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Introduction: SARS-CoV-2 is responsible for the current global pandemic. SARS-CoV-2 infection underlies the novel viral condition coronavirus disease 2019 (COVID-19). COVID-19 causes significant pulmonary sequelae contributing to serious morbidities. The pathogenesis of COVID-19 is complex with a multitude of factors leading to varying levels of injury numerous extrapulmonary organs. This review of 124 published articles documenting COVID- 19 autopsies included 1,142 patients. Method(s): A PubMed search was conducted for COVID-19 autopsy reports published before March 2021 utilizing the query COVID-19 Autopsy. There was no restriction regarding age, sex, or ethnicity of the patients. Duplicate cases were excluded. Findings were listed by organ system from articles that met selection criteria. Result(s): Pulmonary pathology (72% of articles;866/1142 patients): diffuse alveolar damage (563/866), alveolar edema (251/866), hyaline membrane formation (234/866), type II pneumocyte hyperplasia (165/866), alveolar hemorrhage (164/866), and lymphocytic infiltrate (87/866). Vascular pathology (41% of articles;771/1142 patients): vascular thrombi (439/771)-microvascular predominance (294/439)-and inflammatory cell infiltrates (116/771). Cardiac pathology (41% of articles;502/1142 patients): cardiac inflammation (186/502), fibrosis (131/502), cardiomegaly (100/502), hypertrophy (100/502), and dilation (35/502). Hepatic pathology (33% of articles;407/1142 patients): steatosis (106/402) and congestion (102/402). Renal pathology (30% of articles;427/1142 patients): renal arteries arteriosclerosis (111/427), sepsis-associated acute kidney injury (81/427) and acute tubular necrosis (77/427). Conclusion(s): This review revealed anticipated pulmonary pathology, along with significant extrapulmonary involvement secondary to COVID-19, indicating widespread viral tropism throughout the human body. These diverse effects require additional comprehensive longitudinal studies to characterize short-term and long-term COVID-19 sequelae and inform COVID-19 treatment.
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The series of autopsies reported since the beginning of the pandemic have highlighted several patterns of lung damage, both isolated and combined. The factors influencing the occurrence of these different tissue responses to viral aggression by SARS-CoV-2 have not yet been determined. In asymptomatic patients or patients with respiratory symptoms who were not ventilated, lymphocyte pneumonia associated with type II pneumocyte atypical hyperplasia and a few hyaline membranes or focal lesions of acute fibrinous pneumonia have been observed. In critically ill patients, the most frequent pattern is diffuse alveolar damage with interstitial lymphoid infiltration, type II pneumocyte atypia and, very often, capillary or arteriolar microthromboses and/or endothelitis. The precise description of these lesions, which is becoming more and more consensual, makes it possible to understand the favourable effects of corticosteroid therapy in seriously ill patients and the evolution under ventilation towards fibrosis.Copyright © ERS 2021.
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Background: The continuous evolution of SARS-CoV-2 in the diverse immune landscape (natural, vaccine, hybrid) is giving rise to novel immune escape mutations. So far, the resulting new variants (BA.1, BA.2, BA.2.12.1) were observed to cause mild infections, however, BA.5 infections are associated with an increased risk of hospitalization.1 Therefore it is essential to investigate the pathogenesis of BA.5. Method(s): Here we compared the pathogenicity of Pre-Omicron (B.1.351) and Omicron (BA.1, BA.2.12.1, and BA.5) variants in wild-type C57BL/6J mice and K18-hACE2 mice. The virus replication kinetics was also studied in human Calu3, pulmonary alveolar type 2 (AT2) cells, and airway organoids (HAO). Cell-to-cell spread of virus was measured by syncytia formation assay and immunohistochemistry (IHC) of infected lungs. Result(s): In the results, infection in C57BL/6J mice showed severe weight loss ( >15%) for B.1.351 infected mice and moderate ( >5%) for BA.5 infected. C57BL/6J mice showed higher virus replication of B.1.351 followed by BA.5, BA.1, and BA.2.12.1. At the peak of virus replication (2 days) plaque-forming units from lung extract of BA.5 infected mice were two, and three logs higher compared to BA.1 and BA.2.12.1 respectively. BA.5 infection was lethal to 80% of infected K18-hACE2 mice, whereas the mice looked normal after infection with BA.1 and BA.2.12.1. BA.5 infected mice showed high virus replication in brain tissue. Surprisingly the syncytia formation assay and IHC for BA.5 was comparable to that of B.1.351, indicating the higher cell-to-cell spread of BA.5 and B.1.351 compared to BA.1 and BA.2.12.1, which is one of the measures of pathogenicity. Calu3 and HAO showed the same trend of virus replication as was observed in-vivo experiments however AT2 cells were found to be resistant to BA.5 replication. Conclusion(s): These results suggest that the BA.5 variant (lineage) of Omicron has the potential to regain the pathogenicity as it shows increased virulence compared to other Omicron sub-variants. Lethal infection of BA.5 in K18-hACE2 mice may be attributed to catastrophic encephalitis and increased cell-to-cell spread.
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Since December 2019, an outbreak of a novel coronavirus (SARS-CoV-2) infection causing COVID-19 disease has influenced the whole world. Angiotensin converting enzyme 2 (ACE2) receptors on type 2 pneumocytes in humans were determined as the entry for SARSCoV-2. Receptor binding and subsequently endocytosis of ACE2 diminish the cell membrane expression and also the function of ACE2. ACE2 is an enzyme involved in bradykinin metabolism. Lys-des-Arg9-BK occured with enzymatic cleaving of Lys-BK derived from low molecular weight kininogen is inactivated by ACE2 in tissues and it is a vasodilator agent having its own receptor named bradykinin B1. Non-metabolized Lys-des-Arg9-BK can be the reason for tissue vasodilation and increased vascular permeability in the patients with COVID-19. Increased bradykinin levels in patients with hereditary angioedema with C1-INH deficiency (C1-INH-HAE) do not cause increased SARS-CoV-2 infection or more severe disease. Although SARS-CoV-2 infection does not result in increased bradykinin levels, it can increase Lys-des-Arg9-BK levels.Copyright © 2020 Bilimsel Tip Yayinevi. All rights reserved.
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The approval of mRNA vaccine technique against COVID-19 opens a door to research and the creation of new drugs against different infectious pathologies or even cancer, since for several diseases the therapeutic options are limited, and different viral diseases are treated only symptomatically. For these reasons, this study proposed a hypothesis supported by biological studies, that it provides a theoretical basis for the possible development of a drug that used the mRNA technique and the ribonucleolytic action of a ribonuclease for a possible antiviral therapy, and analyzed a future perspective of this technique in order to provide a bibliographic basis on this hypothesis and motivate researchers to carry out biological studies on this topic.Copyright © 2022, Health Biotechnology and Biopharma. All rights reserved.
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Patients with severe COVID-19-associated pneumonia are at risk to develop pulmonary fibrosis. To study the underlying mechanisms, we aim to develop advanced cell culture models that reliably reflect COVID-19-related profibrotic microenvironment. To identify key cellular players, we performed pilot immunohistochemistry analysis on lung tissue from COVID-19 patients with fibrosis collected during autopsy. Results revealed diffuse alveolar damage with macrophage infiltration, and myofibroblast accumulation with enriched collagen deposition surrounding the damaged alveoli. To mimic SARS-CoV-2 infection in alveoli, we infected human primary type II alveolar epithelial cells (AEC2) and found enhanced signaling of profibrotic cytokine transforming growth factor beta (TGFbeta) in some donors. To recreate the early fibrotic niche, an alveolar-macrophage-fibroblast (AMF) tri-culture model was established. After infecting AEC2 with SARS-CoV-2 in this AMF model, gene expression analysis provided evidence for fibroblast-to-myofibroblast transition. Furthermore, we found that overexpression of SARS-CoV-2 papain-like protease (PLpro) can promote TGFbeta signaling in HEK293T and A549 cells. After infecting AEC2 with SARS-CoV-2 PLpro lentivirus in the AMF model, we found signs of epithelial-to-mesenchymal transition and fibroblast-to myofibroblast transition. In future studies, we will use a detailed analysis of COVID-19-associated lung fibrosis with other types of lung fibrosis, to further refine COVID-19-related fibrosis models, including lung-on-chip models.
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Aim: COVID-19 infection has affected the whole world. It has been speculated that the virus might hold on to angiotensin-converting enzyme 2 (ACE 2) surfaces of type 2 alveolar cells. ACE inhibitors and angiotensin receptor antagonists (ARBs) are essential antihypertensive and cardiac failure drugs in the guidelines. In this study, we aimed to find the effect of these drugs on clinical, laboratory courses, and outcomes of COVID-19 patients. Material(s) and Method(s): We included 109 patients in this study. There were 43 patients in the ACE/ARB group and 66 patients in the non-ACE/ARB group. The mean age was 60 years in the ACE/ARB group and 52 years old in the non-ACE/ARB group. Basal symptoms, hemogram, CRP, D-dimer, LDH, Ferritin, AST, duration of hospitalization, percentage of intensive care unit (ICU) need, length of stay in ICU were compared between the groups. Result(s): The mean age in the ACE/ARB group was higher than in the other group and was statistically significant (p=.027). The initial symptoms were not different. There were no differences between the laboratory results of the groups. The ICU need was higher in the patients who do not use the drug than in the users (p<.020). Discussion(s): ACE/ARB usage in COVID-19 patients did not worsen the course of the disease. However, ACE/ARB users before COVID-19 pandemic were taken to ICU at a low rate.Copyright © 2022, Derman Medical Publishing. All rights reserved.
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Background: The new public health emergency of COVID-19 caused by a novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), which originated in Wuhan, Hubei province, China in December 2019, evolved into a pandemic in no time and is still in progression. The novel virus mainly targets the lower respiratory system, leading to viral pneumonia, with other associated complications of multi organ failure. Discussion(s): The bats, in particular Rhinolophus affinis, is a natural host of SARS-CoV-2 and the virus is considered to have spread to humans through yet controversial intermediate host pangolins. The incubation period ranges from 2-14 days and mode of person-to-person transmission is primari-ly via the direct contact with the infected person or through the droplets generated by the infected person during coughing or sneezing. The initiation of the infection process by SARS-CoV-2 virus is the invasion of lung type II alveolar cells via a receptor protein called angiotensin-converting enzyme 2 (ACE2) present on the cell membrane with glycosylated spike (S) viral protein that medi-ates host cell invasion. The main diagnostic tools employed are molecular methods based on nucleic acid detection engaging real-time quantitative polymerase chain reaction (RT-qPCR) and a new immunoassays based on antibodies IgM/IgG. Conclusion(s): Due to the lack of specific clinically approved anticovid-19 drugs or vaccines that could be used for its prevention or treatment, the current management approach is essentially sup-portive and symptomatic. The precautionary measures like, social distancing, cleaning hands with soap or sanitizers, using disinfectant solutions to decontaminate the surfaces of things and proper ventilation, wearing masks and other protective gears to curb transmission. The knowledge regard-ing COVID-19 therapies is still evolving and collaborative efforts are being put in to discover definitive therapies on different themes in the form of vaccines, repurposing drugs, RNA interfer-ence, docking studies, etc.Copyright © 2021 Bentham Science Publishers.
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COVID-19 has led to morbidity in millions of patients, ranging from mild flu-like symptoms to severe respiratory failure, necessitating oxygen supplementation and mechanical ventilation, and ultimately death. The SARS-CoV-2 virus reacts with angiotensin-converting enzyme 2 (ACE2) molecules that are especially found in alveolar epithelial type 2 cells in the lungs and thereby causes a loss in lung surfactant, a protein-lipid mixture that is crucial for both native immunity and reduction of surface ten-sion in the lung alveoli. Lung surfactant insufficiency results in atelectasis and loss of functional lung tissue amid an inflammatory storm and may be countered by treating COVID-19 pneumonia patients with exogenous lung surfactant, preferably by aerosol delivery of a novel dry powder synthetic lung sur-factant. More research on timing, dosing, and delivery of synthetic lung surfactant in patients with COVID-19 pneumonia is of crucial importance to implement this approach in clinical practice.Copyright © 2021 Bentham Science Publishers.
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Human alveolar type II cells (AT2s) are progenitors of the alveolar epithelium and are among the pulmonary cells that are directly exposed to inhaled stimuli. Primary human AT2s can be cultured in three-dimensional alveolospheres, but are difficult to culture in the physiologically relevant air-liquid interface (ALI) format. Human induced pluripotent stem cells (iPSCs) can be directed to differentiate to iPSC-derived AT2s (iAT2s) in alveolospheres, where they transcriptomically resemble fetal lung. Here we report the successful adaptation of iAT2s to ALI culture, which promotes their maturation and permits exposure to inhaled stimuli. We transcriptomically profile iAT2s cultured at ALI and find that they mature as they downregulate cell cycle-associated transcripts. We then evaluate the extent of iAT2 maturation at ALI within the developmental context by comparison to primary AT2s. We find that iAT2s at ALI are more similar to primary AT2s than iAT2s cultured as spheres, and that differences are driven by primary AT2s' response to immune stimuli. We then test the capacity of iAT2s to respond to immune stimuli by infecting with SARSCoV-2. We find that iAT2s mount an epithelial-intrinsic interferon and inflammatory response to SARS-CoV-2 infection, and can serve as a platform for testing antiviral therapeutics. Finally, we demonstrate that iAT2s at ALI respond to cigarette smoke and electronic cigarette vapor, enabling the direct comparison of these common inhaled stimuli. Overall, we describe a novel disease modeling platform that will enable exploration of gene-environment interactions unique to inhaled exposures of the alveolar epithelium.
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Purpose/Objectives: <Most used lower respiratory tract models consist of cell monolayers which lack of tissue and organ level response and of in-vivo phenotype. Ex-vivo lung tissues have short viability and limited availability. Lung organoids, which recapitulates better the 3D cellular complex structures, architecture, and in-vivo function, fail to reach maturity even after 85 -185 days of culture. Therefore, these models have a limited use to study fetal lung diseases. Other lung models, consist of only one structure of the lower track, such as bronchial tubes or alveoli, but fail to recapitulate the whole organ structure. In this work, cell microenvironment was used to promote the self-organization of epithelial and mesenchymal cells into macro-structures, aiming to mimic the whole and adult lower respiratory tract model> Methodology: <Different parts of the microenvironment were considered to create a compliant matrix. Alginate-Gelatin hydrogels were used for 3D encapsulation of mesenchymal origin cells. This hydrogel provided a stiffness like the one on the lung. Base membrane zone proteins were used to induce the attachment and guidance of epithelial cells into 3D structures. The interactions between both cell types, further guided them into lung fate. The morphology of resulting organoids was analyzed using immunostaining and confocal microscopy, LSM710, with the purpose of evaluate polarization, protein markers, and different cell populations. Quantitative PCR was performed to evaluate and compare the expression of lung fate genes with traditional cell monocultures.> Results: <The engineered microenvironment and protocol development done in this work resulted in macro-scale structures, in which branching morphogenesis occurred at day 21. Different structures were identified in the organoid including bronchial tube, bronchioles, and alveoli. Polarization of the organoids was confirmed by visualization of E-cadherin, and ZO-1. Expression of Surfactant Protein B and C into the organoids confirmed the presence of alveolar type II cells, which are only present in the later development stage. Surfactant Protein B, Transmembrane protease, serine 2, TMPRSS-2, and Angiotensin-converting enzyme 2, ACE2 were found to be significantly higher expressed into the organoids in comparison with traditional epithelial cells monolayers.> Conclusion/Significance: <Growth factors are normally used to induce the fate of stem cells into lung organoids;however, these fail to reach maturity. Here, we developed a new methodology to induce the formation of the organoids based on the cell microenvironment. The resulting organoids require less time for development. The initial stage of adult cells can be modulated through culture conditions induce a 3D structure like the adult lung. As such, these organoids have the potential to be used for modeling adult diseases and to develop specific models from patient cells, which is one step forward to personalized medicine. SFTPB is one of the main proteins which facilitates the breathing process. Its high expression into our model may indicate that breathing occurs into our lung organoids. The higher expression of TMPRSS-2 and ACE2 into the organoids has a major significance in the field of virology since both proteins are the mainly entrance of SARS-CoV-2, and influenza H1N1.>.
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SESSION TITLE: Rare Genetic Mutations and Anatomical Variants SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 12:25 pm - 01:25 pm INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a fatal disease affecting older adults that results in progressive scarring of the lung parenchyma. Familial IPF (FPF), defined by disease in two or more first-degree relatives, is estimated to occur in 2–20% of all IPF cases and can present with varying phenotypes which may be difficult to diagnose. Inherited gene variation as well as environmental factors predispose a patient to disease development. Additionally, rare genetic variants in the genes encoding surfactant A (SFTPA1, and SFTPA2) that affect alveolar stability and endoplasmic reticulum stress have been reported in less than 1% of FPF cases. Understanding these genetic variants is essential in the diagnosis and management of patients with FPF. CASE PRESENTATION: A 47-year-old Hispanic male with a history of COVID-19 one year ago (not requiring hospitalization) presented to the hospital for a two-day history of subjective fever and shortness of breath. He was hypoxic requiring oxygen via high flow nasal cannula. He was admitted four months ago for shortness of breath and treated for pneumonia. Since then, he has had chronic dyspnea with exertion. Computed tomography of the chest showed extensive ground glass opacities, worse in the right lung, with basilar and upper lobe honeycombing, and air bronchograms in the bilateral lower lobes. Family history was significant for a mother, maternal aunt, maternal grandfather, and maternal cousin who all died from pulmonary fibrosis. His maternal cousin was treated at our facility, in which genetic sequencing revealed a mutation in SFTPA2, c.697T>C. Our patient was found to have the same genetic mutation. DISCUSSION: The genetic basis of IPF remains poorly understood. Prior studies suggest only 20-30% of FPF cases harbor an identifiable causative genetic variant. Rare variants in two biologic pathways contribute to the known heritability of FPF including pathologic variants in surfactant related genes which cause improper protein trafficking leading to endoplasmic reticulum stress, defects in autophagy, and type II alveolar cell toxicity. SFTPA1 and SFTPA2 variants have been associated with FPF and lung adenocarcinoma in a small number of families and there are few reported cases. While currently the SFTPA2, c.697T>C mutation, previously reported by our group in 2016, is considered a variant of unknown significance, its occurrence in two relatives with serious progressive interstitial lung diseases suggests that it is indeed pathogenic. CONCLUSIONS: Gene sequencing should be considered for all patients with a family history of pulmonary fibrosis as identification of a rare genetic variant may offer guidance to diagnosis, prognostication, and risk stratification when considering lung transplantation as well as identify additional relatives who may be affected by IPF. Reference #1: Kropski JA, Young LR, Cogan JD, et al. Genetic Evaluation and Testing of Patients and Families with Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med. 2017;195(11):1423-1428. doi:10.1164/rccm.201609-1820PP Reference #2: Wang Y, Kuan PJ, Xing C, Cronkhite JT, Torres F, Rosenblatt RL, DiMaio JM, Kinch LN, Grishin NV, Garcia CK. Genetic defects in surfactant protein A2 are associated with pulmonary fibrosis and lung cancer. Am J Hum Genet. 2009 Jan;84(1):52-9. doi: 10.1016/j.ajhg.2008.11.010. Epub 2008 Dec 18. PMID: 19100526;PMCID: PMC2668050. Reference #3: Pulmonary Fibrosis Due to a Novel Surfactant Protein Mutation R.A. Arciniegas Flores, I.A. Vital, K. Medepalli, D. DeMarzo, M.K. Glassberg Csete, R.A. Alvarez. https://doi.org/10.1164/ajrccm-conference.2019.199.1_Meetings.A5437 DISCLOSURES: No relevant relationships by Roger Alvarez No relevant relationships by Eduardo Lopez Gonzalez No relevant relationships by Anita Singh
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SESSION TITLE: Biological Markers in Patients with COVID-19 Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/18/2022 01:30 pm - 02:30 pm PURPOSE: C-REACTIVE PROTEIN (CRP) is an acute phase reactant produced by liver in response to cytokines especially Interleukin-6 (IL-6). CRP consists of five identical subunits arranged symmetrically around a central pore. CRP binds to phospholipid constituents of foreign pathogens and damaged cells to promote the elimination of pathogens and clearance of apoptotic cells. Covid 19 virus through the spike protein binds to Angiotensin Converting Enzyme 2 receptors of host target cells, particularly receptors of alveolar Type 2 epithelial cells. This reaction causes Cytokine storm syndrome with release of several cytokines including IL-6. The purpose of this study is to assess the significance of CRP levels in predicting mortality of Covid 19 infection induced Adult Respiratory Distress syndrome (ARDS) patients admitted in the Intensive Care Unit (ICU). METHODS: We retrospectively reviewed the records of covid 19 induced ARDS patients admitted to ICU between July 1st 2020 and June 30th 2021 in a community hospital. We collected the CRP level on admission and discharge (survived or deceased) during that admission. The discharge CRP level was subtracted from admission CRP level. The positive value was taken as elevated CRP level and negative value was taken as non-elevated CRP. RESULTS: A total of 484 covid patients were admitted at the ICU during that period. Of those, 228 patients had admission and discharge (survived or deceased) CRP lab value available. 177 patients survived with 33 (18.6%) had elevated CRP and 144 (81.4%) had non-elevated CRP levels. 51 patients deceased with 32 (62.7%) had elevated CRP and 10 (37.3%) had non-elevated CRP levels. The p-value is <.00001. CONCLUSIONS: Elevated CRP was associated with high ICU mortality in Covid 19 infected ARDS patients. CLINICAL IMPLICATIONS: CRP can be elevated initially due to Cytokine storm syndrome and later may be related to secondary infection especially with immunosuppressive treatment. Elevated CRP levels indicates higher inflammatory response which should prompt early appropriate intervention. DISCLOSURES: No relevant relationships by Ravi Chandran No relevant relationships by Pranav Vadhul
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Solid tumors are characterized by extensive immune suppressive inflammation, vascular leak, fibrosis and organ damage. Similarly, SARS-CoV-2 infections induce aberrant pulmonary and systemic inflammation, vascular leak, coagulation, fibrosis and fatal organ damage. We previously demonstrated that macrophages in solid tumors strongly expressed phosphatidylinositol 3-kinase gamma (PI3Kγ), a signaling protein that coordinately controls granulocyte and monocyte trafficking to tumors as well as wound-healing-type macrophage transcription in cancer and fibrosis. We also observed that macrophages in COVID-19 lungs strongly expressed PI3Kγ. To identify therapeutic strategies to suppress COVID-19-associated inflammation, we characterized lung tissue of COVID19 patients using multiplex immunohistochemistry and tissue transcriptomics. Lungs of deceased patients exhibited substantial infiltration by neutrophils and wound-healing macrophages, fibrosis and alveolar type II cell depletion. In animal models of lung inflammation, bacterial infections, viral infection and SARS-CoV-2 infection, PI3Kγ deletion or inhibition with the cancer therapeutic IPI-549 (eganelisib) suppressed pulmonary and systemic inflammation, reduced lung damage, and promoted survival. These studies demonstrate the essential role of PI3Kγ in inflammatory diseases as well as cancer and support the use of PI3Kγ inhibitors such as eganelisib to suppress inflammation and promote survival in pulmonary infections like SARS-CoV-2 and cancer.
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We present familial tuberous sclerosis (TS) case complicated by COVID-19. COVID-19 aggravates the course of TS and may lead to a fatal outcome. We review the role of mTORC1 (mechanistic/mammalian Target of Rapamycin Complex 1) in the development and functions of the nervous system and the pathogenesis of TS and COVID-19 with emphasis on the involvement of the brain and lungs. We observed that COVID-19 worsens the course of epilepsy in patients with TS. In TS patients, lymphangioleiomyomatosis may predispose to SARS-CoV-2 invasion into the respiratory system because of the increased expression of ACE2 and TMPRSS2 in type II pneumocytes and thus may worsen the prognosis. We also review the current data on the continuation/termination of everolimus administration in patients with TS associated with COVID-19.
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Introduction: Older age is an important risk factor for severe COVID-19 disease. Understanding the biological mechanisms that link aging to the pathogenesis of COVID-19 is essential for developing of therapeutic strategies. We hypothesized that cell senescence, a basic aging process that plays a pivotal role in lung diseases, is involved in the pathogenesis of COVID-19 including the development of long-lasting lung alterations. Methods: To evaluate the impact of SARS-CoV-2 infection on cell senescence, we 1) analyzed publicly available datasets of scRNA-seq performed in BALF cells from patients with moderate or severe/critical COVID-19;2) investigated lung samples from cynomolgus macaques infected with 106 pfu of a SARS-CoV-2 clinical isolate. Two macaques were sacrificed at 4 days post-infection (dpi.) and two others at 30 dpi. Results: In BALF obtained within 10 days after symptom onset, the expression of several senescence markers, i.e., CDKN2A, CDKN1A (encoding p21), uPAR, CXCL8, IGFBP3, and GDF15 was significantly increased in epithelial cells in BALF from patients with severe COVID-19, suggesting that lung-cell senescence induction was contemporary of viral detection. Next, we investigated macaques at 4 and 30 dpi, corresponding respectively to the viral load peak and to the absence of detectable viral RNA in BALF (1). Immunohistochemical analysis revealed numerous SARS-CoV-2 antigen-stained cells, also co-stained for senescence markers p16- and p21. The lungs at 30 dpi no longer contained the consolidated parenchymal areas seen at 4 dpi but showed extensive lung parenchyma remodelling, with thickening of the alveoli and pulmonary vessel walls and abundant extracellular matrix deposits as assessed by collagen staining. These lesions were accompanied with massive accumulation of p16- and p21-positive cells, mostly pneumocytes II and ECs. Of note, p16 staining of most ECs was seen in pulmonary vessels, notably those occluded by thrombosis and showing intraluminal vWF staining. Cells stained for p16 were also stained for the DNA damage markers γ-H2AX protein and p53-binding protein 1. Conclusions: Our data constitute the first evidence of temporal and topographic relations between senescent-cell accumulation and pulmonary lesions induced by SARS-CoV-2 infection.
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Background: The continuing spread of SARS-CoV-2 provides opportunities for the virus to evolve. Compared to ancestral strains, the 4 major variants of concern (VOC) exhibit Spike mutations that improve entry and/or diminish antibody neutralization. However, mutations have arisen in other viral genes. Several of these genes may counteract innate immunity mediated by antiviral interferons (IFNs). IFNs show extensive diversity, but only IFNα2 and IFNβ are approved for clinical use. We showed previously that diverse IFNs exhibit variable activities against HIV-1 and trigger distinct transcriptomes. Methods: To assess whether SARS-CoV-2 acquired human IFN resistance over time, isolates representing early lineages A, B, B.1, and VOC lineages B.1.1.7 (alpha), B.1.351 (beta), P.1 (gamma) and B.1.617.2 (delta) were tested for sensitivity to multiple IFNs in an alveolar type II epithelial cell (AT2) line, A549, overexpressing ACE2. Cells were pre-treated with IFNs for 18 h in triplicate, then infected to yield ∼105 copies/reaction. Virus copy numbers were evaluated at 24 h by qPCR. We compared the sensitivity of 5 SARS-CoV-2 isolates to 12 IFNα subtypes, IFNβ, IFNω and 3 IFNa;subtypes at 2 pM, within the dynamic range of preliminary IFN inhibition curves. IC50s for IFNβ and IFNa;1 were compared between lineage B and VOC isolates. Results: Among the 17 IFNs tested, IFNβ, IFNα8, IFNω and IFNα5 most potently inhibited SARS-CoV-2 in A549-ACE2 cells. Inhibition curves with a delta variant isolate showed that IFNα2 and IFNa;1 had >10-fold and >1000-fold higher IC50 than IFNβ, respectively. Interestingly, the antiviral activity patterns of diverse IFNα subtypes against SARS-CoV-2 and HIV-1 were different and did not significantly correlate. Compared to the ancestral lineage B, the alpha, beta, gamma and delta variants exhibited on average 5.2-fold (range: 1.9-8.2) and 6.7-fold (range: 1.3-21) fold higher IC50s for IFNβ and IFNa;1, respectively. The alpha and delta isolates were also more resistant to IFNβ and IFNa;1 than a lineage B.1 isolate in another AT2 cell line, Calu-3. Conclusion: Our findings suggest that diverse IFNs may have evolved to restrict distinct virus families. Emerging SARS-CoV-2 variants are more effective than earlier pandemic viruses at antagonizing antiviral IFN responses. These data have implications for deploying IFNs for early COVID-19 therapy and suggest that innate immunity may be a driving force for SARS-CoV-2 evolution.
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Background: Development of spontaneous pneumothorax and pneumomediastinum is one of the complication of COVID-19 viral pneumonitis. This has been described in both mechanically ventilated patients or on non invasive/ high flow nasal cannula oxygen support. The Macklin effect can been proposed as a possible etiology owing to the propensity to the damage to type2 pneumocytes, alveolar rupture secondary to direct alveolar injury. Case: 32 year male, non smoker, non alcoholic with no comorbidities presented to emergency with sudden onset of shortness of breath, left chest pain. HRCT chest done showed left pneumothorax with mediastinal shift. Intercostal drainage tube(ICD) was placed on the left side and patient was stabilised. Patient has had similar complaints one week back for which right sided ICD was placed. Patient had history of COVID-19 infection one month back. He did not require any supplemental oxygen or ventilatory support. Right side ICD was removed 1 week later as there was no air leak. Left side had persistent air leak, with non expanding lung. Patient was put on supplemental oxygen. He was treated with antibiotics, other supplemental oxygen and repeat HRCT chest showed loculated hydropneumothorax with bronchopleural fistula (BPF) on the left side. The patient was discharge with ICD. After improving the general condition, the air leak was surgically corrected with left lobe decortication and BPF closure. Conclusion: COVID 19 infection renders more propensity to damage type 2 pneumocytes. The alveolar rupture is secondary to alveolar injury causing increased tendency for air leak without obviously increased pressures.
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Background and Aims: Patients with chronic lung disease are highly susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leading to COVID-19. ACE2 is the main receptor for SARS-CoV-2 attachment. Our previous study reported higher ACE2 levels in smokers and COPD patients. Current study investigates if patients with interstitial lung diseases (ILDs) such as IPF and LAM have elevated levels of ACE2, transmembrane peptidase serine 2 (TMPRSS2) and Furin, increasing their risk for SARS-CoV-2 infection. Methods: Surgically resected lung tissue from IPF, LAM patients and normal controls (NC) was immunostained for ACE2, TMPRSS2 and Furin. Percentage ACE2 expression was measured in small airway (SA) epithelium and alveolar areas. Analysis was done using computer-assisted Image- ProPlus 7.0 software. Results: Compared to NC, the percentage ACE2 expression significantly increased in the SA epithelium of IPF (p<0.01), LAM (p<0.001) and in alveolar areas of IPF (p<0.001), LAM (p<0.001). We also observed elevated TMPRSS2 and Furin expression in the same lung tissue areas of IPF and LAM against NC. There was significant positive correlation between smoking history and ACE2 expression in the IPF for SA epithelium (r=0.81, p<0.05) and alveolar areas (r=0.94, p<0.01). Conclusions: This study has investigated the ACE2, TMPRSS2, and Furin in resected lung tissue of IPF and LAM, which suggests that people with ILDs are at higher risk of developing severe COVID-19 infection. To further understand and provide potential therapeutic targets for ILDs, we need to explore other cell types such as type II pneumocytes, alveolar macrophages and endothelial cells.
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Case report-IntroductionCOVID-19, the infectious disease caused by the novel coronavirus SARS-CoV-2, and first described in Wuhan, China in December 2019, has affected more than 19 million patients worldwide and resulted in more than 700,000 deaths at the time of writing1. Patients with rheumatic diseases and those receiving immunosuppressive treatment are felt to be at greater risk of complications from this illness, though registry and trial data should help refine our understanding of these risks. We hereby describe a case of COVID-19 complicating an unusual rheumatic illness, resulting in severe multi-system disease and premature death.Case report-Case descriptionA 69 year-old male presented to rheumatology and haematology with symmetrical polyarthritis, thrombocytopenia (18 x 109/L), eosinophilia (25.4 x 109/L), raised C-reactive protein (CRP, 43 mg/L), positive rheumatoid factor (>200), antinuclear antibody (ANA) and anti-Ro. Bone marrow biopsy did not demonstrate evidence of haematological malignancy.Seropositive rheumatoid arthritis and connective tissue disease overlap were diagnosed, and treatment with Prednisolone 60mg daily was initiated. Despite rituximab and intravenous immunoglobulins, thrombocytopenia deteriorated on reducing corticosteroids, however the addition of mycophenolate mofetil (MMF) allowed gradual prednisolone tapering to 3mg daily. Hydroxychloroquine was briefly added but discontinued due to headaches. MMF was discontinued after he developed fungal pneumonia followed by jaundice. Liver biopsy was consistent with drug-induced cholestasis, attributed to co-amoxiclav, and his liver function tests (LFTs) improved on ursodeoxycholic acid. Following a further deterioration in thrombocytopenia, hyperferritinaemia and new onset erythema nodosum, he had a repeat bone marrow examination. This demonstrated large areas of fibrosis and granulomatous inflammation with a dense, pleomorphic T-cell infiltrate, but no haemophagocytosis. Haematologists felt this was reactive and prednisolone dose was increased to 10mg daily.Six months later he developed cholangitis. Magnetic resonance cholangiopancreatography (MRCP) demonstrated a tight 4cm stricture of the distal common bile duct (CBD) within the head of pancreas, which was diffusely swollen without any clear focal mass. Serum amylase was mildly elevated (316 units/L). Concurrent CT thorax, abdomen and pelvis demonstrated bilateral ground-glass changes within the lungs, and a SARS-CoV-2 nasopharyngeal PCR test was positive, though he had no respiratory symptoms or oxygen requirement at that stage.Sadly, four days after the CT scan and before a planned endoscopic retrograde cholangiopancreatography (ERCP) could be performed, he became markedly hypoxic with plain chest X-ray features suggestive of COVID-19 pneumonia. Despite medical management, including doubling of his prednisolone dose, he rapidly deteriorated and died.Case report-DiscussionThis case highlights an unusual presentation of COVID-19 in a patient with a complex background of inflammatory arthritis with immune-mediated thrombocytopenia. At the time of his final illness, these conditions were managed with steroid monotherapy. Based on the COVID-19 risk matrix recommended by the British Society for Rheumatology, he was not identified as a patient requiring shielding.Cholangitis was the major problem precipitating his final admission to hospital, and at the time of admission he had no respiratory symptoms. One week prior to this admission, his father-in-law had died of COVID-19 pneumonia, though they had not been in recent direct contact. Interstitial lung changes were incidentally noted on a CT performed to identify the cause of cholangitis, which prompted the nasopharyngeal PCR that detected SARS-CoV-2. This occurred prior to widespread routine testing of hospital inpatients for SARS-CoV-2 by PCR. Unfortunately he then rapidly developed COVID-19 pneumonia and died before the underlying cause of cholangitis could be definitively identified, though an MRCP demonstrated an obstructed CBD within a diffusely swollen pancreas, where a differential diagnosis of pancreatic malignancy or autoimmune pancreatitis was suggested by the reporting radiologist.There are emerging case reports of COVID-19 resulting in significant pancreatic injuryand a further recent laboratory analysis has suggested that ACE2 receptors, which are utilised by SARS-CoV-2 to gain entry to host cells, are highly expressed on cholangiocytes at a comparable level to type II alveolar cells. Whilst the ultimate cause of cholangitis will remain unknown in this patient, this case highlights the potential for atypical presentations and extra-pulmonary manifestations of COVID-19.Case report-Key learning points COVID-19 is a multi-system illness which can cause significant extra-pulmonary as well as pulmonary pathology, with emerging reports that the biliary tract and pancreas are frequently affected.Evidence to inform accurate prediction of which patients with rheumatic diseases are at highest risk of acquiring severe COVID-19 disease remains insufficient, with current shielding guidelines based on expert consensus.This case highlights the importance of widespread testing for COVID-19 in hospital patients, as not all patients carrying the SARS-CoV-2 virus will demonstrate classical respiratory features of the disease at the point of admission.