The Spectrum of Pulmonary Histomorphology Changes in COVID-19 Cases

Introduction/Objective Pulmonary specimens following COVID-19 virus infection demonstrate a spectrum of pulmonary histomorphology. Six patients with a history of COVID-19 infection are summarized in this review. The purpose of our study is to elucidate any possible correlations between clinical, laboratory, radiographic, and pathologic findings in COVID-19 patients. Further, we aim to characterize both non-specific and specific histomorphology and cytomorphology in COVID-19 patients. Methods/Case Report Six patients with known COVID-19 infection and lung biopsies/resections are identified. A chart review is performed to collect clinical histories, the results of COVID-19 PCR testing, radiographic impressions, pathologic interpretations of histology, and clinical outcomes. Information is summarized and tabulated. Results (if a Case Study enter NA) The most common, non-specific histological findings are focal/diffuse acute lung injury, organizing lung injury, or a combination of both patterns. Unique features of COVID-19 infection are identified in three cases, which illustrate viral cytopathic changes within hyperplastic pneumocytes. These include basophilic, vacuolated, granular cytoplasm and variably sized cytoplasmic/nuclear inclusions. Virus-loaded pneumocytes are typically identified in the organizing phase, and rarely in the acute lung injury phase. Immunohistochemical staining of anti-nuclear capsule antibody with appropriate controls shows focal positive staining in one case. SARS-CoV-2 PCR is positive in formalin-fixed paraffin-embedded (FFPE) tissue, while a serum PCR assay is negative. Conclusion The severity of clinical symptoms and clinical outcome are unrelated to the degree of lung involvement. Viral cytopathic changes are identified in three cases, with these specific findings associated with the organizing phase of lung injury, and either concurrent PCR positivity or positive immunohistochemical staining.

Histomorphological Spectrum of Lung Lesions at Autopsy-A Tertiary Care Centre Experience

Background and aims: A wide variety of pathological conditions involve the lungs. In autopsy, the lungs are examined for disease, injury and other findings suggesting cause of death or related changes.Aims & Objectives: The present study aimed to study the histomorphological spectrum of lung lesions at autopsy and to assess the frequency of different types of lesions;and to associate histomorphological changes with cause of death.Material and Methods: It was a one-year observational study conducted in the Department of Pathology, Govt. Medical College, Jammu. Lung tissue pieces from all medicolegal autopsies received were fixed, examined grossly, processed;paraffin embedded sections obtained were stained with Hematoxylin and Eosin stain and examined under microscope. Findings were recorded and tabulated. Result(s): Out of 264 cases, males were predominantly affected (84%);median age was 38 years. The various changes observed were congestion (68%), edema (45.4%), pneumonia (5%), granulomatous inflammation (3%), diffuse alveolar damage (1.5%), haemorrhage (14.4%), interstitial changes (60%), malaria (0.4%) and malignancy (0.4%). Natural deaths were the commonest cause (75, 28%) followed by asphyxial deaths (65, 24.6%). Conclusion(s): Histopathological examination of lung autopsies highlights many incidental findings, establishes underlying cause of death, serves as a learning tool and also holds scope for detection of newer diseases.Copyright © 2023 JK Science.

Navigating the cellular landscape in tissue: Recent advances in defining the pathogenesis of human disease.

Over the past decade, our understanding of human diseases has rapidly grown from the rise of single-cell spatial biology. While conventional tissue imaging has focused on visualizing morphological features, the development of multiplex tissue imaging from fluorescence-based methods to DNA- and mass cytometry-based methods has allowed visualization of over 60 markers on a single tissue section. The advancement of spatial biology with a single-cell resolution has enabled the visualization of cell-cell interactions and the tissue microenvironment, a crucial part to understanding the mechanisms underlying pathogenesis. Alongside the development of extensive marker panels which can distinguish distinct cell phenotypes, multiplex tissue imaging has facilitated the analysis of high dimensional data to identify novel biomarkers and therapeutic targets, while considering the spatial context of the cellular environment. This mini-review provides an overview of the recent advancements in multiplex imaging technologies and examines how these methods have been used in exploring pathogenesis and biomarker discovery in cancer, autoimmune and infectious diseases.

THE LINK between INFLAMMATION and THROMBOSIS: CLINICAL and IMMUNOHISTOCHEMICAL CHARACTERIZATION of PULMONARY ARTERIAL THROMBOSIS in COVID-19 PATIENTS

Background: Coronavirus-19 disease (COVID-19) has been responsible, to date, for more than 5 million of deaths. Immunothrombosis may be a major factor contributing to mortality in COVID-19 and pulmonary arterial tree involvement that mimics multiple pulmonary embolism could be a major contributor to disease course. Immunomodulatory drugs are of some beneft but mechanism not completely clear. We investigated pulmonary arterial tree clots to better appreciate their immunothrombotic nature, in contrast to the pathological characteristics of non-infammatory thrombi (1). Objectives: The primary objective was to study in depth the arterial thrombosis in COVID-19, by characterizing the immunohistochemical nature of thrombi, performing macroscopic and microscopic analyses, and by comparing clinical, laboratory and anatomical-pathological data of these patients with other patients died for COVID-19 but without evidence of pulmonary arterial thrombosis. Methods: Autopsies were performed in patients (cases) who died for COVID-19 with evidence of pulmonary arterial thrombosis at autopsy fnding but without pathological signs of bronchopneumonia or peripheral venous thrombosis. COVID-19 positive patients without pulmonary arterial thrombosis were selected as control group. Hematoxylin and eosin stained slides were reviewed choosing those with visible pulmonary thrombi. Further histochemical and immunohisto-chemical staining were performed in selected paraffin blocks. Each component of the thrombus was evaluated with the software application QuPath in terms of fbrin, red blood cells, platelets and immune cells percentage after scanning the slides with Aperio System. Laboratory tests were recorded at 2 points: at hospital admission and at Intensive Care Unit transfer. Results: We included 13 patients (cases) and 14 controls, matched for age, gender and time from diagnosis to death. Twenty arterial thrombi were studied. By immuno-histochemistry, arterial thrombi were composed by white blood cells (WBC) [median, IQR range: 10% (5-12.25)], mainly neutrophils [58% (35.2-64.5)], red blood cells [12%, (6-34.25)], fbrin [19% (14.5-42.25)], platelets [39%, (31.75-48)] (Figure 1). Three cases had a history of previous thrombosis. All cases had received anticoagulant treatment during hospitalization, low molecular weight heparin in 12/13 (therapeutic regimen in 4/12, prophylactic in 8/12) while 1/13 continued oral anticoagulants for comorbidity. By comparing laboratory fndings between cases and controls, cases showed signifcantly higher levels of platelet count [median, IQR range: 195000/mmc (157750-274500) vs 143500 (113000-175250), p=0.011], LDH [854 U/l (731-1315) vs 539 (391.5-660), p=0.003)] at hospital admission, and D-dimer at ICU transfer [25072 FEU (6951-50531) vs 1024 (620-5501), p=0.003)]. Conclusion: Pulmonary arterial thrombosis in COVID-19 is a type of immune-mediated infammatory thrombosis, since the amount of WBC is 6-times more than normal value seen in non-infammatory thrombi. Some markers of infammation, necrosis and coagulation are much more increased in this subset of patients. Chest CT angiography rather than simple CT scan at hospital admission could be more useful in this setting, and treatments with antiplatelet agents or anticoagulants, eventually in combination with immunotherapy, might positively affect the outcome.

The use of dirty fuels by low-income households on the South African Highveld

Meaningful proportions of households on the South African Highveld regularly use energy carriers that result in the emission of significant quantities of particulate and gaseous pollutants. Dirty fuels are mostly used by lower-income households, with the exception of recreational wood use that is also prevalent in higher-income households. The dirty fuel use patterns and trends observed on the Highveld are the result of the unique combination of the utility, accessibility, affordability, availability, and desirability of the energy carriers and equipment, climatological factors, markets and infrastructure, as well as the inertia of historic energy use patterns. There are no systematic reviews and prognosis of the use of dirty fuels by low-income households on the South African Highveld that consider critical recent events such as the Covid pandemic and emerging dynamics such as the just transition movement. In this article we will use a literature review as well as our own research to describe dirty fuel use by low-income households on the Highveld, paying specific attention to changes over time. We will attempt to describe what is being used, who the users are, and for which utilities fuels are being used. From these descriptions, specific patterns emerge that shed light on possible avenues and prospects for ending dirty fuel use on the Highveld. © 2022

Biobanking in times of crisis - The COVID-19 Autopsy and Biosample Registry Baden-Wuerttemberg.

Biobanking plays a critical role in diagnostics, biomarker research and development of novel treatment approaches for various diseases. In urgent need of understanding, preventing and treating coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the importance of biobanking including data sharing and management further increased. To provide high quality tissue biomaterials and data for research and public health, the COVID-19 Autopsy and Biosample Registry was established in the state of Baden-Wuerttemberg (BW) in Germany, combining expertise and technologies of the Institutes of Pathology of the five university hospitals in BW (Heidelberg, Tübingen, Ulm, Freiburg, Mannheim). The COVID-19 Autopsy and Biosample Registry BW comprises tissue samples from autopsies and associated data of deceased patients in the context of SARS-CoV-2 infection and/or vaccination against SARS-CoV-2. The aim is to collect autopsy biospecimens, associated clinical and diagnostic data in a timely manner, register them, make them accessible for research projects and thus to support especially tissue-related research addressing COVID-19. By now, the BW network holds multiple collaborations and supported numerous publications to increase the understanding of COVID-19 disease. The achievements of the BW network as a landmark biobanking model project represent a potential blueprint for future disease-related biobanking and registry effort.

Detection of SARS-CoV-2 in tissue: the comparative roles of RT-qPCR, in situ RNA hybridization, and immunohistochemistry.

INTRODUCTION: The emergence of SARS-CoV-2, the causative agent the COVID-19 pandemic, has led to a rapidly expanding arsenal of molecular diagnostic assays for the detection of viral material in tissue specimens. AREAS COVERED: We review the value and shortcomings of available tissue-based assays for SARS-CoV-2 detection in formalin-fixed paraffin-embedded (FFPE) tissue, including immunohistochemistry, in situ hybridization, and quantitative reverse transcription PCR (RT-qPCR). The validation, accuracy, and comparative utility of each method is discussed. Subsequently, we identify commercially available antibodies which render the greatest specificity and reproducibility of staining in FFPE specimens. EXPERT OPINION: We offer expert opinion on the efficacy of such techniques and guidance for future implementation, both clinical and experimental.

Efficacy of tilapia skin xenograft compared to paraffin-impregnated gauze as a full-thickness burn dressing after excisional debridement: A case series

Introduction and importance Due to its high collagen, good adherence to wound bed, and great wound healing properties, Tilapia (Oreochromis niloticus) skin has been studied as a biomaterial in regenerative medicine, including as a burn dressing. This paper evaluated the efficacy of tilapia skin xenograft as a temporary full-thickness burn dressing. Methods Four acute burn patients aged 23–48 years old with total body surface area ranging from 27.5 to 37% with a similar burn area on both sides of the limbs were included. Each limb was dressed in tilapia skin or paraffin-impregnated gauze. Two subjects passed away due to septic shock. All limbs treated with tilapia skin xenograft required fewer dressing changes compared to the limbs treated with paraffin-impregnated gauze. All remaining subjects underwent skin autograft transplantation surgery on the eleventh day after the debridement surgery. No allergic reaction was found in any of the subjects. Outcomes The tilapia xenograft performed better in controlling and containing the exudates compared to the paraffin-impregnated gauze, as reflected in the fewer dressing changes needed. The cause of death of the two patients was questionable as both of them have severe pneumonia and COVID-19 still could not be ruled out yet. Conclusion The tilapia skin xenograft was not inferior to the standard paraffin-impregnated gauze for full-thickness burn dressing in terms of time needed for wound bed preparation for autograft surgery.

Placentas from Mothers with Positive SARS-CoV-2 (COVID-19) Test Results at Labor Showed Neither Specific Histopathological Changes Nor Evidence of COVID-19 Infection

Background: Evidence has shown that pregnancy is a risk factor for severe illness in women with SARS-CoV-2 (COVID-19). Yet their newborns are mostly doing well. The placenta is a complex, highly specialized, but poorly understood organ. The COVID-19 infection related specific pathological changes in placenta and prevalence of transplacental transmission of COVID-19 has not been fully explored and validated. Design: Universal screening for COVID-19 among all pregnant women on admission to labor and delivery unit was initiated in April 2020 at our institute. With IRB approval, 54 term pregnant women with positive COVID-19 nasopharyngeal swap results at admission during April 2020 to Jun 2021 were recruited. Patients' demographic characteristics and clinical presentation were summarized in Table 1. Histopathology of all placentas was independently reviewed by two board certified pathologists. RNA was extracted from Formalin-Fixed Paraffin-Embedded (FFPE) blocks of 15 randomly selected placentas. ThermoFisher TaqPathTM SARS-CoV-2/COVID-19 RT-PCR assays were performed to detect the presence of the virus with proper controls. Results: Hispanic or Latino pregnant women represented 39% of the study cohort tested positive for COVID-19 at admission, followed by American Africa (26%) and Caucasian (17%). Most patient were overweight before pregnancy and 1/3 patients had at least one comorbidity. Majority patients (72%) were completely asymptomatic. The rest of patients had somewhat mild symptoms including sore throat, cough, low-grade fever, and/or loss of taste/smell. All deliveries were term. All neonates were in healthy status at birth. No suspected vertical transmission was observed. Histopathological inspection of placentas showed nonspecific features of maternal or fetal vascular malfunction and inflammation (Table 2). Among 15 placental samples tested, no SARS-CoV-2 virus was detected. Conclusions: Multiple studies indicated that only a very small proportion of neonates delivered to mothers with COVID-19 infection were also tested positive for COVID-19. Our data suggested that COVID-19 infected mothers who were asymptomatic or only with mild symptoms at labor unlikely vertically transmit the virus through the placenta. This finding may ease the anxiety of asymptomatic mothers caused by positive COVID-19 test result at delivery admission. (Table Presented).

The Prevalence of SARS-CoV-2 In Autopsy Tissue from Patients Dying Without Known COVID-19 Disease

Background: Coronavirus disease 2019 (COVID), a respiratory illness (RI) caused by SARS-CoV-2 (CoV2) was first reported in Wuhan, China in December 2019. It spread rapidly and the US confirmed its first case in January 2020. Due to the novelty of CoV2 and COVID, little was known about the epidemiology, clinical course, and diagnostic methods. Since then, studies have shown that CoV2 originated from bats and COVID may have pre-existed undiagnosed outside China before the cases were first reported. Our aim was to evaluate the prevalence of CoV2 in autopsy cases at our institution, where autopsy was not performed on known COVID cases. Design: We searched our pathology database for adult autopsies performed on the lungs and heart in our institution from 6/1/19 - 6/30/20. Cases were divided into groups by cause of death (COD) possibly related to COVID, presence of a clinical RI, and autopsy findings of pneumonia (Pnx). CODs possibly related to COVID (COVID-possible) included bronchopneumonia and multisystem organ failure and CODs unlikely related to COVID (COVID-unlikely) included conditions such as acute myocardial infarction. Total RNA was extracted from archived formalin-fixed-paraffin-embedded (FFPE) lung tissue of all COVID-possible cases and COVID-unlikely cases with Pnx using a commercial kit and following the instructions in the kit. CoV2 RNA was tested for using CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel, testing the N1 region of the CoV2 genome and an RNA integrity control during amplification. An extracted CoV2 sample from our State Department of Health was used as positive control. Results: 88 cases were included;44 males and 44 females with an average age of 66 years. 42/88 (48%) cases were considered COVID-possible with 24/42 (57%) showing RI and/or Pnx. COVID as COD was considered unlikely in 46/88 (52%) with 34/46 (74%) showing no RI or Pnx. See Table 1. CoV2 PCR was performed on a total of 49 cases: 42 COVID-possible and 7 COVID unlikely with Pnx. CoV2 PCR was negative in all 49 cases with appropriate positive control and RNA integrity in all cases. Conclusions: In our single-institution autopsy cohort, CoV2 was not detected in FFPE lung tissue from any cases without a clinical diagnosis of COVID. Our data suggest that patients in our community who died between 6/1/2019 and 06/30/2020 without known COVID were unlikely to have had sub clinical and/or undiagnosed COVID. Therefore, clinical examination and accurate laboratory testing likely identify the majority of cases of COVID.

Oral ixazomib in untreated follicular lymphoma permits COVID-19 vaccine response and its efficacy is associated with clinical factors and gene expression signatures

Background: Standard chemoimmunotherapy for first-line treatment of follicular lymphoma (FL) achieves high rates of disease control but is not curative and carries significant toxicities including prolonged immunosuppression that may attenuate response to vaccinations (Marcus et al., NEJM 2017). While proteasome inhibitors have shown modest activity in R/R FL (Goy et al., JCO 2005), limited data address their use frontline. The comparatively favorable toxicity profile and convenient oral dosing of ixazomib support its investigation in this space. Methods: We evaluated ixazomib and its combination with short-course rituximab (R) for FL as part of an open-label, phase II investigator-initiated trial at the University of Washington / Fred Hutch Cancer Research Center / Seattle Cancer Care Alliance (NCT 02339922). Eligibility included an indication for treatment per NCCN guidelines and no prior standard systemic FL therapy. Ixazomib was administered at 4 mg orally once a week until disease progression or unmanageable toxicity. One course of R at 4 weekly doses of 375 mg/m2 was added during the 7th 28-day cycle, after an initial 6-cycle “window” on ixazomib alone. Available pretreatment formalin-fixed, paraffin-embedded tissue biopsies were subjected to RNA extraction by standard methods and gene expression profiling (GEP) using the NanoString™ PanCancer IO 360 panel to query pathways in proteasomal degradation and lymphomagenesis. Standard GEP quality control and data processing were performed with the ROSALIND® platform. Patients vaccinated per standard of care for COVID-19 while actively receiving ixazomib and ≥ 6 mo after completing R were evaluated for serologic response ≥ 2 weeks after the final dose of vaccine using the Roche Elecsys® Anti-SARS-CoV-2 S assay against the spike protein receptor binding domain. Results: Twenty pts began therapy between Feb 2017 and January 2020. All had grade I/II FL and FLIPI score was 2 in 20% and ≥ 3 in 20%;FLIPI score in all other patients was 0 or 1. Eleven (55%) pts met GELF criteria for high tumor burden disease including 6 (30%) pts with a tumor mass ≥ 7 cm. Median follow-up was 32.1 months (range 5.7 - 51.6). The ORR by Lugano criteria was 35% (CR 5%) during the ixazomib window and 65% (CR 45%) overall. At data cut (June 15, 2021) all patients were alive and 8 (40%) remained progression-free on treatment (Figure 1). By KM estimate, median PFS was 25.8 mo and median DOR was not reached at a median follow-up of 29.6 mo. As expected, high-grade treatment-related AEs were infrequent for ixazomib and R, including grade ≥ 3 events in 3 unique pts (15%;diarrhea, transaminitis, and cytopenias). No grade ≥ 4 or serious AEs were observed. Toxicities led to study-directed drug interruptions in 4 (20%) pts and dose reduction to ixazomib 3 mg weekly in 2 pts (10%). Higher ORR to ixazomib monotherapy was associated with FLIPI > 1 (p = 0.04) and, by exploratory GEP, downregulation of components of proteasomal degradation and upregulation of NF-KB and chemokine signaling (Figure 2). High tumor burden by GELF (p = 0.89) and tumor mass ≥ 7 cm (p = 0.26) were not associated with ORR to ixazomib. All 6 of 6 patients evaluated to date for response to COVID-19 vaccination, administered at a median of 32.5 mo (range 7.0 - 41.0) after last dose of R, achieved positive anti-spike protein antibodies (median anti-S 163.8 AU/mL, range 13.3 - 1139);none was diagnosed with COVID-19. Conclusions: The simple outpatient regimen of weekly oral ixazomib and the addition of 4 doses of R shows significant long-term activity with low toxicity in untreated FL. Extended DOR is achievable especially in patients who respond to ixazomib monotherapy. Ixazomib efficacy was associated with higher FLIPI scores and gene expression signatures implicated in proteasomal degradation and B-cell signaling pathways. Ixazomib deserves further investigation as a biomarker-driven therapeutic in untreated FL, particularly as an option that prioritizes outpatient management and serologic responsiveness to im unization. (Figure Presented).

POS-289 PARAFFIN WASHOUT IMMUNOFLUORESCENCE TECHNIQUE IMPROVE SAFETY AND ADEQUACY OF NATIVE KIDNEY BIOPSY AND TRANSPLANT KIDNEY BIOPSY IN A TERTIARY TEACHING HOSPITAL

Introduction: Kidney biopsy (KB) tissues are usually dissected 0.5-1.0 cm for fresh sample immunofluorescence study (FSIF). Paraffin washed-out immunofluorescence (PWIF) technique doesn’t require segmentation of the kidney biopsy sample that may jeopardise the sample adequacy for histopathological examination (HPE). Hypothetically, it reduces biopsy passes and complications. We examine the safety and adequacy of native kidney biopsy (NKB) and transplant kidney biopsy (TKB) using the FSIF technique and PWIF technique in HPE preparation for immunofluorescent study. Methods: We retrospectively collected clinical history, blood results, and renal biopsy reports for all the patients who had undergone KB using electronic medical records at University Malaya Medical Centre, Kuala Lumpur, Malaysia from 1/1/2015 to 31/4/2021. We performed 1520 KBs (795 NKBs & 725 TKBs) and 1336 KBs with complete data analysed (670 NKBs & 666 TKBs). Sixty-one of the 670 (9.1%) NKBs and 48 of the 666 (7.2%) TKBs employed the PWIF method from 13/10/2020 to 31/4/2021 (6 months) because of the COVID-19 pandemic. We collected 62 NKBs and 65 TKBs from 13/10/2018 to 31/4/2019 (6 months) as the control group which used the FSIF method. The control is chosen as such to correlate with the same months of another year. Results: There were no statistically significant differences in the baseline characteristics between the two groups of each cohort respectively except for the ethnicity distribution in the TKB cohort (p=0.037) and INR in NKB and TKB cohorts (p=0.000 & p=0.002 respectively). PWIF group in NKB and TKB recorded lesser pass (p=0.000 for both), longer HPE core (p=0.001 & p=0.024 respectively), better HPE adequacy (p=0.006 & p=0.012 respectively). There were no statistical differences in the diagnostic yield, immediate pain, gross haematuria, haematoma, and admissions or prolong hospitalisation due to biopsy complications in both groups for NKB and TKB cohorts (Table 1 & 2). [Formula presented] Conclusions: Paraffin washed-out immunofluorescence technique increased the native and transplant kidney biopsy adequacy with a lesser pass and better biopsy sample adequacy for histopathological examination but no difference in the incidence of complications. However, a greater number of cases are required to assess the statistically significant difference in the incidence of complications. No conflict of interest

Pulmonary endothelial nedd9 and the prothrombotic pathophenotype of acute respiratory distress syndrome due to sars-cov-2 infection

Background: The pathobiology of in situ pulmonary thrombosis in acute respiratory distress syndrome (ARDS) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is incompletely characterized. In human pulmonary artery endothelial cells (HPAECs), hypoxia upregulates expression of a pro-thrombotic NEDD9 peptide (N9 ) on the extracellular plasma membrane surface. We hypothesized that increased pulmonary endothelial N9 is a novel feature of the SARS-CoV-2 pathophenotype. Methods: Paraffin-embedded autopsy lung specimens were acquired from patients with ARDS due to SARS-CoV-2 infection (n=13), ARDS of other causes (n=10), and non-disease controls (n=5). Immunofluorescence characterized expression of N9 , fibrin, and TCF12, a putative binding target of SARS-CoV-2 and known transcriptional regulator of NEDD9. We performed RNA-Seq on mRNA isolated from control HPAECs treated with normoxia or hypoxia (0.2% O2 ) for 24 hr. Immunoprecipitation-liquid chromatography-mass spectrometry (IP-LC-MS) profiled protein-protein interactions involving N9 relevant to thrombus stabilization. Results: Compared to non-SARS-CoV-2-ARDS lungs, pulmonary endothelial N9 expression and N9-fibrin colocalization was increased by 174% (P<0.002) and 212% (P<0.001) in SARS-CoV-2-ARDS, respectively. Compared to normoxia, hypoxia increased TCF12 mRNA quantity significantly in HPAECs in vitro [+1.19-fold, P=0.001;false discovery rate (FDR)=0.005]. Pulmonary endothelial nuclear TCF12 expression was also increased by 370% in SARS-CoV-2-ARDS vs. controls. In HPAEC plasma membranes, IP-LC-MS identified a novel protein-protein interaction between NEDD9 and the β3 subunit of the αvβ3 integrin, which regulates fibrin anchoring to endothelial cells. Conclusions: Compared to non-SARS-CoV-2-ARDS, SARS-CoV-2-ARDS is associated with increased pulmonary endothelial N9 expression and N9-fibrin colocalization in microthrombi in situ. Increased hypoxia signaling or SARS-CoV-2-mediated regulation of TCF12 are potential mechanisms by which to explain these findings. Identifying N9 in the pulmonary microthrombi of SARS-CoV-2 lungs may have important pathobiological and, potentially, therapeutic implications for ARDS patients.

LIPOID PNEUMONIA DUE TO PHARYNGOESOPHAGEAL DYSPHAGIA CAUSING PARAFFIN BRONCHOASPIRATION

TYPE: Case Report TOPIC: Occupational and Environmental Lung Diseases INTRODUCTION: We present a case of exogenous lipoid pneumonia caused by paraffin broncoaspiration due to pharyngoesophageal motor dysphagia. CASE PRESENTATION: A 57 year old female consulted for diarrhea. She had a previous history of ischemic stroke related to hypercoagulability syndrome, causing oropharyngeal dysphagia due to pharyngo-esophageal motor incoordination. Owing to possible neurogenic dysfunction she also presented megadolichocolon with chronic diarrhea-constipation syndrome. Due to the epidemiological situation caused by SARS-COV2, a chest X-ray was performed showing increased density of the right middle lobe. The control X-ray exhibited a persistence of this alteration, therefore a thoracic tomographic study was performed (findings included in image), as well as a bronchoalveolar lavage. The bronchoalveolar lavage fluid was initially turbid white which, posterior to resting, revealed a superficial layer of fat, supporting the diagnosis of lipoid pneumonia. The patient was subsequently interrogated. She associated the consumption of oily materials from herbalists and paraffin in order to palliate her constipation symptoms, which in relation to her esophageal motor-pharyngeal incoordination produced bronchoaspiration of the referred oily material. DISCUSSION: Oily substance ingestion was suspended. Subsequently she underwent a corticosteroid treatment and is currently under clinical control. CONCLUSIONS: The ground glass pattern is a finding that causes a wide differential diagnosis in the radiological study, therefore it is of great importance to take an adequate clinical history and to take into account the motor dysfunctions related to swallowing, due to the high consumption of herbalist products that contain oily materials that can cause exogenous lipoid pneumonia. DISCLOSURE: Nothing to declare. KEYWORD: Exogenous_Lipoid_Pneumonia

Multisystemic Cellular Tropism of SARS-CoV-2 in Autopsies of COVID-19 Patients.

Multiorgan tropism of SARS-CoV-2 has previously been shown for several major organs. We have comprehensively analyzed 25 different formalin-fixed paraffin-embedded (FFPE) tissues/organs from autopsies of fatal COVID-19 cases (n = 8), using histopathological assessment, detection of SARS-CoV-2 RNA using polymerase chain reaction and RNA in situ hybridization, viral protein using immunohistochemistry, and virus particles using transmission electron microscopy. SARS-CoV-2 RNA was mainly localized in epithelial cells across all organs. Next to lung, trachea, kidney, heart, or liver, viral RNA was also found in tonsils, salivary glands, oropharynx, thyroid, adrenal gland, testicles, prostate, ovaries, small bowel, lymph nodes, skin and skeletal muscle. Viral RNA was predominantly found in cells expressing ACE2, TMPRSS2, or both. The SARS-CoV-2 replicating RNA was also detected in these organs. Immunohistochemistry and electron microscopy were not suitable for reliable and specific SARS-CoV-2 detection in autopsies. These findings were validated using in situ hybridization on external COVID-19 autopsy samples (n = 9). Apart from the lung, correlation of viral detection and histopathological assessment did not reveal any specific alterations that could be attributed to SARS-CoV-2. In summary, SARS-CoV-2 and its replication could be observed across all organ systems, which co-localizes with ACE2 and TMPRSS2 mainly in epithelial but also in mesenchymal and endothelial cells. Apart from the respiratory tract, no specific (histo-)morphologic alterations could be assigned to the SARS-CoV-2 infection.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Genome Sequencing from Post-Mortem Formalin-Fixed, Paraffin-Embedded Lung Tissues.

Implementation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing in the daily practice of pathology laboratories requires procedure adaptation to formalin-fixed, paraffin-embedded (FFPE) samples. So far, one study reported the feasibility of SARS-CoV-2 genome sequencing on FFPE tissues with only one contributory case of two. This study optimized SARS-CoV-2 genome sequencing using the Ion AmpliSeq SARS-CoV-2 Panel on 22 FFPE lung tissues from 16 deceased coronavirus disease 2019 (COVID-19) patients. SARS-CoV-2 was detected in all FFPE blocks using a real-time RT-qPCR targeting the E gene with crossing point (Cp) values ranging from 16.02 to 34.16. Sequencing was considered as contributory (i.e. with a uniformity >55%) for 17 FFPE blocks. Adapting the number of target amplification PCR cycles according to the RT-qPCR Cp values allowed optimization of the sequencing quality for the contributory blocks (i.e. 20 PCR cycles for blocks with a Cp value <28 and 25 PCR cycles for blocks with a Cp value between 28 and 30). Most blocks with a Cp value >30 were non-contributory. Comparison of matched frozen and FFPE tissues revealed discordance for only three FFPE blocks, all with a Cp value >28. Variant identification and clade classification was possible for 13 patients. This study validates SARS-CoV-2 genome sequencing on FFPE blocks and opens the possibility to explore correlation between virus genotype and histopathologic lesions.