RESUMO
OBJECTIVES: The presence of respiratory viruses and the association with outcomes were assessed in invasively ventilated ICU patients, stratified by admission diagnosis. DESIGN: Prospective observational study. SETTING: Five ICUs in the Netherlands. PATIENTS: Between September 1, 2013, and April 30, 2014, 1,407 acutely admitted and invasively ventilated patients were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nasopharyngeal swabs and tracheobronchial aspirates were collected upon intubation and tested for 14 respiratory viruses. Out of 1,407 patients, 156 were admitted because of a severe acute respiratory infection and 1,251 for other reasons (non-severe acute respiratory infection). Respiratory viruses were detected in 28.8% of severe acute respiratory infection patients and 17.0% in non-severe acute respiratory infection (p < 0.001). In one third, viruses were exclusively detected in tracheobronchial aspirates. Rhinovirus and human metapneumovirus were more prevalent in severe acute respiratory infection patients (9.6% and 2.6% vs 4.5 and 0.2%; p = 0.006 and p < 0.001). In both groups, there were no associations between the presence of viruses and the number of ICU-free days at day 28, crude mortality, and mortality in multivariate regression analyses. CONCLUSIONS: Respiratory viruses are frequently detected in acutely admitted and invasively ventilated patients. Rhinovirus and human metapneumovirus are more frequently found in severe acute respiratory infection patients. Detection of respiratory viruses is not associated with worse clinically relevant outcomes in the studied cohort of patients.
Assuntos
Infecção Hospitalar/virologia , Unidades de Terapia Intensiva , Respiração Artificial , Infecções Respiratórias/virologia , Viroses/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecção Hospitalar/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Países Baixos , Estudos Prospectivos , Infecções Respiratórias/mortalidade , Viroses/mortalidadeRESUMO
Secondary bacterial pneumonia is a frequent complication of influenza, associated with high morbidity and mortality. We hypothesized that treatment with neutralizing influenza A antibody AT10_002 protects against severe secondary pneumococcal infection in a mouse model of influenza A infection. Influenza A (H3N2) virus-infected male C57Bl6 mice were treated intravenously with either AT10_002 or a control 2 days postinfection. Seven days later, both groups were infected with Streptococcus pneumoniae and killed 18 hours later. Mice receiving AT10_002 showed less loss of bodyweight compared with controls (+1% vs -12%, P < .001), lower viral loads in bronchoalveolar lavage fluids (BALFs) (7 vs 194 RNA copies per µL; P < .001), and reduced bacterial outgrowth in lung homogenates (3.3 × 101 vs 2.5 × 105 colony-forming units per mg; P < .001). The treatment group showed lower pulmonary wet weights, lower cell counts, and lower protein levels in BALF compared with controls. Treatment with AT10_002 was associated with lower levels of tumor necrosis factor-α, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (KC), and interferon-γ in BALF and lower IL-6 and KC in lung homogenates. Treatment with anti-influenza antibody AT10_002 is associated with reduced weight loss, viral load, bacterial outgrowth, and lung injury in a murine model of secondary pneumococcal pneumonia following influenza infection.
Assuntos
Anticorpos Antivirais/administração & dosagem , Imunização Passiva/métodos , Fatores Imunológicos/administração & dosagem , Influenza Humana/complicações , Influenza Humana/terapia , Pneumonia Pneumocócica/patologia , Pneumonia Pneumocócica/prevenção & controle , Animais , Carga Bacteriana , Peso Corporal , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/virologia , Citocinas/análise , Modelos Animais de Doenças , Humanos , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Masculino , Camundongos Endogâmicos C57BL , Streptococcus pneumoniae/isolamento & purificação , Resultado do Tratamento , Carga ViralRESUMO
Bispecific antibodies have therapeutic potential by expanding the functions of conventional antibodies. Many different formats of bispecific antibodies have meanwhile been developed. Most are genetic modifications of the antibody backbone to facilitate incorporation of two different variable domains into a single molecule. Here, we present a bispecific format where we have fused two full-sized IgG antibodies via their C termini using sortase transpeptidation and click chemistry to create a covalently linked IgG antibody heterodimer. By linking two potent anti-influenza A antibodies together, we have generated a full antibody dimer with bispecific activity that retains the activity and stability of the two fusion partners.
Assuntos
Anticorpos Biespecíficos/biossíntese , Química Click , Vírus da Influenza A/imunologia , Anticorpos Biespecíficos/química , Anticorpos Biespecíficos/imunologia , Linfócitos B/virologia , Western Blotting , Células Cultivadas , Dimerização , Eletroforese em Gel de Poliacrilamida , Humanos , Vírus da Influenza A/classificação , Ressonância de Plasmônio de SuperfícieRESUMO
The interplay between Clostridium difficile and the host's metabolome is believed to influence the severity of infection. However, the mechanism for this phenomenon remains unclear. In this study, we model one of these metabolic pathways by focusing on tryptophan metabolism in the host. We found that inhibition of tryptophan catabolism in IDO1-knockout mice led to increased mucosal destruction, cecal hemorrhage, and increased production of IFN-γ in response to C. difficile infection, but no significant change in mucosal effector or regulatory T cell numbers or IL-10 mRNA expression. The increased immunopathology in infected IDO1-knockout mice was associated with a lower C. difficile burden and an increased percentage of IFN-γ-expressing neutrophils. We further demonstrated the ability of kynurenine to induce apoptosis in bone marrow-derived neutrophils, whereas the presence of tryptophan reversed this effect, providing a possible mechanism for the increased neutrophil accumulation in IDO1(-/-) mice. We conclude that C. difficile induces tryptophan catabolism in cecal lamina propria cells, which restricts C. difficile-associated immunopathology and the accumulation of IFN-γ-expressing neutrophils. This might represent a self-regulatory mechanism for neutrophils, via the IFN-γ-IDO1 pathway, to restrict their own accumulation during infection. These findings have important clinical implications because IDO inhibitors are used to treat cancer in clinical trials (in patients particularly susceptible to getting C. difficile infection), and treatment with IDO1 inhibitors may exacerbate the severity of C. difficile colitis.
Assuntos
Clostridioides difficile/imunologia , Enterocolite Pseudomembranosa/imunologia , Interferon gama/imunologia , Neutrófilos/imunologia , Triptofano/imunologia , Animais , Antígenos Ly/imunologia , Antígenos Ly/metabolismo , Apoptose/genética , Apoptose/imunologia , Antígeno CD11b/imunologia , Antígeno CD11b/metabolismo , Ceco/imunologia , Ceco/microbiologia , Ceco/patologia , Clostridioides difficile/fisiologia , Enterocolite Pseudomembranosa/genética , Enterocolite Pseudomembranosa/microbiologia , Citometria de Fluxo , Interações Hospedeiro-Patógeno/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interferon gama/metabolismo , Cinurenina/imunologia , Cinurenina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Modelos Imunológicos , Neutrófilos/metabolismo , Triptofano/metabolismoRESUMO
BACKGROUND: Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance. METHODS: 28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation). RESULTS: 13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01).Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1. CONCLUSIONS: Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load. TRIAL REGISTRATION: This trial was registered at the Dutch trial registry (http://www.trialregister.nl): NTR1677.
Assuntos
Asma/metabolismo , Coagulação Sanguínea/fisiologia , Hemostasia/fisiologia , Infecções por Picornaviridae/metabolismo , Rhinovirus , Adulto , Asma/diagnóstico , Asma/virologia , Feminino , Humanos , Masculino , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/virologia , Adulto JovemRESUMO
BACKGROUND: Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality. Anecdotally, TRALI patients have been treated with corticosteroids. However, evidence for its therapeutic rationale in TRALI is lacking. We determined the effects of corticosteroids on lung injury in a "two-hit" mouse model of antibody-mediated TRALI. STUDY DESIGN AND METHODS: BALB/c mice were primed with lipopolysaccharide, after which TRALI was induced by injecting major histocompatibility complex (MHC)-I antibody against H2K(d) . Mice infused with phosphate-buffered saline served as controls. Simultaneously, one group of TRALI mice was infused with methylprednisolone (MPS; 2 mg/kg). Mice were supported by mechanical ventilation for 2 hours, after which bronchoalveolar lavage fluid (BALF) and lung homogenate were obtained. Statistics were obtained by one-way analysis of variance or Kruskal-Wallis. RESULTS: Injection of MHC-I antibodies resulted in TRALI, indicated by pulmonary edema and increased BALF levels of protein and the proinflammatory mediators macrophage inflammatory protein-2, keratinocyte-derived chemokine, and interleukin (IL)-6. Administration of MPS did not affect the amount of edema nor pulmonary protein and chemokine levels. MPS reduced systemic inflammatory reaction as well as IL-6 levels in the BALF. CONCLUSION: In a two-hit model of antibody-mediated TRALI, MPS attenuated the IL-6 host response, but failed to prevent the development of lung injury.
Assuntos
Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/prevenção & controle , Metilprednisolona/uso terapêutico , Reação Transfusional , Lesão Pulmonar Aguda/imunologia , Animais , Anticorpos/efeitos adversos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Antígenos H-2/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Projetos Piloto , Falha de TratamentoRESUMO
BACKGROUND: Patients with allergic asthma have exacerbations which are frequently caused by rhinovirus infection. The antiviral tryptophan-catabolising enzyme indoleamine 2,3-dioxygenase (IDO) is induced by interferon-γ and suppressed by Th2 mediators interleukin (IL)-4 and IL-13. We hypothesised that local IDO activity after viral airway infection is lower in patients with allergic asthma than in healthy controls. OBJECTIVE: To determine whether IDO activity differs between patients with allergic asthma and healthy individuals before and after rhinovirus infection. METHODS: Healthy individuals and patients with allergic asthma were experimentally infected with low-dose (10 TCID50) rhinovirus 16. Blood, bronchoalveolar lavage fluid and exhaled breath condensate (for mass spectrometry by UPLC-MS/MS) were obtained before and after rhinovirus challenge. RESULTS: IDO activity was not induced by rhinovirus infection in either group, despite increases in cold scores. However, baseline pulmonary IDO activity was lower in patients with allergic asthma than in healthy individuals. In contrast, systemic tryptophan and its catabolites were markedly higher in patients with allergic asthma. Moreover, systemic quinolinic acid and tryptophan were associated with eosinophil cationic protein (r=0.43 and r=0.78, respectively) and eosinophils (r=0.38 and r=0.58, respectively) in bronchoalveolar lavage fluid and peak asthma symptom scores after rhinovirus challenge (r=0.53 and r=0.64, respectively). CONCLUSIONS: Rhinovirus infection by itself induces no IDO activity, but the reduced pulmonary IDO activity in patients with allergic asthma at baseline may underlie a reduced control of viral infections. Notably, the enhanced systemic catabolism of tryptophan in patients with allergic asthma was strongly related to the outcome of rhinovirus challenge in asthma and may serve as a prognostic factor.
Assuntos
Asma/complicações , Asma/enzimologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Infecções por Picornaviridae/complicações , Rhinovirus , Triptofano/sangue , Adulto , Asma/fisiopatologia , Biomarcadores/análise , Biomarcadores/sangue , Testes Respiratórios , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Estudos de Casos e Controles , Citocinas/análise , Progressão da Doença , Proteína Catiônica de Eosinófilo/análise , Eosinófilos , Feminino , Humanos , Cinurenina/análise , Cinurenina/sangue , Masculino , Óxido Nítrico/análise , Peroxidase/análise , Infecções por Picornaviridae/virologia , Estudos Prospectivos , Ácido Quinolínico/análise , Ácido Quinolínico/sangue , Triptofano/análise , Adulto Jovem , ortoaminobenzoatos/análise , ortoaminobenzoatos/sangueRESUMO
To explore whether and how T cells can affect myelopoiesis, we investigated myeloid differentiation in a model for T cell-mediated immune activation. We found that CD70-transgenic (CD70TG) mice, which have elevated numbers of interferon-γ (IFN-γ)-producing effector T cells in the periphery and bone marrow, are almost devoid of eosinophilic granulocytes. Induction of allergic airway inflammation in these mice failed to induce eosinophilia as well as airway hyperresponsiveness. CD70TG mice also have strongly reduced numbers of eosinophil lineage-committed progenitors, whereas granulocyte/macrophage progenitors from these mice are unable to generate eosinophils in vitro. We found that granulocyte/macrophage progenitors express IFN-γR1 and that IFN-γ is sufficient to inhibit eosinophil differentiation of both murine and human progenitor cells in vitro. We demonstrate that inhibition of eosinophil development in CD70TG mice is IFN-γ-dependent and that T cell-derived IFN-γ is sufficient to inhibit eosinophil formation in vivo. Finally, we found that IFN-γ produced on anti-CD40 treatment and during viral infection can also suppress eosinophil formation in wild-type mice. These data demonstrate that IFN-γ inhibits the differentiation of myeloid progenitors to eosinophils, indicating that the adaptive immune system plays an important role in orchestrating the formation of the appropriate type of myeloid cells during immune activation.
Assuntos
Células da Medula Óssea/citologia , Eosinófilos/citologia , Interferon gama/imunologia , Leucopoese , Linfócitos T/imunologia , Animais , Asma/imunologia , Células da Medula Óssea/imunologia , Ligante CD27/imunologia , Linhagem Celular , Células Cultivadas , Eosinófilos/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Monócitos/citologia , Células Progenitoras Mieloides/citologia , Neutrófilos/citologia , Linfócitos T/citologiaRESUMO
BACKGROUND: The innate immune response is important in ventilator-induced lung injury (VILI) but the exact pathways involved are not elucidated. The authors studied the role of the intracellular danger sensor NLRP3 inflammasome. METHODS: NLRP3 inflammasome gene expression was analyzed in respiratory epithelial cells and alveolar macrophages obtained from ventilated patients (n = 40). In addition, wild-type and NLRP3 inflammasome deficient mice were randomized to low tidal volume (approximately 7.5 ml/kg) and high tidal volume (approximately 15 ml/kg) ventilation. The presence of uric acid in lung lavage, activation of caspase-1, and NLRP3 inflammasome gene expression in lung tissue were investigated. Moreover, mice were pretreated with interleukin-1 receptor antagonist, glibenclamide, or vehicle before start of mechanical ventilation. VILI endpoints were relative lung weights, total protein in lavage fluid, neutrophil influx, and pulmonary and systemic cytokine and chemokine concentrations. Data represent mean ± SD. RESULTS: Mechanical ventilation up-regulated messenger RNA expression levels of NLRP3 in alveolar macrophages (1.0 ± 0 vs. 1.70 ± 1.65, P less than 0.05). In mice, mechanical ventilation increased both NLRP3 and apoptosis-associated speck-like protein messenger RNA levels, respectively (1.08 ± 0.55 vs. 3.98 ± 2.89; P less than 0.001 and 0.95 ± 0.53 vs. 6.0 ± 3.55; P less than 0.001), activated caspase-1, and increased uric acid levels (6.36 ± 1.85 vs. 41.9 ± 32.0, P less than 0.001). NLRP3 inflammasome deficient mice displayed less VILI due to high tidal volume mechanical ventilation compared with wild-type mice. Furthermore, treatment with interleukin-1 receptor antagonist or glibenclamide reduced VILI. CONCLUSIONS: Mechanical ventilation induced a NLRP3 inflammasome dependent pulmonary inflammatory response. NLRP3 inflammasome deficiency partially protected mice from VILI.
Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/fisiologia , Inflamassomos/genética , Lesão Pulmonar Induzida por Ventilação Mecânica/genética , Lesão Pulmonar Induzida por Ventilação Mecânica/patologia , Animais , Líquido da Lavagem Broncoalveolar/química , Caspase 1/metabolismo , Citocinas/sangue , Citocinas/metabolismo , Ativação Enzimática/fisiologia , Células Epiteliais/metabolismo , Glibureto/farmacologia , Humanos , Macrófagos Alveolares/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR , Infiltração de Neutrófilos , Tamanho do Órgão/fisiologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores de Interleucina-1/antagonistas & inibidores , Respiração Artificial , Volume de Ventilação Pulmonar/fisiologia , Regulação para Cima/fisiologia , Ácido Úrico/metabolismoRESUMO
Influenza accounts for 5-10% of community-acquired pneumonia cases, and is a major cause of mortality. Sterile and bacterial lung injury are associated with procoagulant and inflammatory derangements in the lungs and down-regulation of the protein C (PC) pathway has been correlated with disease severity and mortality in severe bacterial pneumonia and sepsis. In addition, during lethal influenza pneumonia, pulmonary and systemic coagulation are activated, which can be attenuated by the administration of recombinant activated (A) PC. We here determined the role of endogenous PC in lethal H1N1 influenza A infection. Male C57BL/6 mice pretreated with an inhibitory monoclonal antibody directed against murine PC or a control antibody were intranasally infected with a lethal dose of a mouse-adapted H1N1 influenza A strain. Mice were killed at 48 or 96 hours after infection, after which lungs and bronchoalveolar lavage fluid were harvested, or observed for up to 9 days. Anti-PC antibody treatment aggravated pulmonary activation of coagulation as compared with control antibody treatment, as reflected by increased lung concentrations of thrombin-antithrombin complexes and fibrin degradation products, as well as intravascular thrombus formation. Anti-PC antibody treatment aggravated lung histopathology, but lowered bronchoalveolar neutrophil influx and total protein levels, and delayed mortality. In conclusion, endogenous PC has strong effects on the host response to lethal influenza A infection, inhibiting pulmonary coagulopathy and inflammation on the one hand, but facilitating neutrophil influx and protein leak and accelerating mortality on the other hand.
Assuntos
Coagulação Sanguínea , Vírus da Influenza A Subtipo H1N1/patogenicidade , Lesão Pulmonar/virologia , Pulmão/virologia , Infecções por Orthomyxoviridae/virologia , Pneumonia Viral/virologia , Proteína C/metabolismo , Trombose/virologia , Células Epiteliais Alveolares/imunologia , Células Epiteliais Alveolares/virologia , Animais , Anticorpos Monoclonais/administração & dosagem , Antitrombina III/metabolismo , Líquido da Lavagem Broncoalveolar/química , Modelos Animais de Doenças , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Injeções Intraperitoneais , Pulmão/irrigação sanguínea , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Lesão Pulmonar/sangue , Lesão Pulmonar/imunologia , Lesão Pulmonar/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos , Infecções por Orthomyxoviridae/sangue , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Peptídeo Hidrolases/metabolismo , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Proteína C/imunologia , Trombose/sangue , Trombose/imunologia , Trombose/patologia , Fatores de Tempo , Carga ViralRESUMO
Chronic infection results in continuous formation and exhaustion of effector CD8 T cells and in failure of memory CD8 T cell development. Expression of CD70 and other molecules that provide costimulation to T cells is maintained during chronic infection. To analyze the impact of constitutive CD70-driven costimulation, we generated transgenic mice expressing CD70 specifically on T cells. We show that CD70 promoted accumulation of CD8 T cells with characteristics strikingly similar to exhausted effector CD8 T cells found during chronic infection. CD70 on T cells provided costimulation that enhanced primary CD8 T cell responses against influenza. In contrast, memory CD8 T cell maintenance and protection against secondary challenge with influenza was impaired. Interestingly, we found no effect on the formation of either effector or memory CD4 T cells. We conclude that constitutive expression of CD70 is sufficient to deregulate the CD8 T cell differentiation pathway of acute infection reminiscent of events in chronic infection.
Assuntos
Ligante CD27/fisiologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Memória Imunológica , Ativação Linfocitária/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Doença Aguda , Animais , Ligante CD27/biossíntese , Ligante CD27/deficiência , Ligante CD27/genética , Linfócitos T CD8-Positivos/classificação , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Doença Crônica , Homeostase/genética , Homeostase/imunologia , Memória Imunológica/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Ativação Linfocitária/genética , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/patologia , Coriomeningite Linfocítica/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Subpopulações de Linfócitos T/classificaçãoRESUMO
INTRODUCTION: Soluble urokinase-type plasminogen activator receptor (suPAR) has been proposed as a biologic marker of fibrinolysis and inflammation. The aim of this study was to investigate the diagnostic and prognostic value of systemic and pulmonary levels of suPAR in burn patients with inhalation trauma who need mechanical ventilation. METHODS: suPAR was measured in plasma and nondirected lung-lavage fluid of mechanically ventilated burn patients with inhalation trauma. The samples were obtained on the day of inhalation trauma and on alternate days thereafter until patients were completely weaned from the mechanical ventilator. Mechanically ventilated patients without burns and without pulmonary disease served as controls. RESULTS: Systemic levels of suPAR in burn patients with inhalation trauma were not different from those in control patients. On admission and follow up, pulmonary levels of suPAR in patients with inhalation trauma were significantly higher compared with controls. Pulmonary levels of suPAR highly correlated with pulmonary levels of interleukin 6, a marker of inflammation, and thrombin-antithrombin complexes, markers of coagulation, but not plasminogen activator activity, a marker of fibrinolysis. Systemic levels of suPAR were predictive of the duration of mechanical ventilation and length of intensive care unit (ICU) stay. Duration of mechanical ventilation and length of ICU stay were significantly longer in burn-injury patients with systemic suPAR levels > 9.5 ng/ml. CONCLUSIONS: Pulmonary levels of suPAR are elevated in burn patients with inhalation trauma, and they correlate with pulmonary inflammation and coagulation. Although pulmonary levels of suPAR may have diagnostic value in burn-injury patients, systemic levels of suPAR have prognostic value.
Assuntos
Queimaduras/sangue , Receptores de Ativador de Plasminogênio Tipo Uroquinase/sangue , Respiração Artificial , Lesão por Inalação de Fumaça/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/análise , Biomarcadores/sangue , Líquido da Lavagem Broncoalveolar/química , Queimaduras/diagnóstico , Queimaduras/terapia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Estimativa de Kaplan-Meier , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Receptores de Ativador de Plasminogênio Tipo Uroquinase/análise , Lesão por Inalação de Fumaça/diagnóstico , Lesão por Inalação de Fumaça/terapia , Estatísticas não Paramétricas , Adulto JovemRESUMO
Seasonal and pandemic influenza are frequently complicated by bacterial infections, causing additional hospitalization and mortality. Secondary bacterial respiratory infection can be subdivided into combined viral/bacterial pneumonia and post-influenza pneumonia, which differ in their pathogenesis. During combined viral/bacterial infection, the virus, the bacterium and the host interact with each other. Post-influenza pneumonia may, at least in part, be due to resolution of inflammation caused by the primary viral infection. These mechanisms restore tissue homeostasis but greatly impair the host response against unrelated bacterial pathogens. In this review we summarize the underlying mechanisms leading to combined viral/bacterial infection or post-influenza pneumonia and highlight important considerations for effective treatment of bacterial pneumonia during and shortly after influenza.
Assuntos
Influenza Humana/fisiopatologia , Pneumonia Bacteriana/fisiopatologia , Comorbidade , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/epidemiologiaRESUMO
Influenza A is a single stranded (ss)RNA virus that can cause upper respiratory tract infections that in rare cases may progress to pneumonia. Toll-like receptors (TLRs) and CD14 are receptors which recognize viral proteins and nucleic acid of several viruses. CD14 is required for influenza-induced cytokine production during infection of mouse macrophages. In addition, CD14 was shown to bind ssRNA, suggesting an important role for CD14 during infection with influenza. To investigate the role of CD14 during influenza pneumonia we inoculated WT and CD14 KO mice with a non-lethal dose of a mouse adapted strain of influenza A. CD14 KO mice displayed a reduced viral load in the lungs, 2 and 14 days after infection with influenza. Pulmonary cytokine production in CD14 KO mice was reduced at day 2 and elevated at day 8 compared to WT mice. CD14 deficiency did not influence lymphocyte recruitment or lymphocyte activation in lungs and draining lymph nodes 8 days after infection. These data show that CD14 plays a limited role in host defense against infection with influenza.
Assuntos
Vírus da Influenza A/imunologia , Receptores de Lipopolissacarídeos/fisiologia , Infecções por Orthomyxoviridae/imunologia , Animais , Peso Corporal/imunologia , Receptores de Lipopolissacarídeos/genética , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/fisiopatologia , Infecções por Orthomyxoviridae/virologia , Carga ViralRESUMO
T helper 1-driven immune responses have been implicated in protective immunity against viral infections. Interleukin (IL)-12 is a heterodimeric proinflammatory cytokine formed by a p35 and a p40 subunit that can induce differentiation of naïve T cells towards a T helper 1-response. To determine the role of IL-12 in respiratory tract infection with influenza, p35 gene deficient (p35-/-) and normal wild type mice were intranasally infected with influenza A virus. IL-12 p35-/- mice displayed a transiently enhanced rather than an impaired viral clearance, as indicated by a 10-fold reduction in viral loads on day 8 after infection. Although interferon-gamma levels were significantly lower in the lungs of IL-12 p35-/- mice, their cellular immune responses were not altered, as reflected by similar T cell CD69 expression and influenza-specific T cell recruitment. Our data indicate that endogenous IL-12 impairs viral clearance during the late phase of influenza A virus infection in mice.
Assuntos
Vírus da Influenza A/imunologia , Interleucina-12/deficiência , Interleucina-12/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia , Animais , Lavagem Broncoalveolar , Citometria de Fluxo , Imunoglobulinas/sangue , Imunoglobulinas/imunologia , Interleucina-12/biossíntese , Interleucina-12/metabolismo , Pulmão/imunologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/sangue , Infecções por Orthomyxoviridae/virologia , Infecções Respiratórias/sangue , Linfócitos T/imunologia , Carga ViralRESUMO
Toll-like receptors (TLR) induce innate immune responses upon stimulation by a wide variety of pathogens. TLR4 has been implicated in innate immunity against respiratory syncytial virus (RSV) by an interaction with the viral envelope fusion (F) protein. Sendai virus (mouse parainfluenza type 1) shares many features with RSV, including a structurally and functionally similar F protein. To determine the role of TLR4 in host defense against Sendai virus respiratory tract infection, TLR4 mutant and wildtype mice were intranasally infected with Sendai virus. Sendai infection resulted in an increase in viral RNA copies in lung homogenates peaking on day 4. Pulmonary viral loads, histopathology, cytokine levels and leukocyte influx were similar in TLR4 mutant and wildtype mice. In spite of the structural similarities shared by the F proteins of Sendai virus and RSV, TLR4 is not involved in host defense against respiratory tract infection with Sendai virus.
Assuntos
Glicoproteínas de Membrana/metabolismo , Receptores de Superfície Celular/metabolismo , Infecções Respiratórias/metabolismo , Infecções por Respirovirus/metabolismo , Vírus Sendai/imunologia , Animais , Líquido da Lavagem Broncoalveolar/citologia , Citocinas/metabolismo , Feminino , Vírus da Influenza A/imunologia , Contagem de Leucócitos , Leucócitos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Infecções Respiratórias/imunologia , Infecções por Respirovirus/imunologia , Receptor 4 Toll-Like , Receptores Toll-Like , Carga ViralRESUMO
BACKGROUND: Pulmonary coagulopathy is a hallmark of lung injury following inhalation trauma. Locally applied heparin attenuates lung injury in animal models of smoke inhalation. Whether local treatment with heparin benefits patients with inhalation trauma is uncertain. The present trial aims at comparing a strategy using frequent nebulizations of heparin with standard care in intubated and ventilated burn patients with bronchoscopically confirmed inhalation trauma. METHODS: The Randomized Controlled Trial Investigating the Efficacy and Safety of Nebulized HEParin versus Placebo in BURN Patients with Inhalation Trauma (HEPBURN) is an international multi-center, double-blind, placebo-controlled, two-arm study. One hundred and sixteen intubated and ventilated burn patients with confirmed inhalation trauma are randomized to nebulizations of heparin (the nebulized heparin strategy) or nebulizations of normal saline (the control strategy) every four hours for 14 days or until extubation, whichever comes first. The primary endpoint is the number of ventilator-free days, defined as days alive and breathing without assistance during the first 28 days, if the period of unassisted breathing lasts for at least 24 consecutive hours. DISCUSSION: As far as the authors know, HEPBURN is the first randomized, placebo-controlled trial, powered to investigate whether local treatment with heparin shortens duration of ventilation of intubated and ventilated burn patients with inhalation trauma. TRIAL REGISTRATION: NCT01773083 (http://www.clinicaltrials.gov), registered on 16 January 2013.Recruiting. Randomisation commenced on 1 January 2014.
Assuntos
Anticoagulantes/administração & dosagem , Heparina/administração & dosagem , Pulmão/efeitos dos fármacos , Nebulizadores e Vaporizadores , Projetos de Pesquisa , Respiração Artificial , Lesão por Inalação de Fumaça/terapia , Administração por Inalação , Anticoagulantes/efeitos adversos , Bélgica , Protocolos Clínicos , Método Duplo-Cego , Heparina/efeitos adversos , Humanos , Intubação Intratraqueal , Pulmão/patologia , Pulmão/fisiopatologia , Países Baixos , Recuperação de Função Fisiológica , Respiração , Lesão por Inalação de Fumaça/diagnóstico , Lesão por Inalação de Fumaça/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Desmame do RespiradorRESUMO
BACKGROUND: Mechanical ventilation (MV) can cause ventilator-induced lung injury (VILI). The innate immune response mediates this iatrogenic inflammatory condition. The receptor for advanced glycation end products (RAGE) is a multiligand receptor that can amplify immune and inflammatory responses. We hypothesized that RAGE signaling contributes to the pro-inflammatory state induced by MV. METHODS: RAGE expression was analyzed in lung brush and lavage cells obtained from ventilated patients and lung tissue of ventilated mice. Healthy wild-type (WT) and RAGE knockout (KO) mice were ventilated with relatively low (approximately 7.5 ml/kg) or high (approximately 15 ml/kg) tidal volume. Positive end-expiratory pressure was set at 2 cm H2O during both MV strategies. Also, WT and RAGE KO mice with lipopolysaccharide (LPS)-induced lung injury were ventilated with the above described ventilation strategies. In separate experiments, the contribution of soluble RAGE, a RAGE isoform that may function as a decoy receptor, in ventilated RAGE KO mice was investigated. Lung wet-to-dry ratio, cell and neutrophil influx, cytokine and chemokine concentrations, total protein levels, soluble RAGE, and high-mobility group box 1 (HMGB1) presence in lung lavage fluid were analyzed. RESULTS: MV was associated with increased RAGE mRNA levels in both human lung brush samples and lung tissue of healthy mice. In healthy high tidal volume-ventilated mice, RAGE deficiency limited inflammatory cell influx. Other VILI parameters were not affected. In our second set of experiments where we compared RAGE KO and WT mice in a 2-hit model, we observed higher pulmonary cytokine and chemokine levels in RAGE KO mice undergoing LPS/high tidal volume MV as compared to WT mice. Third, in WT mice undergoing the LPS/high tidal volume MV, we observed HMGB1 presence in lung lavage fluid. Moreover, MV increased levels of soluble RAGE in lung lavage fluid, with the highest levels found in LPS/high tidal volume-ventilated mice. Administration of soluble RAGE to LPS/high tidal volume-ventilated RAGE KO mice attenuated the production of inflammatory mediators. CONCLUSIONS: RAGE was not a crucial contributor to the pro-inflammatory state induced by MV. However, the presence of sRAGE limited the production of pro-inflammatory mediators in our 2-hit model of LPS and high tidal volume MV.
RESUMO
Interleukin-1 receptor like 1 (ST2) is a negative regulator of Toll-like receptor (TLR) signaling. TLRs are important for host defense during respiratory tract infections by both influenza and Streptococcus (S.) pneumoniae. Enhanced susceptibility to pneumococcal pneumonia is an important complication following influenza virus infection. We here sought to determine the role of ST2 in primary influenza A infection and secondary pneumococcal pneumonia. ST2 knockout (st2(-/-)) and wild-type (WT) mice were intranasally infected with influenza A virus; in some experiments mice were infected 2 weeks later with S. pneumoniae. Both mouse strains cleared the virus similarly during the first 14 days of influenza infection and had recovered their weights equally at day 14. Overall st2(-/-) mice tended to have a stronger pulmonary inflammatory response upon infection with influenza; especially 14 days after infection modest but statistically significant elevations were seen in lung IL-6, IL-1ß, KC, IL-10, and IL-33 concentrations and myeloperoxidase levels, indicative of enhanced neutrophil activity. Interestingly, bacterial lung loads were higher in st2(-/-) mice during the later stages of secondary pneumococcal pneumonia, which was associated with relatively increased lung IFN-γ levels. ST2 deficiency did not impact on gross lung pathology in either influenza or secondary S. pneumoniae pneumonia. These data show that ST2 plays a limited anti-inflammatory role during both primary influenza and postinfluenza pneumococcal pneumonia.