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Respiratory infections cause significant morbidity and mortality, yet it is unclear why some individuals succumb to severe disease. In patients hospitalized with avian A(H7N9) influenza, we investigated early drivers underpinning fatal disease. Transcriptomics strongly linked oleoyl-acyl-carrier-protein (ACP) hydrolase (OLAH), an enzyme mediating fatty acid production, with fatal A(H7N9) early after hospital admission, persisting until death. Recovered patients had low OLAH expression throughout hospitalization. High OLAH levels were also detected in patients hospitalized with life-threatening seasonal influenza, COVID-19, respiratory syncytial virus (RSV), and multisystem inflammatory syndrome in children (MIS-C) but not during mild disease. In olah-/- mice, lethal influenza infection led to survival and mild disease as well as reduced lung viral loads, tissue damage, infection-driven pulmonary cell infiltration, and inflammation. This was underpinned by differential lipid droplet dynamics as well as reduced viral replication and virus-induced inflammation in macrophages. Supplementation of oleic acid, the main product of OLAH, increased influenza replication in macrophages and their inflammatory potential. Our findings define how the expression of OLAH drives life-threatening viral disease.
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COVID-19 , Influenza Humana , Animais , Humanos , Camundongos , COVID-19/virologia , COVID-19/genética , Influenza Humana/virologia , Replicação Viral , Macrófagos/metabolismo , Macrófagos/virologia , Feminino , Masculino , SARS-CoV-2 , Pulmão/virologia , Pulmão/patologia , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Ácido Oleico/metabolismo , Infecções por Vírus Respiratório Sincicial/virologia , Camundongos Knockout , Carga Viral , Hidrolases de Éster Carboxílico/metabolismo , Hidrolases de Éster Carboxílico/genética , Infecções por Orthomyxoviridae/virologia , Infecções Respiratórias/virologia , CriançaRESUMO
One in ten severe acute respiratory syndrome coronavirus 2 infections result in prolonged symptoms termed long coronavirus disease (COVID), yet disease phenotypes and mechanisms are poorly understood1. Here we profiled 368 plasma proteins in 657 participants ≥3 months following hospitalization. Of these, 426 had at least one long COVID symptom and 233 had fully recovered. Elevated markers of myeloid inflammation and complement activation were associated with long COVID. IL-1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue and anxiety/depression; MATN2, CSF3 and C1QA were elevated in gastrointestinal symptoms and C1QA was elevated in cognitive impairment. Additional markers of alterations in nerve tissue repair (SPON-1 and NFASC) were elevated in those with cognitive impairment and SCG3, suggestive of brain-gut axis disturbance, was elevated in gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2-specific immunoglobulin G (IgG) was persistently elevated in some individuals with long COVID, but virus was not detected in sputum. Analysis of inflammatory markers in nasal fluids showed no association with symptoms. Our study aimed to understand inflammatory processes that underlie long COVID and was not designed for biomarker discovery. Our findings suggest that specific inflammatory pathways related to tissue damage are implicated in subtypes of long COVID, which might be targeted in future therapeutic trials.
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Pesquisa Biomédica , COVID-19 , Humanos , Síndrome de COVID-19 Pós-Aguda , Hospitalização , Imunoglobulina GRESUMO
Critical illness in COVID-19 is an extreme and clinically homogeneous disease phenotype that we have previously shown1 to be highly efficient for discovery of genetic associations2. Despite the advanced stage of illness at presentation, we have shown that host genetics in patients who are critically ill with COVID-19 can identify immunomodulatory therapies with strong beneficial effects in this group3. Here we analyse 24,202 cases of COVID-19 with critical illness comprising a combination of microarray genotype and whole-genome sequencing data from cases of critical illness in the international GenOMICC (11,440 cases) study, combined with other studies recruiting hospitalized patients with a strong focus on severe and critical disease: ISARIC4C (676 cases) and the SCOURGE consortium (5,934 cases). To put these results in the context of existing work, we conduct a meta-analysis of the new GenOMICC genome-wide association study (GWAS) results with previously published data. We find 49 genome-wide significant associations, of which 16 have not been reported previously. To investigate the therapeutic implications of these findings, we infer the structural consequences of protein-coding variants, and combine our GWAS results with gene expression data using a monocyte transcriptome-wide association study (TWAS) model, as well as gene and protein expression using Mendelian randomization. We identify potentially druggable targets in multiple systems, including inflammatory signalling (JAK1), monocyte-macrophage activation and endothelial permeability (PDE4A), immunometabolism (SLC2A5 and AK5), and host factors required for viral entry and replication (TMPRSS2 and RAB2A).
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COVID-19 , Estado Terminal , Predisposição Genética para Doença , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , COVID-19/genética , Predisposição Genética para Doença/genética , Variação Genética/genética , Genótipo , Técnicas de Genotipagem , Monócitos/metabolismo , Fenótipo , Proteínas rab de Ligação ao GTP/genética , Transcriptoma , Sequenciamento Completo do GenomaRESUMO
RATIONALE: Respiratory syncytial virus (RSV) is a common global respiratory virus increasingly recognized as a major pathogen in frail older adults and as a cause of chronic obstructive pulmonary disease (COPD) exacerbations. There is no single test for RSV in adults with acceptable diagnostic accuracy. Trials of RSV vaccines have recently shown excellent safety and efficacy against RSV in older adults; defining the frequency of RSV-related community infections and COPD exacerbations is important for vaccine deployment decisions. OBJECTIVES: This prospective study aimed to establish the frequency of outpatient-managed RSV-related exacerbations of COPD in two well-characterized patient cohorts using a combination of diagnostic methods. METHODS: Participants were recruited at specialist clinics in London, UK and Groningen, NL from 2017 and observed for three consecutive RSV seasons, during exacerbations and at least twice yearly. RSV infections were detected by reverse transcription-polymerase chain reaction (RT-PCR) and serologic testing. MEASUREMENTS AND MAIN RESULTS: 377 patients with COPD attended 1,999 clinic visits and reported 310 exacerbations. There were 27 RSV-related exacerbations (8·7% of total); of these, seven were detected only on PCR, 16 only on serology and 4 by both methods. Increases in RSV specific N-protein antibody were as sensitive as antibody to pre-F or post-F for serodiagnosis of RSV related exacerbations. CONCLUSIONS: RSV is associated with 8.7% of outpatient managed COPD exacerbations in this study. Antibodies to RSV-N protein may have diagnostic value, potentially important in a vaccinated population. The introduction of vaccines that prevent RSV is expected to benefit patients with COPD. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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BACKGROUND: Respiratory syncytial virus (RSV) is a significant cause of infant morbidity and mortality worldwide. Most children experience at least one 1 RSV infection by the age of two 2 years, but not all develop severe disease. However, the understanding of genetic risk factors for severe RSV is incomplete. Consequently, we conducted a genome-wide association study of RSV severity. METHODS: Disease severity was assessed by the ReSVinet scale, in a cohort of 251 infants aged 1 week to 1 year. Genotyping data were collected from multiple European study sites as part of the RESCEU Consortium. Linear regression models were used to assess the impact of genotype on RSV severity and gene expression as measured by microarray. RESULTS: While no SNPs reached the genome-wide statistical significance threshold (P < 5 × 10-8), we identified 816 candidate SNPs with a P-value of <1 × 10-4. Functional annotation of candidate SNPs highlighted genes relevant to neutrophil trafficking and cytoskeletal functions, including LSP1 and RAB27A. Moreover, SNPs within the RAB27A locus significantly altered gene expression (false discovery rate, FDR P < .05). CONCLUSIONS: These findings may provide insights into genetic mechanisms driving severe RSV infection, offering biologically relevant information for future investigations.
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Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Lactente , Criança , Humanos , Estudo de Associação Genômica Ampla , Vírus Sincicial Respiratório Humano/genética , Genótipo , Análise em MicrossériesRESUMO
BACKGROUND: While inflammatory and immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in peripheral blood are extensively described, responses at the upper respiratory mucosal site of initial infection are relatively poorly defined. We sought to identify mucosal cytokine/chemokine signatures that distinguished coronavirus disease 2019 (COVID-19) severity categories, and relate these to disease progression and peripheral inflammation. METHODS: We measured 35 cytokines and chemokines in nasal samples from 274 patients hospitalized with COVID-19. Analysis considered the timing of sampling during disease, as either the early (0-5 days after symptom onset) or late (6-20 days after symptom onset) phase. RESULTS: Patients that survived severe COVID-19 showed interferon (IFN)-dominated mucosal immune responses (IFN-γ, CXCL10, and CXCL13) early in infection. These early mucosal responses were absent in patients who would progress to fatal disease despite equivalent SARS-CoV-2 viral load. Mucosal inflammation in later disease was dominated by interleukin 2 (IL-2), IL-10, IFN-γ, and IL-12p70, which scaled with severity but did not differentiate patients who would survive or succumb to disease. Cytokines and chemokines in the mucosa showed distinctions from responses evident in the peripheral blood, particularly during fatal disease. CONCLUSIONS: Defective early mucosal antiviral responses anticipate fatal COVID-19 but are not associated with viral load. Early mucosal immune responses may define the trajectory of severe COVID-19.
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COVID-19 , Citocinas , Inflamação , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/mortalidade , Masculino , Feminino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Citocinas/sangue , Idoso , Inflamação/imunologia , Imunidade nas Mucosas , Carga Viral , Adulto , Quimiocinas/sangue , Índice de Gravidade de Doença , Mucosa Nasal/imunologia , Mucosa Nasal/virologiaRESUMO
Early life is a time of increased susceptibility to infectious diseases and development of allergy. Innate lymphocytes are crucial components of the initiation and regulation of immune responses at mucosal surfaces, but functional differences in innate lymphocytes early in life are not fully described. We aimed to characterize the abundance and function of different innate lymphocyte cell populations in cord blood in comparison to that of adults. Blood was collected from adult donors and umbilical vessels at birth. Multicolor flow cytometry panels were used to identify and characterize lymphocyte populations and their capacity to produce hallmark cytokines. Lymphocytes were more abundant in cord blood compared to adults, however, mucosal-associated invariant T cells and natural killer T (NKT)-like cells, were far less abundant. The capacity of NKT-like cells to produce cytokines and their expression of the cytotoxic granule protein granzyme B and the marker of terminal differentiation CD57 were much lower in cord blood than in adults. In contrast, natural killer (NK) cells were as abundant in cord blood as in adults, they could produce IFNγ, and their expression of granzyme B was not significantly different from that of adult NK cells, although CD57 expression was lower. All innate lymphoid cell (ILC) subsets were more abundant in cord blood, and ILC1 and ILC2 were capable of production of IFNγ and IL-13, respectively. In conclusion, different innate lymphoid cells differ in both abundance and function in peripheral blood at birth and with important implications for immunity in early life.
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Imunidade Inata , Células Matadoras Naturais , Humanos , Adulto , Recém-Nascido , Citocinas/metabolismo , Subpopulações de Linfócitos , Expressão GênicaRESUMO
BACKGROUND: There is limited knowledge on how local cytokine secretion patterns after nasal allergen challenge correlate with clinical symptoms especially with regard to the "late allergic response," which occurs in approximately 40% to 50% of patients with allergy. OBJECTIVE: We sought to characterize the immunologic and clinical nasal responses to birch pollen allergen challenge with a special focus on the late allergic response. METHODS: In this randomized, double-blind, placebo-controlled trial, birch pollen-allergic participants were challenged with birch pollen extract (n = 20) or placebo (n = 10) on 3 consecutive days. On days 1 and 3, nasal secretions were collected at selected time points over a 24-hour time course for the measurement of 33 inflammatory mediators. Clinical responses were determined through subjective symptom scores and objective nasal airflow measurements. RESULTS: Provoked participants had significantly greater clinical responses and showed significant increases in tryptase and the soluble IL-33 receptor serum stimulation 2 (sST2) in nasal secretions within minutes compared with the placebo group. Eight of 20 provoked participants displayed high IL-13 levels 2 to 8 hours after allergen provocation. This group also showed significant changes in clinical parameters, with a secondary drop in nasal airflow measured by peak nasal inspiratory flow and increased symptoms of nasal obstruction, which significantly differed from IL-13 nonresponders after 6 hours. CONCLUSIONS: IL-13 response status correlates with clinical responses and type 2 cytokine responses in the late phase after allergen provocation.
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Hipersensibilidade , Rinite Alérgica Sazonal , Humanos , Interleucina-13 , Pólen , Alérgenos , Citocinas , Mucosa Nasal , Testes de Provocação NasalRESUMO
Complement, a critical defence against pathogens, has been implicated as a driver of pathology in COVID-19. Complement activation products are detected in plasma and tissues and complement blockade is considered for therapy. To delineate roles of complement in immunopathogenesis, we undertook the largest comprehensive study of complement in COVID-19 to date, comprehensive profiling of 16 complement biomarkers, including key components, regulators and activation products, in 966 plasma samples from 682 hospitalized COVID-19 patients collected across the hospitalization period as part of the UK ISARIC4C (International Acute Respiratory and Emerging Infection Consortium) study. Unsupervised clustering of complement biomarkers mapped to disease severity and supervised machine learning identified marker sets in early samples that predicted peak severity. Compared to healthy controls, complement proteins and activation products (Ba, iC3b, terminal complement complex) were significantly altered in COVID-19 admission samples in all severity groups. Elevated alternative pathway activation markers (Ba and iC3b) and decreased alternative pathway regulator (properdin) in admission samples were associated with more severe disease and risk of death. Levels of most complement biomarkers were reduced in severe disease, consistent with consumption and tissue deposition. Latent class mixed modelling and cumulative incidence analysis identified the trajectory of increase of Ba to be a strong predictor of peak COVID-19 disease severity and death. The data demonstrate that early-onset, uncontrolled activation of complement, driven by sustained and progressive amplification through the alternative pathway amplification loop is a ubiquitous feature of COVID-19, further exacerbated in severe disease. These findings provide novel insights into COVID-19 immunopathogenesis and inform strategies for therapeutic intervention.
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COVID-19 , Humanos , Ativação do Complemento , Proteínas do Sistema Complemento/metabolismo , Complemento C3b , Biomarcadores , Progressão da Doença , Via Alternativa do ComplementoRESUMO
Post-acute cardiac sequelae, following SARS-CoV-2 infection, are well recognized as complications of COVID-19. We have previously shown the persistence of autoantibodies against antigens in skin, muscle, and heart in individuals following severe COVID-19; the most common staining on skin tissue displayed an inter-cellular cement pattern consistent with antibodies against desmosomal proteins. Desmosomes play a critical role in maintaining the structural integrity of tissues. For this reason, we analyzed desmosomal protein levels and the presence of anti-desmoglein (DSG) 1, 2, and 3 antibodies in acute and convalescent sera from patients with COVID-19 of differing clinical severity. We find increased levels of DSG2 protein in sera from acute COVID-19 patients. Furthermore, we find that DSG2 autoantibody levels are increased significantly in convalescent sera following severe COVID-19 but not in hospitalized patients recovering from influenza infection or healthy controls. Levels of autoantibody in sera from patients with severe COVID-19 were comparable to levels in patients with non-COVID-19-associated cardiac disease, potentially identifying DSG2 autoantibodies as a novel biomarker for cardiac damage. To determine if there was any association between severe COVID-19 and DSG2, we stained post-mortem cardiac tissue from patients who died from COVID-19 infection. This confirmed DSG2 protein within the intercalated discs and disruption of the intercalated disc between cardiomyocytes in patients who died from COVID-19. Our results reveal the potential for DSG2 protein and autoimmunity to DSG2 to contribute to unexpected pathologies associated with COVID-19 infection.
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Autoanticorpos , COVID-19 , Humanos , Autoanticorpos/metabolismo , Soroterapia para COVID-19 , SARS-CoV-2 , MiocárdioRESUMO
BACKGROUND: Respiratory syncytial virus (RSV) infections occur in human populations around the globe, causing disease of variable severity, disproportionately affecting infants and older adults (>65 years of age). Immune responses can be protective but also contribute to disease. Experimental studies in animals enable detailed investigation of immune responses, provide insights into clinical questions, and accelerate the development of passive and active vaccination. We aimed to review the role of antibody and T-cell responses in relation to RSV disease severity in animals. METHODS: Systematic review and meta-analysis of animal studies examining the association between T-cell responses/phenotype or antibody titers and severity of RSV disease. The PubMed, Zoological Record, and Embase databases were screened from January 1980 to May 2018 to identify animal studies of RSV infection that assessed serum antibody titer or T lymphocytes with disease severity as an outcome. Sixty-three studies were included in the final review. RESULTS: RSV-specific antibody appears to protect from disease in mice, but such an effect was less evident in bovine RSV. Strong T-cell, Th1, Th2, Th17, CD4/CD8 responses, and weak Treg responses accompany severe disease in mice. CONCLUSIONS: Murine studies suggest that measures of T-lymphocyte activity (particularly CD4 and CD8 T cells) may be predictive biomarkers of severity. Further inquiry is merited to validate these results and assess relevance as biomarkers for human disease.
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Infecções por Vírus Respiratório Sincicial , Vírus Sinciciais Respiratórios , Idoso , Animais , Anticorpos Antivirais , Biomarcadores , Linfócitos T CD8-Positivos , Bovinos , Humanos , Lactente , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Relationships between viral load, severity of illness, and transmissibility of virus are fundamental to understanding pathogenesis and devising better therapeutic and prevention strategies for COVID-19. Here we present within-host modelling of viral load dynamics observed in the upper respiratory tract (URT), drawing upon 2172 serial measurements from 605 subjects, collected from 17 different studies. We developed a mechanistic model to describe viral load dynamics and host response and contrast this with simpler mixed-effects regression analysis of peak viral load and its subsequent decline. We observed wide variation in URT viral load between individuals, over 5 orders of magnitude, at any given point in time since symptom onset. This variation was not explained by age, sex, or severity of illness, and these variables were not associated with the modelled early or late phases of immune-mediated control of viral load. We explored the application of the mechanistic model to identify measured immune responses associated with the control of the viral load. Neutralising antibodies correlated strongly with modelled immune-mediated control of viral load amongst subjects who produced neutralising antibodies. Our models can be used to identify host and viral factors which control URT viral load dynamics, informing future treatment and transmission blocking interventions.
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COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Humanos , Carga ViralRESUMO
BACKGROUND: Acute respiratory viral infections are a major cause of respiratory morbidity and mortality, especially in patients with preexisting lung diseases such as asthma. Toll-like receptors are critical in the early detection of viruses and in activating innate immunity in the respiratory mucosa, but there is no reliable and convenient method by which respiratory mucosal innate immune responses can be measured. OBJECTIVE: We sought to assess in vivo immune responses to an innate stimulus and compare responsiveness between healthy volunteers and volunteers with allergy. METHODS: We administered the Toll-like receptor 7/8 agonist resiquimod (R848; a synthetic analogue of single-stranded RNA) or saline by nasal spray to healthy participants without allergy (n = 12), those with allergic rhinitis (n = 12), or those with allergic rhinitis with asthma (n = 11). Immune mediators in blood and nasal fluid and mucosal gene expression were monitored over time. RESULTS: R848 was well tolerated and significantly induced IFN-α2a, IFN-γ, proinflammatory cytokines (TNF-α, IL-2, IL-12p70), and chemokines (CXCL10, C-C motif chemokine ligand [CCL]2, CCL3, CCL4, and CCL13) in nasal mucosal fluid, without causing systemic immune activation. Participants with allergic rhinitis or allergic rhinitis with asthma had increased IFN-α2a, CCL3, and CCL13 responses relative to healthy participants; those with asthma had increased induction of IFN-stimulated genes DExD/H-box helicase 58, MX dynamin-like GTPase 1, and IFN-induced protein with tetratricopeptide repeats 3. CONCLUSIONS: Responses to nasal delivery of R848 enables simple assessment of mucosal innate responsiveness, revealing that patients with allergic disorders have an increased nasal mucosal IFN and chemokine response to the viral RNA analogue R848. This highlights that dysregulated innate immune responses of the nasal mucosa in allergic individuals may be important in determining the outcome of viral exposure.
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Asma/imunologia , Imidazóis/farmacologia , Imunidade Inata/imunologia , Mucosa Nasal/imunologia , Rinite Alérgica/imunologia , Adulto , Feminino , Humanos , Imunidade Inata/efeitos dos fármacos , Interferons/imunologia , Masculino , Proteínas Quimioatraentes de Monócitos/imunologia , Mucosa Nasal/efeitos dos fármacos , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistasRESUMO
OBJECTIVE: Cartilage and bone damage in RA are associated with elevated IL-1ß. The effects of IL-1ß can be reduced by biological therapies that target IL-1ß or TNF-α. However, the mechanisms responsible for increased IL-1ß and the effect of anti-TNF-α have not been fully elucidated. Recently, sterile-α and armadillo motif containing protein (SARM) was identified as a negative regulator of toll-like receptor (TLR) induced IL-1ß secretion through an interaction with the inflammasome. This study set out to investigate SARM during TLR-induced IL-1ß secretion in RA peripheral blood monocytes and in patients commencing anti-TNF-α treatment. METHODS: Monocytes were isolated from RA patients and healthy controls; disease activity was measured by DAS28. IL-1ß secretion was measured by ELISA following TLR1/2, TLR4 and TLR7/8 stimulation. The mRNA expression of SARM1, IL-1ß and the components of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome were measured by quantitative PCR. SARM protein expression was measured by western blotting. RESULTS: TLR1/2 activation induced elevated IL-1ß in RA monocytes compared with healthy controls (P = 0.0009), which negatively correlated with SARM1 expression (P = 0.0086). Lower SARM expression also correlated with higher disease activity (P = 0.0246). Additionally, patients responding to anti-TNF-α treatment demonstrated a rapid upregulation of SARM, which was not observed in non-responders. CONCLUSION: Together, these data highlight a potential contribution from SARM to RA pathophysiology where decreased SARM may lead to elevated IL-1ß associated with RA pathogenesis. Furthermore, the data additionally present a potential mechanism by which TNF-α blockade can modify IL-1ß secretion.
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Proteínas do Domínio Armadillo/genética , Artrite Reumatoide/genética , Proteínas do Citoesqueleto/genética , Regulação da Expressão Gênica , Inflamassomos/genética , Interleucina-1beta/genética , RNA/genética , Receptor 2 Toll-Like/genética , Adulto , Proteínas do Domínio Armadillo/biossíntese , Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Proteínas do Citoesqueleto/biossíntese , Feminino , Humanos , Inflamassomos/metabolismo , Interleucina-1beta/biossíntese , Masculino , Receptor 2 Toll-Like/biossínteseRESUMO
Allergic diseases of the (upper and lower) airways, the skin and the gastrointestinal tract, are on the rise, resulting in impaired quality of life, decreased productivity, and increased healthcare costs. As allergic diseases are mostly tissue-specific, local sampling methods for respective biomarkers offer the potential for increased sensitivity and specificity. Additionally, local sampling using noninvasive or minimally invasive methods can be cost-effective and well tolerated, which may even be suitable for primary or home care sampling. Non- or minimally invasive local sampling and diagnostics may enable a more thorough endotyping, may help to avoid under- or overdiagnosis, and may provide the possibility to approach precision prevention, due to early diagnosis of these local diseases even before they get systemically manifested and detectable. At the same time, dried blood samples may help to facilitate minimal-invasive primary or home care sampling for classical systemic diagnostic approaches. This EAACI position paper contains a thorough review of the various technologies in allergy diagnosis available on the market, which analytes or biomarkers are employed, and which samples or matrices can be used. Based on this assessment, EAACI position is to drive these developments to efficiently identify allergy and possibly later also viral epidemics and take advantage of comprehensive knowledge to initiate preventions and treatments.
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Hipersensibilidade , Qualidade de Vida , Humanos , Hipersensibilidade/diagnóstico , Hipersensibilidade/terapia , Sistema Respiratório , PeleRESUMO
BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in young infants. However, it is also a significant pathogen in older adults. Validated biomarkers of RSV disease severity would benefit diagnostics, treatment decisions, and prophylactic interventions. This review summarizes knowledge of biomarkers for RSV disease in adults. METHODS: A literature review was performed using Ovid Medline, Embase, Global health, Scopus, and Web of Science for articles published 1946-October 2016. Nine articles were identified plus 9 from other sources. RESULTS: From observational studies of natural infection and challenge studies in volunteers, biomarkers of RSV susceptibility or disease severity in adults were: (1) lower anti-RSV neutralizing antibodies, where neutralizing antibody (and local IgA) may be a correlate of susceptibility/severity; (2) RSV-specific CD8+ T cells in bronchoalveolar lavage fluid preinfection (subjects with higher levels had less severe illness); and (3) elevated interleukin-6 (IL-6), IL-8, and myeloperoxidase levels in the airway are indicative of severe infection. CONCLUSIONS: Factors determining susceptibility to and severity of RSV disease in adults have not been well defined. Respiratory mucosal antibodies and CD8+â T cells appear to contribute to preventing infection and modulation of disease severity. Studies of RSV pathogenesis in at-risk populations are needed.
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Biomarcadores/sangue , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/imunologia , Índice de Gravidade de Doença , Anticorpos Neutralizantes/imunologia , Bronquiolite , Linfócitos T CD8-Positivos/imunologia , Humanos , Imunidade Celular , Inflamação , Interleucina-6 , Interleucina-8 , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/imunologia , Carga ViralRESUMO
Respiratory syncytial virus (RSV) is the leading viral pathogen associated with acute lower respiratory tract infection and hospitalization in children < 5 years of age worldwide. While there are known clinical risk factors for severe RSV infection, the majority of those hospitalized are previously healthy infants. There is consequently an unmet need to identify biomarkers that predict host response, disease severity, and sequelae. The primary objective is to identify biomarkers of severe RSV acute respiratory tract infection (ARTI) in infants. Secondary objectives include establishing biomarkers associated with respiratory sequelae following RSV infection and characterizing the viral load, RSV whole-genome sequencing, host immune response, and transcriptomic, proteomic, metabolomic and epigenetic signatures associated with RSV disease severity. Six hundred thirty infants will be recruited across 3 European countries: the Netherlands, Spain, and the United Kingdom. Participants will be recruited into 2 groups: (1) infants with confirmed RSV ARTI (includes upper and lower respiratory tract infections), 500 without and 50 with comorbidities; and (2) 80 healthy controls. At baseline, participants will have nasopharyngeal, blood, buccal, stool, and urine samples collected, plus complete a questionnaire and 14-day symptom diary. At convalescence (7 weeks ± 1 week post-ARTI), specimen collection will be repeated. Laboratory measures will be correlated with symptom severity scores to identify corresponding biomarkers of disease severity. CLINICAL TRIALS REGISTRATION: NCT03756766.
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Progressão da Doença , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/virologia , Índice de Gravidade de Doença , Biomarcadores , Estudos de Casos e Controles , Epigenômica , Europa (Continente) , Feminino , Humanos , Lactente , Masculino , Metabolômica , Nasofaringe/virologia , Países Baixos , Proteômica , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/virologia , Fatores de Risco , Espanha , Inquéritos e Questionários , Transcriptoma , Reino Unido , Carga ViralRESUMO
BACKGROUND: Neisseria meningitidis (Nm) is a nasopharyngeal commensal carried by healthy individuals. However, invasive infections occurs in a minority of individuals, with devastating consequences. There is evidence that common polymorphisms are associated with invasive meningococcal disease (IMD), but the contributions of rare variants other than those in the complement system have not been determined. METHODS: We identified familial cases of IMD in the UK meningococcal disease study and the European Union Life-Threatening Infectious Disease Study. Candidate genetic variants were identified by whole-exome sequencing of 2 patients with familial IMD. Candidate variants were further validated by in vitro assays. RESULTS: Exomes of 2 siblings with IMD identified a novel heterozygous missense mutation in BPIFA1/SPLUNC1. Sequencing of 186 other nonfamilial cases identified another unrelated IMD patient with the same mutation. SPLUNC1 is an innate immune defense protein expressed in the nasopharyngeal epithelia; however, its role in invasive infections is unknown. In vitro assays demonstrated that recombinant SPLUNC1 protein inhibits biofilm formation by Nm, and impedes Nm adhesion and invasion of human airway cells. The dominant negative mutant recombinant SPLUNC1 (p.G22E) showed reduced antibiofilm activity, increased meningococcal adhesion, and increased invasion of cells, compared with wild-type SPLUNC1. CONCLUSIONS: A mutation in SPLUNC1 affecting mucosal attachment, biofilm formation, and invasion of mucosal epithelial cells is a new genetic cause of meningococcal disease.
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Glicoproteínas/genética , Infecções Meningocócicas/genética , Infecções Meningocócicas/microbiologia , Neisseria meningitidis , Fosfoproteínas/genética , Proteínas do Sistema Complemento , Células Epiteliais , Humanos , Mutação , Neisseria meningitidis/genéticaRESUMO
OBJECTIVE: RA is an autoimmune inflammatory joint disease. Both RF and ACPA are associated with more progressive disease and higher levels of systemic inflammation. Monocyte activation of toll-like receptors (TLRs) by endogenous ligands is a potential source of increased production of systemic cytokines. RA monocytes have elevated TLRs, some of which are associated with the disease activity score using 28 joints (DAS28). The aim of this study was to measure TLR-induced cytokine production from monocytes, stratified by autoantibody status, to assess if their capacity to induce cytokines is related to autoantibody status or DAS28. METHODS: Peripheral blood monocytes isolated from RA patients and healthy controls were stimulated with TLR1/2, TLR2/6, TLR4, TLR5, TLR7, TLR8 and TLR9 ligands for 18 h before measuring IL-6, TNFα and IL-10. Serum was used to confirm the autoantibody status. Cytokine levels were compared with RF, ACPA and DAS28. RESULTS: RA monocytes demonstrated significantly increased IL-6 and TNFα upon TLR1/2 stimulation and IL-6 and IL-10 upon TLR5 activation. TLR7 and TLR9 activation did not induce cytokines and no significant differences were observed between RA and healthy control monocytes upon TLR2/6, TLR4 or TLR8 activation. When stratified by ACPA or RF status there were no correlations between autoantibody status and elevated cytokine levels. However, TLR1/2-induced IL-6 did correlate with DAS28. CONCLUSIONS: Elevated TLR-induced cytokines in RA monocytes were not related to ACPA or RF status. However, TLR1/2-induced IL-6 was associated with disease activity.