Lack of a transcriptional response of primary bronchial epithelial cells from patients with asthma and controls to IL-33

IL-33 and IL-1RL1 are well-replicated asthma genes that act in a single pathway toward type-2 immune responses. IL-33 is expressed by basal epithelial cells, and the release of IL-33 upon epithelial damage can activate innate lymphoid cells, T helper-2 cells, basophilic granulocytes, and mast cells through a receptor complex containing IL-1RL1. However, it is unknown how bronchial epithelial cells respond to IL-33, and whether this response is increased in the disease. We aimed to characterize the IL-33-driven transcriptomic changes in cultured primary bronchial epithelial cells from patients with asthma and healthy controls. Primary bronchial epithelial cells (PBECs) were obtained by bronchial brushing from six healthy control for air-liquid interface (ALI) cultures, whereas we selected eight healthy controls and seven patients with asthma for epithelial organoid cultures. We then stimulated the cultures for 24 h with recombinant IL-33 (rhIL33) at various concentrations with 1, 10, and 50 ng/mL for the ALI cultures and 20 ng/mL and 100 ng/mL for the organoid cultures, followed by RNA-sequencing and differential gene expression analysis. We did not detect any genome-wide significant differentially expressed genes after stimulation of PBECs with IL-33, irrespective of growth in three-dimensional (3-D) epithelial organoids or after differentiation in ALI cultures. These results were identical between PBECs obtained from patients with asthma or from healthy control subjects. We detected very low levels of IL-1RL1 gene expression in these airway epithelial cell cultures. We conclude that bronchial epithelial cells do not have a transcriptional response to IL-33, independent of their differentiation state. Hence, the airway epithelium acts as a source of IL-33 but does not seem to contribute to the response upon release of the alarmin after epithelial damage.NEW & NOTEWORTHY The IL-33/IL-1RL1 pathway stands as a formidable genetic predisposition for asthma, with ongoing clinical developments of various drugs designed to mitigate its influence in patients with asthma. The absence of a transcriptomic reaction to IL-33 within the bronchial epithelium holds significance in the pursuit of identifying biomarkers that can aid in pinpointing those individuals who would derive the greatest benefit from therapies targeting the IL-33 pathway.

Impact of Endobronchial Valve Treatment on Lung Function Decline

INTRODUCTION

Endobronchial valve (EBV) treatment has been shown to be beneficial for patients with severe emphysema. The forced expiratory volume in 1 s (FEV1) was found to be significantly higher compared to baseline for up to 3 years after treatment although the magnitude of improvement gradually decreases over time. So far, it has not been investigated whether this treatment decelerates the decline in lung function. Therefore, our aim was to investigate the lung function decline before and after EBV treatment.

METHODS

We included patients who were treated with EBVs in our hospital, of whom pre-treatment spirometry results were available (at least 4 measurements within at least 2 years before treatment) and who had an annual FEV1 measurement up to 3 years after treatment.

RESULTS

In total, 45 patients were included (73% female, FEV1: 28 ± 7% of predicted, residual volume: 232 ± 32% of predicted) who had a mean pre-treatment FEV1 decline of -64 mL/year. Mean FEV1 "decline" after treatment was +13 mL/year, since FEV1 was still above the baseline level at 3-year follow-up. However, the FEV1 decline between 1 and 3 years of follow-up was not significantly different compared to the pre-treatment decline (-73 mL/year, p = 0.179).

CONCLUSIONS

Our results show that the EBV treatment does not influence the progression of disease in terms of lung function decline. However, the treatment does improve the FEV1 up to a level that is still comparable 3 years after treatment with the baseline level.

Moxidectin and Ivermectin Inhibit SARS-CoV-2 Replication in Vero E6 Cells but Not in Human Primary Bronchial Epithelial Cells

Antiviral therapies are urgently needed to treat and limit the development of severe COVID-19 disease. Ivermectin, a broad-spectrum anti-parasitic agent, has been shown to have anti-SARS-CoV-2 activity in Vero cells at a concentration of 5 μM. These limited in vitro results triggered the investigation of ivermectin as a treatment option to alleviate COVID-19 disease. However, in April 2021, the World Health Organization stated the following: "The current evidence on the use of ivermectin to treat COVID-19 patients is inconclusive." It is speculated that the in vivo concentration of ivermectin is too low to exert a strong antiviral effect. Here, we performed a head-to-head comparison of the antiviral activity of ivermectin and the structurally related, but metabolically more stable moxidectin in multiple in vitro models of SARS-CoV-2 infection, including physiologically relevant human respiratory epithelial cells. Both moxidectin and ivermectin exhibited antiviral activity in Vero E6 cells. Subsequent experiments revealed that these compounds predominantly act on the steps following virus cell entry. Surprisingly, however, in human-airway-derived cell models, both moxidectin and ivermectin failed to inhibit SARS-CoV-2 infection, even at concentrations of 10 μM. These disappointing results call for a word of caution in the interpretation of anti-SARS-CoV-2 activity of drugs solely based on their activity in Vero cells. Altogether, these findings suggest that even using a high-dose regimen of ivermectin, or switching to another drug in the same class, is unlikely to be useful for treatment of SARS-CoV-2 in humans.

Long-acting dual bronchodilator therapy (indacaterol/glycopyrronium) versus nebulized short-acting dual bronchodilator (salbutamol/ipratropium) in chronic obstructive pulmonary disease: A double-blind, randomized, placebo-controlled trial

INTRODUCTION

Most guidelines recommend long-acting bronchodilators over short-acting bronchodilators for patients with chronic obstructive pulmonary disease (COPD). The available evidence for the guidelines was based on dry powder or pressurized metered dose inhalers, but not nebulizations. Nevertheless, there is considerable, poorly evidenced based, use of short acting nebulized bronchodilators.

METHODS

This was an investigator initiated, randomized, active controlled, cross-over, double-blind and double-dummy single centre study in patients with stable COPD. The active comparators were indacaterol/glycopyrronium 110/50 μg as Ultibro® via Breezhaler® (IND/GLY) and salbutamol/ipratropium 2,5/0,5 mg via air driven nebulization (SAL/IPR), both given as a single dose on separate days. The primary end point was the area under the FEV₁ curve from baseline till 6 h. Secondary end points included change in Borg dyspnoea score, adverse events and change in hyperinflation measured by the inspiratory capacity.

RESULTS

A total of 33 COPD patients completed the trial and were evaluable, most of them were ex-smokers. The difference between the tested regimens for the primary endpoint, FEV₁ AUC 0-6 h, 2965 ± 1544 mL (mean ± SD) for IND/GLY versus 3513 ± 1762 mL for SAL/IPR, was not significant (P = 0.08). The peak in FEV1 was higher and was reached faster with SAL/IPR compared to IND/GLY. No other significant differences were detected for the secondary endpoints including the Borg score, or adverse events.

CONCLUSION

Among patients with stable COPD, dry powder long-acting single inhalation of a LABA and a LAMA (IND/GLY) was not superior compared to nebulized short-acting salbutamol plus ipratropium (SAL/IPR) in its bronchodilating effects over 6 h.The effects of the nebulization kicked in faster and peaked higher. The observed differences may be caused by the difference in dosing between the two regimens. The improvement in Borg dyspnoea score did not favour the nebulization. Long-term outcomes were not assessed in this study.

Nasal DNA methylation profiling of asthma and rhinitis

BACKGROUND

Epigenetic signatures in the nasal epithelium, which is a primary interface with the environment and an accessible proxy for the bronchial epithelium, might provide insights into mechanisms of allergic disease.

OBJECTIVE

We aimed to identify and interpret methylation signatures in nasal epithelial brushes associated with rhinitis and asthma.

METHODS

Nasal epithelial brushes were obtained from 455 children at the 16-year follow-up of the Dutch Prevention and Incidence of Asthma and Mite Allergy birth cohort study. Epigenome-wide association studies were performed on children with asthma, rhinitis, and asthma and/or rhinitis (AsRh) by using logistic regression, and the top results were replicated in 2 independent cohorts of African American and Puerto Rican children. Significant CpG sites were related to environmental exposures (pets, active and passive smoking, and molds) during secondary school and were correlated with gene expression by RNA-sequencing (n = 244).

RESULTS

The epigenome-wide association studies identified CpG sites significantly associated with rhinitis (n = 81) and AsRh (n = 75), but not with asthma. We significantly replicated 62 of 81 CpG sites with rhinitis and 60 of 75 with AsRh, as well as 1 CpG site with asthma. Methylation of cg03565274 was negatively associated with AsRh and positively associated with exposure to pets during secondary school. DNA methylation signals associated with AsRh were mainly driven by specific IgE-positive subjects. DNA methylation related to gene transcripts that were enriched for immune pathways and expressed in immune and epithelial cells. Nasal CpG sites performed well in predicting AsRh.

CONCLUSIONS

We identified replicable DNA methylation profiles of asthma and rhinitis in nasal brushes. Exposure to pets may affect nasal epithelial methylation in relation to asthma and rhinitis.

Assessing small airways dysfunction in asthma, asthma remission and healthy controls using particles in exhaled air

Asthma is a chronic disease, characterised by variable airflow obstruction and airway inflammation [1]. Small airways are thought to be a major site of pathology in asthma [2, 3]. There are different tools to assess small airways dysfunction (SAD), such as spirometry, body plethysmography, impulse oscillometry (IOS), multiple-breath nitrogen washout (MBNW), alveolar fraction of exhaled nitric oxide (F_ENO) and gas trapping assessed by high-resolution computed tomography (CT). However, there is no golden standard and some tests are difficult to perform [2, 3].

PExA mass can distinguish asthmatics from healthy individuals. Subjects with complete, but not clinical, asthma remission exhale more PExA mass compared to asthma. Higher PExA mass was associated with better function of both the small and large airways.http://bit.ly/2znHABg

A review on the pathophysiology of asthma remission

Asthma is a chronic respiratory condition, which is highly prevalent worldwide. Although no cure is currently available, it is well recognized that some asthma patients can spontaneously enter remission of the disease later in life. Asthma remission is characterized by absence of symptoms and lack of asthma-medication use. Subjects in asthma remission can be divided into two groups: those in clinical remission and those in complete remission. In clinical asthma remission, subjects still have a degree of lung functional impairment or bronchial hyperresponsiveness, while in complete asthma remission, these features are no longer present. Over longer periods, the latter group is less likely to relapse. This remission group is of great scientific interest due to the higher potential to find biomarkers or biological pathways that elicit or are associated with asthma remission. Despite the fact that the definition of asthma remission varies between studies, some factors are reproducibly observed to be associated with remitted asthma. Among these are lower levels of inflammatory markers, which are lowest in complete remission. Additionally, in both groups some degree of airway remodeling is present. Still, the pathological disease state of asthma remission has been poorly investigated. Future research should focus on at least two aspects: further characterisation of the small airways and airway walls in order to determine histologically true remission, and more thorough biological pathway analyses to explore triggers that elicit this phenomenon. Ultimately, this will result in pharmacological targets that provide the potential to steer the course of asthma towards remission.

Serum periostin does not reflect type 2-driven inflammation in COPD

Although Th2 driven inflammation is present in COPD, it is not clearly elucidated which COPD patients are affected. Since periostin is associated with Th2 driven inflammation and inhaled corticosteroid (ICS)-response in asthma, it could function as a biomarker in COPD. The aim of this study was to analyze if serum periostin is elevated in COPD compared to healthy controls, if it is affected by smoking status, if it is linked to inflammatory cell counts in blood, sputum and endobronchial biopsies, and if periostin can predict ICS-response in COPD patients.Serum periostin levels were measured using Elecsys Periostin immunoassay. Correlations between periostin and inflammatory cell count in blood, sputum and endobronchial biopsies were analyzed. Additionally, the correlation between serum periostin levels and treatment responsiveness after 6 and 30 months was assessed using i.e. ΔFEV1% predicted, ΔCCQ score and ΔRV/TLC ratio. Forty-five COPD smokers, 25 COPD past-smokers, 22 healthy smokers and 23 healthy never-smokers were included. Linear regression analysis of serum periostin showed positive correlations age (B = 0.02, 95%CI 0.01-0.03) and FEV1% predicted (B = 0.01, 95%CI 0.01-0.02) in healthy smokers, but not in COPD patients In conclusion, COPD -smokers and -past-smokers have significantly higher periostin levels compared to healthy smokers, yet periostin is not suitable as a biomarker for Th2-driven inflammation or ICS-responsiveness in COPD.