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Georas SN, Khurana S. Update on asthma biology. J Allergy Clin Immunol 2024; 153:1215-1228. [PMID: 38341182 DOI: 10.1016/j.jaci.2024.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/17/2024] [Accepted: 01/24/2024] [Indexed: 02/12/2024]
Abstract
This is an exciting time to be conducting asthma research. The recent development of targeted asthma biologics has validated the power of basic research to discover new molecules amenable to therapeutic intervention. Advances in high-throughput sequencing are providing a wealth of "omics" data about genetic and epigenetic underpinnings of asthma, as well as about new cellular interacting networks and potential endotypes in asthma. Airway epithelial cells have emerged not only as key sensors of the outside environment but also as central drivers of dysregulated mucosal immune responses in asthma. Emerging data suggest that the airway epithelium in asthma remembers prior encounters with environmental exposures, resulting in potentially long-lasting changes in structure and metabolism that render asthmatic individuals susceptible to subsequent exposures. Here we summarize recent insights into asthma biology, focusing on studies using human cells or tissue that were published in the past 2 years. The studies are organized thematically into 6 content areas to draw connections and spur future research (on genetics and epigenetics, prenatal and early-life origins, microbiome, immune and inflammatory pathways, asthma endotypes and biomarkers, and lung structural alterations). We highlight recent studies of airway epithelial dysfunction and response to viral infections and conclude with a framework for considering how bidirectional interactions between alterations in airway structure and mucosal immunity can lead to sustained lung dysfunction in asthma.
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Affiliation(s)
- Steve N Georas
- Division of Pulmonary and Critical Care Medicine, University of Rochester Medical Center, Rochester, NY.
| | - Sandhya Khurana
- Division of Pulmonary and Critical Care Medicine, University of Rochester Medical Center, Rochester, NY
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Plender EG, Prodanov T, Hsieh P, Nizamis E, Harvey WT, Sulovari A, Munson KM, Kaufman EJ, O'Neal WK, Valdmanis PN, Marschall T, Bloom JD, Eichler EE. Structural and genetic diversity in the secreted mucins, MUC5AC and MUC5B. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585560. [PMID: 38562829 PMCID: PMC10983947 DOI: 10.1101/2024.03.18.585560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The secreted mucins MUC5AC and MUC5B play critical defensive roles in airway pathogen entrapment and mucociliary clearance by encoding large glycoproteins with variable number tandem repeats (VNTRs). These polymorphic and degenerate protein coding VNTRs make the loci difficult to investigate with short reads. We characterize the structural diversity of MUC5AC and MUC5B by long-read sequencing and assembly of 206 human and 20 nonhuman primate (NHP) haplotypes. We find that human MUC5B is largely invariant (5761-5762aa); however, seven haplotypes have expanded VNTRs (6291-7019aa). In contrast, 30 allelic variants of MUC5AC encode 16 distinct proteins (5249-6325aa) with cysteine-rich domain and VNTR copy number variation. We grouped MUC5AC alleles into three phylogenetic clades: H1 (46%, ~5654aa), H2 (33%, ~5742aa), and H3 (7%, ~6325aa). The two most common human MUC5AC variants are smaller than NHP gene models, suggesting a reduction in protein length during recent human evolution. Linkage disequilibrium (LD) and Tajima's D analyses reveal that East Asians carry exceptionally large MUC5AC LD blocks with an excess of rare variation (p<0.05). To validate this result, we used Locityper for genotyping MUC5AC haplogroups in 2,600 unrelated samples from the 1000 Genomes Project. We observed signatures of positive selection in H1 and H2 among East Asians and a depletion of the likely ancestral haplogroup (H3). In Africans and Europeans, H3 alleles show an excess of common variation and deviate from Hardy-Weinberg equilibrium, consistent with heterozygote advantage and balancing selection. This study provides a generalizable strategy to characterize complex protein coding VNTRs for improved disease associations.
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Affiliation(s)
- Elizabeth G Plender
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Timofey Prodanov
- Institute for Medical Biometry and Bioinformatics, Medical Faculty, Heinrich Heine University, Moorenstr. 5, 40225 Düsseldorf, Germany
- Center for Digital Medicine, Heinrich Heine University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - PingHsun Hsieh
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Evangelos Nizamis
- Division of Medical Genetics, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - William T Harvey
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Arvis Sulovari
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Katherine M Munson
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Eli J Kaufman
- Division of Medical Genetics, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Wanda K O'Neal
- Marsico Lung Institute/UNC CF Research Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, 27599, North Carolina, USA
| | - Paul N Valdmanis
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Division of Medical Genetics, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Tobias Marschall
- Institute for Medical Biometry and Bioinformatics, Medical Faculty, Heinrich Heine University, Moorenstr. 5, 40225 Düsseldorf, Germany
- Center for Digital Medicine, Heinrich Heine University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Jesse D Bloom
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
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Sabo MC, Thuong NTT, Chang X, Ardiansyah E, Tram TTB, Hai HT, Nghia HDT, Bang ND, Dian S, Ganiem AR, Shaporifar S, Kumar V, Li Z, Hibberd M, Khor CC, Thwaites GE, Heemskerk D, van Laarhoven A, van Crevel R, Dunstan SJ, Shah JA. MUC5AC Genetic Variation Is Associated With Tuberculous Meningitis Cerebral Spinal Fluid Cytokine Responses and Mortality. J Infect Dis 2023; 228:343-352. [PMID: 36823694 PMCID: PMC10420404 DOI: 10.1093/infdis/jiad050] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/14/2023] [Accepted: 02/22/2023] [Indexed: 02/25/2023] Open
Abstract
BACKGROUND The purpose of this study was to assess if single nucleotide polymorphisms (SNPs) in lung mucins MUC5B and MUC5AC are associated with Mycobacterium tuberculosis outcomes. METHODS Independent SNPs in MUC5B and MUC5AC (genotyped by Illumina HumanOmniExpress array) were assessed for associations with tumor necrosis factor (TNF) concentrations (measured by immunoassay) in cerebral spinal fluid (CSF) from tuberculous meningitis (TBM) patients. SNPs associated with CSF TNF concentrations were carried forward for analyses of pulmonary and meningeal tuberculosis susceptibility and TBM mortality. RESULTS MUC5AC SNP rs28737416 T allele was associated with lower CSF concentrations of TNF (P = 1.8 × 10-8) and IFN-γ (P = 2.3 × 10-6). In an additive genetic model, rs28737416 T/T genotype was associated with higher susceptibility to TBM (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.03-1.49; P = .02), but not pulmonary tuberculosis (OR, 1.11, 95% CI, .98-1.25; P = .10). TBM mortality was higher among participants with the rs28737416 T/T and T/C genotypes (35/119, 30.4%) versus the C/C genotype (11/89, 12.4%; log-rank P = .005) in a Vietnam discovery cohort (n = 210), an independent Vietnam validation cohort (n = 87; 9/87, 19.1% vs 1/20, 2.5%; log-rank P = .02), and an Indonesia validation cohort (n = 468, 127/287, 44.3% vs 65/181, 35.9%; log-rank P = .06). CONCLUSIONS MUC5AC variants may contribute to immune changes that influence TBM outcomes.
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Affiliation(s)
- Michelle C Sabo
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Nguyen T T Thuong
- Oxford University Clinical Research Unit, Ho Chi Minh, Vietnam
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Xuling Chang
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | | | - Trinh T B Tram
- Oxford University Clinical Research Unit, Ho Chi Minh, Vietnam
| | - Hoang T Hai
- Oxford University Clinical Research Unit, Ho Chi Minh, Vietnam
| | - Ho D T Nghia
- Oxford University Clinical Research Unit, Ho Chi Minh, Vietnam
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Nguyen D Bang
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Pham Ngoc Thach Hospital, Ho Chi Minh, Vietnam
| | - Sofiati Dian
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - A Rizal Ganiem
- Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Neurology, Universitas Padjadjaran/Hasan Sadikin Hospital, Bandung, Indonesia
| | - Shima Shaporifar
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Vinod Kumar
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - Zheng Li
- Genome Institute of Singapore, Singapore, Singapore
| | - Martin Hibberd
- London School of Tropical Medicine and Hygiene, London, United Kingdom
| | | | - Guy E Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh, Vietnam
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Dorothee Heemskerk
- Oxford University Clinical Research Unit, Ho Chi Minh, Vietnam
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Amsterdam University Medical Centre, Amsterdam, The Netherlands
| | | | | | - Sarah J Dunstan
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Javeed A Shah
- Department of Medicine, University of Washington, Seattle, Washington, USA
- Veterans Affairs Puget Sound Healthcare System, Seattle, Washington, USA
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Van Buren E, Radicioni G, Lester S, O’Neal WK, Dang H, Kasela S, Garudadri S, Curtis JL, Han MK, Krishnan JA, Wan ES, Silverman EK, Hastie A, Ortega VE, Lappalainen T, Nawijn MC, van den Berge M, Christenson SA, Li Y, Cho MH, Kesimer M, Kelada SNP. Genetic regulators of sputum mucin concentration and their associations with COPD phenotypes. PLoS Genet 2023; 19:e1010445. [PMID: 37352370 PMCID: PMC10325042 DOI: 10.1371/journal.pgen.1010445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 07/06/2023] [Accepted: 04/26/2023] [Indexed: 06/25/2023] Open
Abstract
Hyper-secretion and/or hyper-concentration of mucus is a defining feature of multiple obstructive lung diseases, including chronic obstructive pulmonary disease (COPD). Mucus itself is composed of a mixture of water, ions, salt and proteins, of which the gel-forming mucins, MUC5AC and MUC5B, are the most abundant. Recent studies have linked the concentrations of these proteins in sputum to COPD phenotypes, including chronic bronchitis (CB) and acute exacerbations (AE). We sought to determine whether common genetic variants influence sputum mucin concentrations and whether these variants are also associated with COPD phenotypes, specifically CB and AE. We performed a GWAS to identify quantitative trait loci for sputum mucin protein concentration (pQTL) in the Sub-Populations and InteRmediate Outcome Measures in COPD Study (SPIROMICS, n = 708 for total mucin, n = 215 for MUC5AC, MUC5B). Subsequently, we tested for associations of mucin pQTL with CB and AE using regression modeling (n = 822-1300). Replication analysis was conducted using data from COPDGene (n = 5740) and by examining results from the UK Biobank. We identified one genome-wide significant pQTL for MUC5AC (rs75401036) and two for MUC5B (rs140324259, rs10001928). The strongest association for MUC5B, with rs140324259 on chromosome 11, explained 14% of variation in sputum MUC5B. Despite being associated with lower MUC5B, the C allele of rs140324259 conferred increased risk of CB (odds ratio (OR) = 1.42; 95% confidence interval (CI): 1.10-1.80) as well as AE ascertained over three years of follow up (OR = 1.41; 95% CI: 1.02-1.94). Associations between rs140324259 and CB or AE did not replicate in COPDGene. However, in the UK Biobank, rs140324259 was associated with phenotypes that define CB, namely chronic mucus production and cough, again with the C allele conferring increased risk. We conclude that sputum MUC5AC and MUC5B concentrations are associated with common genetic variants, and the top locus for MUC5B may influence COPD phenotypes, in particular CB.
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Affiliation(s)
- Eric Van Buren
- Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Giorgia Radicioni
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Sarah Lester
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Wanda K. O’Neal
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Hong Dang
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Silva Kasela
- New York Genome Center, New York, New York, United States of America
- Department of Systems Biology, Columbia University, New York, New York, United States of America
| | - Suresh Garudadri
- Division of Pulmonary, Critical Care, Allergy, & Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Jeffrey L. Curtis
- Pulmonary & Critical Care Medicine Division, University of Michigan, Ann Arbor, Michigan, United States of America
- Medical Service, VA Ann Arbor Healthcare System, Ann Arbor, Michigan, United States of America
| | - MeiLan K. Han
- Pulmonary & Critical Care Medicine Division, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jerry A. Krishnan
- Breathe Chicago Center, University of Illinois, Chicago, Illinois, United States of America
| | - Emily S. Wan
- Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- VA Boston Healthcare System, Jamaica Plain, Massachusetts, United States of America
| | - Edwin K. Silverman
- Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Annette Hastie
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Victor E. Ortega
- Department of Internal Medicine, Division of Respiratory Medicine, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Tuuli Lappalainen
- New York Genome Center, New York, New York, United States of America
- Department of Systems Biology, Columbia University, New York, New York, United States of America
| | - Martijn C. Nawijn
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, Groningen, the Netherlands
| | - Maarten van den Berge
- Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, Groningen, the Netherlands
- Department of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Stephanie A. Christenson
- Division of Pulmonary, Critical Care, Allergy, & Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Yun Li
- Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Michael H. Cho
- Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mehmet Kesimer
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Samir N. P. Kelada
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, United States of America
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What Have Mechanistic Studies Taught Us About Childhood Asthma? THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2023; 11:684-692. [PMID: 36649800 DOI: 10.1016/j.jaip.2023.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Childhood asthma is a chronic heterogeneous syndrome consisting of different disease entities or phenotypes. The immunologic and cellular processes that occur during asthma development are still not fully understood but represent distinct endotypes. Mechanistic studies have examined the role of gene expression, protein levels, and cell types in early life development and the manifestation of asthma, many under the influence of environmental stimuli, which can be both protective and risk factors for asthma. Genetic variants can regulate gene expression, controlled partly by different epigenetic mechanisms. In addition, environmental factors, such as living space, nutrition, and smoking, can contribute to these mechanisms. All of these factors produce modifications in gene expression that can alter the development and function of immune and epithelial cells and subsequently different trajectories of childhood asthma. These early changes in a partially immature immune system can have dramatic effects (e.g., causing dysregulation), which in turn contribute to different disease endotypes and may help to explain differential responsiveness to asthma treatment. In this review, we summarize published studies that have aimed to uncover distinct mechanisms in childhood asthma, considering genetics, epigenetics, and environment. Moreover, a discussion of new, powerful tools for single-cell immunologic assays for phenotypic and functional analysis is included, which promise new mechanistic insights into childhood asthma development and therapeutic and preventive strategies.
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Aegerter H, Lambrecht BN. The Pathology of Asthma: What Is Obstructing Our View? ANNUAL REVIEW OF PATHOLOGY 2023; 18:387-409. [PMID: 36270294 DOI: 10.1146/annurev-pathol-042220-015902] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite the advent of sophisticated and efficient new biologics to treat inflammation in asthma, the disease persists. Even following treatment, many patients still experience the well-known symptoms of wheezing, shortness of breath, and coughing. What are we missing? Here we examine the evidence that mucus plugs contribute to a substantial portion of disease, not only by physically obstructing the airways but also by perpetuating inflammation. In this way, mucus plugs may act as an immunogenic stimulus even in the absence of allergen or with the use of current therapeutics. The alterations of several parameters of mucus biology, driven by type 2 inflammation, result in sticky and tenacious sputum, which represents a potent threat, first due to the difficulties in expectoration and second by acting as a platform for viral, bacterial, or fungal colonization that allows exacerbations. Therefore, in this way, mucus plugs are an overlooked but critical feature of asthmatic airway disease.
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Affiliation(s)
- Helena Aegerter
- Laboratory of Immunoregulation and Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent, Belgium; .,Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Bart N Lambrecht
- Laboratory of Immunoregulation and Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent, Belgium; .,Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium.,Department of Pulmonary Medicine, Erasmus MC, Rotterdam, The Netherlands
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7
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Asthma Management in Children. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2023; 11:9-18. [PMID: 36334702 DOI: 10.1016/j.jaip.2022.10.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/05/2022] [Accepted: 10/18/2022] [Indexed: 11/11/2022]
Abstract
Asthma is a common, complex heterogeneous disease often beginning in early life and is characterized by reversible airflow obstruction. The phenotypic differences that exist in children with asthma may impact underlying comorbid conditions and pharmacologic treatment choices. Prenatal factors for increased risk of asthma could include maternal diet and the maternal microbiome. Evidence also suggests that postnatal microbial exposures and colonization contribute to the risk of allergic diseases and asthma. After confirming the diagnosis, asthma management in children centers on 3 broad areas: pharmacologic treatment, treatment of underlying comorbidities, and education of the patient and caregivers on the importance of adherence and device technique. Moreover, social determinants of health significantly impact on symptom burden and treatment response.
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Busse WW, Castro M, Casale TB. Asthma Management in Adults. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2023; 11:21-33. [PMID: 36283607 DOI: 10.1016/j.jaip.2022.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/14/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022]
Abstract
Management of asthma in adults has advanced in the past 10 years. Central to these advances has been further clarification of type (T) 2 mechanisms of airway inflammation and utilization of T2 biomarkers, that is, eosinophils and fractional exhaled nitric oxide. In addition, epithelial cells are emerging as significant contributors to inflammation through generation of alarmins to initiate local injury as well as downstream pathways. Five new biologics, mepolizumab, benralizumab, reslizumab, dupilumab, and tezepelumab, were approved to join omalizumab and revolutionize severe asthma treatment. These biologics significantly prevent exacerbations to spare systemic corticosteroids use and their side effects. Guidelines attest to the effectiveness of inhaled corticosteroids/long-acting β-agonists (formoterol) for both maintenance and rescue therapy. Focused updates to the Expert Panel Report addressed limited but specific questions relevant to asthma control. Future guidelines should include phenotype/endotype-directed therapeutics to gain more precision-directed treatment.
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Affiliation(s)
- William W Busse
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis.
| | - Mario Castro
- Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas, Kansas City, Kan
| | - Thomas B Casale
- Division of Allergy and Immunology, University of South Florida, Tampa, Fla
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Jackson DJ, Bacharier LB, Gergen PJ, Gagalis L, Calatroni A, Wellford S, Gill MA, Stokes J, Liu AH, Gruchalla RS, Cohen RT, Makhija M, Khurana Hershey GK, O'Connor GT, Pongracic JA, Sherenian MG, Rivera-Spoljaric K, Zoratti EM, Teach SJ, Kattan M, Dutmer CM, Kim H, Lamm C, Sheehan WJ, Segnitz RM, Dill-McFarland KA, Visness CM, Becker PM, Gern JE, Sorkness CA, Busse WW, Altman MC. Mepolizumab for urban children with exacerbation-prone eosinophilic asthma in the USA (MUPPITS-2): a randomised, double-blind, placebo-controlled, parallel-group trial. Lancet 2022; 400:502-511. [PMID: 35964610 PMCID: PMC9623810 DOI: 10.1016/s0140-6736(22)01198-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/07/2022] [Accepted: 06/14/2022] [Indexed: 01/13/2023]
Abstract
BACKGROUND Black and Hispanic children living in urban environments in the USA have an excess burden of morbidity and mortality from asthma. Therapies directed at the eosinophilic phenotype reduce asthma exacerbations in adults, but few data are available in children and diverse populations. Furthermore, the molecular mechanisms that underlie exacerbations either being prevented by, or persisting despite, immune-based therapies are not well understood. We aimed to determine whether mepolizumab, added to guidelines-based care, reduced the number of asthma exacerbations during a 52-week period compared with guidelines-based care alone. METHODS This is a randomised, double-blind, placebo-controlled, parallel-group trial done at nine urban medical centres in the USA. Children and adolescents aged 6-17 years, who lived in socioeconomically disadvantaged neighbourhoods and had exacerbation-prone asthma (defined as ≥two exacerbations in the previous year) and blood eosinophils of at least 150 cells per μL were randomly assigned 1:1 to mepolizumab (6-11 years: 40 mg; 12-17 years: 100 mg) or placebo injections once every 4 weeks, plus guideline-based care, for 52 weeks. Randomisation was done using a validated automated system. Participants, investigators, and the research staff who collected outcome measures remained masked to group assignments. The primary outcome was the number of asthma exacerbations that were treated with systemic corticosteroids during 52 weeks in the intention-to-treat population. The mechanisms of treatment response were assessed by study investigators using nasal transcriptomic modular analysis. Safety was assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03292588. FINDINGS Between Nov 1, 2017, and Mar 12, 2020, we recruited 585 children and adolescents. We screened 390 individuals, of whom 335 met the inclusion criteria and were enrolled. 290 met the randomisation criteria, were randomly assigned to mepolizumab (n=146) or placebo (n=144), and were included in the intention-to-treat analysis. 248 completed the study. The mean number of asthma exacerbations within the 52-week study period was 0·96 (95% CI 0·78-1·17) with mepolizumab and 1·30 (1·08-1·57) with placebo (rate ratio 0·73; 0·56-0·96; p=0·027). Treatment-emergent adverse events occurred in 42 (29%) of 146 participants in the mepolizumab group versus 16 (11%) of 144 participants in the placebo group. No deaths were attributed to mepolizumab. INTERPRETATION Phenotype-directed therapy with mepolizumab in urban children with exacerbation-prone eosinophilic asthma reduced the number of exacerbations. FUNDING US National Institute of Allergy and Infectious Diseases and GlaxoSmithKline.
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Affiliation(s)
- Daniel J Jackson
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Leonard B Bacharier
- Department of Pediatrics, Monroe Carell Jr Children's Hospital at Vanderbilt, Nashville, TN, USA
| | - Peter J Gergen
- National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Lisa Gagalis
- National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | | | | | - Michelle A Gill
- Department of Pediatrics, Washington University, St Louis, MO, USA
| | - Jeffrey Stokes
- Department of Pediatrics, Washington University, St Louis, MO, USA
| | - Andrew H Liu
- Pediatric Pulmonary and Sleep Medicine, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO, USA
| | - Rebecca S Gruchalla
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Robyn T Cohen
- Department of Pediatrics, Boston University School of Medicine, Boston, MA, USA
| | - Melanie Makhija
- Division of Allergy and Immunology, Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | | | - George T O'Connor
- Department of Pediatrics, Boston University School of Medicine, Boston, MA, USA
| | - Jacqueline A Pongracic
- Division of Allergy and Immunology, Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Michael G Sherenian
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Division of Asthma Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Katherine Rivera-Spoljaric
- Department of Pediatrics, Washington University, St Louis, MO, USA; St Louis Children's Hospital, St Louis, MO, USA
| | - Edward M Zoratti
- Department of Medicine, Henry Ford Health System, Detroit, MI, USA
| | - Stephen J Teach
- Children's National Hospital, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Meyer Kattan
- Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Cullen M Dutmer
- Pediatrics-Allergy and Immunology, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO, USA
| | - Haejin Kim
- Department of Medicine, Henry Ford Health System, Detroit, MI, USA
| | - Carin Lamm
- Department of Pediatrics, New York Columbia University Medical Center, New York, NY, USA
| | - William J Sheehan
- Children's National Hospital, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - R Max Segnitz
- Department of Medicine, University of Washington, Seattle, WA, USA
| | | | | | - Patrice M Becker
- National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - James E Gern
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Christine A Sorkness
- School of Pharmacy, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - William W Busse
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Matthew C Altman
- Department of Medicine, University of Washington, Seattle, WA, USA; Benaroya Research Institute, Seattle, WA, USA
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Fang L, Roth M. Airway Wall Remodeling in Childhood Asthma-A Personalized Perspective from Cell Type-Specific Biology. J Pers Med 2021; 11:jpm11111229. [PMID: 34834581 PMCID: PMC8625708 DOI: 10.3390/jpm11111229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 12/16/2022] Open
Abstract
Airway wall remodeling is a pathology occurring in chronic inflammatory lung diseases including asthma, chronic obstructive pulmonary disease, and fibrosis. In 2017, the American Thoracic Society released a research statement highlighting the gaps in knowledge and understanding of airway wall remodeling. The four major challenges addressed in this statement were: (i) the lack of consensus to define “airway wall remodeling” in different diseases, (ii) methodologic limitations and inappropriate models, (iii) the lack of anti-remodeling therapies, and (iv) the difficulty to define endpoints and outcomes in relevant studies. This review focuses on the importance of cell-cell interaction, especially the bronchial epithelium, in asthma-associated airway wall remodeling. The pathology of “airway wall remodeling” summarizes all structural changes of the airway wall without differentiating between different pheno- or endo-types of asthma. Indicators of airway wall remodeling have been reported in childhood asthma in the absence of any sign of inflammation; thus, the initiation event remains unknown. Recent studies have implied that the interaction between the epithelium with immune cells and sub-epithelial mesenchymal cells is modified in asthma by a yet unknown epigenetic mechanism during early childhood.
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11
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Hu X, Shen Y, Zhao Y, Wang J, Zhang X, Tu W, Kaufman W, Feng J, Gao P. Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma. Front Immunol 2021; 12:767508. [PMID: 34868022 PMCID: PMC8634667 DOI: 10.3389/fimmu.2021.767508] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/28/2021] [Indexed: 02/05/2023] Open
Abstract
Background Despite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations. Objectives We sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma. Methods Cockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated. Results Cockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs. Conclusions These results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.
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Affiliation(s)
- Xinyue Hu
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Yingchun Shen
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Yilin Zhao
- Department of Respiratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi’an, China
| | - Ji Wang
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Pulmonary Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, Sichuan University, Chengdu, China
| | - Xin Zhang
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Integrated Traditional Chinese and Western Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Wei Tu
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Respirology & Allergy, Third Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - William Kaufman
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Juntao Feng
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Peisong Gao
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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12
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Peebles RS. Stuck in the MUC. J Allergy Clin Immunol 2021; 148:1476-1477. [PMID: 34653516 DOI: 10.1016/j.jaci.2021.09.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/06/2021] [Accepted: 09/28/2021] [Indexed: 11/25/2022]
Affiliation(s)
- R Stokes Peebles
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Nashville, Tenn; Department of Pathology, Microbiology, and Immunology, Nashville, Tenn; United States Department of Veterans Affairs, Nashville, Tenn.
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