Cooperation of immune regulators Tollip and surfactant protein A inhibits influenza A virus infection in mice

BACKGROUND

Influenza A virus (IAV) infection is a significant risk factor for respiratory diseases, but the host defense mechanisms against IAV remain to be defined. Immune regulators such as surfactant protein A (SP-A) and Toll-interacting protein (Tollip) have been shown to be involved in IAV infection, but whether SP-A and Tollip cooperate in more effective host defense against IAV infection has not been investigated.

METHODS

Wild-type (WT), Tollip knockout (KO), SP-A KO, and Tollip/SP-A double KO (dKO) mice were infected with IAV for four days. Lung macrophages were isolated for bulk RNA sequencing. Precision-cut lung slices (PCLS) from WT and dKO mice were pre-treated with SP-A and then infected with IAV for 48 h.

RESULTS

Viral load was significantly increased in bronchoalveolar lavage (BAL) fluid of dKO mice compared to all other strains of mice. dKO mice had significantly less recruitment of neutrophils into the lung compared to Tollip KO mice. SP-A treatment of PCLS enhanced expression of TNF and reduced viral load in dKO mouse lung tissue. Pathway analysis of bulk RNA sequencing data suggests that macrophages from IAV-infected dKO mice reduced expression of genes involved in neutrophil recruitment, IL-17 signaling, and Toll-like receptor signaling.

CONCLUSIONS

Our data suggests that both Tollip and SP-A are essential for the lung to exert more effective innate defense against IAV infection.

Integrated longitudinal multiomics study identifies immune programs associated with acute COVID-19 severity and mortality

BACKGROUNDPatients hospitalized for COVID-19 exhibit diverse clinical outcomes, with outcomes for some individuals diverging over time even though their initial disease severity appears similar to that of other patients. A systematic evaluation of molecular and cellular profiles over the full disease course can link immune programs and their coordination with progression heterogeneity.METHODSWe performed deep immunophenotyping and conducted longitudinal multiomics modeling, integrating 10 assays for 1,152 Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study participants and identifying several immune cascades that were significant drivers of differential clinical outcomes.RESULTSIncreasing disease severity was driven by a temporal pattern that began with the early upregulation of immunosuppressive metabolites and then elevated levels of inflammatory cytokines, signatures of coagulation, formation of neutrophil extracellular traps, and T cell functional dysregulation. A second immune cascade, predictive of 28-day mortality among critically ill patients, was characterized by reduced total plasma Igs and B cells and dysregulated IFN responsiveness. We demonstrated that the balance disruption between IFN-stimulated genes and IFN inhibitors is a crucial biomarker of COVID-19 mortality, potentially contributing to failure of viral clearance in patients with fatal illness.CONCLUSIONOur longitudinal multiomics profiling study revealed temporal coordination across diverse omics that potentially explain the disease progression, providing insights that can inform the targeted development of therapies for patients hospitalized with COVID-19, especially those who are critically ill.TRIAL REGISTRATIONClinicalTrials.gov NCT04378777.FUNDINGNIH (5R01AI135803-03, 5U19AI118608-04, 5U19AI128910-04, 4U19AI090023-11, 4U19AI118610-06, R01AI145835-01A1S1, 5U19AI062629-17, 5U19AI057229-17, 5U19AI125357-05, 5U19AI128913-03, 3U19AI077439-13, 5U54AI142766-03, 5R01AI104870-07, 3U19AI089992-09, 3U19AI128913-03, and 5T32DA018926-18); NIAID, NIH (3U19AI1289130, U19AI128913-04S1, and R01AI122220); and National Science Foundation (DMS2310836).

Asthma Pathogenesis: Phenotypes, Therapies and Gaps. Summary of the Aspen Lung Conference 2023

Although substantial progress has been made in our understanding of asthma pathogenesis and phenotypes over the 60-year history of Aspen Lung Conferences on asthma, many ongoing challenges exist in our understanding of the clinical and molecular heterogeneity of the disease and an individual patient's response to therapy. This report summarizes the proceedings of the 2023 Aspen Lung Conference, which was organized to review the clinical and molecular heterogeneity of asthma and to better understand the impact of genetic, environmental, cellular, and molecular influences on disease susceptibility, heterogeneity, and severity. The goals of the conference were to review new information about asthma phenotypes, cellular processes, and cellular signatures underlying disease heterogeneity and treatment response. The report concludes with ongoing gaps in our understanding of asthma pathobiology and provides some recommendations for future research to better understand the clinical and basic mechanisms underlying disease heterogeneity in asthma and to advance the development of new treatments for this growing public health problem.

The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Proteomic, miRNA and bacterial biomarker patterns in atopic dermatitis patients and their course upon anti-IL-4Rα therapy

BACKGROUND

Identification of biomarkers is required for a systems medicine approach and personalized treatment in atopic dermatitis (AD). These biomarkers may not only aid in diagnosing but also might be suitable to predict the effectiveness of targeted treatment.

OBJECTIVE

We aimed to identify proteomic, microbial and miRNA biomarkers in AD patients and investigated their course in relation to the clinical response upon anti-IL-4Rα therapy.

METHODS

Proteomic and miRNA screening was performed in AD patients in comparison to healthy controls. Differentially regulated serum proteins, miRNA and selected skin microbiota were measured consecutively in 50 AD patients before and upon systemic dupilumab treatment. A random forest classifier was used to predict the outcome of dupilumab therapy based on the initial biomarker patterns.

RESULTS

We identified 27 proteomic candidates, miRNA and three microbial strains to be dysregulated in AD. CCL17, CCL13, CCL22, E-selectin and BDNF were differently regulated and significantly associated with treatment response. In contrast, neither the microbial composition nor the miRNA pattern was associated with treatment response upon dupilumab treatment.

CONCLUSION

AD patients display defined dysregulations regarding their systemic proteomic serum profile, miRNA patterns and their skin microbiome. The proteomic profile and selected skin bacteria changed profoundly upon anti-IL-4Rα therapy which was associated with an overall clinical response. This was not seen in miRNA-related biomarkers. Our findings support the hypothesis that biomarker profiles reflect treatment responses and may in the future be used to develop a personalized medicine approach for the treatment of AD patients.

Features of acute COVID-19 associated with post-acute sequelae of SARS-CoV-2 phenotypes: results from the IMPACC study

Post-acute sequelae of SARS-CoV-2 (PASC) is a significant public health concern. We describe Patient Reported Outcomes (PROs) on 590 participants prospectively assessed from hospital admission for COVID-19 through one year after discharge. Modeling identified 4 PRO clusters based on reported deficits (minimal, physical, mental/cognitive, and multidomain), supporting heterogenous clinical presentations in PASC, with sub-phenotypes associated with female sex and distinctive comorbidities. During the acute phase of disease, a higher respiratory SARS-CoV-2 viral burden and lower Receptor Binding Domain and Spike antibody titers were associated with both the physical predominant and the multidomain deficit clusters. A lower frequency of circulating B lymphocytes by mass cytometry (CyTOF) was observed in the multidomain deficit cluster. Circulating fibroblast growth factor 21 (FGF21) was significantly elevated in the mental/cognitive predominant and the multidomain clusters. Future efforts to link PASC to acute anti-viral host responses may help to better target treatment and prevention of PASC.

An epithelial gene signature of trans-IL-6 signaling defines a subgroup of type 2-low asthma

BACKGROUND

Asthma is stratified into type 2-high and type 2-low inflammatory phenotypes. Limited success has been achieved in developing drugs that target type 2-low inflammation. Previous studies have linked IL-6 signaling to severe asthma. IL-6 cooperates with soluble-IL-6Rα to activate cell signaling in airway epithelium.

OBJECTIVE

We sought to study the role of sIL-6Rα amplified IL-6 signaling in airway epithelium and to develop an IL-6+ sIL-6Rα gene signature that may be used to select asthma patients who potentially respond to anti-IL-6 therapy.

METHODS

Human airway epithelial cells were stimulated with combinations of IL-6, sIL-6Rα, and inhibitors, sgp130 (Olamkicept), and anti-IL-6R (Tocilizumab), to assess effects on pathway activation, epithelial barrier integrity, and gene expression. A gene signature was generated to identify IL-6 high patients using bronchial biopsies and nasal brushes.

RESULTS

Soluble-IL-6Rα amplified the activation of the IL-6 pathway, shown by the increase of STAT3 phosphorylation and stronger gene induction in airway epithelial cells compared to IL-6 alone. Olamkicept and Tocilizumab inhibited the effect of IL-6 + sIL-6Rα on gene expression. We developed an IL-6 + sIL-6Rα gene signature and observed enrichment of this signature in bronchial biopsies but not nasal brushes from asthma patients compared to healthy controls. An IL-6 + sIL-6Rα gene signature score was associated with lower levels of sputum eosinophils in asthma.

CONCLUSION

sIL-6Rα amplifies IL-6 signaling in bronchial epithelial cells. Higher local airway IL-6 + sIL-6Rα signaling is observed in asthma patients with low sputum eosinophils.

Tollip deficiency exaggerates airway type 2 inflammation in mice exposed to allergen and influenza A virus: role of the ATP/IL-33 signaling axis

Toll-interacting protein (Tollip) is a negative regulator of the pro-inflammatory response to viruses, including influenza A virus (IAV). Genetic variation of Tollip has been associated with reduced airway epithelial Tollip expression and poor lung function in patients with asthma. Whether Tollip deficiency exaggerates type 2 inflammation (e.g., eosinophils) and viral infection in asthma remains unclear. We sought to address this critical, but unanswered question by using a Tollip deficient mouse asthma model with IAV infection. Further, we determined the underlying mechanisms by focusing on the role of the ATP/IL-33 signaling axis. Wild-type and Tollip KO mice were intranasally exposed to house dust mite (HDM) and IAV with or without inhibitors for IL-33 (i.e., soluble ST2, an IL-33 decoy receptor) and ATP signaling (i.e., an antagonist of the ATP receptor P2Y13). Tollip deficiency amplified airway type 2 inflammation (eosinophils, IL-5, IL-13 and mucins), and the release of ATP and IL-33. Blocking ATP receptor P2Y13 decreased IL-33 release during IAV infection in HDM-challenged Tollip KO mice. Furthermore, soluble ST2 attenuated airway eosinophilic inflammation in Tollip KO mice treated with HDM and IAV. HDM challenges decreased lung viral load in wild-type mice, but Tollip deficiency reduced the protective effects of HDM challenges on viral load. Our data suggests that during IAV infection, Tollip deficiency amplified type 2 inflammation and delayed viral clearance, in part by promoting ATP signaling and subsequent IL-33 release. Our findings may provide several therapeutic targets, including ATP and IL-33 signaling inhibition for attenuating excessive airway type 2 inflammation in human subjects with Tollip deficiency and IAV infection.

The SARS-CoV-2 pandemic and asthma: What we have learned and what is still unknown

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has brought new insights into the immunologic intricacies of asthma. In this review, we discuss the epidemiology of asthma in patients infected with SARS-CoV-2 and the risk of severe infection. Type 2 inflammation had an overall protective effect against SARS-CoV-2 infection by various mechanisms summarized in this review. Asthma, intranasal, and inhaled corticosteroids decreased the angiotensin-converting enzyme 2 receptor, an important receptor for SARS-CoV-2 entry into host cells. We summarize the nuances of the treatment of type 2 inflammation despite its underlying protective effects. Research to date has shown that patients on various allergen immunotherapies and biologics do benefit from being vaccinated.

Integrated longitudinal multi-omics study identifies immune programs associated with COVID-19 severity and mortality in 1152 hospitalized participants

Hospitalized COVID-19 patients exhibit diverse clinical outcomes, with some individuals diverging over time even though their initial disease severity appears similar. A systematic evaluation of molecular and cellular profiles over the full disease course can link immune programs and their coordination with progression heterogeneity. In this study, we carried out deep immunophenotyping and conducted longitudinal multi-omics modeling integrating ten distinct assays on a total of 1,152 IMPACC participants and identified several immune cascades that were significant drivers of differential clinical outcomes. Increasing disease severity was driven by a temporal pattern that began with the early upregulation of immunosuppressive metabolites and then elevated levels of inflammatory cytokines, signatures of coagulation, NETosis, and T-cell functional dysregulation. A second immune cascade, predictive of 28-day mortality among critically ill patients, was characterized by reduced total plasma immunoglobulins and B cells, as well as dysregulated IFN responsiveness. We demonstrated that the balance disruption between IFN-stimulated genes and IFN inhibitors is a crucial biomarker of COVID-19 mortality, potentially contributing to the failure of viral clearance in patients with fatal illness. Our longitudinal multi-omics profiling study revealed novel temporal coordination across diverse omics that potentially explain disease progression, providing insights that inform the targeted development of therapies for hospitalized COVID-19 patients, especially those critically ill.

Circulating CC16 and Asthma: A Population-based, Multicohort Study from Early Childhood through Adult Life

Rationale: Club cell secretory protein (CC16) is an antiinflammatory protein highly expressed in the airways. CC16 deficiency has been associated with lung function deficits, but its role in asthma has not been established conclusively. Objectives: To determine 1) the longitudinal association of circulating CC16 with the presence of active asthma from early childhood through adult life and 2) whether CC16 in early childhood predicts the clinical course of childhood asthma into adult life. Methods: We assessed the association of circulating CC16 and asthma in three population-based birth cohorts: the Tucson Children's Respiratory Study (years 6-36; total participants, 814; total observations, 3,042), the Swedish Barn/Children, Allergy, Milieu, Stockholm, Epidemiological survey (years 8-24; total participants, 2,547; total observations, 3,438), and the UK Manchester Asthma and Allergy Study (years 5-18; total participants, 745; total observations, 1,626). Among 233 children who had asthma at the first survey in any of the cohorts, baseline CC16 was also tested for association with persistence of symptoms. Measurements and Main Results: After adjusting for covariates, CC16 deficits were associated with increased risk for the presence of asthma in all cohorts (meta-analyzed adjusted odds ratio per 1-SD CC16 decrease, 1.20; 95% confidence interval [CI], 1.12-1.28; P < 0.0001). The association was particularly strong for asthma with frequent symptoms (meta-analyzed adjusted relative risk ratio, 1.40; 95% CI, 1.24-1.57; P < 0.0001), was confirmed for both atopic and nonatopic asthma, and was independent of lung function impairment. After adjustment for known predictors of persistent asthma, children with asthma in the lowest CC16 tertile had a nearly fourfold increased risk for having frequent symptoms persisting into adult life compared with children with asthma in the other two CC16 tertiles (meta-analyzed adjusted odds ratio, 3.72; 95% CI, 1.78-7.76; P < 0.0001). Conclusions: Circulating CC16 deficits are associated with the presence of asthma with frequent symptoms from childhood through midadult life and predict the persistence of asthma symptoms into adulthood. These findings support a possible protective role of CC16 in asthma and its potential use for risk stratification.

Questions in Mild Asthma: An Official American Thoracic Society Research Statement

Background: Patients with mild asthma are believed to represent the majority of patients with asthma. Disease-associated risks such as exacerbations, lung function decline, and death have been understudied in this patient population. There have been no prior efforts from major societies to describe research needs in mild asthma. Methods: A multidisciplinary, diverse group of 24 international experts reviewed the literature, identified knowledge gaps, and provided research recommendations relating to mild asthma definition, pathophysiology, and management across all age groups. Research needs were also investigated from a patient perspective, generated in conjunction with patients with asthma, caregivers, and stakeholders. Of note, this project is not a systematic review of the evidence and is not a clinical practice guideline. Results: There are multiple unmet needs in research on mild asthma driven by large knowledge gaps in all areas. Specifically, there is an immediate need for a robust mild asthma definition and an improved understanding of its pathophysiology and management strategies across all age groups. Future research must factor in patient perspectives. Conclusions: Despite significant advances in severe asthma, there remain innumerable research areas requiring urgent attention in mild asthma. An important first step is to determine a better definition that will accurately reflect the heterogeneity and risks noted in this group. This research statement highlights the topics of research that are of the highest priority. Furthermore, it firmly advocates the need for engagement with patient groups and for more support for research in this field.

Treating asthma in the time of COVID

The Precision Interventions for Severe and/or Exacerbation-Prone Asthma clinical trials network is actively assessing novel treatments for severe asthma during the coronavirus disease (COVID-19) pandemic and has needed to adapt to various clinical dilemmas posed by the COVID-19 pandemic. Pharmacologic interactions between established asthma therapies and novel drug interventions for COVID-19 infection, including antivirals, biologics, and vaccines, have emerged as a critical and unanticipated issue in the clinical care of asthma. In particular, impaired metabolism of some long-acting beta-2 agonists by the cytochrome P4503A4 enzyme in the setting of antiviral treatment using ritonavir-boosted nirmatrelvir (NVM/r, brand name Paxlovid) may increase risk for adverse cardiovascular events. Although available data have documented the potential for such interactions, these issues are largely unappreciated by clinicians who treat asthma, or those dispensing COVID-19 interventions in patients who happen to have asthma. Because these drug-drug interactions have not previously been relevant to patient care, clinicians have had no guidance on management strategies to reduce potentially serious interactions between treatments for asthma and COVID-19. The Precision Interventions for Severe and/or Exacerbation-Prone Asthma network considered the available literature and product information, and herein share our considerations and plans for treating asthma within the context of these novel COVID-19-related therapies.

Low CC16 mRNA Expression Levels in Bronchial Epithelial Cells Are Associated with Asthma Severity

Rationale: CC16 is a protein mainly produced by nonciliated bronchial epithelial cells (BECs) that participates in host defense. Reduced CC16 protein concentrations in BAL and serum are associated with asthma susceptibility. Objectives: Few studies have investigated the relationship between CC16 and asthma progression, and none has focused on BECs. In this study, we sought to determine if CC16 mRNA expression levels in BECs are associated with asthma severity. Methods: Association analyses between CC16 mRNA expression levels in BECs (242 asthmatics and 69 control subjects) and asthma-related phenotypes in Severe Asthma Research Program were performed using a generalized linear model. Measurements and Main Results: Low CC16 mRNA expression levels in BECs were significantly associated with asthma susceptibility and asthma severity, high systemic corticosteroids use, high retrospective and prospective asthma exacerbations, and low pulmonary function. Low CC16 mRNA expression levels were significantly associated with high T2 inflammation biomarkers (fractional exhaled nitric oxide and sputum eosinophils). CC16 mRNA expression levels were negatively correlated with expression levels of Th2 genes (IL1RL1, POSTN, SERPINB2, CLCA1, NOS2, and MUC5AC) and positively correlated with expression levels of Th1 and inflammation genes (IL12A and MUC5B). A combination of two nontraditional T2 biomarkers (CC16 and IL-6) revealed four asthma endotypes with different characteristics of T2 inflammation, obesity, and asthma severity. Conclusions: Our findings indicate that low CC16 mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations, partially through immunomodulation of T2 inflammation. CC16 is a potential nontraditional T2 biomarker for asthma development and progression.

Roflumilast May Increase Risk of Exacerbations When Used to Treat Poorly Controlled Asthma in People with Obesity

Rationale: People with obesity often have severe, difficult-to-control asthma. There is a need to develop better treatments for this population. One potential treatment is roflumilast, a phosphodiesterase 4 inhibitor, as it is reported to have efficacy for the treatment of asthma and can promote weight loss. Objectives: To investigate the potential efficacy of roflumilast for the treatment of poorly controlled asthma in people with obesity. Methods: A randomized, double-masked, placebo-controlled trial of 24 weeks of roflumilast versus placebo for the treatment of poorly controlled asthma in people with obesity (body mass index of 30 kg/m2 or higher). The primary outcome was a change in ACT (Asthma Control Test) score. Results: Twenty-two people were randomized to roflumilast and 16 to placebo. Roflumilast had no effect on change in the ACT (increased by 2.6 [interquartile range (IQR), 0.5-4.4] in those on roflumilast vs. 2.0 [IQR, 0.7-3.3] in those on placebo). Participants assigned to roflumilast had a 3.5-fold (relative risk [RR] 95% confidence interval [CI], 1.3-9.4) increased risk of an episode of poor asthma control and an 8.1-fold (RR 95% CI, 1.01-65.0) increased risk of an urgent care visit for asthma. Ten participants (56%) assigned to roflumilast required a course of oral corticosteroids for asthma exacerbations, and none in the placebo group. Participants losing 5% or more of their body weight experienced a clinically and statistically significant improvement in asthma control (ACT increased by 4.4 [IQR, 2.5-6.3] vs. 1.5 [IQR, 0.0-3.0] in those who lost less than 5%). Conclusions: Roflumilast had no effect on asthma control. Of concern, roflumilast was associated with an increased risk of exacerbation in obese individuals with poorly controlled asthma. These results highlight the importance of studying interventions in different subpopulations of people with asthma, particularly people with obesity and asthma who may respond differently to medications than lean people with asthma. Weight loss of at least 5% was associated with improved asthma control, indicating that interventions other than roflumilast promoting weight loss may have efficacy for the treatment of poorly controlled asthma in people with obesity. Clinical trial registered with www.clinicaltrials.gov (NCT03532490).

Predictors and associations of the persistent airflow limitation phenotype in asthma: a post-hoc analysis of the ATLANTIS study

BACKGROUND

Persistent airflow limitation (PAL) occurs in a subset of patients with asthma. Previous studies on PAL in asthma have included relatively small populations, mostly restricted to severe asthma, or have no included longitudinal data. The aim of this post-hoc analysis was to investigate the determinants, clinical implications, and outcome of PAL in patients with asthma who were included in the ATLANTIS study.

METHODS

In this post-hoc analysis of the ATLANTIS study, we assessed the prevalence, clinical characteristics, and implications of PAL across the full range of asthma severity. The study population included patients aged 18-65 years who had been diagnosed with asthma at least 6 months before inclusion. We defined PAL as a post-bronchodilator FEV₁/forced vital capacity (FVC) of less than the lower limit of normal at recruitment. Asthma severity was defined according to the Global Initiative for Asthma. We used Mann-Whitney U test, t test, or χ² test to analyse differences in baseline characteristics between patients with and without PAL. Logistic regression was used for multivariable analysis of the associations between PAL and baseline data. Cox regression was used to analyse risk of exacerbation in relation to PAL, and a linear mixed-effects model was used to analyse change in FEV₁ over time in patients with versus patients without PAL. Results were validated in the U-BIOPRED cohort.

FINDINGS

Between June 30, 2014 and March 3, 2017, 773 patients were enrolled in the ATLANTIS study of whom 760 (98%) had post-bronchodilator FEV₁/FVC data available. Of the included patients with available data, mean age was 44 years (SD 13), 441 (58%) of 760 were women, 578 (76%) were never-smokers, and 248 (33%) had PAL. PAL was not only present in patients with severe asthma, but also in 21 (16%) of 133 patients with GINA step 1 and 24 (29%) of 83 patients with GINA step 2. PAL was independently associated with older age at baseline (46 years in PAL group vs 43 years in non-PAL group), longer duration of asthma (24 years vs 12 years), male sex (51% vs 38%), higher blood eosinophil counts (median 0·27 × 10⁹ cells per L vs 0·20 × 10⁹ cells per L), more small airway dysfunction, and more exacerbations during 1 year of follow-up. Associations between PAL, age, and eosinophilic inflammation were validated in the U-BIOPRED cohort, whereas associations with sex, duration of asthma, and risk of exacerbations were not validated.

INTERPRETATION

PAL is not only present in severe disease, but also in a considerable proportion of patients with milder disease. In patients with mild asthma, PAL is associated with eosinophilic inflammation and a higher risk of exacerbations. Our findings are important because they suggest that increasing treatment intensity should be considered in patients with milder asthma and PAL.

FUNDING

Chiesi Farmaceutici and Dutch Ministry of Economic Affairs and Climate Policy (by means of the public-private partnership programme).

Nebulised interferon beta-1a (SNG001) in hospitalised COVID-19: SPRINTER Phase III Study

Background

Despite the availability of vaccines and therapies, patients are being hospitalised with COVID-19. Interferon-β is a naturally-occurring protein that stimulates host immune responses against most viruses, including SARS-CoV-2. SNG001 is a recombinant interferon-β1a formulation delivered to the lungsvianebuliser. SPRINTER assessed the efficacy and safety of SNG001 in adults hospitalised due to COVID-19 who required oxygenvianasal prongs or mask.

Methods

Patients were randomised double-blind to SNG001 (N=309) or placebo (N=314) once-daily for 14 days plus standard of care (SoC). The primary objective was to evaluate recovery after administration of SNG001versusplacebo, in terms of times to hospital discharge and recovery to no limitation of activity. Key secondary endpoints were: progression to severe disease or death; progression to intubation or death; and death.

Results

Median time to hospital discharge was 7.0 and 8.0 days with SNG001 and placebo, respectively (hazard ratio 1.06 [95%CI 0.89, 1.27]; p=0.51); time to recovery was 25.0 days in both groups (1.02 [0.81, 1.28]; p=0.89). There were no significant SNG001–placebo differences for the key secondary endpoints, with a 25.7% relative risk reduction in progression to severe disease or death (10.7% and 14.4%, respectively; odds ratio 0.71 [0.44, 1.15]; p=0.161). Serious adverse events were reported by 12.6% and 18.2% patients with SNG001 and placebo, respectively.

Conclusions

Although the primary objective of the study was not met, SNG001 had a favourable safety profile, and the key secondary endpoints analysis suggested that SNG001 may have prevented progression to severe disease.

Study registration number: ISRCTN85436698

Development of a tool to detect small airways dysfunction in asthma clinical practice

Background

Small airways dysfunction (SAD) in asthma is difficult to measure and a gold standard is lacking. The aim of this study was to develop a simple tool including items of the small airways dysfunction tool (SADT) questionnaire, basic patient characteristics and respiratory tests available depending on clinical setting, to predict SAD in asthma.

Methods

This study was based on the data of the multinational ATLANTIS (Assessment of Small Airways Involvement in Asthma) study including the earlier developed SADT questionnaire. Key SADT-items together with clinical information was now used to build logistic regression models to predict SAD group (less likely or more likely to have SAD). Diagnostic ability of the models was expressed as area under the receiver operating characteristic curve (AUC) and positive likelihood ratios (LR+).

Results

SADT-item 8, “I sometimes wheeze when I am sitting or lying quietly”, and the patient characteristics age, age at asthma diagnosis and BMI could reasonably well detect SAD (AUC:0.74, LR+:2.3). The diagnostic ability increased by adding spirometry (FEV1pp; AUC:0.87, LR+:5.0) and oscillometry (R5-R20 and AX; AUC:0.96, LR+:12.8).

Conclusion

If access to respiratory tests is limited (e.g.primary care in many countries), patients with SAD could reasonably well be identified by asking about wheezing at rest and a few patient characteristics. In (advanced) hospital settings patients with SAD could be identified with considerably higher accuracy using spirometry and oscillometry.

Wellness and Coping of Physicians Who Worked in ICUs During the Pandemic: A Multicenter Cross-Sectional North American Survey

OBJECTIVES

Few surveys have focused on physician moral distress, burnout, and professional fulfilment. We assessed physician wellness and coping during the COVID-19 pandemic.

DESIGN

Cross-sectional survey using four validated instruments.

SETTING

Sixty-two sites in Canada and the United States.

SUBJECTS

Attending physicians (adult, pediatric; intensivist, nonintensivist) who worked in North American ICUs.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

We analysed 431 questionnaires (43.3% response rate) from 25 states and eight provinces. Respondents were predominantly male (229 [55.6%]) and in practice for 11.8 ± 9.8 years. Compared with prepandemic, respondents reported significant intrapandemic increases in days worked/mo, ICU bed occupancy, and self-reported moral distress (240 [56.9%]) and burnout (259 [63.8%]). Of the 10 top-ranked items that incited moral distress, most pertained to regulatory/organizational ( n = 6) or local/institutional ( n = 2) issues or both ( n = 2). Average moral distress (95.6 ± 66.9), professional fulfilment (6.5 ± 2.1), and burnout scores (3.6 ± 2.0) were moderate with 227 physicians (54.6%) meeting burnout criteria. A significant dose-response existed between COVID-19 patient volume and moral distress scores. Physicians who worked more days/mo and more scheduled in-house nightshifts, especially combined with more unscheduled in-house nightshifts, experienced significantly more moral distress. One in five physicians used at least one maladaptive coping strategy. We identified four coping profiles (active/social, avoidant, mixed/ambivalent, infrequent) that were associated with significant differences across all wellness measures.

CONCLUSIONS

Despite moderate intrapandemic moral distress and burnout, physicians experienced moderate professional fulfilment. However, one in five physicians used at least one maladaptive coping strategy. We highlight potentially modifiable factors at individual, institutional, and regulatory levels to enhance physician wellness.

Comparison of the antiarrhythmic potential of doxapram and its metabolite ketodoxaparam

Background

A few years ago, the TASK-1 channel has been established as a potential new target for the therapy of atrial fibrillation (AF). In the heart, TASK-1 is almost exclusively expressed in the atria and is significantly upregulated in AF patients. Therefore, it plays an important role in the shortening of the atrial action potential observed during AF, making TASK-1 a promising target for AF therapy. This could be proven in a porcine model of persistent AF in which an intravenous application of the TASK-1 inhibitor doxapram led to a termination of AF and the restoration of sinus rhythm (SR). Doxapram's metabolite ketodoxapam is described in the literature as being active with limited data available on its usage. Therefore, the effect of ketodoxapram on TASK-1 and its possible use in AF therapy still needs to be investigated.

Purpose

The purpose of the present study was to assess the potential of ketodoxapram in the termination of AF. Furthermore, a comparison between doxapram and ketodoxapram was performed based on electrophysiological and pharmacological data.

Methods

UPLC-MS/MS assays were developed and validated for the measurement of doxapram and ketodoxapram in porcine plasma and brain tissue. Using these assays, the pharmacokinetics of both substances, after intravenous injections of 1 mg/kg, were determined in pigs. Furthermore, brain and plasma concentrations were measured to assess brain-to-plasma ratios. A porcine AF model was used to estimate the antiarrhythmic potential. Electrophysiological properties were evaluated, using two-electrode voltage clamp experiment on Xenopus laevis oocytes which heterologously expressed atrial potassium channels, to calculate the effect of doxapram and ketodoxapram on channel function. Furthermore, whole-cell patch clamp measurements were performed on isolated human cardiomyocytes.

Results

Doxapram and ketodoxapram showed strong inhibitory effects on TASK-1 (IC50 1.0 μM and 0.8 μM) and TASK-3 (5.9 μM and 1.5 μM), but no significant effect on the other measured ion channels. The maximal inhibition on TASK-1 was 96%. The brain-to-plasma ratio for doxapram (0.58) was almost ten-fold higher than for ketodoxapram (0.065), hinting at a reduced crossing of the blood-brain barrier (BBB) for ketodoxapram. The terminal half-life (t1/2) of ketodoxapram (1.71 h) was longer and the maximal concentration (Cmax; 4,604 ng/ml) was higher than for doxapram (1.38 h; 1,780 ng/ml). In a porcine model of AF, ketodoxapram led to a significantly reduced AF burdens comparable to doxapram.

Conclusions

Doxapram and ketodoxapram both show strong inhibitory effects on TASK-1, making them good candidates for a TASK-1 based AF therapy. Ketodoxapram with its longer t1/2, reduced crossing of the BBB and higher Cmax points towards a possible superiority in the treatment of AF compared to doxapram. Studies in a porcine AF model showed promising results for the use of doxapram and ketodoxapram in AF therapy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Research Foundation

Dapagliflozin exhibits class I antiarrhythmic effects which suppress action potential formation in human atrial cardiomyocytes

Background

Recently, inhibitors of sodium-glucose transporter 2 (SGLT2i) were shown to have tremendous cardioprotective effects in patients with type 2 diabetes mellitus (T2DM) as well as heart failure (HF) patients, regardless of their glycemic status. Among other beneficial effects on cardiovascular outcome an antiarrhythmic effect of SGLT2i was indicated. In patients with T2DM therapy with SGLT2i was associated with a significantly reduced risk of atrial arrhythmias and sudden cardiac death. As sodium-glucose transporter 2 (SGLT2) is not expressed within the heart underlying molecular modes of action remain unclear. Therefore, investigating possible antiarrhythmic mechanisms is crucial to determine whether SGLT2i might be beneficial for all patients suffering from arrhythmias, regardless of other comorbidities.

Purpose

To assess antiarrhythmic effects of SGLT2i on a molecular and cellular level. Therefore, direct electrophysiological effects of dapagliflozin – the most advanced SGLT2i in clinical trials – on action potential (AP) formation in atrial cardiomyocytes (CM) was investigated.

Methods

Effects of dapagliflozin on human NaV1.5, heterologously expressed in Chinese hamster ovary (CHO) cells, was investigated using the patch-clamp method. Further, effects on voltage-gated sodium channels (NaV) were also measured in human atrial CM. Consequences of dapagliflozin treatment on AP formation were studied on isolated human and porcine atrial CM using the patch-clamp technique. APs were elicited in current-clamp mode by injection of brief current pulses.

Results

Dapagliflozin (100 μM) significantly decreased peak sodium currents in human atrial CM as well as CHO cells, expressing human NaV1.5 channel subunits. Additionally, half-activation potential of voltage-gated sodium channels was significantly increased after administration of dapagliflozin. Furthermore, dapagliflozin (100 μM) suppressed AP formation in CM isolated from human and porcine left and right atrial tissue. In human CM action potential amplitude (APA) was significantly reduced by 34.3%, while APA inhibition by dapagliflozin averaged out at 30.7% for porcine CM. In porcine CM action potential duration at 50% (APD50) and 90% repolarization (APD90) were also significantly reduced.

Conclusion

Dapagliflozin suppresses AP formation in human and porcine atrial CM by inhibiting voltage-gated sodium currents. Therefore, we suppose that dapagliflozin exhibits class I antiarrhythmic effects.

Funding Acknowledgement

Type of funding sources: None.

Evaluating the reversibility potential of atrial cardiomyopathy on a clinical and cellular level

Background

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with various remodelling processes of the electrical and structural properties of the atrium, collectively referred to as atrial cardiomyopathy. Because these remodelling processes contribute significantly to the high recurrence rates and chronification of AF, the exact time course of their development and their reversion potential need to be further characterized.

Purpose

To investigate the time course and reversibility of atrial cardiomyopathy on a clinical, cellular and molecular level.

Methods

A clinically relevant porcine large animal model was used to study the structural and functional implications of atrial cardiomyopathy after different periods of burst pacing-induced AF (2, 4 and 8 weeks) and after a recovery period, following electrical cardioversion. The pigs were clinically characterized at each time point by echocardiography, cardiac MRI, and electrophysiological studies. After extraction of the heart, action potentials (APs) and ionic currents were measured on isolated atrial cardiomyocytes (CM) using the patch-clamp technique.

Results

After 4 weeks of AF induction, APD90 of isolated atrial cardiomyocytes was attenuated by 26%. Extending the AF induction period to 8 weeks caused an even stronger APD90 reduction by one-third, compared to SR controls. Accompanying, the TASK-1 current density was strongly upregulated in AF pigs. Those observations were in line with significant changes of the right atrial effective refractory period (AERP). At baseline, AERPS1=400 ms yielded 186 ms, whereas it was reduced to 141 ms after eight weeks of AF. Addressing the reversibility of those changes, following cardioversion of AF and an 8 week long SR recovery period, AERP baseline values were almost restored. Likewise, APD90 shortening was partially reversed. Furthermore, indication of reversibility of AF-associated remodelling was also observed on a structural level. After eight weeks of AF induction, echocardiography revealed severe dilatation of both atria, whereas atrial diameters decreased significantly after restoration of SR.

Conclusion

Remodelling processes underlying atrial cardiomyopathy display a partial reversibility upon restoration and maintenance of SR.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DFG German Research Foundation

Atrial tattoos lines: a new method to terminate atrial fibrillation

Introduction

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting more than 4% of the world's population. Furthermore, the vulnerable substrate underlying atrial cardiomyopathy remains far from being understood. Atrial cardiomyopathy is a highly complex and heterogeneous disease that occurs in the context of various clinical backgrounds, which explains the heterogenous success of established atrial ablation strategies such as pulmonary vein isolation. Here we developed a new interventional method for the treatment of AF using a tattooing procedure of silver nanowires in the atria to create circular lines of increased conductivity to prevent irregular electrical propagation.

Purpose

In a translational study, we tested a newly developed interventional method to terminate AF by injecting lines of silver nanowires to increase tissue conductivity.

Methods

The developed tattoo method was tested in vivo using an established large animal AF model of the domestic pig. Pigs (n=10) with atrial fibrillation were either treated with right atrial tattoo lines using a transmural injection procedure of silver nanowires as closed lines in the atrium or got a sham treatment with saline injections. Over 21 days, AF was induced and monitored (AF burden) by an intracardiac dual-chamber device with a biofeedback induction algorithm. Initially and before final termination, conventional electrophysiological investigation and atrial 3D mapping, echocardiography and epicardial multi electrode array (MEA) measurements were performed. Following the 21 days observation period, the heart was extracted and freshly isolated atrial cardiomyocytes were subjected to cellular electrophysiological, molecular and histochemical characterization. Electrophysiological data was used for in silico modelling of arrhythmia termination and wave propagation. The study protocol was approved by the animal ethics committee.

Results

The AF burden was significantly reduced (AF burden &lt;10%) in the group treated with the new atrial tattoo line method compared to sham treated pigs. The bi-atrial diameters, quantified by echocardiography, were significantly smaller in the treatment group. Atrial refractory period was significantly shorter in the sham treated pigs. A significant increase of connexin 43 was observed in the injection area of silver nanowires in the myocardium. Measurements with MEA demonstrated increased conduction velocity by a factor of 1.5–2.0 in the areas of silver nanowire injections. Additionally, in silico modelling showed the termination of AF via the created conduction lines.

Conclusion

The newly developed interventional method of the creation of atrial lines with increased tissue conductivity using silver nanowires could successfully terminate AF in pigs. Perspectively, this new myocardial tattooing technique may be a promising treatment strategy for patients with complex atrial cardiomyopathies to terminate atrial arrhythmias.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Else Kröner Fresenius Foundation

Phenotypes of disease severity in a cohort of hospitalized COVID-19 patients: Results from the IMPACC study

BACKGROUND

Better understanding of the association between characteristics of patients hospitalized with coronavirus disease 2019 (COVID-19) and outcome is needed to further improve upon patient management.

METHODS

Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) is a prospective, observational study of 1164 patients from 20 hospitals across the United States. Disease severity was assessed using a 7-point ordinal scale based on degree of respiratory illness. Patients were prospectively surveyed for 1 year after discharge for post-acute sequalae of COVID-19 (PASC) through quarterly surveys. Demographics, comorbidities, radiographic findings, clinical laboratory values, SARS-CoV-2 PCR and serology were captured over a 28-day period. Multivariable logistic regression was performed.

FINDINGS

The median age was 59 years (interquartile range [IQR] 20); 711 (61%) were men; overall mortality was 14%, and 228 (20%) required invasive mechanical ventilation. Unsupervised clustering of ordinal score over time revealed distinct disease course trajectories. Risk factors associated with prolonged hospitalization or death by day 28 included age ≥ 65 years (odds ratio [OR], 2.01; 95% CI 1.28-3.17), Hispanic ethnicity (OR, 1.71; 95% CI 1.13-2.57), elevated baseline creatinine (OR 2.80; 95% CI 1.63- 4.80) or troponin (OR 1.89; 95% 1.03-3.47), baseline lymphopenia (OR 2.19; 95% CI 1.61-2.97), presence of infiltrate by chest imaging (OR 3.16; 95% CI 1.96-5.10), and high SARS-CoV2 viral load (OR 1.53; 95% CI 1.17-2.00). Fatal cases had the lowest ratio of SARS-CoV-2 antibody to viral load levels compared to other trajectories over time (p=0.001). 589 survivors (51%) completed at least one survey at follow-up with 305 (52%) having at least one symptom consistent with PASC, most commonly dyspnea (56% among symptomatic patients). Female sex was the only associated risk factor for PASC.

INTERPRETATION

Integration of PCR cycle threshold, and antibody values with demographics, comorbidities, and laboratory/radiographic findings identified risk factors for 28-day outcome severity, though only female sex was associated with PASC. Longitudinal clinical phenotyping offers important insights, and provides a framework for immunophenotyping for acute and long COVID-19.

FUNDING

NIH.

Small Peptide Derivatives Within the Carbohydrate Recognition Domain of SP-A2 Modulate Asthma Outcomes in Mouse Models and Human Cells

Surfactant Protein-A (SP-A) is an innate immune modulator that regulates a variety of pulmonary host defense functions. We have shown that SP-A is dysfunctional in asthma, which could be partly due to genetic heterogeneity. In mouse models and primary bronchial epithelial cells from asthmatic participants, we evaluated the functional significance of a particular single nucleotide polymorphism of SP-A2, which results in an amino acid substitution at position 223 from glutamine (Q) to lysine (K) within the carbohydrate recognition domain (CRD). We found that SP-A 223Q humanized mice had greater protection from inflammation and mucin production after IL-13 exposure as compared to SP-A-2 223K mice. Likewise, asthmatic participants with two copies the major 223Q allele demonstrated better lung function and asthma control as compared to asthmatic participants with two copies of the minor SP-A 223K allele. In primary bronchial epithelial cells from asthmatic participants, full-length recombinant SP-A 223Q was more effective at reducing IL-13-induced MUC5AC gene expression compared to SP-A 223K. Given this activity, we developed 10 and 20 amino acid peptides of SP-A2 spanning position 223Q. We show that the SP-A 223Q peptides reduce eosinophilic inflammation, mucin production and airways hyperresponsiveness in a house dust mite model of asthma, protect from lung function decline during an IL-13 challenge model in mice, and decrease IL-13-induced MUC5AC gene expression in primary airway epithelial cells from asthmatic participants. These results suggest that position 223 within the CRD of SP-A2 may modulate several outcomes relevant to asthma, and that short peptides of SP-A2 retain anti-inflammatory properties similar to that of the endogenous protein.

Tollip Inhibits IL-33 Release and Inflammation in Influenza A Virus-Infected Mouse Airways

Respiratory influenza A virus (IAV) infection continues to pose significant challenges in healthcare of human diseases including asthma. IAV infection in mice was shown to increase IL-33, a key cytokine in driving airway inflammation in asthma, but how IL-33 is regulated during viral infection remains unclear. We previously found that a genetic mutation in Toll-interacting protein (Tollip) was linked to less airway epithelial Tollip expression, increased neutrophil chemokines, and lower lung function in asthma patients. As Tollip is involved in maintaining mitochondrial function, and mitochondrial stress may contribute to extracellular ATP release and IL-33 secretion, we hypothesized that Tollip downregulates IL-33 secretion via inhibiting ATP release during IAV infection. Wild-type and Tollip knockout (KO) mice were infected with IAV and treated with either an ATP converter apyrase or an IL-33 decoy receptor soluble ST2 (sST2). KO mice significantly lost more body weight and had increased extracellular ATP, IL-33 release, and neutrophilic inflammation. Apyrase treatment reduced extracellular ATP levels, IL-33 release, and neutrophilic inflammation in Tollip KO mice. Excessive lung neutrophilic inflammation in IAV-infected Tollip KO mice was reduced by sST2, which was coupled with less IL-33 release. Our data suggest that Tollip inhibits IAV infection, potentially by inhibiting extracellular ATP release and reducing IL-33 activation and lung inflammation. In addition, sST2 may serve as a potential therapeutic approach to mitigate respiratory viral infection in human subjects with Tollip deficiency.

The COVID-19 viral 3a protein forms a potassium channel that can be inhibited by antiarrhythmic drugs

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Deutsche Gesellschaft für Kardiologie /German Cardiac Society Joachim Herz Stiftung /Joachim Herz Foundation

Background/Introduction

Supraventricular and ventricular arrhythmias can often be observed in patients with COVID-19 infection. Both, the clinically observed increase in cardiac biomarkers as well as histological studies indicate virus replication within cardiomyocytes. The 3a open reading frame of the viral genome encodes for a transmembrane protein that is transported to the cell membrane where it can serve as a potassium channel.

Purpose

The aim of this study was to investigate whether COVID-19 infected induced pluripotent stem cell (iPSC)-derived cardiomyocytes also express the 3a protein and whether the potassium currents that are conducted through the 3a protein can be inhibited by clinically used antiarrhythmic drugs.

Methods and Results

iPSC-derived cardiomyocytes were infected with COVID-19 and subsequently subjected to immunoblotting, where expression of the 3a protein could be observed. Plasmid DNA, encoding the COVID-19 3a protein, was generated by gene synthesis and used for in vitro transcription of cRNA. 3–5 days after intracytoplasmic injection of the 3a protein cRNA into Xenopus laevis oocytes, potassium currents could be measured by two-electrode voltage clamp recordings. While class I and class IV antiarrhythmic drugs showed only minor effects on the potassium currents of the 3a protein, a robust inhibition by several beta-blockers and by class III antiarrhythmic drugs could be observed. The strongest effects were found with dofetilide (58.1 % inhibition at 100 µM) and amiodarone (50.1 % inhibition at 100 µM, IC50 level 4.7 µM). An in silico docking analysis, based on the recently revealed crystal structure of the 3a protein, identified the amino acid residues K61 and D142 as part of the binding site of amiodarone. After deactivation of these amino acid residues by site-directed mutagenesis, the inhibition by amiodarone was significantly attenuated.

Conclusion

The COVID-19 viral 3a protein is expressed in COVID-19-infected iPS-derived cardiomyocytes and forms a potassium channel that can be inhibited by antiarrhythmic drugs.

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

The Precision Interventions for Severe and/or Exacerbation-Prone (PrecISE) Asthma Network: An overview of Network organization, procedures, and interventions

Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. A current challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.

Evaluation of sputum eosinophil count as a predictor of treatment response to mepolizumab

For patients with asthma, eosinophilic airway inflammation is associated with poor lung function, increased disease severity, reduced quality of life and increased risk of exacerbations [1, 2]. As such, several biologic therapies targeting cytokines involved in eosinophil survival and activation have been developed, with the aim of reducing eosinophilic inflammation [3]. The response to these cytokine-targeting biologics has typically been assessed by monitoring clinical outcomes. Reductions in blood eosinophils have also been monitored [2], since these cells are easily accessible and are reflective of eosinophilic airway inflammation [4, 5]. However, the utility of sputum eosinophils as a biomarker for assessing the therapeutic response to biologic therapies remains an area of ongoing scientific debate and has been largely unexplored, owing to logistical challenges associated with their collection and measurement.

In patients with severe eosinophilic asthma and sputum eosinophil counts of ≥3–<30%, sputum eosinophils may not represent a more useful biomarker than blood eosinophils for predicting clinical treatment response to mepolizumabhttps://bit.ly/3pOTw93

Tollip interaction with STAT3: a novel mechanism to regulate human airway epithelial responses to type 2 cytokines

BACKGROUND

Toll-interacting protein (Tollip) is one of the key negative regulators in host innate immunity. Genetic variation of Tollip has been associated with less Tollip expression and poor lung function in asthmatic patients, but little is known about the role of Tollip in human airway type 2 inflammatory response, a prominent feature in allergic asthma.

OBJECTIVE

Our goal was to determine the role and underlying mechanisms of Tollip in human airway epithelial responses such as eotaxin to type 2 cytokine IL-13.

METHODS

Tollip deficient primary human airway epithelial cells from 4 healthy donors were generated by the gene knockdown approach and stimulated with IL-13 to measure activation of transcription factor STAT3, and eotaxin-3, an eosinophilic chemokine.

RESULTS

Following IL-13 treatment, Tollip deficient cells had significantly higher levels of STAT3 activation and eotaxin-3 than the scrambled control counterpart, which was reduced by a STAT3 inhibitor. Interaction between Tollip and STAT3 proteins was identified by co-immunoprecipitation.

CONCLUSION

Our results, for the first time, suggest that Tollip inhibits excessive eotaxin-3 induction by IL-13, in part through the interaction and inhibition of STAT3. These findings lend evidence to the potential of a STAT3 inhibitor as a therapeutic target, especially for type 2 inflammation-high asthmatics with Tollip deficiency.

The OM-85 bacterial lysate inhibits SARS-CoV-2 infection of epithelial cells by downregulating SARS-CoV-2 receptor expression

Background

Treatments for coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), are urgently needed but remain limited. SARS-CoV-2 infects cells through interactions of its spike (S) protein with angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) on host cells. Multiple cells and organs are targeted, particularly airway epithelial cells. OM-85, a standardized lysate of human airway bacteria with strong immunomodulating properties and an impeccable safety profile, is widely used to prevent recurrent respiratory infections. We found that airway OM-85 administration inhibits Ace2 and Tmprss2 transcription in the mouse lung, suggesting that OM-85 might hinder SARS-CoV-2/host cell interactions.

Objectives

We sought to investigate whether and how OM-85 treatment protects nonhuman primate and human epithelial cells against SARS-CoV-2.

Methods

ACE2 and TMPRSS2 mRNA and protein expression, cell binding of SARS-CoV-2 S1 protein, cell entry of SARS-CoV-2 S protein–pseudotyped lentiviral particles, and SARS-CoV-2 cell infection were measured in kidney, lung, and intestinal epithelial cell lines, primary human bronchial epithelial cells, and ACE2-transfected HEK293T cells treated with OM-85 in vitro.

Results

OM-85 significantly downregulated ACE2 and TMPRSS2 transcription and surface ACE2 protein expression in epithelial cell lines and primary bronchial epithelial cells. OM-85 also strongly inhibited SARS-CoV-2 S1 protein binding to, SARS-CoV-2 S protein–pseudotyped lentivirus entry into, and SARS-CoV-2 infection of epithelial cells. These effects of OM-85 appeared to depend on SARS-CoV-2 receptor downregulation.

Conclusions

OM-85 inhibits SARS-CoV-2 epithelial cell infection in vitro by downregulating SARS-CoV-2 receptor expression. Further studies are warranted to assess whether OM-85 may prevent and/or reduce the severity of coronavirus disease 2019.

Myeloid-associated differentiation marker is a novel SP-A-associated transmembrane protein whose expression on airway epithelial cells correlates with asthma severity

Surfactant protein A (SP-A) is well-known for its protective role in pulmonary immunity. Previous studies from our group have shown that SP-A mediates eosinophil activities, including degranulation and apoptosis. In order to identify potential binding partners on eosinophils for SP-A, eosinophil lysates were subjected to SP-A pull-down and tandem mass spectrometry (MS/MS) analysis. We identified one membrane-bound protein, myeloid-associated differentiation marker (MYADM), as a candidate SP-A binding partner. Blocking MYADM on mouse and human eosinophils ex vivo prevented SP-A from inducing apoptosis; blocking MYADM in vivo led to increased persistence of eosinophilia and airway hyper-responsiveness in an ovalbumin (OVA) allergy model and increased airways resistance and mucus production in a house dust mite (HDM) asthma model. Examination of a subset of participants in the Severe Asthma Research Program (SARP) cohort revealed a significant association between epithelial expression of MYADM in asthma patients and parameters of airway inflammation, including: peripheral blood eosinophilia, exhaled nitric oxide (FeNO) and the number of exacerbations in the past 12 months. Taken together, our studies provide the first evidence of MYADM as a novel SP-A-associated protein that is necessary for SP-A to induce eosinophil apoptosis and we bring to light the potential importance of this previously unrecognized transmembrane protein in patients with asthma.

Pharmacogenetic studies of long-acting beta agonist and inhaled corticosteroid responsiveness in randomised controlled trials of individuals of African descent with asthma

BACKGROUND

Pharmacogenetic studies in asthma cohorts, primarily made up of White people of European descent, have identified loci associated with response to inhaled beta agonists and corticosteroids (ICSs). Differences exist in how individuals from different ancestral backgrounds respond to long-acting beta agonist (LABA) and ICSs. Therefore, we sought to understand the pharmacogenetic mechanisms regulating therapeutic responsiveness in individuals of African descent.

METHODS

We did ancestry-based pharmacogenetic studies of children (aged 5-11 years) and adolescents and adults (aged 12-69 years) from the Best African Response to Drug (BARD) trials, in which participants with asthma uncontrolled with low-dose ICS (fluticasone propionate 50 μg in children, 100 μg in adolescents and adults) received different step-up combination therapies. The hierarchal composite outcome of pairwise superior responsiveness in BARD was based on asthma exacerbations, a 31-day difference in annualised asthma-control days, or a 5% difference in percentage predicted FEV₁. We did whole-genome admixture mapping of 15 159 ancestral segments within 312 independent regions, stratified by the two age groups. The two co-primary outcome comparisons were the step up from low-dose ICS to the quintuple dose of ICS (5 × ICS: 250 μg twice daily in children and 500 μg twice daily in adolescents and adults) versus double dose (2-2·5 × ICS: 100 μg twice daily in children, 250 μg twice daily in adolescents and adults), and 5 × ICS versus 100 μg fluticasone plus a LABA (salmeterol 50 μg twice daily). We used a genome-wide significance threshold of p<1·6 × 10^-4, and tested for replication using independent cohorts of individuals of African descent with asthma.

FINDINGS

We included 249 unrelated children and 267 unrelated adolescents and adults in the BARD pharmacogenetic analysis. In children, we identified a significant admixture mapping peak for superior responsiveness to 5 × ICS versus 100 μg fluticasone plus salmeterol on chromosome 12 (odds ratio [OR_{local African}] 3·95, 95% CI 2·02-7·72, p=6·1 × 10^-5) fine mapped to a locus adjacent to RNFT2 and NOS1 (rs73399224, OR_{allele dose} 0·17, 95% CI 0·07-0·42, p=8·4 × 10^-5). In adolescents and adults, we identified a peak for superior responsiveness to 5 × ICS versus 2·5 × ICS on chromosome 22 (OR_{local African} 3·35, 1·98-5·67, p=6·8 × 10^-6) containing a locus adjacent to TPST2 (rs5752429, OR_{allele dose} 0·21, 0·09-0·52, p=5·7 × 10^-4). We replicated rs5752429 and nominally replicated rs73399224 in independent African American cohorts.

INTERPRETATION

BARD is the first genome-wide pharmacogenetic study of LABA and ICS response in clinical trials of individuals of African descent to detect and replicate genome-wide significant loci. Admixture mapping of the composite BARD trial outcome enabled the identification of novel pharmacogenetic variation accounting for differential therapeutic responses in people of African descent with asthma.

FUNDING

National Institutes of Health, National Heart, Lung, and Blood Institute.

Paradoxical effects of cigarette smoke and COPD on SARS-CoV-2 infection and disease

BACKGROUND

How cigarette smoke (CS) and chronic obstructive pulmonary disease (COPD) affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection and severity is controversial. We investigated the effects of COPD and CS on the expression of SARS-CoV-2 entry receptor ACE2 in vivo in COPD patients and controls and in CS-exposed mice, and the effects of CS on SARS-CoV-2 infection in human bronchial epithelial cells in vitro.

METHODS

We quantified: (1) pulmonary ACE2 protein levels by immunostaining and ELISA, and both ACE2 and/or TMPRSS2 mRNA levels by RT-qPCR in two independent human cohorts; and (2) pulmonary ACE2 protein levels by immunostaining and ELISA in C57BL/6 WT mice exposed to air or CS for up to 6 months. The effects of CS exposure on SARS-CoV-2 infection were evaluated after in vitro infection of Calu-3 cells and differentiated human bronchial epithelial cells (HBECs), respectively.

RESULTS

ACE2 protein and mRNA levels were decreased in peripheral airways from COPD patients versus controls but similar in central airways. Mice exposed to CS had decreased ACE2 protein levels in their bronchial and alveolar epithelia versus air-exposed mice. CS treatment decreased viral replication in Calu-3 cells, as determined by immunofluorescence staining for replicative double-stranded RNA (dsRNA) and western blot for viral N protein. Acute CS exposure decreased in vitro SARS-CoV-2 replication in HBECs, as determined by plaque assay and RT-qPCR.

CONCLUSIONS

ACE2 levels were decreased in both bronchial and alveolar epithelial cells from COPD patients versus controls, and from CS-exposed versus air-exposed mice. CS-pre-exposure potently inhibited SARS-CoV-2 replication in vitro. These findings urge to investigate further the controversial effects of CS and COPD on SARS-CoV-2 infection.

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

Patient characteristics, biomarkers, and exacerbation risk in severe, uncontrolled asthma

BACKGROUND

Greater precision in asthma exacerbation risk prediction may improve outcomes. We sought to identify clinical characteristics and biomarkers associated with elevated exacerbation risk in patients with severe, uncontrolled asthma.

METHODS

Data were pooled from seven similarly designed Phase II and III randomized controlled clinical trials of biologic therapies for the treatment of severe, uncontrolled asthma that enrolled comparable patient populations. Annualized asthma exacerbation rates (AAERs) for patients randomized to placebo were assessed by baseline clinical characteristics and by biomarker concentrations at baseline and over the study duration.

RESULTS

The AAER for the 2016 patients in the combined placebo group was 0.91 (95% CI 0.84‒0.98). Baseline characteristics associated with greater AAER were frequent or severe exacerbations within the prior 12 months, nasal polyposis, maintenance oral corticosteroid use, Asian race, and Asian or Western European region. AAER increased with baseline blood eosinophil counts and fractional exhaled nitric oxide (FeNO) concentration, with the greatest AAER occurring for patients with eosinophils ≥300 cells·μL^-1 and FeNO ≥50 ppb. No relationship was observed between baseline serum immunoglobulin E concentration and AAER. Combining type 2 inflammation criteria for eosinophils and FeNO had greater prognostic value than either biomarker alone. Persistent eosinophil and FeNO elevations throughout the study period were associated with greater AAER.

CONCLUSIONS

Exacerbation history, maintenance corticosteroid use, nasal polyposis, Asian race, geographic region, and elevations in blood eosinophil counts and FeNO concentrations (particularly when combined and/or persistently achieving type 2 inflammation criteria) were associated with increased exacerbation risk in patients with severe, uncontrolled asthma.

CC16 Binding to α4β1 Integrin Protects against Mycoplasma pneumoniae Infection

Rationale CC16 (club cell secretory protein) is a pneumoprotein produced predominantly by pulmonary club cells. Circulating CC16 is associated with protection from the inception and progression of the two most common obstructive lung diseases (asthma and chronic obstructive pulmonary disease). Objectives Although exact mechanisms remain elusive, studies consistently suggest a causal role of CC16 in mediating antiinflammatory and antioxidant functions in the lung. We sought to determine any novel receptor systems that could participate in CC16's role in obstructive lung diseases. Methods Protein alignment of CC16 across species led to the discovery of a highly conserved sequence of amino acids, leucine-valine-aspartic acid (LVD), a known integrin-binding motif. Recombinant CC16 was generated with and without the putative integrin-binding site. A Mycoplasma pneumoniae mouse model and a fluorescent cellular adhesion assay were used to determine the impact of the LVD site regarding CC16 function during live infection and on cellular adhesion during inflammatory conditions. Measurements and Main Results CC16 bound to integrin α₄β₁), also known as the adhesion molecule VLA-4 (very late antigen 4), dependent on the presence of the LVD integrin-binding motif. During infection, recombinant CC16 rescued lung function parameters both when administered to the lung and intravenously but only when the LVD integrin-binding site was intact; likewise, neutrophil recruitment during infection and leukocyte adhesion were both impacted by the loss of the LVD site. Conclusions We discovered a novel receptor for CC16, VLA-4, which has important mechanistic implications for the role of CC16 in circulation as well as in the lung compartment.

PrecISE: Precision Medicine in Severe Asthma: An adaptive platform trial with biomarker ascertainment

Severe asthma accounts for almost half the cost associated with asthma. Severe asthma is driven by heterogeneous molecular mechanisms. Conventional clinical trial design often lacks the power and efficiency to target subgroups with specific pathobiological mechanisms. Furthermore, the validation and approval of new asthma therapies is a lengthy process. A large proportion of that time is taken by clinical trials to validate asthma interventions. The National Institutes of Health Precision Medicine in Severe and/or Exacerbation Prone Asthma (PrecISE) program was established with the goal of designing and executing a trial that uses adaptive design techniques to rapidly evaluate novel interventions in biomarker-defined subgroups of severe asthma, while seeking to refine these biomarker subgroups, and to identify early markers of response to therapy. The novel trial design is an adaptive platform trial conducted under a single master protocol that incorporates precision medicine components. Furthermore, it includes innovative applications of futility analysis, cross-over design with use of shared placebo groups, and early futility analysis to permit more rapid identification of effective interventions. The development and rationale behind the study design are described. The interventions chosen for the initial investigation and the criteria used to identify these interventions are enumerated. The biomarker-based adaptive design and analytic scheme are detailed as well as special considerations involved in the final trial design.