommend triple therapy for patients with asthma who remain uncontrolled on inhaled corticosteroid/long-acting β₂-agonist therapy. Previously, triple therapy was only available via multiple inhalers. Single-inhaler fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) is approved as maintenance treatment for asthma; however, real-world information on adherence and persistence is limited.

OBJECTIVE

To compare adherence and persistence among adult patients with asthma receiving single-inhaler FF/UMEC/VI versus multiple-inhaler triple therapy (MITT) in the United States.

METHODS

This retrospective cohort study used IQVIA PharMetrics Plus data to evaluate patients with asthma who initiated once-daily FF/UMEC/VI 100/62.5/25 mcg or MITT between September 18, 2017, and September 30, 2019. Inverse probability weighting and multivariable regression adjusted for differences in characteristics between the FF/UMEC/VI and MITT cohorts. Adherence was assessed using proportion of days covered (PDC) and proportion of patients achieving PDC ≥0.8 and PDC ≥0.5. Non-persistence was identified as a >45-day gap between fills.

RESULTS

The study included 1396 FF/UMEC/VI and 5115 MITT initiators. Three months after initiation, FF/UMEC/VI users had significantly higher mean PDC versus MITT users (0.68 vs 0.59; P < .001) and 31% more likely to be adherent (PDC ≥0.8; 40.6% vs 31.3%; adjusted risk ratio [95% confidence interval (CI)]: 1.31 [1.13-1.54]; P < .001). Similar patterns were observed at 6 and 12 months post initiation. In addition, FF/UMEC/VI users were 49% more likely to persist at 12 months than MITT users (25.9% vs 15.1%, adjusted hazard ratio [95% CI]: 1.49 [1.39-1.60]; P < .001).

CONCLUSIONS

Patients with asthma initiating triple therapy with FF/UMEC/VI had significantly better adherence and persistence compared with MITT initiators.

Mepolizumab for urban children with exacerbation-prone eosinophilic asthma in the USA (MUPPITS-2): a randomised, double-blind, placebo-controlled, parallel-group trial

BACKGROUND

Black and Hispanic children living in urban environments in the USA have an excess burden of morbidity and mortality from asthma. Therapies directed at the eosinophilic phenotype reduce asthma exacerbations in adults, but few data are available in children and diverse populations. Furthermore, the molecular mechanisms that underlie exacerbations either being prevented by, or persisting despite, immune-based therapies are not well understood. We aimed to determine whether mepolizumab, added to guidelines-based care, reduced the number of asthma exacerbations during a 52-week period compared with guidelines-based care alone.

METHODS

This is a randomised, double-blind, placebo-controlled, parallel-group trial done at nine urban medical centres in the USA. Children and adolescents aged 6-17 years, who lived in socioeconomically disadvantaged neighbourhoods and had exacerbation-prone asthma (defined as ≥two exacerbations in the previous year) and blood eosinophils of at least 150 cells per μL were randomly assigned 1:1 to mepolizumab (6-11 years: 40 mg; 12-17 years: 100 mg) or placebo injections once every 4 weeks, plus guideline-based care, for 52 weeks. Randomisation was done using a validated automated system. Participants, investigators, and the research staff who collected outcome measures remained masked to group assignments. The primary outcome was the number of asthma exacerbations that were treated with systemic corticosteroids during 52 weeks in the intention-to-treat population. The mechanisms of treatment response were assessed by study investigators using nasal transcriptomic modular analysis. Safety was assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03292588.

FINDINGS

Between Nov 1, 2017, and Mar 12, 2020, we recruited 585 children and adolescents. We screened 390 individuals, of whom 335 met the inclusion criteria and were enrolled. 290 met the randomisation criteria, were randomly assigned to mepolizumab (n=146) or placebo (n=144), and were included in the intention-to-treat analysis. 248 completed the study. The mean number of asthma exacerbations within the 52-week study period was 0·96 (95% CI 0·78-1·17) with mepolizumab and 1·30 (1·08-1·57) with placebo (rate ratio 0·73; 0·56-0·96; p=0·027). Treatment-emergent adverse events occurred in 42 (29%) of 146 participants in the mepolizumab group versus 16 (11%) of 144 participants in the placebo group. No deaths were attributed to mepolizumab.

INTERPRETATION

Phenotype-directed therapy with mepolizumab in urban children with exacerbation-prone eosinophilic asthma reduced the number of exacerbations.

FUNDING

US National Institute of Allergy and Infectious Diseases and GlaxoSmithKline.

Asthma amplifies dementia risk: Evidence from CSF biomarkers and cognitive decline

Introduction

Evidence from epidemiology, neuroimaging, and animal models indicates that asthma adversely affects the brain, but the nature and extent of neuropathophysiological impact remain unclear.

Methods

We tested the hypothesis that asthma is a risk factor for dementia by comparing cognitive performance and cerebrospinal fluid biomarkers of glial activation/neuroinflammation, neurodegeneration, and Alzheimer's disease (AD) pathology in 60 participants with asthma to 315 non-asthma age-matched control participants (45-93 years), in a sample enriched for AD risk.

Results

Participants with severe asthma had higher neurogranin concentrations compared to controls and those with mild asthma. Positive relationships between cardiovascular risk and concentrations of neurogranin and α-synuclein were amplified in severe asthma. Severe asthma also amplified the deleterious associations that apolipoprotein E ε4 carrier status, cardiovascular risk, and phosphorylated tau181/amyloid beta42 have with rate of cognitive decline.

Discussion

Our data suggest that severe asthma is associated with synaptic degeneration and may compound risk for dementia posed by cardiovascular disease and genetic predisposition.

Highlights

Those with severe asthma showed evidence of higher dementia risk than controls evidenced by: higher levels of the synaptic degeneration biomarker neurogranin regardless of cognitive status, cardiovascular or genetic risk, and controlling for demographics.steeper increase in levels of synaptic degeneration biomarkers neurogranin and α-synuclein with increasing cardiovascular risk.accelerated cognitive decline with higher cardiovascular risk, genetic predisposition, or pathological tau.

Seasonal airway microbiome and transcriptome interactions promote childhood asthma exacerbations

BACKGROUND

Seasonal variation in respiratory illnesses and exacerbations in pediatric populations with asthma is well described, though whether upper airway microbes play season-specific roles in these events is unknown.

OBJECTIVE

We hypothesized that nasal microbiota composition is seasonally dynamic and that discrete microbe-host interactions modify risk of asthma exacerbation in a season-specific manner.

METHODS

Repeated nasal samples from children with exacerbation-prone asthma collected during periods of respiratory health (baseline; n = 181 samples) or first captured respiratory illness (n = 97) across all seasons, underwent bacterial (16S ribosomal RNA gene) and fungal (internal transcribed spacer region 2) biomarker sequencing. Virus detection was performed by multiplex PCR. Paired nasal transcriptome data were examined for seasonal dynamics and integrative analyses.

RESULTS

Upper airway bacterial and fungal microbiota and rhinovirus detection exhibited significant seasonal dynamics. In seasonally adjusted analysis, variation in both baseline and respiratory illness microbiota related to subsequent exacerbation. Specifically, in the fall, when respiratory illness and exacerbation events were most frequent, several Moraxella and Haemophilus members were enriched both in virus-positive respiratory illnesses and those that progressed to exacerbations. The abundance of 2 discrete bacterial networks, characteristically comprising either Streptococcus or Staphylococcus, exhibited opposing interactions with an exacerbation-associated SMAD3 nasal epithelial transcriptional module to significantly increase the odds of subsequent exacerbation (odds ratio = 14.7, 95% confidence interval = 1.50-144, P = .02; odds ratio = 39.17, 95% confidence interval = 2.44-626, P = .008, respectively).

CONCLUSIONS

Upper airway microbiomes covary with season and with seasonal trends in respiratory illnesses and asthma exacerbations. Seasonally adjusted analyses reveal specific bacteria-host interactions that significantly increase risk of asthma exacerbation in these children.

Association of mold levels in urban children's homes with difficult-to-control asthma

BACKGROUND

Mold sensitization and exposure are associated with asthma severity, but the specific species that contribute to difficult-to-control (DTC) asthma are unknown.

OBJECTIVE

We sought to determine the association between overall and specific mold levels in the homes of urban children and DTC asthma.

METHODS

The Asthma Phenotypes in the Inner-City study recruited participants, aged 6 to 17 years, from 8 US cities and classified each participant as having either DTC asthma or easy-to-control (ETC) asthma on the basis of treatment step level. Dust samples had been collected in each participant's home (n = 485), and any dust remaining (n = 265 samples), after other analyses, was frozen at -20^oC. The dust samples (n = 265) were analyzed using quantitative PCR to determine the concentrations of the 36 molds in the Environmental Relative Moldiness Index. Logistic regression was performed to discriminate specific mold content of dust from homes of children with DTC versus ETC asthma.

RESULTS

Frozen-dust samples were available from 54% of homes of children with DTC (139 of 253) and ETC asthma (126 of 232). Only the average concentration of the mold Mucor was significantly (P < .001) greater in homes of children with DTC asthma. In homes with window air-conditioning units, the Mucor concentration contributed about a 22% increase (1.6 odds ratio; 95% CI, 1.2-2.2) in the ability to discriminate between cases of DTC and ETC asthma.

CONCLUSIONS

Mucor levels in the homes of urban youth were a predictor of DTC asthma, and these higher Mucor levels were more likely in homes with a window air-conditioner.

Current unmet needs and potential solutions to uncontrolled asthma

Despite the availability of effective inhaled therapies, many patients with asthma have poor asthma control. Uncontrolled asthma presents a significant burden on the patient and society, and, for many, remains largely preventable. There are numerous reasons why a patient may remain uncontrolled despite access to therapies, including incorrect inhaler technique, poor adherence to treatment, oversight of triggers and suboptimal medical care. Shared decision-making, good patient–clinician communication, supported self-management, multidisciplinary patient education, new technology and risk stratification may all provide solutions to this major unmet need in asthma. Novel treatments such as biologics could benefit patients’ lives, while the investigations into biomarkers, non-Type 2 asthma, treatable traits and disease modification give an exciting glimpse into the future of asthma care.

Despite effective therapies, many patients with asthma have poor asthma control, which is preventable. The benefits of shared decision-making, supported self-management, risk stratification and novel treatments in transforming patient care are reviewed.https://bit.ly/3A386Nm

Holy Grail: the journey towards disease modification in asthma

At present, there is no cure for asthma, and treatment typically involves therapies that prevent or reduce asthma symptoms, without modifying the underlying disease. A “disease-modifying” treatment can be classed as able to address the pathogenesis of a disease, preventing progression or leading to a long-term reduction in symptoms. Such therapies have been investigated and approved in other indications, e.g. rheumatoid arthritis and immunoglobulin E-mediated allergic disease. Asthma's heterogeneous nature has made the discovery of similar therapies in asthma more difficult, although novel therapies (e.g. biologics) may have the potential to exhibit disease-modifying properties. To investigate the disease-modifying potential of a treatment, study design considerations can be made, including: appropriate end-point selection, length of trial, age of study population (key differences between adults/children in physiology, pathology and drug metabolism) and comorbidities in the patient population. Potential future focus areas for disease-modifying treatments in asthma include early assessments (e.g. to detect patterns of remodelling) and interventions for patients genetically susceptible to asthma, interventions to prevent virally induced asthma and therapies to promote a healthy microbiome. This review explores the pathophysiology of asthma, the disease-modifying potential of current asthma therapies and the direction future research may take to achieve full disease remission or prevention.

Asthma is a complex, heterogeneous disease, which currently has no cure; this review explores the disease-modifying potential of asthma therapies and the direction future research may take to achieve disease remission or prevention.https://bit.ly/31AxYou

Respiratory Infections and Anti-Infective Medication Use From Phase 3 Dupilumab Respiratory Studies

BACKGROUND

Patients with asthma and/or chronic rhinosinusitis with nasal polyps (CRSwNP) experience recurrent respiratory tract infections. Dupilumab targets type 2 inflammation, a common underlying pathophysiology of both conditions, with proven efficacy.

OBJECTIVE

To examine investigator-reported respiratory infection adverse events and anti-infective medication use with dupilumab versus placebo in patients with moderate-to-severe asthma or severe CRSwNP.

METHODS

We performed a post hoc analysis of the pivotal phase 3 trials LIBERTY ASTHMA QUEST (NCT02414854) and LIBERTY NP SINUS-52 (NCT02898454) in moderate-to-severe asthma and severe CRSwNP, respectively.

RESULTS

Investigator-reported respiratory infection events occurred at a significantly lower incidence in patients treated with dupilumab versus placebo, in both asthma (22% lower; P < .0001; 95% CI 0.71-0.85) and CRSwNP (38% lower; P <.0001; 95% CI 0.51-0.75). Reported upper and lower respiratory tract infection events were numerically or significantly lower in dupilumab-treated patients in both conditions, as were the number of patients experiencing investigator-reported infections. Significantly less systemic anti-infective medication use occurred in dupilumab versus placebo in asthma (24% lower; P < .0001; 95% CI 0.70-0.83) and CRSwNP patients (49% lower; P < .0001; 95% CI 0.43-0.61), and significantly fewer dupilumab-treated patients used anti-infective medications. When examined by season and month, the data indicated that investigator-reported respiratory infections and anti-infective medication use were less frequent in dupilumab- versus placebo-treated patients throughout the calendar year.

CONCLUSIONS

Dupilumab treatment was associated with a reduced incidence of investigator-reported respiratory infections in patients with moderate-to-severe asthma or severe CRSwNP. Further studies are required to determine the mechanism behind this reduction.

Neuroimaging and biomarker evidence of neurodegeneration in asthma

BACKGROUND

Epidemiologic studies have shown that Alzheimer's disease (AD) and related dementias (ADRD) are seen more frequently with asthma, especially with greater asthma severity or exacerbation frequency.

OBJECTIVE

To examine the changes in brain structure that may underlie this phenomenon, we examined diffusion-weighted magnetic resonance imaging (dMRI) and blood-based biomarkers of AD (phosphorylated tau 181, p-Tau181), neurodegeneration (neurofilament light chain, NfL), and glial activation (glial fibrillary acidic protein, GFAP).

METHODS

dMRI data were obtained in 111 individuals with asthma, ranging in disease severity from mild to severe, and 135 healthy controls. Regression analyses were used to test the relationships between asthma severity and neuroimaging measures, as well as AD pathology, neurodegeneration, and glial activation, indexed by plasma p-Tau181, NfL, and GFAP, respectively. Additional relationships were tested with cognitive function.

RESULTS

Asthma participants had widespread and large-magnitude differences in several dMRI metrics, which were indicative of neuroinflammation and neurodegeneration, and which were robustly associated with GFAP and, to a lesser extent, NfL. The AD biomarker p-Tau181 was only minimally associated with neuroimaging outcomes. Further, asthma severity was associated with deleterious changes in neuroimaging outcomes, which in turn were associated with slower processing speed, a test of cognitive performance.

CONCLUSIONS

Asthma, particularly when severe, is associated with characteristics of neuroinflammation and neurodegeneration, and may be a potential risk factor for neural injury and cognitive dysfunction. There is a need to determine how asthma may affect brain health and whether treatment directed toward characteristics of asthma associated with these risks can mitigate these effects.

Role of amygdala in stress-induced upregulation of airway IL-1 signaling in asthma

Psychological stress, an important contributor to asthma morbidity, potentiates the immune response to allergen, but the brain mechanisms mediating this response are not fully understood. The amygdala is likely to play an important role, given its sensitivity to threat and connectivity with descending immune modulatory pathways. In this study, we recruited thirty asthmatic participants and examined glucose metabolism in the amygdala, using [F-18]fluorodeoxyglucose positron emission tomography, during a laboratory stressor. Stress hormone and airway inflammatory measurements were also acquired. Results showed that activity in the amygdala was significantly increased during the stressor, compared to a matched control task (p < .05 corrected). Moreover, the increase in amygdala activity was associated with a greater increase in sputum IL-1R1 mRNA and alpha amylase response (p < .05 corrected), which were also positively correlated (p = .01). These findings suggest that heightened amygdala reactivity may contribute to asthma morbidity via descending proinflammatory sympathetic signaling pathways.

Heterogeneity of magnitude, allergen immunodominance, and cytokine polarization of cockroach allergen-specific T cell responses in allergic sensitized children

BACKGROUND

Characterization of allergic responses to cockroach (CR), a common aeroallergen associated with asthma, has focused mainly on IgE reactivity, but little is known about T cell responses, particularly in children. We conducted a functional evaluation of CR allergen-specific T cell reactivity in a cohort of CR allergic children with asthma.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from 71 children, with mild-to-moderate asthma who were enrolled in a CR immunotherapy (IT) clinical trial, prior to treatment initiation. PBMC were stimulated with peptide pools derived from 11 CR allergens, and CD4+ T cell responses assessed by intracellular cytokine staining.

RESULTS

Highly heterogeneous responses in T cell reactivity were observed among participants, both in terms of the magnitude of cytokine response and allergen immunodominance. Reactivity against Bla g 9 and Bla g 5 was most frequent. The phenotype of the T cell response was dominated by IL-4 production and a Th2 polarized profile in 54.9% of participants, but IFNγ production and Th1 polarization was observed in 25.3% of the participants. The numbers of regulatory CD4+ T cells were also highly variable and the magnitude of effector responses and Th2 polarization were positively correlated with serum IgE levels specific to a clinical CR extract.

CONCLUSIONS

Our results demonstrate that in children with mild-to-moderate asthma, CR-specific T cell responses display a wide range of magnitude, allergen dominance, and polarization. These results will enable examination of whether any of the variables measured are affected by IT and/or are predictive of clinical outcomes.

Understanding the key issues in the treatment of uncontrolled persistent asthma with type 2 inflammation

Asthma is a complex respiratory disease that varies in severity and response to treatment. Several asthma phenotypes with unique clinical and inflammatory characteristics have been identified. Endotypes, based on distinct molecular profiles, help to further elucidate the heterogeneity within asthma. Type 2 inflammation, involving both the innate (type 2 innate lymphoid cell) and adaptive (T-helper type 2 cells) immune systems, underpins the complex pathophysiology of chronic inflammation in asthma, as well as the presence of comorbid disease (e.g. chronic rhinosinusitis with nasal polyps, allergic rhinitis and atopic dermatitis). Type 2 inflammation is characterised by upregulation of the type 2 cytokines interleukin (IL)-4, IL-5 and IL-13, IgE-mediated release of immune mediators and dysfunction of epithelial or epidermal barriers. Targeting these key proximal type 2 cytokines has shown efficacy in recent studies adopting a personalised approach to treatment using targeted biologics. Elevated levels of biomarkers downstream of type 2 cytokines, including fractional exhaled nitric oxide, serum IgE and blood and sputum eosinophils, have been linked to mechanisms involved in type 2 inflammation. They have the potential to aid diagnosis, and to predict and monitor response to treatment. The objective of this review is to summarise the current understanding of the biology of type 2 inflammation in asthma, examine its influence on type 2 inflammatory comorbidities, and discuss how type 2 inflammatory biomarkers can be harnessed to further personalise treatments in the age of biologic medicines.

This review covers the pathophysiology of type 2 inflammation in asthma, its influence on type 2 comorbidities, and ways in which type 2 biomarkers can be harnessed to improve diagnosis and further personalise treatments in the age of biologic medicineshttps://bit.ly/2MSOI2O

Impact of baseline patient characteristics on dupilumab efficacy in type 2 asthma

Severe asthma affects an estimated 5–10% of the total asthma patient population [1]. Various demographic factors, such as sex, age, obesity and age of onset, have been associated with asthma disease severity [2, 3], and the efficacy of asthma treatments has previously been found to vary depending on patient demographics [4, 5].

Dupilumab treatment versus placebo improved exacerbation rate and lung function outcomes in patients with uncontrolled moderate-to-severe asthma and high type 2 biomarkers at baseline, regardless of baseline characteristics in the phase 3 QUEST studyhttps://bit.ly/3yR7MlD

Development of nasal allergen challenge with cockroach in children with asthma

BACKGROUND

Nasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma.

METHODS

Ten adults (18-37 years) followed by 25 children (8-14 years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9 µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells.

RESULTS

67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120 µg/mL [IQR 0.0380-0.379 µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P = .03), lower cockroach-specific IgG/IgE ratios (children, P = .002), and increased cockroach-specific IL-5-producing T lymphocytes (P = .045). The NAC was well tolerated.

CONCLUSION

We report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.

Baseline FeNO as a prognostic biomarker for subsequent severe asthma exacerbations in patients with uncontrolled, moderate-to-severe asthma receiving placebo in the LIBERTY ASTHMA QUEST study: a post-hoc analysis

BACKGROUND

Fractional exhaled nitric oxide (FeNO) has potential as a prognostic biomarker in asthma, but its prognostic value among other recognised indicators is unclear. We assessed the added prognostic value of baseline FeNO to blood eosinophil count and prior severe asthma exacerbations for subsequent exacerbations.

METHODS

In this post-hoc analysis of the 52-week, double-blind, phase 3 LIBERTY ASTHMA QUEST study, we identified 620 patients with moderate-to-severe asthma who were randomly assigned to placebo; had uncontrolled asthma with inhaled glucocorticoids plus up to two controllers; one or more exacerbations in the previous year; FEV₁ percent predicted 40-80%; FEV₁ reversibility of 12% or higher and 200 mL; Asthma Control Questionnaire (ACQ-5) score of 1·5 or higher; and complete data on baseline type 2 biomarkers (FeNO, eosinophils, and total IgE) with no baseline minimum requirement. Annualised severe exacerbation rate was assessed by baseline FeNO (<25 ppb, ≥25 to <50 ppb, ≥50 ppb; negative binomial model) and cross-classified by baseline blood eosinophils (<150 cells per μL, ≥150 to <300 cells per μL, ≥300 cells per μL) and prior exacerbations (one, two or more), all adjusted for baseline ACQ-5, postbronchodilator FEV₁, and other clinical characteristics. Post-hoc analyses were done in the intention-to-treat population. The LIBERTY ASTHMA QUEST STUDY is registered on ClinicalTrials.gov, NCT02414854, and is complete.

FINDINGS

Patients with baseline FeNO of 50 ppb or higher (n=144) had a 1·54-times higher exacerbation rate than patients with FeNO of less than 25 ppb (n=291; relative risk 1·54 [95% CI 1·11-2·14]; p=0·0097). Patients with baseline FeNO of 25 to <50 ppb (n=185) had a 1·33-times higher exacerbation rate than patients with FeNO of less than 25 ppb (1·33 [0·99-1·78]; p=0·0572). Patients with baseline FeNO of 25 ppb or higher, a blood eosinophil count of 150 cells per μL or higher, and two or more prior exacerbations (n=157) had an exacerbation rate 3·62-times higher than patients with FeNO of less than 25 ppb, a blood eosinophil count of less than 150 cells per μL, and one prior exacerbation (n=116; 3·62 [1·67-7·81]; p=0·0011).

INTERPRETATION

In uncontrolled, moderate-to-severe asthma, higher baseline FeNO levels were associated with greater risk of severe asthma exacerbations, particularly in combination with elevated eosinophil count and prior exacerbations, supporting the added value of FeNO as a prognostic biomarker. Further research is needed to confirm FeNO as an independent predictor for asthma exacerbations.

FUNDING

Sanofi and Regeneron Pharmaceuticals.

Inducible expression quantitative trait locus analysis of the MUC5AC gene in asthma in urban populations of children

BACKGROUND

Mucus plugging can worsen asthma control, lead to reduced lung function and fatal exacerbations. MUC5AC is the secretory mucin implicated in mucus plugging, and MUC5AC gene expression has been associated with development of airway obstruction and asthma exacerbations in urban children with asthma. However, the genetic determinants of MUC5AC expression are not established.

OBJECTIVES

This study sought to assess single-nucleotide polymorphisms (SNPs) that influence MUC5AC expression and relate to pulmonary functions in childhood asthma.

METHODS

This study used RNA-sequencing data from upper airway samples and performed cis-expression quantitative trait loci (eQTL) and allele-specific expression analyses in 2 cohorts of predominantly Black and Hispanic urban children, a high asthma-risk birth cohort, and an exacerbation-prone asthma cohort. Inducible MUC5AC eQTLs were further investigated during incipient asthma exacerbations. Significant eQTLs SNPs were tested for associations with lung function measurements and their functional consequences were investigated in DNA regulatory databases.

RESULTS

Two independent groups of SNPs in the MUC5AC gene that were significantly associated with MUC5AC expression were identified. Moreover, these SNPs showed stronger eQTL associations with MUC5AC expression during asthma exacerbations, which is consistent with inducible expression. SNPs in 1 group also showed significant association with decreased pulmonary functions. These SNPs included multiple EGR1 transcription factor binding sites, suggesting a mechanism of effect.

CONCLUSIONS

These findings demonstrate the applicability of organ-specific RNA-sequencing data to determine genetic factors contributing to a key disease pathway. Specifically, they suggest important genetic variations that may underlie propensity to mucus plugging in asthma and could be important in targeted asthma phenotyping and disease management strategies.

Uncontrolled asthma across GINA treatment steps 2 - 5 in a large US patient cohort

OBJECTIVE

Despite advances in treatment, asthma remains uncontrolled in many patients, with increased risk of exacerbation and associated healthcare resource utilization (HCRU). We describe patient characteristics, exacerbations, asthma control, and HCRU using GINA treatment step (GS) as a proxy for asthma severity. .

METHODS

Using a large, US, health-claims database, 4 longitudinal cohorts of 517,738 patients in GS2-5, including a subgroup of patients with baseline eosinophil (EOS) counts, were analyzed retrospectively (study period 2010 - 2016). Index for each cohort was patients' first time entering the GS, determined by first claim of first regimen. Uncontrolled asthma was defined according to published criteria as a multi-dimensional measure that includes number of exacerbations. Key variables including, baseline characteristics, post-index exacerbations, and HCRU (all-cause and asthma-specific events) are summarized by descriptive statistics.

RESULTS

Uncontrolled asthma was reported in 19.8% patients in GS2, 44.8% in GS3, 49.3% in GS4, and 58.6% in GS5. Annualized mean (SD) rates of exacerbation 12 months post-index generally increased across GS2-5 (0.26 [0.86], 0.32 [0.79], 0.36 [0.83], 0.29 [0.86], respectively). HCRU also increased with increasing GS, with higher HCRU among the uncontrolled cohort within each GS. In patients with EOS ≥300 cells/µL, uncontrolled asthma also increased with increasing GS (21.8%, 43.9%, 50.5%, 67.2% for GS2-5, respectively).

CONCLUSIONS

This large database study provides real-world evidence of the substantial degree of uncontrolled asthma in US clinical practice across GS, supporting calls for better asthma management. Healthcare burden tends to increase with lack of control in all groups, highlighting the need for improved patient education, adherence, access, and treatment optimization.

Supplemental data for this article can be accessed at publisher's website.

What is the contribution of IgE to nasal polyposis?

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.