Effects of combination treatment with tezepelumab and allergen immunotherapy on nasal responses to allergen: A randomized controlled trial

BACKGROUND

Thymic stromal lymphopoietin (TSLP) has been shown to play a central role in the initiation and persistence of allergic responses.

OBJECTIVE

We evaluated whether tezepelumab, a human monoclonal anti-TSLP antibody, improved the efficacy of subcutaneous allergen immunotherapy (SCIT) and promoted the development of tolerance in patients with allergic rhinitis.

METHODS

We conducted a double-blind parallel design trial in patients with cat allergy. A total of 121 patients were randomized to receive either intravenous tezepelumab plus subcutaneous cat SCIT, cat SCIT alone, tezepelumab alone, or placebo for 52 weeks, followed by 52 weeks of observation. Nasal allergen challenge (NAC), skin testing, and blood and nasal samples were obtained throughout the study.

RESULTS

At week 52, the NAC-induced total nasal symptom scores (TNSS) (calculated as area under the curve [AUC0-1h] and as peak score [Peak0-1h] during the first hour after NAC) were significantly reduced in patients receiving tezepelumab/SCIT compared to SCIT alone. At week 104, one year after stopping treatment, the primary end point TNSS AUC0-1h was not significantly different in the tezepelumab/SCIT group compared to SCIT alone, while TNSS Peak0-1h was significantly lower in those receiving combination treatment versus SCIT. Transcriptomic analysis of nasal epithelial samples demonstrated that treatment with the combination of SCIT/tezepelumab, but neither monotherapy, caused persistent downregulation of a gene network related to type 2 inflammation that was associated with improvement in NAC responses.

CONCLUSIONS

Inhibition of TSLP augments the efficacy of SCIT during therapy and may promote tolerance after a 1-year course of treatment. (ClinicalTrials.gov NCT02237196).

Environmental contributions to the interactions of COVID-19 and asthma: A secondary publication and update

An outbreak of coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) started in Wuhan, Hubei Province, China and quickly spread around the world. Current evidence is contradictory on the association of asthma with COVID-19 and associated severe outcomes. Type 2 inflammation may reduce the risk for severe COVID-19. Whether asthma diagnosis may be a risk factor for severe COVID-19, especially for those with severe disease or non-allergic phenotypes, deserves further attention and clarification. In addition, COVID-19 does not appear to provoke asthma exacerbations, and asthma therapeutics should be continued for patients with exposure to COVID-19. Changes in the intensity of pollinization, an earlier start and extension of the pollinating season, and the increase in production and allergenicity of pollen are known direct effects that air pollution has on physical, chemical, and biological properties of the pollen grains. They are influenced and triggered by meteorological variables that could partially explain the effect on COVID-19. SARS-CoV-2 is capable of persisting in the environment and can be transported by bioaerosols which can further influence its transmission rate and seasonality. The COVID-19 pandemic has changed the behavior of adults and children globally. A general trend during the pandemic has been human isolation indoors due to school lockdowns and loss of job or implementation of virtual work at home. A consequence of this behavior change would presumably be changes in indoor allergen exposures and reduction of inhaled outdoor allergens. Therefore, lockdowns during the pandemic might have improved some specific allergies, while worsening others, depending on the housing conditions.

Ischaemic preconditioning improves upper-body endurance performance without altering ⩒O2 kinetics

PURPOSE

Whilst pre-exercise ischaemic preconditioning (IPC) can improve lower-body exercise performance, its impact on upper-limb performance has received little attention. This study examines the influence of IPC on upper-body exercise performance and oxygen uptake (⩒O₂) kinetics.

METHODS

Eleven recreationally-active males (24 ± 2 years) completed an arm-crank graded exercise test to exhaustion to determine the power outputs at the ventilatory thresholds (VT1 and VT2) and ⩒O_2peak (40.0 ± 7.4 ml·kg^-1·min^-1). Four main trials were conducted, two following IPC (4 × 5-min, 220 mmHg contralateral upper-limb occlusion), the other two following SHAM (4 × 5-min, 20 mmHg). The first two trials consisted of a 15-minute constant work rate and the last two time-to-exhaustion (TTE) arm-crank tests at the power equivalents of 95% VT1 (LOW) and VT2 (HIGH), respectively. Pulmonary ⩒O₂ kinetics, heart rate, blood-lactate concentration, and rating of perceived exertion were recorded throughout exercise.

RESULTS

TTE during HIGH was longer following IPC than SHAM (459 ± 115 vs 395 ± 102 s, p = 0.004). Mean response time and change in ⩒O₂ between 2-min and end exercise (Δ⩒O₂) were not different between IPC and SHAM for arm-cranking at both LOW (80.3 ± 19.0 vs 90.3 ± 23.5 s [p = 0.06], 457 ± 184 vs 443 ± 245 ml [p = 0.83]) and HIGH (96.6 ± 31.2 vs 92.1 ± 24.4 s [p = 0.65], 617 ± 321 vs 649 ± 230 ml [p = 0.74]). Heart rate, blood-lactate concentration, and rating of perceived exertion did not differ between conditions (all p≥0.05).

CONCLUSION

TTE was longer following IPC during upper-body exercise despite unchanged ⩒O₂ kinetics.

EAACI position paper on the clinical use of the bronchial allergen challenge: Unmet needs and research priorities

Allergic asthma (AA) is a common asthma phenotype, and its diagnosis requires both the demonstration of IgE-sensitization to aeroallergens and the causative role of this sensitization as a major driver of asthma symptoms. Therefore, a bronchial allergen challenge (BAC) would be occasionally required to identify AA patients among atopic asthmatics. Nevertheless, BAC is usually considered a research tool only, with existing protocols being tailored to mild asthmatics and research needs (eg long washout period for inhaled corticosteroids). Consequently, existing BAC protocols are not designed to be performed in moderate-to-severe asthmatics or in clinical practice. The correct diagnosis of AA might help select patients for immunomodulatory therapies. Allergen sublingual immunotherapy is now registered and recommended for controlled or partially controlled patients with house dust mite-driven AA and with FEV1 ≥ 70%. Allergen avoidance is costly and difficult to implement for the management of AA, so the proper selection of patients is also beneficial. In this position paper, the EAACI Task Force proposes a methodology for clinical BAC that would need to be validated in future studies. The clinical implementation of BAC could ultimately translate into a better phenotyping of asthmatics in real life, and into a more accurate selection of patients for long-term and costly management pathways.

WAO-ARIA consensus on chronic cough - Part III: Management strategies in primary and cough-specialty care. Updates in COVID-19

Background

Chronic cough management necessitates a clear integrated care pathway approach. Primary care physicians initially encounter the majority of chronic cough patients, yet their role in proper management can prove challenging due to limited access to advanced diagnostic testing. A multidisciplinary approach involving otolaryngologists and chest physicians, allergists, and gastroenterologists, among others, is central to the optimal diagnosis and treatment of conditions which underly or worsen cough. These include infectious and inflammatory, upper and lower airway pathologies, or gastro-esophageal reflux. Despite the wide armamentarium of ancillary testing conducted in cough multidisciplinary care, such management can improve cough but seldom resolves it completely. This can be due partly to the limited data on the role of tests (eg, spirometry, exhaled nitric oxide), as well as classical pharmacotherapy conducted in multidisciplinary specialties for chronic cough. Other important factors include presence of multiple concomitant cough trigger mechanisms and the central neuronal complexity of chronic cough. Subsequent management conducted by cough specialists aims at control of cough refractory to prior interventions and includes cough-specific behavioral counseling and pharmacotherapy with neuromodulators, among others. Preliminary data on the role of neuromodulators in a proof-of-concept manner are encouraging but lack strong evidence on efficacy and safety.

Objectives

The World Allergy Organization (WAO)/Allergic Rhinitis and its Impact on Asthma (ARIA) Joint Committee on Chronic Cough reviewed the recent literature on management of chronic cough in primary, multidisciplinary, and cough-specialty care. Knowledge gaps in diagnostic testing, classical and neuromodulator pharmacotherapy, in addition to behavioral therapy of chronic cough were also analyzed.

Outcomes

This third part of the WAO/ARIA consensus on chronic cough suggests a management algorithm of chronic cough in an integrated care pathway approach. Insights into the inherent limitations of multidisciplinary cough diagnostic testing, efficacy and safety of currently available antitussive pharmacotherapy, or the recently recognized behavioral therapy, can significantly improve the standards of care in patients with chronic cough.

WAO-ARIA consensus on chronic cough - Part 1: Role of TRP channels in neurogenic inflammation of cough neuronal pathways

BACKGROUND

Cough features a complex peripheral and central neuronal network. The function of the chemosensitive and stretch (afferent) cough receptors is well described but partly understood. It is speculated that chronic cough reflects a neurogenic inflammation of the cough reflex, which becomes hypersensitive. This is mediated by neuromediators, cytokines, inflammatory cells, and a differential expression of neuronal (chemo/stretch) receptors, such as transient receptor potential (TRP) and purinergic P2X ion channels; yet the overall interaction of these mediators in neurogenic inflammation of cough pathways remains unclear.

OBJECTIVES

The World Allergy Organization/Allergic Rhinitis and its Impact on Asthma (WAO/ARIA) Joint Committee on Chronic Cough reviewed the current literature on neuroanatomy and pathophysiology of chronic cough. The role of TRP ion channels in pathogenic mechanisms of the hypersensitive cough reflex was also examined.

OUTCOMES

Chemoreceptors are better studied in cough neuronal pathways compared to stretch receptors, likely due to their anatomical overabundance in the respiratory tract, but also their distinctive functional properties. Central pathways are important in suppressive mechanisms and behavioral/affective aspects of chronic cough. Current evidence strongly suggests neurogenic inflammation induces a hypersensitive cough reflex marked by increased expression of neuromediators, mast cells, and eosinophils, among others. TRP ion channels, mainly TRP V1/A1, are important in the pathogenesis of chronic cough due to their role in mediating chemosensitivity to various endogenous and exogenous triggers, as well as a crosstalk between neurogenic and inflammatory pathways in cough-associated airways diseases.

WAO-ARIA consensus on chronic cough - Part II: Phenotypes and mechanisms of abnormal cough presentation - Updates in COVID-19

BACKGROUND

Chronic cough can be triggered by respiratory and non-respiratory tract illnesses originating mainly from the upper and lower airways, and the GI tract (ie, reflux). Recent findings suggest it can also be a prominent feature in obstructive sleep apnea (OSA), laryngeal hyperresponsiveness, and COVID-19. The classification of chronic cough is constantly updated but lacks clear definition. Epidemiological data on the prevalence of chronic cough are informative but highly variable. The underlying mechanism of chronic cough is a neurogenic inflammation of the cough reflex which becomes hypersensitive, thus the term hypersensitive cough reflex (HCR). A current challenge is to decipher how various infectious and inflammatory airway diseases and esophageal reflux, among others, modulate HCR.

OBJECTIVES

The World Allergy Organization/Allergic Rhinitis and its Impact on Asthma (WAO/ARIA) Joint Committee on Chronic Cough reviewed the current literature on classification, epidemiology, presenting features, and mechanistic pathways of chronic cough in airway- and reflux-related cough phenotypes, OSA, and COVID-19. The interplay of cough reflex sensitivity with other pathogenic mechanisms inherent to airway and reflux-related inflammatory conditions was also analyzed.

OUTCOMES

Currently, it is difficult to clearly ascertain true prevalence rates in epidemiological studies of chronic cough phenotypes. This is likely due to lack of standardized objective measures needed for cough classification and frequent coexistence of multi-organ cough origins. Notwithstanding, we emphasize the important role of HCR as a mechanistic trigger in airway- and reflux-related cough phenotypes. Other concomitant mechanisms can also modulate HCR, including type2/Th1/Th2 inflammation, presence or absence of deep inspiration-bronchoprotective reflex (lower airways), tissue remodeling, and likely cough plasticity, among others.

Inferring Respiratory Minute Volume from Wrist Motion

Exposure to air pollutants poses major health risk for patients with chronic pulmonary diseases such as asthma, bronchitis, and emphysema. Such risk can be mitigated by continuous exposure tracking. The effective dose of exposure is directly proportional to the respiratory minute volume, aka minute ventilation (VE). Till date, the clinical standard for measuring VE is Spirometry, a highly invasive and cumbersome modality, which is not suitable for continuous day-to-day use. This paper presents a novel non-invasive method toward continuous assessment of VE using a wrist-mount wearable motion sensor. Data from 25 healthy subjects were collected while they performed ambulatory and sedentary activities and physical exercises. Noise and artifacts of the motion signal are removed and the processed signal is used to extract explanatory features. The features are used to train and evaluate multiple regression models, among which, the probabilistic Gaussian process regression achieves the best performance in inferring VE from the wearable motion signal. The effects of inter- and intra-personal variations are explored to demonstrate the potential of the proposed method for continuously monitoring pollutant exposure risk in respiratory health applications.

Acute asthma management during SARS-CoV2-pandemic 2020

Background

The current COVID-19 pandemic has changed many medical practices in order to provide additional protection to both our patients and healthcare providers. In many cases this includes seeing patients through electronic means such as telehealth or telephone rather than seeing them in person. Asthma exacerbations cannot always be treated in this way.

Problem

Current emergency unit asthma guidelines recommend bronchodilators be administered by metered dose inhaler (MDI) and spacer for mild-moderate asthma and include it as a choice even in severe asthma, but many emergency units continue to prefer nebulised therapy for patients who urgently require beta-agonists. The utilization of nebulised therapy potentially increases the risk of aerosolization of the coronavirus. Since nosocomial transmission of respiratory pathogens is a major threat in the context of the SARS-CoV-2 pandemic, use of nebulised therapy is of even greater concern due to the potential increased risk of infection spread to nearby patients and healthcare workers.

Practical implications

We propose a risk stratification plan that aims to avoid nebulised therapy, when possible, by providing an algorithm to help better delineate those who require nebulised therapy. Protocols that include strategies to allow flexibility in using MDIs rather than nebulisers in all but the most severe patients should help mitigate this risk of aerosolised infection transmission to patients and health care providers. Furthermore, expedient treatment of patients with high dose MDI therapy augmented with more rapid initiation of systemic therapy may help ensure patients are less likely to deteriorate to the stage where nebulisers are required.

Emerging concepts and challenges in implementing the exposome paradigm in allergic diseases and asthma: a Practall document

Exposome research can improve the understanding of the mechanistic connections between exposures and health to help mitigate adverse health outcomes across the life span. The exposomic approach provides a risk profile instead of single predictors and thus is particularly applicable to allergic diseases and asthma. Under the PRACTALL collaboration between the European Academy of Allergy and Clinical Immunology (EAACI) and the American Academy of Allergy, Asthma, and Immunology (AAAAI), we evaluated the current concepts and the unmet needs on the role of the exposome in allergic diseases and asthma.

Low-Power Wearable Systems for Continuous Monitoring of Environment and Health for Chronic Respiratory Disease

We present our efforts toward enabling a wearable sensor system that allows for the correlation of individual environmental exposures with physiologic and subsequent adverse health responses. This system will permit a better understanding of the impact of increased ozone levels and other pollutants on chronic asthma conditions. We discuss the inefficiency of existing commercial off-the-shelf components to achieve continuous monitoring and our system-level and nano-enabled efforts toward improving the wearability and power consumption. Our system consists of a wristband, a chest patch, and a handheld spirometer. We describe our preliminary efforts to achieve a submilliwatt system ultimately powered by the energy harvested from thermal radiation and motion of the body with the primary contributions being an ultralow-power ozone sensor, an volatile organic compounds sensor, spirometer, and the integration of these and other sensors in a multimodal sensing platform. The measured environmental parameters include ambient ozone concentration, temperature, and relative humidity. Our array of sensors also assesses heart rate via photoplethysmography and electrocardiography, respiratory rate via photoplethysmography, skin impedance, three-axis acceleration, wheezing via a microphone, and expiratory airflow. The sensors on the wristband, chest patch, and spirometer consume 0.83, 0.96, and 0.01 mW, respectively. The data from each sensor are continually streamed to a peripheral data aggregation device and are subsequently transferred to a dedicated server for cloud storage. Future work includes reducing the power consumption of the system-on-chip including radio to reduce the entirety of each described system in the submilliwatt range.

Inflammatory cytokine response to ambient particles varies due to field collection procedures

In vitro assays of biological activity induced by particulate matter (PM) are a tool for investigating mechanisms of PM health effects. They have potential application to exposure assessment in chronic disease epidemiology. However, there has been little reporting of the impact of real-world PM collection techniques on assay results. Therefore, we examined the effect of sampling duration and postsampling delays in freezing on PM-induced biological activity. Duplicate samples of respirable ambient Los Angeles PM were collected on polyurethane foam filters during 17 days and during three contemporaneous consecutive shorter periods. After collection, one duplicate was stored at ambient temperature for 24 hours before freezing; the other was frozen immediately. Cytokine response (IL-1β, IL-6, IL-8, and TNF-α) to PM aqueous extract was assessed in THP-1 cells, a model for evaluating monocyte/macrophage lineage cell responses. There was consistent 3- to 4-fold variation in PM-induced cytokine levels across the three collection intervals. Compared with levels induced by PM pooled across the three periods, continuously collected PM-induced levels were reduced by 25% (IL-6) to 39% (IL-8). The pattern of cytokine gene expression response was similar. Cytokine level variation by time to freezing was not statistically significant. PM-induced inflammatory response varied substantially over a weekly time scale. We conclude that long PM sampling interval induced less activity than the average of equivalent shorter consecutive sampling intervals. Time to freezing was less important. Implications for development of metrics of long-term spatial variation in biological exposure metrics for study of chronic disease merit further investigation.

Severe DRESS syndrome managed with therapeutic plasma exchange

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare but increasingly described phenomenon of immune activation and organ dysfunction in association with a wide variety of medications. This reaction shows a broad spectrum of clinical presentation and severity, ranging from mild to lethal. Treatment strategies of immune suppression appear be helpful in some cases, but treatment failures occur frequently with reported mortality rates of 5% to 10%. We present a pediatric case of DRESS syndrome associated with either lamotrigine or bupropion, leading to multiorgan involvement and life-threatening complications of respiratory failure and cardiac arrest. After failing to improve with removal of these medications and administration of systemic corticosteroids, our patient showed dramatic, sustained clinical response to therapeutic plasma exchange. To our knowledge, this is the first reported case of therapeutic plasma exchange used for life-threatening DRESS syndrome in a pediatric patient. This case suggests needed research for this therapeutic option in life-threatening DRESS syndrome resistant to high-dose steroids.

Role of GSTM1 in resistance to lung inflammation

Lung inflammation resulting from oxidant/antioxidant imbalance is a common feature of many lung diseases. In particular, the role of enzymes regulated by the NF-E2-related factor 2 transcription factor has recently received increased attention. Among these antioxidant genes, glutathione S-transferase Mu 1 (GSTM1) has been most extensively characterized because it has a null polymorphism that is highly prevalent in the population and associated with increased risk of inflammatory lung diseases. Present evidence suggests that GSTM1 acts through interactions with other genes and environmental factors, especially air pollutants. Here, we review GSTM1 gene expression and regulation and summarize the findings from epidemiological, clinical, animal, and in vitro studies on the role played by GSTM1 in lung inflammation. We discuss limitations in the existing knowledge base and future perspectives and evaluate the potential of pharmacologic and genetic manipulation of the GSTM1 gene to modulate pulmonary inflammatory responses.

Asthma outcomes: exacerbations

BACKGROUND

The goals of asthma treatment include preventing recurrent exacerbations. Yet there is no consensus about the terminology for describing or defining "exacerbation" or about how to characterize an episode's severity.

OBJECTIVE

National Institutes of Health institutes and other federal agencies convened an expert group to propose how asthma exacerbation should be assessed as a standardized asthma outcome in future asthma clinical research studies.

METHODS

We used comprehensive literature reviews and expert opinion to compile a list of asthma exacerbation outcomes and classified them as either core (required in future studies), supplemental (used according to study aims and standardized), or emerging (requiring validation and standardization). This work was discussed at a National Institutes of Health-organized workshop in March 2010 and finalized in September 2011.

RESULTS

No dominant definition of "exacerbation" was found. The most widely used definitions included 3 components, all related to treatment, rather than symptoms: (1) systemic use of corticosteroids, (2) asthma-specific emergency department visits or hospitalizations, and (3) use of short-acting β-agonists as quick-relief (sometimes referred to as "rescue" or "reliever") medications.

CONCLUSIONS

The working group participants propose that the definition of "asthma exacerbation" be "a worsening of asthma requiring the use of systemic corticosteroids to prevent a serious outcome." As core outcomes, they propose inclusion and separate reporting of several essential variables of an exacerbation. Furthermore, they propose the development of a standardized, component-based definition of "exacerbation" with clear thresholds of severity for each component.