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At the stroke of the New Year 2020, COVID-19, a zoonotic disease that would turn into a global pandemic, was identified in the Chinese city of Wuhan. Although unique in its transmission and virulence, COVID-19 is similar to zoonotic diseases, including other SARS variants (e.g., SARS-CoV) and MERS, in exhibiting severe flu-like symptoms and acute respiratory distress. Even at the molecular level, many parallels have been identified between SARS and COVID-19 so much so that the COVID-19 virus has been named SARS-CoV-2. These similarities have provided several opportunities to treat COVID-19 patients using clinical approaches that were proven to be effective against SARS. Importantly, the identification of similarities in how SARS-CoV and SARS-CoV-2 access the host, replicate, and trigger life-threatening pathological conditions have revealed opportunities to repurpose drugs that were proven to be effective against SARS. In this article, we first provided an overview of COVID-19 etiology vis-à-vis other zoonotic diseases, particularly SARS and MERS. Then, we summarized the characteristics of droplets/aerosols emitted by COVID-19 patients and how they aid in the transmission of the virus among people. Moreover, we discussed the molecular mechanisms that enable SARS-CoV-2 to access the host and become more contagious than other betacoronaviruses such as SARS-CoV. Further, we outlined various approaches that are currently being employed to diagnose and symptomatically treat COVID-19 in the clinic. Finally, we reviewed various approaches and technologies employed to develop vaccines against COVID-19 and summarized the attempts to repurpose various classes of drugs and novel therapeutic approaches.

The American Thoracic Society Core Curriculum updates clinicians annually in adult and pediatric pulmonary disease, medical critical care, and sleep medicine in a 3- to 4-year recurring cycle of topics. The topics of the 2020 Pulmonary Core Curriculum include pulmonary vascular disease (submassive pulmonary embolism, chronic thromboembolic pulmonary hypertension, and pulmonary hypertension) and pulmonary infections (community-acquired pneumonia, pulmonary nontuberculous mycobacteria, opportunistic infections in immunocompromised hosts, and coronavirus disease [COVID-19]).

Vasculitis in patients with sarcoidosis is rare and can affect any sized blood vessel. Limited information describing this association is available.A single-institution medical records review study was performed reviewing all patients with a diagnosis code for sarcoidosis and vasculitis between January 1, 1998, and December 31, 2019. Data were abstracted regarding diagnosis, treatment, and outcomes from medical records. Patients were diagnosed with vasculitis based on biopsy and/or arterial imaging. Comparison between patients presenting with large and/or medium vessel vasculitis (L/MVV) versus patients with only small vessel vasculitis (SVV) was performed.Seventeen patients were identified during the study period. Nine patients (56% female) had L/MVV, and 8 (50% female) had SVV. Sarcoidosis preceded vasculitis in 4 (44%) L/MVV and 3 (38%) SVV. The mean ± SD age at sarcoidosis diagnosis was 53.2 ± 17.8 and 51.9 ± 11.4 years, and the mean ± SD age at vasculitis diagnosis was 57.4 ± 19.6 and 59.0 ± 13.4 years in L/MVV and SVV, respectively. Number of organ systems involved by sarcoidosis was similar (median [interquartile range], 3 [1-4] L/MVV vs 2.5 [1.75-3.25] SVV). The mean length of follow-up was 11.5 ± 12.8 in L/MVV and 13.1 ± 14.3 years in SVV. Complete response to therapy for vasculitis was observed in 8 of 9 with L/MVV and 7 of 8 with SVV. Four patients with SVV were able to stop all immunosuppression as compared with only 1 patient with L/MVV at the last follow-up.This series observed a comparable number of patients with L/MVV and SVV. Although a variety of treatments were used, most patients achieved remission regardless of vessel size affected. Clinicians should be aware of the overlap between sarcoidosis and vasculitis.

Introduction.Pathogen-associated molecular patterns’ (PAMPs) are microbial signatures that are recognized by host myeloid C-type lectin receptors (CLRs). These CLRs interact with micro-organisms via their carbohydrate recognition domains (CRDs) and engage signalling pathways within the cell resulting in pro-inflammatory and microbicidal responses.Gap statement.In this article, we extend our laboratory study of additional CLRs that recognize fungal ligands againstPneumocystis murinaandPneumocystis cariniiand their purified major surface glycoproteins (Msgs).Aim.To study the potential of newly synthesized hFc-CLR fusions on binding toPneumocystisand its Msg.Methods.A library of new synthesized hFc-CLR fusions was screened againstPneumocystis murinaandPneumocystis cariniiorganisms and their purified major surface glycoproteins (Msgs) found on the respective fungi via modified ELISA. Immunofluorescence assay (IFA) was implemented and quantified to verify results. mRNA expression analysis by quantitative PCR (q-PCR) was employed to detect respective CLRs found to bind fungal organisms in the ELISA and determine their expression levels in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model.Results.We detected a number of the CLR hFc-fusions displayed significant binding withP. murinaandP. cariniiorganisms, and similarly to their respective Msgs. Significant organism and Msg binding was observed for CLR members C-type lectin domain family 12 member A (CLEC12A), Langerin, macrophage galactose-type lectin-1 (MGL-1), and specific intracellular adhesion molecule-3 grabbing non-integrin homologue-related 3 (SIGNR3). Immunofluorescence assay (IFA) with the respective CLR hFc-fusions against wholeP. murinalife forms corroborated these findings. Lastly, we surveyed the mRNA expression profiles of the respective CLRs tested above in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model and determined that macrophage galactose type C-type lectin (Mgl-1), implicated in recognizing terminal N-acetylgalactosamine (GalNAc) found in the glycoproteins of microbial pathogens was significantly up-regulated during infection.Conclusion.The data herein add to the growing list of CLRs recognizingPneumocystisand provide insights for further study of organism/host immune cell interactions.

BACKGROUND Little is known about the autoreactive B cells in antineutrophil cytoplasmic antibody–associated (ANCA-associated) vasculitis (AAV). We aimed to investigate tolerance checkpoints of circulating antigen-specific proteinase 3–reactive (PR3+) B cells. METHODS Multicolor flow cytometry in combination with bioinformatics and functional in vitro studies were performed on baseline samples of PBMCs from 154 well-characterized participants of the RAVE trial (NCT00104299) with severely active PR3-AAV and myeloperoxidase-AAV (MPO-AAV) and 27 healthy controls (HCs). Clinical data and outcomes from the trial were correlated with PR3+ B cells (total and subsets). RESULTS The frequency of PR3+ B cells among circulating B cells was higher in participants with PR3-AAV (4.77% median [IQR, 3.98%–6.01%]) than in participants with MPO-AAV (3.16% median [IQR, 2.51%–5.22%]) and participants with AAV compared with HCs (1.67% median [IQR, 1.27%–2.16%], P < 0.001 for all comparisons), implying a defective central tolerance checkpoint in patients with AAV. Only PBMCs from participants with PR3-AAV contained PR3+ B cells capable of secreting PR3-ANCA IgG in vitro, proving they were functionally distinct from those of participants with MPO-AAV and HCs. Unsupervised clustering identified subtle subsets of atypical autoreactive PR3+ memory B cells accumulating through the maturation process in patients with PR3-AAV. PR3+ B cells were enriched in the memory B cell compartment of participants with PR3-AAV and were associated with higher serum CXCL13 levels, suggesting an increased germinal center activity. PR3+ B cells correlated with systemic inflammation (C-reactive protein and erythrocyte sedimentation rate, P < 0.05) and complete remission (P < 0.001). CONCLUSION This study suggests the presence of defective central antigen-independent and peripheral antigen-dependent checkpoints in patients with PR3-AAV, elucidating the selection process of autoreactive B cells. Trial registration ClinicalTrials.gov NCT00104299. Funding The Vasculitis Foundation, the National Institute of Allergy and Infectious Diseases of the NIH, and the Mayo Foundation for Education and Research.

Pneumocystisspp. interacts with epithelial cells in the alveolar spaces of the lung. It is thought that the binding ofPneumocystisto host cell epithelium is needed for life cycle completion and proliferation. The effect of this interaction on lung epithelial cells have previously shown that the trophic form of this organism greatly inhibits p34cdc2activity, a serine/threonine kinase required for transition from G2to M phase in the cell cycle. To gain further insight into the host response during Pneumocystis pneumonia (PCP), we used microarray technology to profile epithelial cell (A549) gene expression patterns followingPneumocystis cariniiinteraction. Furthermore, we isolated separate populations of cyst and trophic forms ofP. carinii, which were then applied to the lung epithelial cells. Differential expression of genes involved in various cellular functions dependent on the specificP. cariniilife form in contact with the A549 cell were identified. The reliability of our data was further confirmed by Northern blot analysis on a number of selected up or down regulated transcripts. The transcriptional response toP. cariniiwas dominated by cytokines, apoptotic, and anti-apoptotic related genes. These results reveal several previously unknown effects ofP. cariniion the lung epithelial cell and provide insight into the complex interactions of host and pathogen.

BackgroundExuberant inflammation during Pneumocystis pneumonia leads to lung injury. CARD9 is a central mediator of inflammatory signaling mediated by C-type lectin receptors. CARD9 inhibitor BRD5529 has been shown to be an effective in vitro inhibitor of Pneumocystis β-glucan-induced proinflammatory signaling and downstream TNF-alpha production, suggesting its viability as a candidate for preliminary drug testing as an anti- inflammatory agent in the rodent Pneumocystis pneumonia model (PCP).MethodsTo assess for potential toxicity, mice were injected intraperitoneally (IP) daily either with vehicle or BRD5529 at 0.1 mg/kg or 1.0 mg/kg for two weeks. Mouse weights were taken daily. At day 14, mice were euthanized, weighed, and analyzed by flexiVent™ for lung stiffness. Lungs, liver, and kidney were then harvested for H&E staining and pathology scoring. Lung samples were further analyzed for proinflammatory cytokines via ELISA and extracellular matrix generation via quantitative PCR (q-PCR). Blood collection postmortem was performed for blood chemistry analysis.ResultsBRD5529 at both doses of IP administration resulted in no significant changes in daily or final weight gain. Analysis of lung stiffness by flexiVent™ showed no significant differences between the control or treated groups. Furthermore, ELISA results for proinflammatory IL-1 Beta, IL-6, and TNF-alpha showed no major differences in the respective groups. qPCR analysis of extracellular matrix transcripts collagen type I, alpha 1 (Col1a1) and fibronectin (Fn) were statically similar as well in the treated and control groups. Examination and pathology scoring of H&E slides from lung, liver, and kidney from the each of the mice in all groups and subsequent pathology scoring showed no significant change. Blood chemistry analysis revealed similar, non-significant patterns.ConclusionsBRD5529 in our initial general safety and toxicology assessments displayed no inherent safety concerns in the analyzed parameters. These data support broader in vivo testing of the inhibitor as a timed adjunct therapy to the deleterious proinflammatory host immune response often associated with anti-Pneumocystis therapy.

Established technology, operational infrastructure, and nursing resources were leveraged to develop a remote patient monitoring (RPM) program for ambulatory management of patients with COVID-19. The program included two care-delivery models with different monitoring capabilities supporting variable levels of patient risk for severe illness. The primary objective of this study was to determine the feasibility and safety of a multisite RPM program for management of acute COVID-19 illness. We report an evaluation of 7074 patients served by the program across 41 US states. Among all patients, the RPM technology engagement rate was 78.9%. Rates of emergency department visit and hospitalization within 30 days of enrollment were 11.4% and 9.4%, respectively, and the 30-day mortality rate was 0.4%. A multisite RPM program for management of acute COVID-19 illness is feasible, safe, and associated with a low mortality rate. Further research and expansion of RPM programs for ambulatory management of other acute illnesses are warranted.

Pneumocystis species interaction with myeloid cells is well known, especially in macrophages; however, how the organism binds to lung epithelial cells is incompletely understood. Ephrin type-A receptor 2 (EphA2) has been previously identified as a lung epithelial pattern recognition receptor that binds to fungal β-glucans. Herein, we also report that EphA2 can also bind Pneumocystis β-glucans, both in isolated forms and also on exposed surfaces of the organism. Furthermore, binding of Pneumocystis β-glucans resulted in phosphorylation of the EphA2 receptor, which has been shown to be important for downstream proinflammatory response. Indeed, we also show that interleukin 6 cytokine is significantly increased when lung epithelial cells are exposed to Pneumocystis β-glucans, and that this response could be blocked by preincubation with a specific antibody to EphA2. Our study presents another Pneumocystis lung epithelial cell receptor with implications for initial colonization and possible therapeutic intervention.

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic, progressive pulmonary disease characterized by aberrant tissue remodeling, formation of scar tissue within the lungs and continuous loss of lung function. The areas of fibrosis seen in lungs of IPF patients share many features with normal aging lung with cellular senescence being one. The contribution of the immune system to the etiology of IPF remains poorly understood. Evidence obtained from animal models and human studies suggests that innate and adaptive immune processes can orchestrate existing fibrotic responses. Currently, there is only modestly effective pharmacotherapy for IPF. Mesenchymal stem cells (MSCs)-based therapies have emerged as a potential option treatment of IPF. This study explores the possibility of using autologous MSCs as an IPF therapy and present an attempt to determine if the disease occurring in the lungs can be reflected on peripheral blood immune status. MethodsComprehensive characterization of autologous adipose derived MSCs (aMSCs) from five IPF patients and five age and gender matched Healthy Controls (HC) was done using flow cytometry, Droplet Digital PCR (ddPCR), Multiplex Luminex xMAP technology and confocal microscopy. For assessing the self renewal capacity and osteogenic differentiation IncuCyte Live Cell Imaging technology was used. Multi-parameter quantitative flow cytometry of un-manipulated whole blood of another group of 15 IPF patients and 87 (30 age and gender matched) HC was used to analyze 110 peripheral phenotypes.ResultsThere are no differences between autologous aMSCs from IPF patients and HC in their stem cell properties, self renewal capacity, plasticity for osteogenic differentiation, secretome content, cell cycle inhibitor marker levels and mitochondrial health. IPF patients had altered peripheral blood immunophenotype including reduced B cells subsets, increased T cell subsets, and increased granulocytes among others demonstrating clear and significant differences.ConclusionsOur results indicate that there is no difference in aMSCs properties from IPF patients and HC, suggesting that autologous aMSCs may be an acceptable option for IPF therapy.Characterization of peripheral immune phenotype may be a valuable indicator for successful therapy, and for potentially staging the disease.

Background Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive pulmonary disease characterized by aberrant tissue remodeling, formation of scar tissue within the lungs and continuous loss of lung function. The areas of fibrosis seen in lungs of IPF patients share many features with normal aging lung including cellular senescence. The contribution of the immune system to the etiology of IPF remains poorly understood. Evidence obtained from animal models and human studies suggests that innate and adaptive immune processes can orchestrate existing fibrotic responses. Currently, there is only modest effective pharmacotherapy for IPF. Mesenchymal stem cells (MSCs)-based therapies have emerged as a potential option treatment of IPF. This study characterizes the functionality of autologous MSCs for use as an IPF therapy and presents an attempt to determine whether the disease occurring in the lungs is associated with an alterated immune system. Methods Comprehensive characterization of autologous adipose-derived MSCs (aMSCs) from 5 IPF patient and 5 age- and gender-matched healthy controls (HC) was done using flow cytometry, PCR (ddPCR), multiplex Luminex xMAP technology, confocal microscopy self-renewal capacity and osteogenic differentiation. Additionally, multi-parameter quantitative flow cytometry of unmanipulated whole blood of 15 IPF patients and 87 (30 age- and gender-matched) HC was used to analyze 110 peripheral phenotypes to determine disease-associated changes in the immune system. Results There are no differences between autologous aMSCs from IPF patients and HC in their stem cell properties, self-renewal capacity, osteogenic differentiation, secretome content, cell cycle inhibitor marker levels and mitochondrial health. IPF patients had altered peripheral blood immunophenotype including reduced B cells subsets, increased T cell subsets and increased granulocytes demonstrating disease-associated alterations in the immune system. Conclusions Our results indicate that there are no differences in aMSC properties from IPF patients and HC, suggesting that autologous aMSCs may be an acceptable option for IPF therapy. The altered immune system of IPF patients may be a valuable biomarker for disease burden and monitoring therapeutic response

Myeloid C-type lectin receptors (CLRs) are innate immune recognition molecules that bind to microorganisms via their carbohydrate recognition domains. In this study, we utilized a library of CLRs that recognize fungal mannans. We used this library to screen against Pneumocystis carinii (Pc) homogenates or purified Pc major surface glycoprotein (Msg) present on Pneumocystis. The results demonstrated that all of the mammalian CLR hFc-fusions tested displayed significant interaction/binding with Pc organisms, and furthermore to isolated Msg. Highest Pc organism and Msg binding activities were with CLR members Mincle, Dectin-2, DC-SIGN and MCL. An immunofluorescence assay with the respective CLR hFc-fusions against whole Pc life forms corroborated these findings. Although some of these CLRs have been implicated previously as important for Pneumocystis pathogenesis (Dectin-1/Dectin-2/Mincle), this is the first analysis of head-to-head comparison of known fungal mannan binding CLR-hFc fusions with Pc. Lastly, heat treatment resulted in reducted CLR binding.

Rationale: Prompt diagnosis of invasive fungal infections is important because of the associated morbidity and mortality; however, diagnosis is challenging because of the nonspecific symptoms and radiographic findings.Objectives: To conduct a systematic review and meta-analysis of studies that evaluated the diagnostic accuracy of serum and bronchoalveolar lavage (BAL) galactomannan (GM) and serum or BAL polymerase chain reaction (PCR) in patients with suspected invasive aspergillosis (IA), β-d-glucan in critically ill patients at risk for candidiasis or candidemia, and serology testing and antigen detection in patients with endemic mycoses (histoplasmosis, blastomycosis, and coccidioidomycosis).Methods: Studies were selected and appraised by pairs of reviewers. Bivariate random effects meta-analysis was used to generate pooled sensitivity, specificity, and diagnostic likelihood ratios.Results: Serum GM in patients with impaired immunity suspected of having IA had sensitivity of 0.71 (95% confidence interval [CI], 0.64-0.78) and specificity of 0.89 (95% CI, 0.84-0.92). A cutoff of 1 optical density index yielded optimal sensitivity and specificity. BAL GM in patients with impaired immunity suspected of having IA had sensitivity of 0.84 (95% CI, 0.73-0.91) and specificity of 0.88 (95% CI, 0.81-0.91). Serum or whole-blood PCR in immunocompromised patients with suspected IA had sensitivity of 0.81 (95% CI, 0.73-0.86) and specificity of 0.79 (95% CI, 0.68-0.86). BAL PCR in patients at high risk for IA had high sensitivity of 0.90 (95% CI, 0.77-0.96) and specificity of 0.96 (95% CI, 0.93-0.98) for diagnosing IA. β-d-glucan assay in patients in the intensive care unit at risk for invasive candidiasis or candidemia had sensitivity of 0.81 (95% CI, 0.74-0.86) and specificity of 0.60 (95% CI, 0.49-0.71). Data on diagnostic accuracy of antigen detection and serology testing for endemic mycoses were limited and heterogeneous (varied according to test, patient immunity, and suspected endemic disease).Conclusions: The diagnosis of invasive fungal infections remains a challenge. Various serum and BAL markers can aid in diagnosis. This evidence supports the development of clinical practice recommendations by the American Thoracic Society.

B-cell activation is increasingly linked to numerous fibrotic lung diseases, and it is well known that aggregates of lymphocytes form in the lung of many of these patients. Activation of B-cells by pattern recognition receptors (PRRs) drives the release of inflammatory cytokines, chemokines, and metalloproteases important in the pathophysiology of pulmonary fibrosis. However, the specific mechanisms of B-cell activation in patients with idiopathic pulmonary fibrosis (IPF) are poorly understood. Herein, we have demonstrated that B-cell activation by microbial antigens contributes to the inflammatory and profibrotic milieu seen in patients with IPF. B-cell stimulation by CpG and β-glucan via PRRs resulted in activation of mTOR-dependent and independent pathways. Moreover, we showed that the B-cell–secreted inflammatory milieu is specific to the inducing antigen and causes differential fibroblast migration and activation. B-cell responses to infectious agents and subsequent B-cell–mediated fibroblast activation are modifiable by antifibrotics, but each seems to exert a specific and different effect. These results suggest that, upon PRR activation by microbial antigens, B-cells can contribute to the inflammatory and fibrotic changes seen in patients with IPF, and antifibrotics are able to at least partially reverse these responses.

Objective To report the Mayo Clinic experience with coronavirus disease 2019 (COVID-19) related to patient outcomes. Methods We conducted a retrospective chart review of patients with COVID-19 diagnosed between March 1, 2020, and July 31, 2020, at any of the Mayo Clinic sites. We abstracted pertinent comorbid conditions such as age, sex, body mass index, Charlson Comorbidity Index variables, and treatments received. Factors associated with hospitalization and mortality were assessed in univariate and multivariate models. Results A total of 7891 patients with confirmed COVID-19 infection with research authorization on file received care across the Mayo Clinic sites during the study period. Of these, 7217 patients were adults 18 years or older who were analyzed further. A total of 897 (11.4%) patients required hospitalization, and 354 (4.9%) received care in the intensive care unit (ICU). All hospitalized patients were reviewed by a COVID-19 Treatment Review Panel, and 77.5% (695 of 897) of inpatients received a COVID-19–directed therapy. Overall mortality was 1.2% (94 of 7891), with 7.1% (64 of 897) mortality in hospitalized patients and 11.3% (40 of 354) in patients requiring ICU care. Conclusion Mayo Clinic outcomes of patients with COVID-19 infection in the ICU, hospital, and community compare favorably with those reported nationally. This likely reflects the impact of interprofessional multidisciplinary team evaluation, effective leveraging of clinical trials and available treatments, deployment of remote monitoring tools, and maintenance of adequate operating capacity to not require surge adjustments. These best practices can help guide other health care systems with the continuing response to the COVID-19 pandemic.

TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: COVID-19 infection is associated with a broad-range of clinical presentations from asymptomatic infection to severe pneumonia with multi-system features. Similarly, short- and long-term outcomes vary widely. Although multiple studies have addressed outcomes of patients hospitalized with COVID-19 infection, Community-based studies are sparse and are needed to provide a broader perspective of the lasting impact of this disease, especially lung damage. METHODS: This is a retrospective, Community-based, cohort study of residents of Rochester, Minnesota, who were enrolled in the Mayo Clinic COVID-19 database. Subjects were included if they were diagnosed with COVID-19 infection from March 01, 2020 to May 31, 2020. The clinical presentation, laboratory results, pulmonary function results, and chest imaging findings at the time of presentation and events in the following months until December 31, 2020 were assessed by review of medical records and imaging studies. RESULTS: We identified 570 community patients with COVID-19 infection;median age 38.5 years (range 18-98 years) - 526 patients did not require hospitalization while 44 (7.5%) patients (median age 51.8 years, range 20 - 81) had hypoxemia warranting admission (moderate to severe disease based on WHO clinical progression scale)[i]. At the time of hospitalization, all has undergone chest radiography, and 42 patients (95%) had chest CT with all demonstrating peripheral patchy ground glass opacities (GGOs) bilaterally.Thirteen patients (29.5%) returned for chest radiograph (median interval, 5.9 months);4 of them (13%) had residual parenchymal opacities, of whom nearly all (94%) were 45 years or older. Twenty-five patients had follow-up CT scans three months after initial diagnosis;8 patients (32%) had complete resolution of the CT infiltrates. Seventeen patients (9 females and 8 males) had residual parenchymal opacities with the most common being peripheral and bibasilar GGOs;5 patients had residual reticulonodular scarring and traction bronchiectasis on imaging. 6 patients (13.6%) underwent pulmonary function testing at follow-up visit (median interval 4.6 months), of whom 2 manifested abnormal findings consisting of mild restriction. Overall, 50% of the patients had evidence of residual lung disease (imaging and/or pulmonary function) three months after presentation. Ten patients (59%) with residual disease on chest CT had been hospitalized (six requiring ICU level of care) and manifested significantly elevated inflammatory markers (ferritin, interleukin-6 and C-reactive protein);9 out of these 10 patients with residual disease did not receive steroids at the time of hospitalization. Seven patients (41%) with residual lung infiltrates on CT scan was not hospitalized and didn’t have evidence of severe inflammatory disease. CONCLUSIONS: In our study, we assessed the initial severity and outcomes of subjects diagnosed with COVID-19 in our community and found 3% to manifest persistent lung abnormalities following the acute infection. The residual radiological findings consisted mainly of GGOs affecting the peripheral zones of the lung;however, in a minority of the patients, fibrotic changes were present. Almost two thirds of the patients with persistently abnormal imaging had been hospitalized for at least two days and had high serologic inflammatory markers (C-reactive protein, Ferritin and interleukin-6). This might indicate that the resultant fibrosis is mainly driven by post-inflammatory processes rather than the direct effect of the virus. conversely a considerable number of patients developed interstitial infiltrates without evidence of acute inflammatory reaction which may suggest another non-inflammatory etiology of these findings. Furthermore, most of our patients who manifested lung fibrosis on follow-up CT had not received steroids. Although the long-term course and significance of these residual radiologic findings are not established, prior data of Middle East Respiratory Syndrome and Se ere Acute Respiratory Syndrome suggest that most of these lesions resolve over time among those who survived hospitalization. CLINICAL IMPLICATIONS: The results of this community-based study will provide a broader perspective of the lasting impact of COVID-19 on the lungs. DISCLOSURES: No relevant relationships by Faysal Al-ghoula, source=Web Response Research - industry initiated (clinical relationship with AstraZeneca Pharmaceuticals, LP Please note: 2020 Added 04/27/2021 by Philippe Bauer, source=Web Response, value=Grant/Research Support Research - industry initiated (clinical relationship with Corvus Pharmaceuticals, Inc Please note: 2021 Added 04/27/2021 by Philippe Bauer, source=Web Response, value=Grant/Research Support No relevant relationships by Eva Carmona, source=Web Response No relevant relationships by Tobias Peikert, source=Web Response No relevant relationships by Jay Ryu, source=Web Response

Introduction: Sarcoidosis associated pulmonary hypertension (SAPH) is a leading contributor to sarcoidosis-related mortality. The 6-min walk test (6MWT) is widely used in assessment of cardiorespiratory conditions. A reduced 6-min walk distance (6MWD) has been associated with increased mortality in SAPH. We examined patients from the Registry of Sarcoidosis Associated Pulmonary Hypertension (ReSAPH) who had performed 6MWT at enrollment to identify variables that affect 6MWD, and the prognostic value of 6MWT variables regarding death or lung transplantation. Material and methods: ReSAPH patients with available 6MWT were included. Variables analyzed using pre-defined cutoffs included 6MWD, initial and end of test Borg dyspnea score, oxygen saturation, and heart rate at beginning, end, and after 1-min recovery, absolute change in oxygen saturation, modified distance-saturation product (mDSP), and the heart rate recovery at 1-min (HRR). Findings: 174 patients met inclusion criteria; 48 patients died and 8 underwent lung transplantation. Patients with 6MWD300 m (p = 0.012). No associations with outcome were observed with mDSP cutoff 200 m%, desaturation≥5% and oxygen saturation

Pneumocystis jirovecii, the opportunistic fungus that causes Pneumocystis pneumonia (PCP) in humans, is a significant contributor to morbidity and mortality in immunocompromised patients. Given the profound deleterious inflammatory effects of the major β-glucan cell wall carbohydrate constituents of Pneumocystis through Dectin-1 engagement and downstream caspase recruitment domain-containing protein 9 (CARD9) immune activation, we sought to determine whether the pharmacodynamic activity of the known CARD9 inhibitor BRD5529 might have a therapeutic effect on macrophage innate immune signaling and subsequent downstream anti-inflammatory activity. The small-molecule inhibitor BRD5529 was able to significantly reduce both phospho-p38 and phospho-pERK1 signaling and tumor necrosis factor alpha (TNF-α) release during stimulation of macrophages with Pneumocystis cell wall β-glucans.

OBJECTIVES The aim of this study was to assess bleomycin-induced pulmonary fibrosis on ex vivo mouse lungs using ultrasound image grading and texture analysis. METHODS Excised mouse lungs were divided into 3 groups: control, mild fibrosis, and severe fibrosis based on the monitored indicators of health. B-mode ultrasound images were obtained via scanning the mouse lungs ex vivo. The surface smoothness, echo density, and angle of lesions or the lung margin were graded, and the imaging contrast, correlation, homogeneity, and entropy were assessed via texture analysis. RESULTS The grades of surface smoothness, echo density, and angle were statistically higher for the severe fibrosis group compared with those of the control and mild fibrosis groups (P

Caspase recruitment domain-containing protein 9 (CARD9) is an adaptor molecule critical for key signaling pathways initiated through C-type lectin receptors (CLRs). Previous studies demonstrated that Pneumocystis organisms are recognized through a variety of CLRs. However, the role of the downstream CARD9 adaptor signaling protein in host defense against Pneumocystis infection remains to be elucidated. Herein, we analyzed the role of CARD9 in host defense against Pneumocystis both in CD4-depleted CARD9-/- and immunocompetent hosts. Card9 gene-disrupted (CARD9-/- ) mice were more susceptible to Pneumocystis, as evidenced by reduced fungal clearance in infected lungs compared to wild-type infected mice. Our data suggests that this defect was due to impaired proinflammatory responses. Furthermore, CARD9-/- macrophages were severely compromised in their ability to differentiate and express M1 and M2 macrophage polarization markers, to enhanced mRNA expression for Dectin-1 and Mincle, and most importantly, to kill Pneumocystis in vitro. Remarkably, compared to wild-type mice, and despite markedly increased organism burdens, CARD9-/- animals did not exhibit worsened survival during PCP, perhaps related to decreased lung injury due to altered influx of inflammatory cells and decreased levels of proinflammatory cytokines in response to the organism. Lastly, although innate phase cytokines were impaired in the CARD9-/- animals during PCP, T-helper cell cytokines were normal in immunocompetent CARD9-/- animals infected with Pneumocystis. Taken together, our data demonstrate that CARD9 has a critical function in innate immune responses against Pneumocystis. This article is protected by copyright. All rights reserved.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which presents an unprecedented challenge to medical providers worldwide. Although most SARS-CoV-2-infected individuals manifest with a self-limited mild disease that resolves with supportive care in the outpatient setting, patients with moderate to severe COVID-19 will require a multidisciplinary collaborative management approach for optimal care in the hospital setting. Laboratory and radiologic studies provide critical information on disease severity, management options, and overall prognosis. Medical management is mostly supportive with antipyretics, hydration, oxygen supplementation, and other measures as dictated by clinical need. Among its medical complications is a characteristic proinflammatory cytokine storm often associated with end-organ dysfunction, including respiratory failure, liver and renal insufficiency, cardiac injury, and coagulopathy. Specific recommendations for the management of these medical complications are discussed. Despite the issuance of emergency use authorization for remdesivir, there are still no proven effective antiviral and immunomodulatory therapies, and their use in COVID-19 management should be guided by clinical trial protocols or treatment registries. The medical care of patients with COVID-19 extends beyond their hospitalization. Postdischarge follow-up and monitoring should be performed, preferably using telemedicine, until the patients have fully recovered from their illness and are released from home quarantine protocols.

IntroductionSarcoidosis-associated pulmonary hypertension (SAPH) is associated with reduced survival in single-centre studies. The international Registry for SAPH (ReSAPH) with long-term follow-up was established to enrich our knowledge of this complication of sarcoidosis. This analysis aims to elucidate factors associated with reduced transplant-free survival in SAPH patients.MethodsReSAPH contains prospectively collected outcomes of SAPH patients since the time of registry enrolment. Information analysed includes right heart catheterisation data, pulmonary function testing, chest radiography, Scadding stage and 6-min walk distance (6MWD), among others. Cox regression models were used to identify independent predictors of transplant-free survival.ResultsData from 215 patients followed for a mean±sd 2.5±1.9 years were available for analysis. In the 159 precapillary patients, the Kaplan–Meier-adjusted 1-, 3- and 5-year transplant-free survival was 89.2%, 71.7% and 62.0%, respectively. Kaplan–Meier-adjusted 1-, 3- and 5-year transplant-free survival in the incident group was 83.5%, 70.3% and 58.3%, respectively, and in the prevalent group was 94.7%, 72.2% and 66.3%, respectively. Patients with reduced diffusing capacity of the lung for carbon monoxide (DLCO) (1)/forced vital capacity (FVC) ratio were identified as independent risk factors for reduced transplant-free survival in the precapillary cohort.ConclusionReduced DLCO (1/FVC ratio was identified as an independent risk factor for worsened outcomes.

Aims Cardiac sarcoidosis (CS) often presents with ventricular arrhythmias, heart block, and cardiomyopathy. The prognosis of CS with contemporary management is uncertain. We estimated the impact of baseline and treatment variables on left ventricular ejection fraction (LVEF), ventricular assist device placement, heart transplant, and death. Methods and results We identified patients with CS seen from 1994-2014 at two large academic medical centres. All met the 2014 Heart Rhythm Society expert consensus criteria for diagnosis. From the 574 patients identified, 91 met inclusion criteria. Twenty-two (24.2%) were diagnosed by endomyocardial biopsy. Cardiomyopathy was the primary presentation in 47 patients (51.6%). Within 90 days of diagnosis, 41 patients (45.0%) received prednisone alone, 29 (31.9%) received alternative immunosuppression with or without prednisone, and 21 (23.1%) received no immunosuppression. During follow-up, 31 of 47 cardiomyopathy patients experienced improvement in LVEF, while 23 experienced decline in LVEF or clinical exacerbation, and 15 of 22 patients presenting with ventricular arrhythmia had recurrence. These results did not differ by treatment group. During a median follow-up of 44 months for our cohort, 14 patients reached the composite endpoint of ventricular assist device placement, heart transplant, or death. Survival without the composite outcome did not differ by treatment group, but was worse among patients presenting with cardiomyopathy (log-rank = 0.005). Conclusion In a large series of CS subjects, rates of ventricular arrhythmia and heart failure events remain high with no treatment regimen clearly associated with better outcome. Patients with cardiomyopathy at diagnosis were more likely to reach the composite endpoint.