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Intracavitary pulmonary aspergilloma is a persistent and life-threatening infection that carries a mortality rate of up to 15%. It occurs when Aspergillus species gain entry to an existing lung cavity. In the absence of definitive treatment, patients may succumb to severe complications such as massive hemoptysis, cachexia, or secondary infections. Aspergillomas often show limited response to antifungal medications, mainly due to insufficient drug concentrations within the cavities. Surgery is frequently the preferred treatment option, but it poses significant risks, and many individuals are ineligible due to underlying health issues. We present the most extensive non-surgical fungal ball cohort to date, managed using an innovative multimodal strategy that combines antifungal therapy before and after bronchoscopic debulking. This was a cross-sectional observational study. For those who cannot undergo surgery, our medical center has pioneered a multimodal approach to aspergilloma resection. This approach combines bronchoscopic endoscopy with antifungal therapy and has been applied successfully to more than 18 patients that are presented in this series. The median age of the cohort was 58 years (range: 32-73), with an equal sex distribution. The mean percent predicted FEV1 was 65.3%. The mean follow-up duration was 3.6 years (range: 0.5-10 years). The cohort receiving antifungals systematically prior to debridement showed a reduction of the pre-existing cavity (40.38 mm versus 34.02 mm, p = 0.021). Across the 18 patients during the follow-up period, 94% remained recurrence-free (defined by symptoms and radiology). Our study fills a critical knowledge gap regarding the significance of initiating antifungal treatment before bronchoscopic debulking and presents a viable approach in these cases for which there is a current unmet therapeutic need.
The use of both medical and interventional methods to treat difficult fungal masses: A collection of cases showing efficacy for patients who can't undergo surgeryIntracavitary pulmonary aspergilloma is a serious and potentially deadly infection with a death rate of up to 15%. It happens when certain types of fungi invade existing lung cavities. Without proper treatment, patients may experience severe complications like heavy bleeding from the lungs, weight loss, or other infections. Traditional antifungal medications often don't work well because they can't reach high enough concentrations in the cavities. Surgery is usually the best option, but it's risky and not possible for many due to other health problems. Our study introduces a new way to treat aspergilloma without surgery. We've treated a significant number of patients using a combination of antifungal drugs and a procedure called bronchoscopic debulking. This involves removing the fungal growth using a thin tube inserted through the airways. Our research involved observing 18 patients treated this way. They were mostly middle-aged, with equal numbers of men and women. Their lung function was moderately impaired, and we followed them for an average of 3.6 years. We found that giving antifungal drugs before the debulking procedure helped reduce the size of the cavities. After treatment, almost all patients remained free of symptoms and signs of recurrence. This study highlights the importance of starting antifungal therapy before bronchoscopic debulking and offers a promising option for patients who can't have surgery.
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Antifúngicos , Broncoscopia , Aspergilose Pulmonar , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Estudos Transversais , Antifúngicos/administração & dosagem , Aspergilose Pulmonar/tratamento farmacológico , Adulto , Resultado do Tratamento , Terapia CombinadaRESUMO
Cryptococcosis is a major worldwide disseminated invasive fungal infection. Cryptococcosis, particularly in its most lethal manifestation of cryptococcal meningitis, accounts for substantial mortality and morbidity. The breadth of the clinical cryptococcosis syndromes, the different patient types at-risk and affected, and the vastly disparate resource settings where clinicians practice pose a complex array of challenges. Expert contributors from diverse regions of the world have collated data, reviewed the evidence, and provided insightful guideline recommendations for health practitioners across the globe. This guideline offers updated practical guidance and implementable recommendations on the clinical approaches, screening, diagnosis, management, and follow-up care of a patient with cryptococcosis and serves as a comprehensive synthesis of current evidence on cryptococcosis. This Review seeks to facilitate optimal clinical decision making on cryptococcosis and addresses the myriad of clinical complications by incorporating data from historical and contemporary clinical trials. This guideline is grounded on a set of core management principles, while acknowledging the practical challenges of antifungal access and resource limitations faced by many clinicians and patients. More than 70 societies internationally have endorsed the content, structure, evidence, recommendation, and pragmatic wisdom of this global cryptococcosis guideline to inform clinicians about the past, present, and future of care for a patient with cryptococcosis.
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Antifúngicos , Criptococose , Humanos , Criptococose/diagnóstico , Criptococose/tratamento farmacológico , Antifúngicos/uso terapêutico , Guias de Prática Clínica como Assunto , Saúde Global , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/tratamento farmacológicoRESUMO
Prophylactic vaccination strategies designed to prevent diseases caused by pathogens using the phagolysosome of innate immune cells as a site of intracellular replication and survival have been largely ineffective. These include Mycobacterium tuberculosis (Mtb), Leishmania spp., and Cryptococcus spp. These failed strategies have traditionally targeted CD4+ T helper (Th) 1 cell-mediated immune memory, deeming it crucial for vaccine efficacy. This failure warrants an investigation of alternative mediators of protection. Here, we suggest three novel approaches to activate phagocytic cells prior to or at the time of infection. We hypothesize that preventing the formation of the pathogen niche within the phagolysosome is essential for preventing disease, and a greater emphasis on the timing of phagocyte activation should generate more effective prophylactic treatment options.
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Mycobacterium tuberculosis , Humanos , Memória Imunológica , Linfócitos T Auxiliares-Indutores , FagossomosRESUMO
Rationale: The pathobiology of Staphylococcus aureus in non-cystic fibrosis bronchiectasis (nCFB) is poorly defined. When present at high density or "inoculum," some methicillin-sensitive S. aureus (MSSA) can inefficiently degrade antistaphylococcal ß-lactam antibiotics via BlaZ penicillinases (termed the "inoculum effect" [IE]). Given the high burden of organisms in bronchiectatic airways, this is particularly relevant. Objectives: Drawing from a prospectively collected biobank, we sought to understand the prevalence, natural history, potential for transmission, and antibiotic resistance profiles among nCFB-derived MSSA isolates. Methods: All individuals attending a regional consultancy nCFB clinic with sputum collected between 1981 and 2017 were considered, and those with one or more S. aureus-positive cultures composed the cohort. Each individual's most recent biobank isolate was subjected to whole-genome sequencing (including the blaZ gene), antibacterial susceptibility testing, and comparative ß-lactam testing at standard (5 × 105 colony-forming unit [cfu]/ml) and high (5 × 107 cfu/ml) inocula to assess for the IE and pronounced IE. Results: Seventy-four (35.4%) of 209 individuals had one or more sputum samples with S. aureus (68 MSSA, 6 methicillin-resistant S. aureus). Those with S. aureus infection were more likely to be female. Among 60 of 74 MSSA isolates subjected to whole-genome sequencing, no evidence of transmission was identified, although specific multilocus sequence typing types were prevalent, including ST-1, ST-15, ST-30, and ST-45. Antibiotic resistance was uncommon, except for macrolides (â¼20%). Among the 60 MSSA samples, the prevalence of IE and pronounced IE was observed to be drug specific: meropenem (0% and 0%, respectively), cefepime (3% and 5%, respectively), ceftazidime (8% and 0%, respectively), cloxacillin (12% and 0%, respectively), cefazolin (23% and 0%, respectively), and piperacillin-tazobactam (37% and 17%, respectively). The cefazolin IE was associated with blaZ type A (P < 0.01) and ST-30 (P < 0.01), whereas the piperacillin-tazobactam IE was associated with type C blaZ (P < 0.001) and ST-15 (P < 0.05). Conclusions:S. aureus infection was common, although no evidence of transmission was apparent in our nCFB cohort. Although routine susceptibility testing did not identify significant resistance, inoculum-related resistance was found to be relevant for commonly used nCFB antibiotics, including cefazolin and piperacillin-tazobactam. Given previous associations between IEs and negative patient outcomes, further work is warranted to understand how this phenotype impacts nCFB disease progression.
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Bronquiectasia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bronquiectasia/tratamento farmacológico , Cefazolina , Feminino , Fibrose , Genômica , Humanos , Masculino , Testes de Sensibilidade Microbiana , Piperacilina , Prevalência , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Tazobactam , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , beta-Lactamases/metabolismo , beta-Lactamas/farmacologia , beta-Lactamas/uso terapêuticoRESUMO
Pseudomonas aeruginosa is an opportunistic pathogen that often infects individuals with the genetic disease cystic fibrosis, and contributes to airway blockage and loss of lung function. Natural killer (NK) cells are cytotoxic, granular lymphocytes that are part of the innate immune system. NK cell secretory granules contain the cytolytic proteins granulysin, perforin and granzymes. In addition to their cytotoxic effects on cancer and virally infected cells, NK cells have been shown to play a role in an innate defense against microbes, including bacteria. However, it is not known if NK cells kill extracellular P. aeruginosa or how bacterial killing might occur at the molecular level. Here we show that NK cells directly kill extracellular P. aeruginosa using NK effector molecules. Live cell imaging of a co-culture of YT cells, a human NK cell line, and GFP-expressing P. aeruginosa in the presence of the viability dye propidium iodide demonstrated that YT cell killing of P. aeruginosa is contact-dependent. CRISPR knockout of granulysin or perforin in YT cells had no significant effect on YT cell killing of P. aeruginosa. Pre-treatment of YT and NK cells with the serine protease inhibitor 3,4-dichloroisocoumarin (DCI) to inhibit all granzymes, resulted in an inhibition of killing. Although singular CRISPR knockout of granzyme B or H had no effect, knockout of both in YT cells completely abrogated killing of P. aeruginosa in comparison to wild type YT cell controls. Nitrocefin assays suggest that the bacterial membrane is damaged. Inhibition of killing by antioxidants suggest that ROS are required for the bactericidal mode-of-action. Taken together, these results identify that NK cells kill P. aeruginosa through a membrane damaging, contact-dependent process that requires granzyme induced ROS production, and moreover, that granzyme B and H are redundant in this killing process.
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Glicoproteínas de Membrana , Pseudomonas aeruginosa , Granzimas/metabolismo , Humanos , Células Matadoras Naturais , Glicoproteínas de Membrana/metabolismo , Perforina/metabolismo , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Pseudomonas aeruginosa/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Humans have developed complex immune systems that defend against invading microbes, including fungal pathogens. Many highly specialized cells of the immune system share the ability to store antimicrobial compounds in membrane bound organelles that can be immediately deployed to eradicate or inhibit growth of invading pathogens. These membrane-bound organelles consist of secretory vesicles or granules, which move to the surface of the cell, where they fuse with the plasma membrane to release their contents in the process of degranulation. Lymphocytes, macrophages, neutrophils, mast cells, eosinophils, and basophils all degranulate in fungal host defence. While anti-microbial secretory vesicles are shared among different immune cell types, information about each cell type has emerged independently leading to an uncoordinated and confusing classification of granules and incomplete description of the mechanism by which they are deployed. While there are important differences, there are many similarities in granule morphology, granule content, stimulus for degranulation, granule trafficking, and release of granules against fungal pathogens. In this review, we describe the similarities and differences in an attempt to translate knowledge from one immune cell to another that may facilitate further studies in the context of fungal host defence.
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Cryptococcus gattii is a major cause of life-threatening mycosis in immunocompetent individuals and responsible for the ongoing epidemic outbreak of cryptococcosis in the Pacific Northwest of North America. This deadly fungus is known to evade important host immune responses, including dendritic cell (DC) maturation and concomitant T cell immunity, via immune evasion mechanisms that remain unclear. Here, we demonstrate that primary human DCs phagocytose C. gattii but the maturation of phagosomes to phagolysosomes was blocked as a result of sustained filamentous actin (F-actin) that entrapped and concealed the phagosomes from recognition. Superresolution structured illumination microscopy (SR-SIM) revealed that the persistent phagosomal F-actin formed a cage-like structure that sterically hindered and functionally blocked the fusion of lysosomes. Blocking lysosome fusion was sufficient to inhibit phagosomal acidification and subsequent intracellular fungal killing by DCs. Retention of phagosomal F-actin by C. gattii also caused DC immunoparalysis. Disrupting the retained F-actin cage with cytochalasin D not only restored DC phagosomal maturation but also promoted DC costimulatory maturation and robust T cell activation and proliferation. Collectively, these results reveal a unique mechanism of DC immune evasion that enhances intracellular fungal pathogenicity and may explain suppressed cell-mediated immunity.IMPORTANCECryptococcus yeast species typically display characteristics of opportunistic pathogens, with the exception of C. gattii, which can cause life-threatening respiratory and disseminated brain infections in otherwise healthy people. The pathogenesis of C. gattii is not well understood, but an important characteristic is that C. gattii is capable of evading host cell-mediated immune defenses initiated by DCs. Here, we report that when virulent C. gattii becomes ingested by a DC, the intracellular compartment containing the fungi is covered by a persistent protein cage structure consisting of F-actin. This F-actin cage acts as a barrier to prevent interaction with other intracellular compartments, and as a result, the DC fails to kill the fungi and activate important cell-mediated immune responses. We propose that this unique immune evasion mechanism permits C. gattii to remain unchallenged within host cells, leading to persistent infection.
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Actinas/metabolismo , Cryptococcus gattii/imunologia , Cryptococcus gattii/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Fagossomos/metabolismo , Biomarcadores , Comunicação Celular/imunologia , Criptococose/imunologia , Criptococose/metabolismo , Criptococose/microbiologia , Humanos , Imunofenotipagem , Ativação Linfocitária , Linfócitos T/imunologia , Linfócitos T/metabolismo , VirulênciaRESUMO
OBJECTIVE: To describe the burden of pneumococcal disease and associated risk factors in the Canadian adult population, delineate available pneumococcal vaccines and associated efficacy and effectiveness data, and review current pneumococcal vaccine recommendations and community-acquired pneumonia (CAP) prevention strategies in Canada. QUALITY OF EVIDENCE: Pneumococcal vaccination guidelines from the Canadian National Advisory Committee on Immunization in 2013 and 2016 constitute level III evidence for CAP prevention in the Canadian adult population. MAIN MESSAGE: It is recommended that immunosuppressed adults of all ages receive the 13-valent pneumococcal conjugate vaccine (PCV13) (grades A and B recommendations). In 2016, the National Advisory Committee on Immunization also recommended that all adults aged 65 years and older receive PCV13 (grade A recommendation) on an individual basis, followed by the 23-valent pneumococcal polysaccharide vaccine (grade B recommendation). This update is based on a large clinical study that demonstrated PCV13 efficacy against vaccine-type CAP in this population. CONCLUSION: Physicians should focus on improving pneumococcal vaccination rates among adults, which remain low. Vaccination with PCV13 should also be considered for adults with chronic conditions, whose baseline risk is often higher than that for healthy individuals aged 65 years and older.
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Infecções Comunitárias Adquiridas/prevenção & controle , Esquemas de Imunização , Vacinas Pneumocócicas/administração & dosagem , Pneumonia Pneumocócica/prevenção & controle , Comitês Consultivos , Canadá , Infecções Comunitárias Adquiridas/imunologia , Infecções Comunitárias Adquiridas/microbiologia , Humanos , Vacinas Pneumocócicas/imunologia , Pneumonia Pneumocócica/imunologia , Guias de Prática Clínica como Assunto , Streptococcus pneumoniae , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologiaRESUMO
Burkholderia cepacia complex (Bcc), which includes B. cenocepacia and B. multivorans, pose a life-threatening risk to patients with cystic fibrosis. Eradication of Bcc is difficult due to the high level of intrinsic resistance to antibiotics, and failure of many innate immune cells to control the infection. Because of the pathogenesis of Bcc infections, we wondered if a novel mechanism of microbial host defense involving direct antibacterial activity by natural killer (NK) cells might play a role in the control of Bcc. We demonstrate that NK cells bound Burkholderia, resulting in Src family kinase activation as measured by protein tyrosine phosphorylation, granule release of effector proteins such as perforin and contact-dependent killing of the bacteria. These studies provide a means by which NK cells could play a role in host defense against Bcc infection.
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Infecções por Burkholderia/imunologia , Burkholderia cepacia/fisiologia , Burkholderia/fisiologia , Fibrose Cística/imunologia , Células Matadoras Naturais/imunologia , Adesão Celular , Degranulação Celular , Linhagem Celular , Citotoxicidade Imunológica , Humanos , Imunidade Celular , Perforina/metabolismo , Fosforilação , Transdução de Sinais , Quinases da Família src/metabolismoRESUMO
It is now evident that NK cells kill bacteria, fungi, and parasites in addition to tumor and virus-infected cells. In addition to a number of recent publications that have identified the receptors and ligands, and mechanisms of cytotoxicity, new insights are reflected in the reports from researchers all over the world at the 17th Meeting of the Society for Natural Immunity held in San Antonio, TX, USA from May 28 through June 1, 2018. We will provide an overview of the field and discuss how the presentations at the meeting might shape our knowledge and future directions in the field.
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Bactérias/imunologia , Fungos/imunologia , Imunidade Celular , Células Matadoras Naturais/imunologia , Vírus/imunologia , Animais , Congressos como Assunto , Humanos , Imunidade Inata , Sociedades Científicas , TexasRESUMO
Cryptococcus neoformans is a fungal pathogen that causes fatal meningitis and pneumonia. During host defense to Cryptococcus, NK cells directly recognize and kill C. neoformans using cytolytic degranulation analogous to killing of tumor cells. This fungal killing requires independent activation of Src family kinase (SFK) and Rac1-mediated pathways. Recognition of C. neoformans requires the natural cytotoxicity receptor, NKp30; however, it is not known whether NKp30 activates both signal transduction pathways or whether a second receptor is involved in activation of one of the pathways. We used primary human NK cells and a human NK cell line and found that NKp30 activates SFK â PI3K but not Rac1 cytotoxic signaling, which led to a search for the receptor leading to Rac1 activation. We found that NK cells require integrin-linked kinase (ILK) to activate Rac1 for effective fungal killing. This observation led to our identification of ß1 integrin as an essential anticryptococcal receptor. These findings demonstrate that multiple receptors, including ß1 integrins and NKp30 and their proximal signaling pathways, are required for recognition of Cryptococcus, which activates a central cytolytic antimicrobial pathway leading to fungal killing.
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Criptococose/imunologia , Cryptococcus neoformans/fisiologia , Integrina beta1/metabolismo , Células Matadoras Naturais/imunologia , Proteínas rac1 de Ligação ao GTP/metabolismo , Adolescente , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Humanos , Imunidade Inata , Masculino , Receptor 3 Desencadeador da Citotoxicidade Natural/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Quinases da Família src/metabolismoRESUMO
Cryptococcus is the most important cause of fungal meningitis in immunocompromised individuals. Host defense against Cryptococcus involves direct killing by NK cells. That NK cells from HIV-infected patients fail to polarize perforin to the microbial synapse and kill C. neoformans led us to explore the mechanisms used to reposition and polarize the cytolytic granules to the synapse. Using live-cell imaging, we observed microtubule and granule movements in response to Cryptococcus that revealed a kinesin-dependent event. Eg5-kinesin bound to perforin-containing granules and was required for association with the microtubules. Inhibition of Eg5-kinesin abrogated dynein-dependent granule convergence to the MTOC and granule and MTOC polarization to the synapse and suppressed NK cell killing of Cryptococcus. In contrast, Eg5-kinesin was dispensable for tumor killing. This reveals an alternative mechanism of MTOC repositioning and granule polarization, not used in tumor cytotoxicity, in which Eg5-kinesin is required to initiate granule movement, leading to microbial killing.
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Cryptococcus/imunologia , Cryptococcus/patogenicidade , Grânulos Citoplasmáticos/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Cinesinas/metabolismo , Linhagem Celular , Células Cultivadas , Grânulos Citoplasmáticos/genética , Citotoxicidade Imunológica , Humanos , Cinesinas/genéticaRESUMO
The natural history and epidemiology of Pseudomonas aeruginosa infections in non-cystic fibrosis (non-CF) bronchiectasis is not well understood. As such it was our intention to determine the evolution of airway infection and the transmission potential of P. aeruginosa in patients with non-CF bronchiectasis. A longitudinal cohort study was conducted from 1986-2011 using a biobank of prospectively collected isolates from patients with non-CF bronchiectasis. Patients included were ≥18 years old and had ≥2 positive P. aeruginosa cultures over a minimum 6-month period. All isolates obtained at first and most recent clinical encounters, as well as during exacerbations, that were morphologically distinct on MacConkey agar were genotyped by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 203 isolates from 39 patients were analysed. These were compared to a large collection of globally epidemic and local CF strains, as well as non-CF isolates. We identified four patterns of infection in non-CF bronchiectasis including: 1) persistence of a single strain (n=26; 67%); 2) strain displacement (n=8; 20%); 3) temporary disruption (n=3; 8%); and 4) chaotic airway infection (n=2; 5%). Patterns of infection were not significant predictors of rates of lung function decline or progression to end-stage disease and acquisition of new strains did not associate with the occurrence of exacerbations. Rarely, non-CF bronchiectasis strains with similar pulsotypes were observed in CF and non-CF controls, but no CF epidemic strains were observed. While rare shared strains were observed in non-CF bronchiectasis, whole-genome sequencing refuted patient-patient transmission. We observed a higher incidence of strain-displacement in our patient cohort compared to those observed in CF studies, although this did not impact on outcomes.
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BACKGROUND: Variation in hospital management of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) may prolong length of stay, increasing the risk of hospital-acquired complications and worsening quality of life. We sought to determine whether an evidence-based computerized AECOPD admission order set could improve quality and reduce length of stay. METHODS: The order set was designed by a provincial COPD working group and implemented voluntarily among three physician groups in a Canadian tertiary-care teaching hospital. The primary outcome was length of stay for patients admitted during order set implementation period, compared to the previous 12 months. Secondary outcomes included length of stay of patients admitted with and without order set after implementation, all-cause readmissions, and emergency department visits. RESULTS: There were 556 admissions prior to and 857 admissions after order set implementation, for which the order set was used in 47%. There was no difference in overall length of stay after implementation (median 6.37 days (95% confidence interval 5.94, 6.81) pre-implementation vs. 6.02 days (95% confidence interval 5.59, 6.46) post-implementation, p = 0.26). In the post-implementation period, order set use was associated with a 1.15-day reduction in length of stay (95% confidence interval - 0.5, - 1.81, p = 0.001) compared to patients admitted without the order set. There was no difference in readmissions. CONCLUSIONS: Use of a computerized guidelines-based admission order set for COPD exacerbations reduced hospital length of stay without increasing readmissions. Interventions to increase order set use could lead to greater improvements in length of stay and quality of care.
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Tempo de Internação/estatística & dados numéricos , Sistemas de Registro de Ordens Médicas/normas , Admissão do Paciente/normas , Readmissão do Paciente/estatística & dados numéricos , Doença Pulmonar Obstrutiva Crônica , Canadá , Sistemas de Apoio a Decisões Administrativas , Prática Clínica Baseada em Evidências/métodos , Humanos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Melhoria de Qualidade , Exacerbação dos Sintomas , Centros de Atenção Terciária/organização & administraçãoRESUMO
Natural killer (NK) cells use the activating receptor NKp30 as a microbial pattern-recognition receptor to recognize, activate cytolytic pathways, and directly kill the fungi Cryptococcus neoformans and Candida albicans. However, the fungal pathogen-associated molecular pattern (PAMP) that triggers NKp30-mediated killing remains to be identified. Here we show that ß-1,3-glucan, a component of the fungal cell wall, binds to NKp30. We further demonstrate that ß-1,3-glucan stimulates granule convergence and polarization, as shown by live cell imaging. Through Src Family Kinase signaling, ß-1,3-glucan increases expression and clustering of NKp30 at the microbial and NK cell synapse to induce perforin release for fungal cytotoxicity. Rather than blocking the interaction between fungi and NK cells, soluble ß-1,3-glucan enhances fungal killing and restores defective cryptococcal killing by NK cells from HIV-positive individuals, implicating ß-1,3-glucan to be both an activating ligand and a soluble PAMP that shapes NK cell host immunity.
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Candida albicans/imunologia , Cryptococcus neoformans/imunologia , Células Matadoras Naturais/imunologia , Moléculas com Motivos Associados a Patógenos/imunologia , Linhagem Celular , Polaridade Celular/imunologia , Grânulos Citoplasmáticos/imunologia , Citotoxicidade Imunológica , Infecções por HIV/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Sinapses Imunológicas/imunologia , Ligantes , Microscopia de Força Atômica , Receptor 3 Desencadeador da Citotoxicidade Natural/imunologia , Perforina/imunologia , Proteínas Recombinantes/imunologia , Solubilidade , beta-Glucanas/imunologiaRESUMO
Candida albicans bloodstream infection causes fungal septicaemia and death in over half of afflicted patients. Polymorphonuclear leukocytes (PMN) mediate defense against invasive candidiasis, but their role in protection versus tissue injury and sepsis is unclear. We observe PMN intravascular swarming and subsequent clustering in response to C. albicans yeast in a lethal septic mouse and human pulmonary circulation model. Live C. albicans sequester to the endothelium and are immediately captured by complement-dependent PMN chemotaxis, which is required for host survival. However, complement activation also leads to Leukotriene B4 (LTB4)-mediated intravascular PMN clustering and occlusion, resulting in capillaritis with pulmonary hemorrhage and hypoxemia. This clustering is unique to fungi and triggered by fungal cell wall components. PMN clustering is absent in mice lacking LTB4-receptor, and capillaritis is attenuated upon pharmacological LTB4 blockade without affecting phagocytosis. Therefore, therapeutically disrupting infection-induced capillaritis may limit organ injury without impairing host defense during fungal sepsis.
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Arteriopatias Oclusivas/microbiologia , Candida albicans/imunologia , Candidíase/imunologia , Leucotrieno B4/imunologia , Infiltração de Neutrófilos/imunologia , Neutrófilos/imunologia , Sepse/imunologia , Animais , Arteriopatias Oclusivas/imunologia , Candidíase/microbiologia , Candidíase/patologia , Células Cultivadas , Feminino , Humanos , Pulmão/irrigação sanguínea , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Sepse/microbiologia , Sepse/patologiaRESUMO
Cryptococcal disease, caused by Cryptococcus neoformans and Cryptococcus gattii, is associated with significant morbidity and mortality but limited data exist on its incidence and impact. A study utilizing the Nationwide Inpatient Sample from 2000 to 2007 to examine the epidemiology and impact of cryptococcal disease in the United States was undertaken. The International Classification of Diseases 9th Version code was used to identify hospital discharges with diagnosis of Cryptococcus (117.5). Our primary outcome was the incidence rate of cryptococcal admissions. The impact of AIDS, age, and sex on hospitalization rates, mortality, and costs was assessed. The results showed that a total of 10,077 hospitalizations for cryptococcosis occurred corresponding to a weighted estimate of 49,010 cases. The median age was 43 years (interquartile range 34-54), and 26% were female. Approximately 64% of cases occurred in persons with AIDS. Although rates declined overall, age-adjusted rates were significantly higher in males with AIDS than in uninfected persons (p < 0.001). The mortality rate decreased but was greater in HIV-uninfected versus infected cohorts (12% versus 10%, p < 0.001). Conversely, hospital costs were greater in persons with AIDS ($40,671 versus $40,096, p=0.02). Although cryptococcal disease rates are decreasing over time, the associated mortality and costs remain concerning.
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Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Criptococose/epidemiologia , Custos de Cuidados de Saúde/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Adulto , Fatores Etários , Canadá/epidemiologia , Criptococose/diagnóstico , Cryptococcus gattii , Cryptococcus neoformans , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Vigilância da População , Fatores SexuaisRESUMO
Cryptococcus is among the most common invasive fungal pathogens globally and is one of the leading causes of acquired immunodeficiency virus-related deaths. Cryptococcus neoformans and Cryptococcus gattii are the most clinically relevant species and account for most cryptococcal disease. Pulmonary manifestations can range from mild symptoms to life-threatening infection. Treatment is tailored based on the severity of pulmonary infection, the presence of disseminated or central nervous system disease, and patient immune status. Amphotericin B and flucytosine followed by fluconazole remain the standard agents for the treatment of severe cryptococcal infection.
Assuntos
Antifúngicos/uso terapêutico , Criptococose/complicações , Pulmão/patologia , Infecções Respiratórias/etiologia , Criptococose/patologia , Cryptococcus gattii , Humanos , Infecções Respiratórias/tratamento farmacológicoRESUMO
Cyclic GMP-AMP synthase (cGAS) is a newly identified DNA sensor that recognizes foreign DNA, including the genome of herpes simplex virus 1 (HSV-1). Upon binding of viral DNA, cGAS produces cyclic GMP-AMP, which interacts with and activates stimulator of interferon genes (STING) to trigger the transcription of antiviral genes such as type I interferons (IFNs), and the production of inflammatory cytokines. HSV-1 UL24 is widely conserved among members of the herpesviruses family and is essential for efficient viral replication. In this study, we found that ectopically expressed UL24 could inhibit cGAS-STING-mediated promoter activation of IFN-ß and interleukin-6 (IL-6), and UL24 also inhibited interferon-stimulatory DNA-mediated IFN-ß and IL-6 production during HSV-1 infection. Furthermore, UL24 selectively blocked nuclear factor κB (NF-κB) but not IFN-regulatory factor 3 promoter activation. Coimmunoprecipitation analysis demonstrated that UL24 bound to the endogenous NF-κB subunits p65 and p50 in HSV-1-infected cells, and UL24 was also found to bind the Rel homology domains (RHDs) of these subunits. Furthermore, UL24 reduced the tumor necrosis factor alpha (TNF-α)-mediated nuclear translocation of p65 and p50. Finally, mutational analysis revealed that the region spanning amino acids (aa) 74 to 134 of UL24 [UL24(74-134)] is responsible for inhibiting cGAS-STING-mediated NF-κB promoter activity. For the first time, UL24 was shown to play an important role in immune evasion during HSV-1 infection.IMPORTANCE NF-κB is a critical component of the innate immune response and is strongly induced downstream of most pattern recognition receptors (PRRs), leading to the production of IFN-ß as well as a number of inflammatory chemokines and interleukins. To establish persistent infection, viruses have evolved various mechanisms to counteract the host NF-κB pathway. In the present study, for the first time, HSV-1 UL24 was demonstrated to inhibit the activation of NF-κB in the DNA sensing signal pathway via binding to the RHDs of the NF-κB subunits p65 and p50 and abolishing their nuclear translocation.
Assuntos
Herpesvirus Humano 1/fisiologia , Subunidade p50 de NF-kappa B/fisiologia , Transdução de Sinais , Fator de Transcrição RelA/fisiologia , Proteínas Virais/fisiologia , Transporte Ativo do Núcleo Celular , Animais , Chlorocebus aethiops , Regulação Viral da Expressão Gênica , Células HEK293 , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Interferon beta/genética , Interferon beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Mapas de Interação de Proteínas , Células VeroRESUMO
BACKGROUND: Intracavitary pulmonary aspergilloma is a chronic, debilitating fungal infection. Without definitive therapy, death can occur from massive hemoptysis, cachexia, or secondary infection. Although surgical resection is the standard therapy, it is not possible for many patients owing to poor pulmonary function or medical comorbidities. Aspergilloma removal through bronchoscopy is an important alternative therapy that may be available in select cases. METHODS: We retrospectively reviewed all cases referred to the University of Calgary Interventional Pulmonary Service for transbronchial removal of intracavitary aspergilloma from January 1, 2009, to January 1, 2014. RESULTS: Ten patients with intracavitary pulmonary aspergilloma were identified. In 3 patients, the aspergilloma cavity was not accessible by bronchoscopy. Successful removal of the aspergilloma with symptom improvement or resolution was achieved in 6 of 7 cases. One of the patients was lost to follow-up. Minor hypoxia lasting 12 to 72 hours was observed in 5 cases. Severe sepsis requiring an extended critical care unit stay occurred in 1 case. Follow-up ranged from 9 months to 5 years. CONCLUSIONS: Although not without risk of minor hypoxia and possible sepsis, for carefully selected patients, bronchoscopic removal of symptomatic intracavitary pulmonary aspergilloma may be an alternative therapy to surgical resection for this life-threatening disease.