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MicroRNAs (miRNAs) exert powerful effects on immunological function by tuning networks of target genes that orchestrate cell activity. We sought to identify miRNAs and miRNA-regulated pathways that control the type 2 helper T cell (T H 2 cell) responses th

Rationale: T-helper type 2 (Th2) inflammation, mediated by IL-4, IL-5, and IL-13, is considered the central molecular mechanism underlying asthma, and Th2 cytokines are emerging therapeutic targets. However, clinical studies increasingly suggest that asthma is heterogeneous.Objectives: To determine whether this clinical heterogeneity reflects heterogeneity in underlying molecular mechanisms related to Th2 inflammation.Methods: Using microarray and polymerase chain reaction analyses of airway epithelial brushings from 42 patients with mild-to-moderate asthma and 28 healthy control subjects, we classified subjects with asthma based on high or low expression of IL-13-inducible genes. We then validated this classification and investigated its clinical implications through analyses of cytokine expression in bronchial biopsies, markers of inflammation and remodeling, responsiveness to inhaled corticosteroids, and reproducibility on repeat examination.Measurements and Main Results: Gene expression analyses identified two evenly sized and distinct subgroups, "Th2-high" and "Th2-low" asthma (the latter indistinguishable from control subjects). These subgroups differed significantly in expression of IL-5 and IL-13 in bronchial biopsies and in airway hyperresponsiveness, serum IgE, blood and airway eosinophilia, subepithelial fibrosis, and airway mucin gene expression (all P < 0.03). The lung function improvements expected with inhaled corticosteroids were restricted to Th2-high asthma, and Th2 markers were reproducible on repeat evaluation.Conclusions: Asthma can be divided into at least two distinct molecular phenotypes defined by degree of Th2 inflammation. Th2 cytokines are likely to be a relevant therapeutic target in only a subset of patients with asthma. Furthermore, current models do not adequately explain non-Th2-driven asthma, which represents a significant proportion of patients and responds poorly to current therapies. [ABSTRACT FROM AUTHOR]

Background: Tryptase, a mast cell protease, has been identified as a potential therapeutic target in managing patients with refractory asthma. We assessed the efficacy, safety, pharmacokinetics, and pharmacodynamics of MTPS9579A, an anti-tryptase antibody, in a phase 2a randomized trial for patients with uncontrolled asthma and a phase 1c trial to understand activity within the lower respiratory tract., Methods: Phase 2a patients (n = 134) received 1800 mg MTPS9579A or placebo intravenously every 4 weeks for 48 weeks. The primary endpoint was time to the first composite exacerbation event. Phase 1c patients (n = 27) received one intravenous dose of 300 or 1800 mg MTPS9579A or placebo. Both trials measured MTPS9579A concentrations and effects on tryptase in serum and nasal lining fluid; phase 1c also analyzed bronchial lining fluid., Results: MTPS9579A did not meet the primary endpoint (hazard ratio = 0.90; 95% CI: 0.55-1.47; p = 0.6835); exacerbation rates in the placebo group were low. Serum and nasal MTPS9579A pharmacokinetics and tryptase levels were consistent with data from healthy volunteers. However, in phase 1c patients, compared to nasal levels, MTPS9579A bronchial concentrations were 6.8-fold lower, and bronchial active and total tryptase levels were higher (119-fold and 30-fold, respectively). Pharmacokinetic/pharmacodynamic modeling predicted intravenous doses of 3800 mg every 4 weeks would be necessary to achieve 95% active tryptase inhibition from baseline., Conclusions: The MTPS9579A dose tested in the phase 2a study was insufficient to inhibit tryptase in bronchial lining fluid, likely contributing to the observed lack of efficacy., (© 2024 Genentech and The Author(s). Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: The effects of inhaled corticosteroids (ICS) on healthy airways are poorly defined., Objectives: To delineate the effects of ICS on gene expression in healthy airways, without confounding caused by changes in disease-related genes and disease-related alterations in ICS responsiveness., Methods: Randomized open-label bronchoscopy study of high-dose ICS therapy in 30 healthy adult volunteers randomized 2:1 to (i) fluticasone propionate 500 mcg bd daily or (ii) no treatment, for 4 weeks. Laboratory staff were blinded to allocation. Biopsies and brushings were analysed by immunohistochemistry, bulk RNA sequencing, DNA methylation array and metagenomics., Results: ICS induced small between-group differences in blood and lamina propria eosinophil numbers, but not in other immunopathological features, blood neutrophils, FeNO, FEV 1 , microbiome or DNA methylation. ICS treatment upregulated 72 genes in brushings and 53 genes in biopsies, and downregulated 82 genes in brushings and 416 genes in biopsies. The most downregulated genes in both tissues were canonical markers of type-2 inflammation (FCER1A, CPA3, IL33, CLEC10A, SERPINB10 and CCR5), T cell-mediated adaptive immunity (TARP, TRBC1, TRBC2, PTPN22, TRAC, CD2, CD8A, HLA-DQB2, CD96, PTPN7), B-cell immunity (CD20, immunoglobulin heavy and light chains) and innate immunity, including CD48, Hobit, RANTES, Langerin and GFI1. An IL-17-dependent gene signature was not upregulated by ICS., Conclusions: In healthy airways, 4-week ICS exposure reduces gene expression related to both innate and adaptive immunity, and reduces markers of type-2 inflammation. This implies that homeostasis in health involves tonic type-2 signalling in the airway mucosa, which is exquisitely sensitive to ICS., (© 2024 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

The role of alternative splicing in chronic obstructive pulmonary disease (COPD) is still largely unknown. We aimed to investigate the differences in alternatively splicing events between patients with mild-to-moderate and severe COPD compared with non-COPD control subjects and to identify splicing factors associated with aberrant alternative splicing in COPD. For this purpose, we performed genome-wide RNA-sequencing analysis of bronchial brushings from 23 patients with mild-to-moderate COPD, 121 with severe COPD, and 23 non-COPD control subjects. We found a significant difference in the frequency of alternative splicing events in patients with mild-to-moderate and severe COPD compared with non-COPD control subjects. There were from two to eight times (depending on event type) more differential alternative splicing events in the severe than in the mild-to-moderate stage. The severe COPD samples showed less intron retention and more exon skipping. It is interesting that the transcript levels of the top 10 differentially expressed splicing factors were significantly correlated with the percentage of many alternatively spliced transcripts in severe COPD. The aberrant alternative splicing in severe COPD was predicted to increase the overall protein-coding capacity of gene products. In conclusion, we observed large and significant differences in alternative splicing between bronchial samples of patients with COPD and control subjects, with more events observed in severe than in mild-to-moderate COPD. The changes in the expression of several splicing factors correlated with prevalence of alternative splicing in severe COPD. Alternative splicing can indirectly impact gene expression by changing the relative abundance of protein-coding isoforms potentially influencing pathophysiological changes. The results provide a better understanding of COPD-related alternative splicing changes.

Tryptase, the most abundant mast cell granule protein, is elevated in severe asthma patients independent of type 2 inflammation status. Higher active β tryptase allele counts are associated with higher levels of peripheral tryptase and lower clinical benefit from anti-IgE therapies. Tryptase is a therapeutic target of interest in severe asthma and chronic spontaneous urticaria. Active and inactive allele counts may enable stratification to assess response to therapies in asthmatic patient subpopulations. Tryptase gene loci TPSAB1 and TPSB2 have high levels of sequence identity, which makes genotyping a challenging task. Here, we report a targeted next-generation sequencing (NGS) assay and downstream bioinformatics analysis for determining polymorphisms at tryptase TPSAB1 and TPSB2 loci. Machine learning modeling using multiple polymorphisms in the tryptase loci was used to improve the accuracy of genotyping calls. The assay was tested and qualified on DNA extracted from whole blood of healthy donors and asthma patients, achieving accuracy of 96%, 96% and 94% for estimation of inactive α and βΙΙΙFS tryptase alleles and α duplication on TPSAB1, respectively. The reported NGS assay is a cost-effective method that is more efficient than Sanger sequencing and provides coverage to evaluate known as well as unreported tryptase polymorphisms., Competing Interests: At the time of the study, all authors were employees of Roche. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: A subset of COPD patients develops advanced disease with severe airflow obstruction, hyperinflation and extensive emphysema. We propose that the pathogenesis in these patients differs from mild-moderate COPD and is reflected by bronchial gene expression. The aim of the present study was to identify a unique bronchial epithelial gene signature for severe COPD patients., Methods: We obtained RNA sequencing data from bronchial brushes from 123 ex-smokers with severe COPD, 23 with mild-moderate COPD and 23 non-COPD controls. We identified genes specific to severe COPD by comparing severe COPD to non-COPD controls, followed by removing genes that were also differentially expressed between mild-moderate COPD and non-COPD controls. Next, we performed a pathway analysis on these genes and evaluated whether this signature is retained in matched nasal brushings., Results: We identified 219 genes uniquely differentially expressed in severe COPD. Interaction network analysis identified VEGFA and FN1 as the key genes with the most interactions. Genes were involved in extracellular matrix regulation, collagen binding and the immune response. Of interest were 10 genes ( VEGFA , DCN , SPARC , COL6A2 , MGP , CYR61 , ANXA6 , LGALS1 , C1QA and C1QB ) directly connected to fibronectin 1 ( FN1 ). Most of these genes were lower expressed in severe COPD and showed the same effect in nasal brushings., Conclusions: We found a unique severe COPD bronchial gene signature with key roles for VEGFA and FN1 , which was retained in the upper airways. This supports the hypothesis that severe COPD, at least partly, comprises a different pathology and supports the potential for biomarker development based on nasal brushes in COPD., Competing Interests: Conflict of interest: W. Timens declares consultancy payments to their institution from Merck Sharp & Dohme and Bristol Myers Squibb, in the 36 months prior to manuscript submission; as well as board membership of the Dutch Society of Pathology and membership of the Council for Research and Innovation of the Federation of Medical Specialists. Conflict of interest: D-J. Slebos declares grants or contracts to their institution from the following US companies in the 36 months prior to manuscript submission: PulmonX Corp., PneumRx/BTG/Boston Scientific, FreeFlowMedical, Nuvaira, PulmAir, GALA, CSA Medical and Apreo; consulting fees paid to their institution from PulmonX Corp., PneumRx/BTG/Boston Scientific, Nuvaira and Apreo; payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from PulmonX Corp, PneumRx/BTG/Boston Scientific and Nuvaira; support for attending meeting and/or travel from PulmonX Corp., PneumRx/BTG/Boston Scientific and Nuvaira; and receipt by their institution of study material/devices from PulmonX Corp., PneumRx/BTG/Boston Scientific, FreeFlowMedical, Nuvaira, PulmAir, GALA and CSA Medical, all in the 36 months prior to manuscript submission. Conflict of interest: D.F. Choy is an employee of Genentech, Inc., a member of the Roche Group, and is a co-inventor, as part of that employment, for pending patents related to the diagnosis and treatment of chronic respiratory diseases. They also hold stocks and/or options in Roche. Conflict of interest: A. Chakrabarti is an employee of Genentech, Inc., a member of the Roche Group. Conflict of interest: M. Grimbaldeston is an employee of Genentech, Inc., a member of the Roche Group, and has received stock options. Conflict of interest: C.M. Rosenberger is an employee of Genentech, Inc., a member of the Roche Group, and has received support for attending conferences from their employer. They hold stocks and stock options in Roche. Conflict of interest: C-A. Brandsma declares a research grant from Genentech, related to the current manuscript. Conflict of interest: M. van den Berge declares a research grant from Genentech, related to the current manuscript. Conflict of interest: All other authors declare no competing interests., (Copyright ©The authors 2023.)

Background: Patients with type-2 (T2) cytokine-low severe asthma often have persistent symptoms despite suppression of T2 inflammation with corticosteroids., Objectives: We sought to analyze whole blood transcriptome from 738 samples in T2-biomarker-high/-low patients with severe asthma to relate transcriptomic signatures to T2 biomarkers and asthma symptom scores., Methods: Bulk RNA-seq data were generated for blood samples (baseline, week 24, week 48) from 301 participants recruited to a randomized clinical trial of corticosteroid optimization in severe asthma. Unsupervised clustering, differential gene expression analysis, and pathway analysis were performed. Patients were grouped by T2-biomarker status and symptoms. Associations between clinical characteristics and differentially expressed genes (DEGs) associated with biomarker and symptom levels were investigated., Results: Unsupervised clustering identified 2 clusters; cluster 2 patients were blood eosinophil-low/symptom-high and more likely to be receiving oral corticosteroids (OCSs). Differential gene expression analysis of these clusters, with and without stratification for OCSs, identified 2960 and 4162 DEGs, respectively. Six hundred twenty-seven of 2960 genes remained after adjusting for OCSs by subtracting OCS signature genes. Pathway analysis identified dolichyl-diphosphooligosaccharide biosynthesis and assembly of RNA polymerase I complex as significantly enriched pathways. No stable DEGs were associated with high symptoms in T2-biomarker-low patients, but numerous associated with elevated T2 biomarkers, including 15 that were upregulated at all time points irrespective of symptom level., Conclusions: OCSs have a considerable effect on whole blood transcriptome. Differential gene expression analysis demonstrates a clear T2-biomarker transcriptomic signature, but no signature was found in association with T2-biomarker-low patients, including those with a high symptom burden., (Crown Copyright © 2023. Published by Elsevier Inc. All rights reserved.)

Altered myeloid inflammation and lymphopenia are hallmarks of severe infections. We identified the upregulated EN-RAGE gene program in airway and blood myeloid cells from patients with acute lung injury from SARS-CoV-2 or other causes across 7 cohorts. This program was associated with greater clinical severity and predicted future mechanical ventilation and death. EN-RAGE hi myeloid cells express features consistent with suppressor cell functionality, including low HLA-DR and high PD-L1. Sustained EN-RAGE program expression in airway and blood myeloid cells correlated with clinical severity and increasing expression of T cell dysfunction markers. IL-6 upregulated many EN-RAGE program genes in monocytes in vitro. IL-6 signaling blockade by tocilizumab in a placebo-controlled clinical trial led to rapid normalization of EN-RAGE and T cell gene expression. This identifies IL-6 as a key driver of myeloid dysregulation associated with worse clinical outcomes in COVID-19 patients and provides insights into shared pathophysiological mechanisms in non-COVID-19 ARDS., Competing Interests: J.A.H., H.S., J.V.H., C.O., L.O., X.G., N.W., A.Q., D.C., A.C, D.F.C., T.R., J.M.M., F.C., A.T., M.B., L.T., A.R., S.B.K., R.N.B., and C.M.R. were employees of Genentech, Inc. at the time of this study and own equity in Roche. The COMET study was supported in part by Genentech funding. C.J.Y. is a scientific advisory board member for and holds equity in Related Sciences and ImmunAI, a consultant for and holds equity in Maze Therapeutics, and a consultant for TRex Bio. C.J.Y. has received research support from Chan Zuckerberg Initiative, Chan Zuckerberg Biohub, and Genentech. C.S.C. has received research funding from Roche-Genentech for an unrelated project as well as from NIH, DOD, and Quantum Leap Healthcare Collaborative. C.S.C. is a consultant for Vasomune, Quark, and GEn1E Lifesciences. C.H. is a consultant for Spring Discovery but does not have any financial interest in the company nor is the work related to what is covered in this manuscript. A.R. is a co-founder and equity holder of Celsius Therapeutics, an equity holder in Immunitas Therapeutics and, until 31 July 2020, was a scientific advisory board member of Thermo Fisher Scientific, Syros Pharmaceuticals, Asimov, and Neogene Therapeutics. A.R. is a named inventor on multiple patents related to single-cell and spatial genomics filed by or issued to the Broad Institute., (© 2023 The Authors.)

Angiopoietin-2 (Ang-2) is associated with vascular endothelial injury and permeability in the acute respiratory distress syndrome (ARDS) and sepsis. Elevated circulating Ang-2 levels may identify critically ill patients with distinct pathobiology amenable to targeted therapy. We hypothesized that plasma Ang-2 measured shortly after hospitalization among patients with sepsis would be associated with the development of ARDS and poor clinical outcomes. To test this hypothesis, we measured plasma Ang-2 in a cohort of 757 patients with sepsis, including 267 with ARDS, enrolled in the emergency department or early in their ICU course before the COVID-19 pandemic. Multivariable models were used to test the association of Ang-2 with the development of ARDS and 30-day morality. We found that early plasma Ang-2 in sepsis was associated with higher baseline severity of illness, the development of ARDS, and mortality risk. The association between Ang-2 and mortality was strongest among patients with ARDS and sepsis as compared to those with sepsis alone (OR 1.81 vs. 1.52 per log Ang-2 increase). These findings might inform models testing patient risk prediction and strengthen the evidence for Ang-2 as an appealing biomarker for patient selection for novel therapeutic agents to target vascular injury in sepsis and ARDS., (© 2023. The Author(s).)

Background: Chronic spontaneous urticaria (CSU) is a dermatologic condition characterized by spontaneous, pruritic hives and/or angioedema that persists for 6 weeks or longer with no identifiable trigger. Antihistamines and second-line therapies such as omalizumab are effective for some CSU patients, but others remain symptomatic, with significant impact on quality of life. This variable response to treatment and autoantibody levels across patients highlight clinically heterogeneous subgroups., Objective: We aimed to highlight pathways involved in CSU by investigating the genetics of CSU risk and subgroups., Methods: We performed a genome-wide association study (GWAS) of 679 CSU patients and 4446 controls and a GWAS of chronic urticaria (CU)-index, which measures IgG autoantibodies levels, by comparing 447 CU index-low to 183 CU index-high patients. We also tested whether polygenic scores for autoimmune-related disorders were associated with CSU risk and CU index., Results: We identified 2 loci significantly associated with disease risk. The strongest association mapped to position 56 of HLA-DQA1 (P = 1.69 × 10 -9 ), where the arginine residue was associated with increased risk (odds ratio = 1.64). The second association signal colocalized with expression-quantitative trait loci for ITPKB in whole blood (P colocalization  = .997). The arginine residue at position 56 of HLA-DQA1 was also associated with increased risk of CU index-high (P = 6.15 × 10 -5 , odds ratio = 1.86), while the ITKPB association was not (P = .64). Polygenic scores for 3 autoimmune-related disorders (hypothyroidism, type 1 diabetes, and vitiligo) were associated with CSU risk and CU index (P < 2.34 × 10 -3 , odds ratio > 1.72)., Conclusion: A GWAS of CSU identified 2 genome-wide significant loci, highlighting the shared genetics between CU index and autoimmune disorders., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Approximately 5% to 10% of patients with asthma have severe disease, with a consistent preponderance in females. Current asthma guidelines recommend stepwise treatment to achieve symptom control with no differential treatment considerations for either sex., Objective: To examine whether patient sex affects outcomes when using a composite T2-biomarker score to adjust corticosteroid (CS) treatment in patients with severe asthma compared with standard care., Methods: This is a post hoc analysis, stratifying patient outcomes by sex, of a 48-week, multicenter, randomized controlled clinical trial comparing a biomarker-defined treatment algorithm with standard care. The primary outcome was the proportion of patients with a reduction in CS treatment (inhaled and oral corticosteroids). Secondary outcomes included exacerbation rates, hospital admissions, and lung function., Results: Of the 301 patients randomized, 194 (64.5%) were females and 107 (35.5%) were males. The biomarker algorithm led to a greater proportion of females being on a lower CS dose versus standard care, which was not seen in males (effect estimate: females, 3.57; 95% CI, 1.14-11.18 vs males, 0.54; 95% CI, 0.16-1.80). In T2-biomarker-low females, reducing CS dose was not associated with increased exacerbations. Females scored higher in all domains of the 7-item Asthma Control Questionnaire, apart from FEV1, but with no difference when adjusted for body mass index/anxiety and/or depression. Dissociation between symptoms and T2 biomarkers were noted in both sexes, with a higher proportion of females being symptom high/T2-biomarker low (22.8% vs 15.6%; P = .0002), whereas males were symptom low/T2-biomarker high (22.3% vs 11.4%; P < .0001)., Conclusions: This exploratory post hoc analysis identified that females achieved a greater benefit from biomarker-directed CS optimization versus symptom-directed treatment., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP) are alarmins that are released upon airway epithelial injury from insults such as viruses and cigarette smoke, and play critical roles in the activation of immune cell populations such as mast cells, eosinophils and group 2 innate lymphoid cells. Both cytokines were previously understood to primarily drive type 2 (T2) inflammation, but there is emerging evidence for a role for these alarmins to additionally mediate non-T2 inflammation, with recent clinical trial data in asthma and COPD cohorts with non-T2 inflammation providing support. Currently available treatments for both COPD and asthma provide symptomatic relief with disease control, improving lung function and reducing exacerbation rates; however, there still remains an unmet need for further improving lung function and reducing exacerbations, particularly for those not responsive to currently available treatments. The epithelial cytokines/alarmins are involved in exacerbations; biologics targeting TSLP and IL-33 have been shown to reduce exacerbations in moderate-to-severe asthma, either in a broad population or in specific subgroups, respectively. For COPD, while there is clinical evidence for IL-33 blockade impacting exacerbations in COPD, clinical data from anti-TSLP therapies is awaited. Clinical data to date support an acceptable safety profile for patients with airway diseases for both anti-IL-33 and anti-TSLP antibodies in development. We examine the roles of IL-33 and TSLP, their potential use as drug targets, and the evidence for target patient populations for COPD and asthma, together with ongoing and future trials focused on these targets., Competing Interests: Conflict of interest: A.A. Calderon has nothing to declare. C. Dimond, D.F. Choy, R. Pappu, M.A. Grimbaldeston and D. Mohan are employees of Genentech, Inc., a member of the Roche group, and are Roche stockholders. D.F. Choy and M.A. Grimbaldeston are co-inventors on patents that have been filed or are pending relating to the diagnosis and treatment of chronic respiratory diseases for Genentech, Inc. D. Mohan was previously an employee and shareholder of GSK. K.F. Chung received personal payments for service on an advisory board for Roche, Merck, Rickett-Beckinson and Shinogi, data safety monitoring board for Nocion, and for speaking engagements from Novartis and AstraZeneca; and received the MRC, EPSRC, and GSK grants for his institution., (Copyright ©The authors 2023.)

Background: The binding of IL-33 to its receptor ST2 (alias of IL1RL1) leads to the release of inflammatory mediators and may play a role in the pathogenesis of atopic dermatitis. Astegolimab is a fully human, IgG 2 mAb that binds to ST2 and inhibits IL-33 signaling., Objectives: This study sought to assess the efficacy, safety, and pharmacokinetics of astegolimab in patients with atopic dermatitis., Methods: This was a randomized, placebo-controlled, phase 2 study in which adults with chronic atopic dermatitis were randomized 1:1 to receive astegolimab 490 mg every 4 weeks or placebo, for 16 weeks. The primary outcome was the percentage of change from baseline to week 16 of the Eczema Area and Severity Index score., Results: A total of 65 patients were enrolled in the study (placebo, n = 32; astegolimab, n = 33). The adjusted mean percentage of change from baseline to week 16 in the Eczema Area and Severity Index score was -51.47% for astegolimab compared with -58.24% for placebo, with a nonsignificant treatment difference of 6.77% (95% CI: -16.57-30.11; P = .5624). No differences were observed between treatment groups for secondary efficacy outcomes and in exploratory biomarkers (blood eosinophils, serum IL-5, serum CCL13). With the use of loading dose, pharmacokinetic exposure was sufficient from week 1. Astegolimab was well-tolerated, with a safety profile consistent with that observed in previous clinical trials., Conclusions: In patients with atopic dermatitis, astegolimab did not show a significant difference compared to placebo for the primary or secondary outcomes., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Clinical studies of type 2 (T2) cytokine-related neutralizing antibodies in asthma have identified a substantial subset of patients with low levels of T2 inflammation who do not benefit from T2 cytokine neutralizing antibody treatment. Non-T2 mechanisms are poorly understood in asthma but represent a redefined unmet medical need., Objective: We sought to gain a better understanding of genetic contributions to T2-low asthma., Methods: We utilized an unbiased genome-wide association study of patients with moderate to severe asthma stratified by T2 serum biomarker periostin. We also performed additional expression and biological analysis for the top genetic hits., Results: We identified a novel protective single nucleotide polymorphism at chr19q13.41, which is selectively associated with T2-low asthma and establishes Kallikrein-related peptidase 5 (KLK5) as the causal gene mediating this association. Heterozygous carriers of the single nucleotide polymorphisms have reduced KLK5 expression. KLK5 is secreted by human bronchial epithelial cells and elevated in asthma bronchial alveolar lavage. T2 cytokines IL-4 and IL-13 downregulate KLK5 in human bronchial epithelial cells. KLK5, dependent on its catalytic function, induces epithelial chemokine/cytokine expression. Finally, overexpression of KLK5 in airway or lack of an endogenous KLK5 inhibitor, SPINK5, leads to spontaneous airway neutrophilic inflammation., Conclusion: Our data identify KLK5 to be the causal gene at a novel locus at chr19q13.41 associated with T2-low asthma., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The most recognizable phenotype of severe asthma comprises people who are blood eosinophil and FeNO-high, driven by type 2 (T2) cytokine biology, which responds to targeted biological therapies. However, in many people with severe asthma, these T2 biomarkers are suppressed but poorly controlled asthma persists. The mechanisms driving asthma in the absence of T2 biology are poorly understood., Objectives: To explore airway pathology in T2 biomarker-high and -low severe asthma., Methods: T2 biomarker-high severe asthma (T2-high, n = 17) was compared with biomarker-intermediate (T2-intermediate, n = 21) and biomarker-low (T2-low, n = 20) severe asthma and healthy controls (n = 28). Bronchoscopy samples were processed for immunohistochemistry, and sputum for cytokines, PGD 2 and LTE 4 measurements., Results: Tissue eosinophil, neutrophil and mast cell counts were similar across severe asthma phenotypes and not increased when compared to healthy controls. In contrast, the remodelling features of airway smooth muscle mass and MUC5AC expression were increased in all asthma groups compared with health, but similar across asthma subgroups. Submucosal glands were increased in T2-intermediate and T2-low asthma. In spite of similar tissue cellular inflammation, sputum IL-4, IL-5 and CCL26 were increased in T2-high versus T2-low asthma, and several further T2-associated cytokines, PGD 2 and LTE 4 , were increased in T2-high and T2-intermediate asthma compared with healthy controls., Conclusions: Eosinophilic tissue inflammation within proximal airways is suppressed in T2 biomarker-high and T2-low severe asthma, but inflammatory and structural cell activation is present, with sputum T2-associated cytokines highest in T2 biomarker-high patients. Airway remodelling persists and may be important for residual disease expression beyond eosinophilic exacerbations. Registered at ClincialTrials.gov: NCT02883530., (© 2022 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Asthma is a complex, heterogeneous disease with a high unmet medical need, despite therapies targeting a multitude of pathways. The ability to quantitatively integrate preclinical and clinical data on these pathways could aid in the development and testing of novel targets and therapeutics. In this work, we develop a computational model of asthma biology, including key cell types and mediators, and create a virtual population capturing clinical heterogeneity. The simulated responses to therapies targeting IL-13, IL-4Rα, IL-5, IgE, and TSLP demonstrate agreement with clinical endpoints and biomarkers of type 2 (T2) inflammation, including blood eosinophils, FEV1, IgE, and FeNO. We use the model to explore the potential benefit of targeting the IL-33 pathway with anti-IL-33 and anti-ST2. Model predictions are compared with data on blood eosinophils, FeNO, and FEV1 from recent anti-IL-33 and anti-ST2 trials and used to interpret trial results based on pathway biology and pharmacology. Results of sensitivity analyses on the contributions of IL-33 to the predicted biomarker changes suggest that anti-ST2 therapy reduces circulating blood eosinophil levels primarily through its impact on eosinophil progenitor maturation and IL-5-dependent survival, and induces changes in FeNO and FEV1 through its effect on immune cells involved in T2 cytokine production. Finally, we also investigate the impact of ST2 genetics on the conferred benefit of anti-ST2. The model includes representation of a wide array of biologic mechanisms and interventions that will provide mechanistic insight and support clinical program design for a wide range of novel therapies during drug development., (© 2022 Genentech Inc. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Rationale: The past 25 years have seen huge progress in understanding of the pathobiology of type-2 (T2) asthma, identification of measurable biomarkers, and the emergence of novel monoclonal antibody treatments. Although present in a minority of patients with severe asthma, very little is known about the mechanisms underlying T2-low asthma, making it a significant unmet need in asthma research. Objectives: The objective of this study was to explore the differences between study exacerbators and nonexacerbators, to describe physiological changes at exacerbation in those who are T2 HIGH and T2 LOW at the time of exacerbation, and to evaluate the stability of inflammatory phenotypes when stable and at exacerbation. Methods: Exacerbation assessment was a prespecified secondary analysis of data from a 48-week, multicenter, randomized controlled clinical study comparing the use of biomarkers and symptoms to adjust steroid treatment in a T2-low severe asthma-enriched cohort. Participants were phenotyped as T2 LOW (fractional exhaled nitric oxide ⩽ 20 ppb and blood eosinophil count ⩽ 150 cells/µl) or T2 HIGH (fractional exhaled nitric oxide > 20 or blood eosinophil count > 150) at study enrollment and at each exacerbation. Here, we report the findings of the exacerbation analyses, including comparison of exacerbators and nonexacerbators, the physiological changes at exacerbation in those who had evidence of T2 biology at exacerbation versus those that did not, and the stability of inflammatory phenotypes when stable and at exacerbation. Measurements and Main Results: Of the 301 participants, 60.8% (183) had one or more self-reported exacerbations (total of 390). Exacerbators were more likely to be female, have a higher body mass index, and have more exacerbations requiring oral corticosteroid and unscheduled primary care attendances for exacerbations. At enrollment, 23.6% (71) were T2 LOW and 76.4% (230) T2 HIGH . The T2 LOW group had more asthma primary care attendances, were more likely to have a previous admission to HDU (high dependency unit)/ICU and to be receiving maintenance oral corticosteroids. At exacerbation, the T2 LOW events were indistinguishable from T2 HIGH exacerbations in terms of lung function (mean fall in T2 LOW FEV 1, 200 [400] ml vs. T2 HIGH 200 [300] ml; P  = 0.93) and symptom increase (ACQ5: T2 LOW , 1.4 [0.8] vs. T2 HIGH , 1.3 [0.8]; P  = 0.72), with no increase in T2 biomarkers from stable to exacerbation state in the T2 LOW exacerbations. The inflammatory phenotype within individual patients was dynamic; inflammatory phenotype at study entry did not have a significant association with exacerbation phenotype. Conclusions: Asthma exacerbations demonstrating a T2 LOW phenotype were physiologically and symptomatically similar to T2 HIGH exacerbations. T2 LOW asthma was an unstable phenotype, suggesting that exacerbation phenotyping should occur at the time of exacerbation. The clinically significant exacerbations in participants without evidence of T2 biology at the time of exacerbation highlight the unmet and pressing need to further understand the mechanisms at play in non-T2 asthma. Clinical trial registered with www.clinicaltrials.gov (NCT02717689).

Background: Janus Kinases (JAKs) mediate activity of many asthma-relevant cytokines. GDC-0214, an inhaled small molecule JAK1 inhibitor, has previously been shown to reduce fractional exhaled nitric oxide (FeNO) in patients with mild asthma, but required an excessive number of inhalations., Aim: To assess whether GDC-4379, a new inhaled JAK inhibitor, reduces FeNO and peripheral biomarkers of inflammation., Methods: This study assessed the activity of GDC-4379 in a double-blind, randomized, placebo-controlled, Phase 1 study in patients with mild asthma. Participants included adults (18-65y) with a diagnosis of asthma for ≥6 months, forced expiratory volume in 1 s (FEV 1 )> 70% predicted, FeNO >40 ppb, using as-needed short-acting beta-agonist medication only. Four sequential, 14-day, ascending-dose cohorts (10 mg QD, 30 mg QD, 40 mg BID, and 80 mg QD) of 12 participants each were randomized 2:1 to GDC-4379 or placebo. The primary activity outcome was percent change from baseline (CFB) in FeNO to Day 14 compared to the pooled placebo group. Safety, tolerability, pharmacokinetics, and pharmacodynamic biomarkers, including blood eosinophils, serum CCL17, and serum CCL18, were also assessed., Results: Of 48 enrolled participants, the mean age was 25 years and 54% were female. Median (range) FeNO at baseline was 79 (41-222) ppb. GDC-4379 treatment led to dose-dependent reductions in FeNO. Compared to placebo, mean (95% CI) percent CFB in FeNO to Day 14 was: -6 (-43, 32) at 10 mg QD, -26 (-53, 2) at 30 mg QD, -55 (-78, -32) at 40 mg BID and -52 (-72, -32) at 80 mg QD. Dose-dependent reductions in blood eosinophils and serum CCL17 were also observed. Higher plasma drug concentrations corresponded with greater FeNO reductions. No serious AEs occurred. The majority of AEs were mild to moderate. The most common AEs were headache and oropharyngeal pain. Minor changes in neutrophils were noted at 80 mg QD, but were not considered clinically meaningful., Conclusions: In patients with mild asthma, 14-day treatment with GDC-4379 reduced FeNO levels and peripheral biomarkers of inflammation. Treatment was well tolerated without any major safety concerns., Australian New Zealand Clinical Trials Registry: ACTRN12619000227190., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous inflammatory airway disease. The epithelial-derived IL-33 and its receptor ST2 have been implicated in airway inflammation and infection. We aimed to determine whether astegolimab, a selective ST2 IgG2 monoclonal antibody, reduces exacerbations in COPD., Methods: COPD-ST2OP was a single-centre, randomised, double-blinded, placebo-controlled phase 2a trial in moderate-to-very severe COPD. Participants were randomly assigned (1:1) with a web-based system to received 490 mg subcutaneous astegolimab or subcutaneous placebo, every 4 weeks for 44 weeks. The primary endpoint was exacerbation rate assessed for 48 weeks assessed with a negative binomial count model in the intention-to-treat population, with prespecified subgroup analysis by baseline blood eosinophil count. The model was the number of exacerbations over the 48-week treatment period, with treatment group as a covariate. Safety was assessed in the whole study population until week 60. Secondary endpoints included Saint George's Respiratory Questionnaire for COPD (SGRQ-C), FEV 1 , and blood and sputum cell counts. The trial was registered with ClinicalTrials.gov, NCT03615040., Findings: The exacerbation rate at 48 weeks in the intention-to-treat analysis was not significantly different between the astegolimab group (2·18 [95% CI 1·59 to 2·78]) and the placebo group (2·81 [2·05 to 3·58]; rate ratio 0·78 [95% CI 0·53 to 1·14]; p=0·19]). In the prespecified analysis stratifying patients by blood eosinophil count, patients with 170 or fewer cells per μL had 0·69 exacerbations (0·39 to 1·21), whereas those with more than 170 cells per μL had 0·83 exacerbations (0·49 to 1·40). For the secondary outcomes, the mean difference between the SGRQ-C in the astegolimab group versus placebo group was -3·3 (95% CI -6·4 to -0·2; p=0·039), and mean difference in FEV 1 between the two groups was 40 mL (-10 to 90; p=0·094). The difference in geometric mean ratios between the two groups for blood eosinophil counts was 0·59 (95% CI 0·51 to 0·69; p<0·001) and 0·25 (0·19 to 0·33; p<0·001) for sputum eosinophil counts. Incidence of treatment-emergent adverse events was similar between groups., Interpretation: In patients with moderate-to-very severe COPD, astegolimab did not significantly reduce exacerbation rate, but did improve health status compared with placebo., Funding: Funded by Genentech and National Institute for Health Research Biomedical Research Centres., Competing Interests: Declaration of interests CEB reports funding from Genentech to support this study; grants from AstraZeneca, GlaxoSmithKline, Roche/Genentech, Boehringer Ingelheim, Novartis, Chiesi, Merck Sharp & Dohme, Sanofi, Regeneron, 4DPharma, and Mologic; and consulting fee paid to institution from AstraZeneca, GlaxoSmithKline, Roche/Genentech, Boehringer Ingelheim, Novartis, Chiesi, Merck Sharp & Dohme, Sanofi, Regeneron, and 4DPharma. NJG reports an investigator led grant from GlaxoSmithKline; National Institute for Health Research fellowship; and lecture honoraria from GlaxoSmithKline and Chiesi. AW reports a research grant from Sanofi Genzyme. CJ reports a Medical Research Council clinical research training fellowship. MAG, DFC, and DC are employed by Genentech and receive stock options. All other authors declare no competing interests., (Crown Copyright © 2022 Published by Elsevier Ltd. All rights reserved.)

Asthma and inflammatory airway diseases restrict airflow in the lung, compromising gas exchange and lung function. Inhaled corticosteroids (ICSs) can reduce inflammation, control symptoms, and improve lung function; however, a growing number of patients with severe asthma do not benefit from ICS. Using bronchial airway epithelial brushings from patients with severe asthma or primary human cells, we delineated a corticosteroid-driven fibroblast growth factor (FGF)-dependent inflammatory axis, with FGF-responsive fibroblasts promoting downstream granulocyte colony-stimulating factor (G-CSF) production, hyaluronan secretion, and neutrophilic inflammation. Allergen challenge studies in mice demonstrate that the ICS, fluticasone propionate, inhibited type 2-driven eosinophilia but induced a concomitant increase in FGFs, G-CSF, hyaluronan, and neutrophil infiltration. We developed a model of steroid-induced neutrophilic inflammation mediated, in part, by induction of an FGF-dependent epithelial-mesenchymal axis, which may explain why some individuals do not benefit from ICS. In further proof-of-concept experiments, we found that combination therapy with pan-FGF receptor inhibitors and corticosteroids prevented both eosinophilic and steroid-induced neutrophilic inflammation. Together, these results establish FGFs as therapeutic targets for severe asthma patients who do not benefit from ICS.

Genome-wide association studies (GWAS) have identified many common variant loci associated with asthma susceptibility, but few studies investigate the genetics underlying moderate-to-severe asthma risk. Here, we present a whole-genome sequencing study comparing 3181 moderate-to-severe asthma patients to 3590 non-asthma controls. We demonstrate that asthma risk is genetically correlated with lung function measures and that this component of asthma risk is orthogonal to the eosinophil genetics that also contribute to disease susceptibility. We find that polygenic scores for reduced lung function are associated with younger asthma age of onset. Genome-wide, seven previously reported common asthma variant loci and one previously reported lung function locus, near THSD4, reach significance. We replicate association of the lung function locus in a recently published GWAS of moderate-to-severe asthma patients. We additionally replicate the association of a previously reported rare (minor allele frequency < 1%) coding variant in IL33 and show significant enrichment of rare variant burden in genes from common variant allergic disease loci. Our findings highlight the contribution of lung function genetics to moderate-to-severe asthma risk, and provide initial rare variant support for associations with moderate-to-severe asthma risk at several candidate genes from common variant loci., (© 2022. The Author(s).)

Exacerbations of symptoms represent an unmet need for people with asthma. Bacterial dysbiosis and opportunistic bacterial infections have been observed in, and may contribute to, more severe asthma. However, the molecular mechanisms driving these exacerbations remain unclear. We show here that bacterial lipopolysaccharide (LPS) induces oncostatin M (OSM) and that airway biopsies from patients with severe asthma present with an OSM-driven transcriptional profile. This profile correlates with activation of inflammatory and mucus-producing pathways. Using primary human lung tissue or human epithelial and mesenchymal cells, we demonstrate that OSM is necessary and sufficient to drive pathophysiological features observed in severe asthma after exposure to LPS or Klebsiella pneumoniae . These findings were further supported through blockade of OSM with an OSM-specific antibody. Single-cell RNA sequencing from human lung biopsies identified macrophages as a source of OSM. Additional studies using Osm -deficient murine macrophages demonstrated that macrophage-derived OSM translates LPS signals into asthma-associated pathologies. Together, these data provide rationale for inhibiting OSM to prevent bacterial-associated progression and exacerbation of severe asthma.

Identification of covariates, including biomarkers, spirometry, and diaries/questionnaires, that predict asthma exacerbations would allow better clinical predictions, shorter phase II trials and inform decisions on phase III design, and/or initiation (go/no-go). The objective of this work was to characterize asthma-exacerbation hazard as a function of baseline and time-varying covariates. A repeated time-to-event (RTTE) model for exacerbations was developed using data from a 52-week phase IIb trial, including 502 patients with asthma randomized to placebo or 70 mg, 210 mg, or 490 mg astegolimab every 4 weeks. Covariate analysis was performed for 20 baseline covariates using the full random effects modeling approach, followed by time-varying covariate analysis of nine covariates using the stepwise covariate model (SCM) building procedure. Following the SCM, an astegolimab treatment effect was explored. Diary-based symptom score (difference in objective function value [dOFV] of -83.7) and rescue medication use (dOFV = -33.5), and forced expiratory volume in 1 s (dOFV = -14.9) were identified as significant time-varying covariates. Of note, time-varying covariates become more useful with more frequent measurements, which should favor the daily diary scores over others. The most influential baseline covariates were exacerbation history and diary-based symptom score (i.e., symptom score was important as both time-varying and baseline covariate). A (nonsignificant) astegolimab treatment effect was included in the final model because the limited data set did not allow concluding the remaining effect size as irrelevant. Without time-varying covariates, the treatment effect was statistically significant (p < 0.01). This work demonstrated the utility of a population RTTE approach to characterize exacerbation hazard in patients with severe asthma., (© 2021 Genentech, Inc. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: Understanding why patients with severe asthma do not follow healthcare provider (HCP) advice to adjust treatment is critical to achieving personalised disease management., Methods: We reviewed patient choice to follow HCP advice to adjust asthma treatment in a UK-based randomised, controlled, single-blind (study participant), multicentre, parallel group 48-week clinical study comparing biomarker-directed treatment adjustment with standard care in severe asthma., Results: Of 1572 treatment advisories (291 participants), instructions were followed in 1377 cases (87.6%). Patients were more likely to follow advice to remain on treatment (96.7%) than to either reduce (70.3%) or increase (67.1%) their treatment, with 64% of patients following all treatment advice. Multivariate analysis associated belonging to an ethnic minority group (OR 3.10, 95% CI 1.68-5.73) and prior study medication changes (two or more changes: OR 2.77, 95% CI 1.51-5.10) with failure to follow treatment advice. In contrast, emergency room attendance in the prior year (OR 0.54, 95% CI 0.32-0.92) was associated with following treatment advice. The largest effect was seen with transition onto or off oral corticosteroids (OR 29.28, 95% CI 16.07-53.36) when compared with those requested to maintain treatment. Centre was also an important determinant regarding the likelihood of patients to follow treatment advice., Conclusions: Belonging to an ethnic minority group and multiple prior treatment adjustments were associated with not following HCP treatment advice. Patients also responded differently to HCP advice across UK specialist centres. These findings have implications for the generalisability of models of care in severe asthma and require further focused studies., Competing Interests: Conflict of interest: J. Busby has nothing to disclose. Conflict of interest: J.G. Matthews has nothing to disclose. Conflict of interest: R. Chaudhuri reports grants, personal fees for advisory board work and nonfinancial support for meeting attendance from AstraZeneca, personal fees for advisory board work from GlaxoSmithKline and Novartis, personal fees for advisory board work and nonfinancial support for meeting attendance from Chiesi, nonfinancial support for meeting attendance from Napp Pharmaceuticals, outside the submitted work. Conflict of interest: I.D. Pavord reports personal fees for lectures, advisory board honoraria, sponsorship to attend scientific meetings, and payments for organising educational events from AstraZeneca, personal fees for lectures, advisory board honoraria, and sponsorship to attend scientific meetings from Boehringer Ingelheim and GlaxoSmithKline, personal fees for lectures from Aerocrine and Chiesi, personal fees for lectures and advisory board honoraria from Almirall and Novartis, advisory board honoraria from Genentech, Regeneron, Sanofi, Circassia and Knopp, personal fees for lectures, payments for organising educational events, and sponsorship to attend scientific meetings from Teva, grants from the National Institute for Health Research, outside the submitted work. Conflict of interest: T.C. Hardman has nothing to disclose. Conflict of interest: J.R. Arron has patents “Diagnosis and treatments relating to Th2 inhibition” (US 9,684,000 B2) and “Diagnosis and treatments relating to Th2 inhibition” (US 9,995,755 B2) issued with rights assigned to Genentech, a member of the Roche group, and is an employee of Genentech, Inc. and owns stocks/options in the Roche group. Conflict of interest: P. Bradding reports grants from Genentech, other (consultancy work on behalf of the University of Leicester) from Roche and Boehringer Ingelheim, outside the submitted work. Conflict of interest: C.E. Brightling reports grants and personal fees from GlaxoSmithKline, AstraZeneca, Sanofi, Novartis, Chiesi, Genentech, Gossamer, Mologic and 4D Pharma, all paid to the institution and outside the submitted work. Conflict of interest: D.F. Choy is an employee of Genentech, Inc. and owns stocks/options in the Roche group. Conflict of interest: D.C. Cowan has nothing to disclose. Conflict of interest: R. Djukanovic reports receiving fees for lectures at symposia organised by Novartis, AstraZeneca and Teva, consultation for Teva and Novartis as member of advisory boards, and participation in a scientific discussion about asthma organised by GlaxoSmithKline; he is a co-founder and current consultant, and has shares in Synairgen, a University of Southampton spin-out company. Conflict of interest: C.E. Hanratty has nothing to disclose. Conflict of interest: T.W. Harrison reports grants, personal fees and nonfinancial support from AstraZeneca, grants and personal fees from GlaxoSmithKline, personal fees from Vectura, Synairgen and Chiesi, outside the submitted work. Conflict of interest: C.T. Holweg is an employee and stock owner of Genentech Inc., a member of the Roche Group, outside the submitted work. Conflict of interest: P.H. Howarth reports employment by GlaxoSmithKline. Conflict of interest: S.J. Fowler reports personal fees for lectures and support to attend an international conference from AstraZeneca, grants and personal fees for lectures from Boehringer Ingelheim, personal fees for lectures, participation in an advisory board, and support to attend an national conference from Chiesi, personal fees for lectures from GlaxoSmithKline, Novartis and Teva, outside the submitted work. Conflict of interest: J.L. Lordan has nothing to disclose. Conflict of interest: A.H. Mansur reports personal and institution payment for talks, advisory board meetings, sponsorship to attend conferences and education grants for service developments from GlaxoSmithKline, AstraZeneca, Novartis, Sanofi, Teva and others, outside the submitted work. Conflict of interest: A. Menzies-Gow reports grants and personal fees from AstraZeneca, personal fees from Novartis, GlaxoSmithKline, Sanofi and Vectura, personal fees and nonfinancial support from Teva and Boehringer Ingelheim, outside the submitted work. Conflict of interest: R.M. Niven has received lecture fees, advisory board activity and been supported to attend international meetings/conferences in the last 5 years by the following companies: AstraZeneca, Boehringer, Boston Scientific, Chiesi, Napp, Novartis and Teva. None of these have any relevance to the manuscript; R.M. Niven owns no shares or stocks and is not personally or in any family way connected to any pharmaceutical companies. Conflict of interest: D.S. Robinson has nothing to disclose. Conflict of interest: S.M. Walker has nothing to disclose. Conflict of interest: A. Woodcock reports personal fees for lectures from GlaxoSmithKline, personal fees for lectures and consultancy from Novartis, personal fees for consultancy from Chiesi, other (chairing research projects) from Reacta Biotech, Axalbion and Medicines Evaluation Unit, outside the submitted work. Conflict of interest: L.G. Heaney reports other (sponsorship for meeting attendance) from AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline and Napp Pharmaceutical, personal fees for lectures and advisory board work from Novartis, Hoffman la Roche/Genentech Inc., Sanofi, GlaxoSmithKline, AstraZeneca, Teva, Theravance and Circassia, grants from Medimmune, Novartis UK, Roche/Genentech Inc., and GlaxoSmithKline, and is academic lead for the Medical Research Council Stratified Medicine UK Consortium in severe asthma, which involves industrial partnerships with Amgen, Genentech/Hoffman la Roche, AstraZeneca, Medimmune, GlaxoSmithKline, Aerocrine and Vitalograph, outside the submitted work., (Copyright ©The authors 2022.)

Background: Chronic obstructive pulmonary disease (COPD) exacerbations are heterogenous and profoundly impact the disease trajectory. Bioactive lipid lysophosphatidic acid (LPA) has been implicated in airway inflammation but the significance of LPA in COPD exacerbation is not known. The aim of the study was to investigate the utility of serum LPA species (LPA16:0, 18:0, 18:1, 18:2, 20:4) as biomarkers of COPD exacerbation., Patients and Methods: LPA species were measured in the baseline placebo sera of a COPD randomized controlled trial. Tertile levels of each LPA were used to assign patients into biomarker high, medium, and low subgroups. Exacerbation rate and risk were compared among the LPA subgroups., Results: The levels of LPA species were intercorrelated (rho 0.29-0.91). Patients with low and medium levels of LPA (LPA16:0, 20:4) had significantly higher exacerbation rate compared to the respective LPA-high patients [estimated rate per patient per year (95% CI)]: LPA16:0-low = 1.2 (0.8-1.9) (p = 0.019), LPA16:0-medium = 1.3 (0.8-2.0) (p = 0.013), LPA16:0-high = 0.5 (0.2-0.9); LPA20:4-low = 1.4 (0.9-2.1) (p = 0.0033), LPA20:4-medium = 1.2 (0.8-1.8) (p = 0.0089), LPA20:4-high = 0.4 (0.2-0.8). These patients also had earlier time to first exacerbation (hazard ratio (95% CI): LPA16:0-low = 2.6 (1.1-6.0) (p = 0.028), LPA16:0-medium = 2.7 (1.2-6.3) (p = 0.020); LPA20.4-low = 2.8 (1.2-6.6) (p = 0.017), LPA20:4-medium = 2.7 (1.2-6.4) (p = 0.021). Accordingly, these patients had a significant increased exacerbation risk compared to the respective LPA-high subgroups [odd ratio (95% CI)]: LPA16:0-low = 3.1 (1.1-8.8) (p = 0.030), LPA16:0-medium = 3.0 (1.1-8.3) (p = 0.031); LPA20:4-low = 3.8 (1.3-10.9) (p = 0.012), LPA20:4-medium = 3.3 (1.2-9.5) (p = 0.025). For the other LPA species (LPA18:0, 18:1, 18:2), the results were mixed; patients with low and medium levels of LPA18:0 and 18:2 had increased exacerbation rate, but only LPA18:0-low patients had significant increase in exacerbation risk and earlier time to first exacerbation compared to the LPA18:0-high subgroup., Conclusions: The study provided evidence of association between systemic LPA levels and exacerbation in COPD. Patients with low and medium levels of specific LPA species (LPA16:0, 20:4) had increased exacerbation rate, risk, and earlier time to first exacerbation. These non-invasive biomarkers may aid in identifying high risk patients with dysregulated LPA pathway to inform risk management and drug development., (© 2021. The Author(s).)

Background: The IL-33/ST2 pathway is linked with asthma susceptibility. Inhaled allergens, pollutants, and respiratory viruses, which trigger asthma exacerbations, induce release of IL-33, an epithelial-derived "alarmin." Astegolimab, a human IgG 2 mAb, selectively inhibits the IL-33 receptor, ST2. Approved biologic therapies for severe asthma mainly benefit patients with elevated blood eosinophils (type 2-high), but limited options are available for patients with low blood eosinophils (type 2-low). Inhibiting IL-33 signaling may target pathogenic pathways in a wider spectrum of asthmatics., Objectives: This study evaluated astegolimab efficacy and safety in patients with severe asthma., Methods: This double-blind, placebo-controlled, dose-ranging study (ZENYATTA [A Study to Assess the Efficacy and Safety of MSTT1041A in Participants With Uncontrolled Severe Asthma]) randomized 502 adults with severe asthma to subcutaneous placebo or 70-mg, 210-mg, or 490-mg doses of astegolimab every 4 weeks. The primary endpoint was the annualized asthma exacerbation rate (AER) at week 54. Enrollment caps ensured ∼30 patients who were eosinophil-high (≥300 cells/μL) and ∼95 patients who were eosinophil-low (<300 cells/μL) per arm., Results: Overall, adjusted AER reductions relative to placebo were 43% (P = .005), 22% (P = .18), and 37% (P = .01) for 490-mg, 210-mg, and 70-mg doses of astegolimab, respectively. Adjusted AER reductions for patients who were eosinophil-low were comparable to reductions in the overall population: 54% (P = .002), 14% (P = .48), and 35% (P = .05) for 490-mg, 210-mg, and 70-mg doses of astegolimab. Adverse events were similar in astegolimab- and placebo-treated groups., Conclusions: Astegolimab reduced AER in a broad population of patients, including those who were eosinophil-low, with inadequately controlled, severe asthma. Astegolimab was safe and well tolerated., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: COPD exacerbations are heterogeneous and can be triggered by bacterial, viral, or noninfectious insults. Exacerbations are also heterogeneous in neutrophilic or eosinophilic inflammatory responses. A noninvasive peripheral biomarker of COPD exacerbations characterised by bacterial/neutrophilic inflammation is lacking. Granulocyte-colony stimulating factor (G-CSF) is a key cytokine elevated during bacterial infection and mediates survival, proliferation, differentiation and function of neutrophils., Objective: We hypothesised that high peripheral G-CSF would be indicative of COPD exacerbations with a neutrophilic and bacterial phenotype associated with microbial dysbiosis., Methods: Serum G-CSF was measured during hospitalised exacerbation (day 0 or D0) and after 30 days of recovery (Day30 or D30) in 37 subjects. In a second cohort, serum and sputum cytokines were measured in 59 COPD patients during stable disease, at exacerbation, and at 2-weeks and 6-weeks following exacerbation., Results: Serum G-CSF was increased during exacerbation in a subset of patients. These exacerbations were enriched for bacterial but not viral or type-2 biologies. The median serum G-CSF level was 1.6-fold higher in bacterial exacerbation compared to nonbacterial exacerbation (22 pg·mL -1 versus 13 pg·mL -1 , p=0.0007). Serum G-CSF classified bacterial exacerbations with an area under the curve (AUC) for the receiver operating characteristic (ROC) curve equal to 0.76. Exacerbations with a two-fold or greater increase in serum G-CSF were characterised by neutrophilic inflammation, with increased sputum and blood neutrophils, and high sputum interleukin (IL)-1β, IL-6 and serum amyloid A1 (SAA1) levels. These exacerbations were preceded by dysbiosis, with decreased microbiome diversity and enrichment of respiratory pathogens such as Haemophilus and Moraxella . Furthermore, serum G-CSF at exacerbation classified neutrophilic-dysbiotic exacerbations (AUC for the ROC curve equal to 0.75)., Conclusions: High serum G-CSF enriches for COPD exacerbations characterised by neutrophilic inflammation with underlying bacterial dysbiosis., Competing Interests: Conflict of interest: A. Chakrabarti reports personal fees from and stock in Genentech, Inc., during the conduct of the study and outside the submitted work. Conflict of interest: J.S. Mar reports personal fees from and equity in Genentech, Inc., outside the submitted work. Conflict of interest: D.F. Choy is an employee of Genentech, Inc. Conflict of interest: Y. Cao reports personal fees from and stock in Genentech, Inc., during the conduct of the study and outside the submitted work. Conflict of interest: N. Rathore reports personal fees from and stock in Genentech, Inc., during the conduct of the study and outside the submitted work. Conflict of interest: X. Yang reports personal fees from Genentech, Inc., during the conduct of the study and outside the submitted work. Conflict of interest: G.W. Tew reports personal fees from Genentech, Inc., during the conduct of the study and outside the submitted work. Conflict of interest: O. Li is a salaried employee of Genentech, Inc. and received nonfinancial support from Genentech, Inc., during the conduct of the study. Conflict of interest: P.G. Woodruff reports consulting fees from Regeneron, Sanofi, Glenmark Pharma, Theravance and NGM Pharma, and visiting professor honoraria from Amgen and Genentech, outside the submitted work. Conflict of interest: C.E. Brightling is an employee of the University of Leicester. Conflict of interest: M. Grimbaldeston is an employee of Genentech, Inc., and reports personal fees and nonfinancial support during the conduct of the study. Conflict of interest: S.A. Christenson reports consulting fees from AstraZeneca, GlaxoSmithKline, Amgen and Glenmark; personal fees for invited lectures from Sunovion and Genentech; and personal fees for writing for UpToDate, all outside the submitted work. Conflict of interest: M. Bafadhel reports grants from AstraZeneca; honoraria for consulting and advisory boards, as well as travel to conferences, from AstraZeneca, Chiesi and GSK. She is a scientific advisor to and minor shareholder in AlbusHealth, all outside the submitted work. Conflict of interest: C.M. Rosenberger reports personal fees from and stock in Genentech, Inc., during the conduct of the study and outside the submitted work., (Copyright ©The authors 2021.)

Psoriasis is a chronic inflammatory skin disease that develops under the influence of the IL-23/T helper 17 cell axis and is characterized by intense inflammation and prominent epidermal hyperplasia. In this study, we demonstrate that galectin-8, a β-galactoside‒binding lectin, is upregulated in the epidermis of human psoriatic skin lesions as well as in a mouse model of psoriasis induced by intradermal IL-23 injections and in IL-17A‒treated keratinocytes. We show that keratinocyte proliferation is less prominent in galectin-8‒knockout mice after intradermal IL-23 treatment than in wild-type mice. In addition, we show that galectin-8 levels in keratinocytes are positively correlated with the ability of the cells to proliferate and that transitioning from mitosis into G1 phase is delayed in galectin-8‒knockout HaCaT cells after cell-cycle synchronization and release. We demonstrate by immunofluorescence staining and immunoblotting the presence of galectin-8 within the mitotic apparatus. We reveal by coimmunoprecipitation and mass spectrometry analysis that α-tubulin interacts with galectin-8 during mitosis. Finally, we show that in the absence of galectin-8, pericentrin compactness is lessened and mitotic microtubule length is shortened, as demonstrated by immunofluorescence staining. We conclude that galectin-8 is upregulated in psoriasis and contributes to the hyperproliferation of keratinocytes by maintaining centrosome integrity during mitosis through interacting with α-tubulin., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Asthma treatment guidelines recommend increasing corticosteroid dose to control symptoms and reduce exacerbations. This approach is potentially flawed because symptomatic asthma can occur without corticosteroid responsive type-2 (T2)-driven eosinophilic inflammation, and inappropriately high-dose corticosteroid treatment might have little therapeutic benefit with increased risk of side-effects. We compared a biomarker strategy to adjust corticosteroid dose using a composite score of T2 biomarkers (fractional exhaled nitric oxide [FENO], blood eosinophils, and serum periostin) with a standardised symptom-risk-based algorithm (control)., Methods: We did a single-blind, parallel group, randomised controlled trial in adults (18-80 years of age) with severe asthma (at treatment steps 4 and 5 of the Global Initiative for Asthma) and FENO of less than 45 parts per billion at 12 specialist severe asthma centres across England, Scotland, and Northern Ireland. Patients were randomly assigned (4:1) to either the biomarker strategy group or the control group by an online electronic case-report form, in blocks of ten, stratified by asthma control and use of rescue systemic steroids in the previous year. Patients were masked to study group allocation throughout the entirety of the study. Patients attended clinic every 8 weeks, with treatment adjustment following automated treatment-group-specific algorithms: those in the biomarker strategy group received a default advisory to maintain treatment and those in the control group had their treatment adjusted according to the steps indicated by the trial algorithm. The primary outcome was the proportion of patients with corticosteroid dose reduction at week 48, in the intention-to-treat (ITT) population. Secondary outcomes were inhaled corticosteroid (ICS) dose at the end of the study; cumulative dose of ICS during the study; proportion of patients on maintenance oral corticosteroids (OCS) at study end; rate of protocol-defined severe exacerbations per patient year; time to first severe exacerbation; number of hospital admissions for asthma; changes in lung function, Asthma Control Questionnaire-7 score, Asthma Quality of Life Questionnaire score, and T2 biomarkers from baseline to week 48; and whether patients declined to progress to OCS. A secondary aim of our study was to establish the proportion of patients with severe asthma in whom T2 biomarkers remained low when corticosteroid therapy was decreased to a minimum ICS dose. This study is registered with ClinicalTrials.gov, NCT02717689 and has been completed., Findings: Patients were recruited from Jan 8, 2016, to July 12, 2018. Of 549 patients assessed, 301 patients were included in the ITT population and were randomly assigned to the biomarker strategy group (n=240) or to the control group (n=61). 28·4% of patients in the biomarker strategy group were on a lower corticosteroid dose at week 48 compared with 18·5% of patients in the control group (adjusted odds ratio [aOR] 1·71 [95% CI 0·80-3·63]; p=0·17). In the per-protocol (PP) population (n=121), a significantly greater proportion of patients were on a lower corticosteroid dose at week 48 in the biomarker strategy group (30·7% of patients) compared with the control group (5·0% of patients; aOR 11·48 [95% CI 1·35-97·83]; p=0·026). Patient choice to not follow treatment advice was the principle reason for loss to PP analysis. There was no difference in secondary outcomes between study groups and no loss of asthma control among patients in the biomarker strategy group who reduced their corticosteroid dose., Interpretation: Biomarker-based corticosteroid adjustment did not result in a greater proportion of patients reducing corticosteroid dose versus control. Understanding the reasons for patients not following treatment advice in both treatment strategies is an important area for future research. The prevalence of T2 biomarker-low severe asthma was low., Funding: This study was funded, in part, by the Medical Research Council UK., (Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: The anti-interleukin 13 (IL-13) monoclonal antibody lebrikizumab improves lung function in patients with moderate-to-severe uncontrolled asthma, but its effects on airway inflammation and remodelling are unknown. CLAVIER was designed to assess lebrikizumab's effect on eosinophilic inflammation and remodelling., Objective: To report safety and efficacy results from enrolled participants with available data from CLAVIER., Methods: We performed bronchoscopy on patients with uncontrolled asthma before and after 12 weeks of randomized double-blinded treatment with lebrikizumab (n = 31) or placebo (n = 33). The pre-specified primary end-point was relative change in airway subepithelial eosinophils per mm 2 of basement membrane (cells/mm 2 ). Pre-specified secondary and exploratory outcomes included change in IL-13-associated biomarkers and measures of airway remodelling., Results: There was a baseline imbalance in tissue eosinophils and high variability between treatment groups. There was no discernible change in adjusted mean subepithelial eosinophils/mm 2 in response to lebrikizumab (95% CI, -82.5%, 97.5%). As previously observed, FEV 1 increased after lebrikizumab treatment. Moreover, subepithelial collagen thickness decreased 21.5% after lebrikizumab treatment (95% CI, -32.9%, -10.2%), and fractional exhaled nitric oxide, CCL26 and SERPINB2 mRNA expression in bronchial tissues also reduced. Lebrikizumab was well tolerated, with a safety profile consistent with other lebrikizumab asthma studies., Conclusions & Clinical Relevance: We did not observe reduced tissue eosinophil numbers in association with lebrikizumab treatment. However, in pre-specified exploratory analyses, lebrikizumab treatment was associated with reduced degree of subepithelial fibrosis, a feature of airway remodelling, as well as improved lung function and reduced key pharmacodynamic biomarkers in bronchial tissues. These results reinforce the importance of IL-13 in airway pathobiology and suggest that neutralization of IL-13 may reduce asthmatic airway remodelling., Clinical Trial Registration: NCT02099656., (© 2020 The Authors. Clinical & Experimental Allergy published by John Wiley & Sons Ltd.)

Introduction : Human asthma is a heterogeneous disorder on molecular, pathological, and clinical levels. The paradigm of asthma as an allergic process driven by type 2 cytokines and mediators has led to targeted biologic therapies resulting in some clinical benefit in patient subsets. However, some patient subsets and clinical manifestations do not benefit from these interventions, thus redefining unmet needs. Clinical studies of type 2 directed therapies have identified new targets under investigation in clinical development; these include epithelial alarmins, non-type 2 cytokines, cytokine receptor signaling, mast cells and neuroinflammation. Areas covered : We consider lessons learned concerning asthma pathogenesis from observational studies and clinical trials of biologic agents that target type 2 mediators. We also provide a perspective on emerging therapeutic hypotheses to target processes independent of or orthogonal to type 2 inflammation in asthma. Expert opinion : Type 2 inflammation is continuous, not discrete, and is likely a modifier of underlying dysregulated airway physiology. Non-type 2 inflammatory mediators (e.g., IL17, IL6, IFNs), microbiome, alarmins (e.g., TSLP, IL33), mast cells and sensory neurons may represent orthogonal targets to type 2 mediators. There is a need to better match targets and outcome measures in biologically defined patient populations to appropriately test hypotheses in the clinic.

Introduction: Asthma exacerbations spike in the spring and autumn months, yet the seasonal variation of asthma symptoms and lung function is poorly studied., Methods: Seasonal variation of lung function, rescue medication use and patient-reported symptoms was evaluated by post hoc analyses of the Phase III lebrikizumab (anti-IL-13) LAVOLTA I and II studies in 2148 subjects with uncontrolled asthma. Lung function measurements (prebronchodilator FEV 1 , forced vital capacity (FVC) and peak expiratory flow (PEF)), rescue medication use and Standardised Asthma Quality of Life Questionnaire (AQLQ(S)) were measured every 4 weeks over 52 weeks. By-month estimates normalised by hemispheric season were based on mixed-effect models with repeated measures (MMRM), adjusted by study stratification factors as covariates when appropriate. The dependency of clinical outcomes with seasonal variability was assessed by employing linear contrasts comparing hemisphere normalised December versus July group means from an MMRM regression and presented as the difference in means (adjusted 95% CI)., Results: FEV 1 , FVC and PEF, rescue medication use and AQLQ(S) progressively worsened towards winter, unlike spring and autumn surges in asthma exacerbations. The December versus July mean differences were: (1) PEF=-6.5 (-8.7 to -4.2) L/min, 2) prebronchodilator FEV 1 =-42 (-57 to -27) mL, (3) FVC=-41 (-59 to -23) mL and (4) AQLQ(S)=-0.15 (-0.19 to -0.1) units. Among AQLQ questions, discomfort or distress related to cough was most variable with respect to season (-0.33 (-0.42 to -0.24) units)., Discussion: Interpretation of interventional studies biased by seasonal exposures may be confounded by seasonal variability., Trials Registration Numbers: NCT01867125 and NCT01868061., Competing Interests: Competing interests: RB, XY, TS, JO, CTJH, JA and DFC are employees of Genentech, Inc and hold Roche stocks and/or options. JGM was previously an employee of Genentech at the time of this study., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Measles virus is directly responsible for more than 100,000 deaths yearly. Epidemiological studies have associated measles with increased morbidity and mortality for years after infection, but the reasons why are poorly understood. Measles virus infects immune cells, causing acute immune suppression. To identify and quantify long-term effects of measles on the immune system, we used VirScan, an assay that tracks antibodies to thousands of pathogen epitopes in blood. We studied 77 unvaccinated children before and 2 months after natural measles virus infection. Measles caused elimination of 11 to 73% of the antibody repertoire across individuals. Recovery of antibodies was detected after natural reexposure to pathogens. Notably, these immune system effects were not observed in infants vaccinated against MMR (measles, mumps, and rubella), but were confirmed in measles-infected macaques. The reduction in humoral immune memory after measles infection generates potential vulnerability to future infections, underscoring the need for widespread vaccination., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Severe asthma patients with low type 2 inflammation derive less clinical benefit from therapies targeting type 2 cytokines and represent an unmet need. We show that mast cell tryptase is elevated in severe asthma patients independent of type 2 biomarker status. Active β-tryptase allele count correlates with blood tryptase levels, and asthma patients carrying more active alleles benefit less from anti-IgE treatment. We generated a noncompetitive inhibitory antibody against human β-tryptase, which dissociates active tetramers into inactive monomers. A 2.15 Å crystal structure of a β-tryptase/antibody complex coupled with biochemical studies reveal the molecular basis for allosteric destabilization of small and large interfaces required for tetramerization. This anti-tryptase antibody potently blocks tryptase enzymatic activity in a humanized mouse model, reducing IgE-mediated systemic anaphylaxis, and inhibits airway tryptase in Ascaris-sensitized cynomolgus monkeys with favorable pharmacokinetics. These data provide a foundation for developing anti-tryptase as a clinical therapy for severe asthma., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Inhibition of interleukin (IL)-13, a Type 2 inflammatory mediator in asthma, improves lung function and reduces exacerbations; however, more effective therapies are needed. A subset of asthma patients also exhibits elevated IL-17, which is associated with greater disease severity, neutrophilic inflammation, and steroid resistance. BITS7201A is a novel, humanized bispecific antibody that binds and neutralizes both IL-13 and IL-17., Methods: Safety, pharmacokinetics, and immunogenicity of BITS7201A were evaluated in a phase 1 study. Part A was a single ascending-dose design with 5 cohorts: 30-, 90-, and 300-mg subcutaneous (SC), and 300- and 750-mg intravenous (IV). Part B was a multiple ascending-dose design with 3 cohorts: 150-, 300-, and 600-mg SC every 4 weeks × 3 doses. Both parts enrolled approximately 8 healthy volunteers into each cohort (6 active: 2 placebo). Part B included an additional cohort of patients with mild asthma (600-mg SC)., Results: Forty-one subjects (31 active, 10 placebo) and 26 subjects (20 active, 6 placebo) were enrolled into Parts A and B, respectively. The cohort with mild asthma patients was terminated after enrollment of a single patient. No deaths, serious adverse events, or dose-limiting adverse events occurred. In Part A, 12 active (39%) and 5 placebo subjects (50%), and in Part B, 6 active (30%) and 3 placebo subjects (50%) experienced at least 1 treatment-emergent adverse event (TEAE). The most common AEs were fatigue (n = 3) and influenza-like illness (n = 2). One injection-site reaction was reported. Two subjects with elevated blood eosinophil counts at baseline had transient elevations in blood eosinophils (≥Grade 2, > 1500 cells/μL). In Parts A and B, 16 of 30 (53%) and 16 of 17 (94%) active subjects, respectively, tested positive for anti-drug antibodies (ADAs). No anaphylaxis or hypersensitivity events occurred. BITS7201A exhibited single- and multiple-dose pharmacokinetic characteristics consistent with an IgG monoclonal antibody; exposure generally increased dose-proportionally. Postdose elevations of the serum pharmacodynamic biomarkers, IL-17AA and IL-17FF, occurred, confirming target engagement., Conclusions: BITS7201A was well tolerated, but was associated with a high incidence of ADA formation., Trial Registration: ClinicalTrials.gov , NCT02748642; registered April 6, 2016 (retrospectively registered).

Rationale: Quantification of type 2 inflammation provided a molecular basis for heterogeneity in asthma. Non-type 2 pathways that contribute to asthma pathogenesis are not well understood., Objectives: To identify dysregulated pathways beyond type 2 inflammation., Methods: We applied RNA sequencing to airway epithelial brushings obtained from subjects with stable mild asthma not on corticosteroids (n = 19) and healthy control subjects (n = 16). Sequencing reads were mapped to human and viral genomes. In the same cohort, and in a separate group with severe asthma (n = 301), we profiled blood gene expression with microarrays., Measurements and Main Results: In airway brushings from mild asthma on inhaled corticosteroids, RNA sequencing yielded 1,379 differentially expressed genes (false discovery rate < 0.01). Pathway analysis revealed increased expression of type 2 markers, IFN-stimulated genes (ISGs), and endoplasmic reticulum (ER) stress-related genes. Airway epithelial ISG expression was not associated with type 2 inflammation in asthma or with viral transcripts but was associated with reduced lung function by FEV 1 (ρ = -0.72; P = 0.0004). ER stress was confirmed by an increase in XBP1 (X-box binding protein 1) splicing in mild asthma and was associated with both type 2 inflammation and ISG expression. ISGs were also the most activated genes in blood cells in asthma and were correlated with airway ISG expression (ρ = 0.55; P = 0.030). High blood ISG expression in severe asthma was similarly unrelated to type 2 inflammation., Conclusions: ISG activation is prominent in asthma, independent of viral transcripts, orthogonal to type 2 inflammation, and associated with distinct clinical features. ER stress is associated with both type 2 inflammation and ISG expression.

Background: Patients with difficult-to-control asthma consume 50-60% of healthcare costs attributed to asthma and cost approximately five-times more than patients with mild stable disease. Recent evidence demonstrates that not all patients with asthma have a typical type 2 (T2)-driven eosinophilic inflammation. These asthmatics have been called 'T2-low asthma' and have a minimal response to corticosteroid therapy. Adjustment of corticosteroid treatment using sputum eosinophil counts from induced sputum has demonstrated reduced severe exacerbation rates and optimized corticosteroid dose. However, it has been challenging to move induced sputum into the clinical setting. There is therefore a need to examine novel algorithms to target appropriate levels of corticosteroid treatment in difficult asthma, particularly in T2-low asthmatics. This study examines whether a composite non-invasive biomarker algorithm predicts exacerbation risk in patients with asthma on high-dose inhaled corticosteroids (ICS) (± long-acting beta agonist) treatment, and evaluates the utility of this composite score to facilitate personalized biomarker-specific titration of corticosteroid therapy., Methods/design: Patients recruited to this pragmatic, multi-centre, single-blinded randomised controlled trial are randomly allocated into either a biomarker controlled treatment advisory algorithm or usual care group in a ratio of 4:1. The primary outcome measure is the proportion of patients with any reduction in ICS or oral corticosteroid dose from baseline to week 48. Secondary outcomes include the rate of protocol-defined severe exacerbations per patient per year, time to first severe exacerbation from randomisation, dose of inhaled steroid at the end of the study, cumulative dose of inhaled corticosteroid during the study, proportion of patients on oral corticosteroids at the end of the study, proportion of patients who decline to progress to oral corticosteroids despite composite biomarker score of 2, frequency of hospital admission for asthma, change in the 7-item Asthma Control Questionnaire (ACQ-7), Asthma Quality of Life Questionnaire (AQLQ), forced expiratory volume in 1 s (FEV1), exhaled nitric oxide, blood eosinophil count, and periostin levels from baseline to week 48. Blood will also be taken for whole blood gene expression; serum, plasma, and urine will be stored for validation of additional biomarkers., Discussion: Multi-centre trials present numerous logistical issues that have been addressed to ensure minimal bias and robustness of study conduct., Trial Registration: ClinicalTrials.gov, NCT02717689 . Registered on 16 March 2016.

Blood eosinophil counts and serum periostin levels are biomarkers of type 2 inflammation. Although serum levels of HDL and apoA-I have been associated with less severe airflow obstruction in asthma, it is not known whether serum lipids or lipoprotein particles are correlated with type 2 inflammation in asthmatics. Here, we assessed whether serum lipids and lipoproteins correlated with blood eosinophil counts or serum periostin levels in 165 atopic asthmatics and 163 nonasthmatic subjects with and without atopy. Serum lipids and lipoproteins were quantified using standard laboratory assays and NMR spectroscopy. Absolute blood eosinophils were quantified by complete blood counts. Periostin levels were measured using the Elecsys® periostin assay. In atopic asthmatics, blood eosinophils negatively correlated with serum HDL cholesterol and total HDL particles measured by NMR spectroscopy (HDL NMR ). Serum periostin levels negatively correlated with total HDL NMR In contrast, blood eosinophil counts positively correlated with serum triglyceride levels. This study demonstrates for the first time that HDL particles were negatively correlated, whereas serum triglycerides were positively correlated, with blood eosinophils in atopic asthmatics. This supports the concept that serum levels of HDL and triglycerides may be linked to systemic type 2 inflammation in atopic asthma., (Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.)