Pre-existing chronic liver disease is associated with poor outcome in patients with SARS-CoV2 infection

COVID-19 is characterized by predominant respiratory and gastrointestinal symptoms. Liver enzymes derangement is seen in 15-55% of the patients. Cirrhosis is characterized by immune dysregulation, leading to concerns that these patients may be at increased risk of complications following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Patients with metabolic dysfunction-associated fatty liver (MAFLD) had shown a 4-sixfold increase in severity of COVID-19, and its severity and mortality increased in patients with higher fibrosis scores. Patients with chronic liver disease had shown that cirrhosis is an independent predictor of severity of COVID-19 with increased hospitalization and mortality. An international European registry study included 756 patients with chronic liver disease from 29 countries reports high mortality in patients with cirrhosis (32%). Data of 228 patients collected from 13 Asian countries on patients with CLD, known or newly diagnosed, with confirmed COVID-19 (APCOLIS study) showed that SARSCoV- 2 infection produces acute liver injury in 43% of CLD patients without cirrhosis. Additionally, 20% of compensated cirrhosis patients develop either ACLF or acute decompensation. In decompensated cirrhotics, the liver injury was progressive in 57% of patients, with 43% mortality. Patients with CLD and associated diabetes and obesity had a worse outcome. Liver related complications were seen in nearly half of the decompensated cirrhotics, which were of greater severity and with higher mortality. Increase in Child Turcotte Pugh (CTP) score and model for end-stage liver disease (MELD) score increases the mortality in these patients. In a subsequent study of 532 patients from 17 Asian countries was obtained with 121 cases of cirrhosis. An APCOLIS risk score was developed, which included presence of comorbidity, low platelet count, AKI, HE and respiratory failure predicts poor outcome and an APCOLIS score of 34 gave a sensitivity and specificity of 79.3%, PPV of 54.8% and NPV of 92.4% and predicted higher mortality (54.8% vs 7.6%, OR = 14.3 [95 CI 5.3-41.2], p<0.001) in cirrhosis patients with Covid-19. The APCOLIS score is helpful in triaging and prognostication of cirrhotics with Coivd-19. The impact of COVID-19 on patients with cirrhosis due to non-alcoholic fatty liver disease (NASH-CLD) was separately studied in 177 NASH-CLD patients. Obese patients with diabetes and hypertension had a higher prevalence of symptomatic COVID. Presence of diabetes [HR 2.27], fraility [HR 2.68], leucocyte counts [HR 1.69] and COVID-19 were independent predictors of worsening liver functions in patients with NASH-CLD. Severity of Covid in Cirrhosis could also be assessed by measuring ICAM1 the Intercellular Adhesion Molecule, an indicator of Endothelial Injury Marker. in Cirrhosis with Covid 19 Immunosuppression should be reduced prophylactically in patients with autoimmune liver disease and post-transplantation with no COVID-19. Hydroxychloroquine and remdesivir are found to be safe in limited studies in a patient with cirrhosis and COVID-19. And is safe in cirrhosis patients. However, flare of AIH has been reported in AIH patients. For hepatologists, cirrhosis with COVID-19 is a pertinent issue as the present pandemic cause severe disease in patients with chronic liver disease leading to more hospitalization and decompensation.

Endothelial glycocalyx shedding during active COVID-19 infection and its effect on disease severity

Background: COVID-19 pandemic was caused by the SARS-CoV-2 virus that was thought to be associated with microvascular endothelial injury. This study aimed to demonstrate the effect of COVID-19 on markers of endothelial shedding and its effect on patient morbidity and mortality. Settings and design: This was a prospective cohort study. Method(s): This study was conducted at the isolation hospital at Alexandria Main University hospitals on 40 adult patients infected with COVID-19. Patients were divided according to the severity of the presenting symptoms into two groups;moderate and severe. Serum levels of Syndecan-1 and Heparan sulfate were measured at hospital admission and at the end of the first week. Clinical and demographic data along with laboratory investigations and outcomes were compared between the two groups. Result(s): Our results indicated that patients with severe symptoms of COVID-19 had notably high levels of syndecan-1 and Heparan sulfate compared to patients with moderate symptoms on day 1 and day 7. Further investigations revealed that D-dimer, CRP, and IL-6 levels in patients with severe symptoms were higher in patients with severe symptoms. Our results also indicated that IL-6 increased on day 4 and gradually decreased on day 7 in both groups. Furthermore, serum levels of Syndecan-1, Heparan sulfate, D-dimer, and CRP decreased gradually from day 1 to day 7 in both groups. There was an association between markers of endothelial shedding with thrombotic and cardiovascular complications. It seems that the serum Syndecan-1 and Heparan sulfate might be good candidates to monitor COVID-19 activity. Conclusion(s): Patients with severe symptoms of COVID-19 have high serum levels of syndecan 1 compared to patients with moderate symptoms and have higher mortality and more prolonged hospital stay due to more endothelial injury and inflammatory reaction. Syndecan-1 may be used to monitor disease progression and severity.Copyright © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

Mild COVID-19: a silent threat

Case Report: Pulmonary embolism (PE) is a form of venous thromboembolism (VTE) which causes an obstruction of the pulmonary vasculature. Massive PE can be a fatal, accounting for over 100,000 death/year in the US. Incidence of PEs is increased in COVID-19 infections, due to a hypercoagulable state resulting from endothelial injury, stasis and increase in prothrombic factors. We report a case of a 48-year-old male with past medical history of mild form of COVID-19 infection approx. 6 months back. He was brought to the ED after cardiac arrest resuscitated in the ambulance. 3 days prior to the cardiac arrest he presented in the ED for nonspecific upper respiratory tract symptoms, for which he received symptomatic treatment. During that visit all the workup was negative except for sinus tachycardia. The cause of patient's cardiac arrest was found to be massive bilateral PE leading to right ventricular strain, shock, and HFrEF (20%). Our patient received thrombolytic, ECMO, thrombectomy, anticoagulation, and required complex treatment for several complication during hospitalization. Was eventually discharged home recovered. COVID-19 pandemic has been one of the worst in human history, causing millions of deaths. Symptoms of COVID-19 infection vary from mild upper respiratory disease to respiratory failure or severe VTEs. Multiple studies including a large national study in Sweden reported COVID-19 being an independent risk factor for VTEs, risk extending up to 180 days after COVID-19 infection, especially in unvaccinated population as seen in our patient. New variants of SARS-Cov 2 pose a challenge to control the spread of COVID-19 infection. As more studies support COVID-19 infection association with hypercoagulability status, varied nonspecific symptomology of PE remains a diagnostic and treatment dilemma. Physicians should have low threshold for investigating PEs in patients with unexplained sinus tachycardia or non-specific respiratory distress, especially in an unvaccinated post-COVID-19 patient, including historical mild forms of infection. Many studies have arguably advocated "treatment to prevent thrombotic events” in post COVID- 19 infection, however, vaccination remains the corner stone to reduce morbidity and mortality associated with serious thrombotic events like massive PEs in patients exposed to COVID1-19.

Left Atrial Septal Pouch Thrombosis after Covid19 Infection: Is Immunothrombosis the Culprit Mechanism?

Aims: The atrial septal pouch (ASP) is an incomplete fusion between septum primum (SP) and septum secundum (SS), resulting in a kangaroo pouch, that has a high prevalence in general populations (47%) and it is a potential site of blood stasis and thrombosis. After the novel coronavirus disease (COVID19) -related thrombotic complications, immunothrombosis has been widely investigated and proposed as key pathogenic mechanism linking coagulation and inflammation, leading sometimes to intracardiac thrombosis. In this paper we describe a case of thrombus in the ASP interestingly developed after COVID19 and made a literature review. Methods and Results: A 85 years old woman with a history of hypertension and chronic atrial fibrillation (AF) in therapy with dabigatran, was admitted to our hospital for dyspnea, atypical chest pain and fever. Laboratory exams showed only mild leukocytosis and elevated levels of d-dimer;EKG confirmed AF with a normal ventricular rate and CT scan excluded pulmonary embolism. Transthoracic and transesophageal echocardiogram (TEE) (Figure 1) showed a mobile ovoid mass (13x26 mm) attached to a left-sided ASP mimicking a myxoma, no mass was seen in the left atrial appendage (LAA). Four months earlier she had been hospitalized for idiopathic thrombocytopenia and concurrent COVID19 infection with mild symptoms, therefore dabigatran was discontinued for a month. The patient underwent surgery and histopathology confirmed it was a thrombus. In the PubMed search we conducted for reports demonstrating ASP masses, or alleged thromboembolism (TE) from this site, we found 25 reports, whose characteristics are briefly summarized in Table 1. Interestingly mild thrombocytopenia was described just in one case. Conclusion(s): In addition to the LAA, the atrial septal pouch is a newly described, common anatomic entity of the interatrial septum, that potentially serves as a site of stasis and thrombus formation. Despite its high prevalence, the finding of a thrombus in this site is very rare. According to Virchow triad, we assume that in this case an endothelial injury and hypercoagulability could have played a pivotal role, since the concomitant thrombocytopenia and high levels of d-dimer. This could be the first case of a thrombus in the ASP associated with COVID19-immunothrombosis. (Table Presented).

COVID-19 is a systemic vascular hemopathy: insight for mechanistic and clinical aspects

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is presenting as a systemic disease associated with vascular inflammation and endothelial injury. Severe forms of SARS-CoV-2 infection induce acute respiratory distress syndrome (ARDS) and there is still an ongoing debate on whether COVID-19 ARDS and its perfusion defect differs from ARDS induced by other causes. Beside pro-inflammatory cytokines (such as interleukin-1 beta [IL-1beta] or IL-6), several main pathological phenomena have been seen because of endothelial cell (EC) dysfunction: hypercoagulation reflected by fibrin degradation products called D-dimers, micro- and macrothrombosis and pathological angiogenesis. Direct endothelial infection by SARS-CoV-2 is not likely to occur and ACE-2 expression by EC is a matter of debate. Indeed, endothelial damage reported in severely ill patients with COVID-19 could be more likely secondary to infection of neighboring cells and/or a consequence of inflammation. Endotheliopathy could give rise to hypercoagulation by alteration in the levels of different factors such as von Willebrand factor. Other than thrombotic events, pathological angiogenesis is among the recent findings. Overexpression of different proangiogenic factors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF-2) or placental growth factors (PlGF) have been found in plasma or lung biopsies of COVID-19 patients. Finally, SARS-CoV-2 infection induces an emergency myelopoiesis associated to deregulated immunity and mobilization of endothelial progenitor cells, leading to features of acquired hematological malignancies or cardiovascular disease, which are discussed in this review. Altogether, this review will try to elucidate the pathophysiology of thrombotic complications, pathological angiogenesis and EC dysfunction, allowing better insight in new targets and antithrombotic protocols to better address vascular system dysfunction. Since treating SARS-CoV-2 infection and its potential long-term effects involves targeting the vascular compartment and/or mobilization of immature immune cells, we propose to define COVID-19 and its complications as a systemic vascular acquired hemopathy. Copyright © 2021, The Author(s), under exclusive licence to Springer Nature B.V.

Identification of a red cell hemostatic mechanism causing COVID-19 microvascular obstruction

Background: Severe COVID-19 infection is associated with a wide spectrum of clinical manifestations, leading to systemic thromboinflammation and multiorgan dysfunction. The primary cause of multiorgan damage is widespread endothelial injury, leading to microangiopathy and organ ischemia. The molecular mechanisms by which ischemic endothelial cells causes microvascular obstruction remains ill defined. Aim(s): Identification of distinct microvascular occlusion mechanisms in COVID-19. Method(s): The microvasculature of multiple organs from patients dying from COVID-19, myocardial infarction or stroke were analyzed by H&E, immunohistochemistry, SEM and CLEM. Animal models of gut ischemia and stroke were also examined. Intravital confocal microscopy examined endothelial injury and microvascular obstruction mechanisms mediated by platelets, red cells and fibrin. Result(s): We demonstrate the existence of a distinct microvascular hemostatic mechanism mediated by hemolyzed red blood cells (RBC), independent of platelets and fibrin. Extensive RBC hemolysis was apparent in the microvasculature of COVID-19 patients and in humans with major organ ischemia, leading to widespread microvascular obstruction. This RBC hemostatic mechanism was triggered by organ ischemia and associated with localized accumulation of hemolyzed RBCs at sites of endothelial necroptosis. RBC hemolysis was impaired in animals lacking the necroptosis mediator, MLKL or the C9 component of complement, indicating the involvement of cell intrinsic and extrinsic membrane lytic processes. Intravital microscopy revealed that the RBC hemostatic mechanism was triggered by the fragmentation of lyzed RBCs and the deposition of RBC membranes on the surface of dying endothelial cells, forming an endovascular sealant that prevents interstitial bleeding. Conclusion(s): Our studies demonstrate the existence of a previously unidentified microvascular hemostatic mechanism mediated by hemolyzed RBCs. Dysregulation of this hemostatic mechanism is linked to microvascular obstruction and bleeding in COVID-19 and ischemic diseases.

Downregulation of thrombomodulin-thrombin-activated protein C pathway as a mechanism for SARS-CoV-2 induced endotheliopathy and microvascular thrombosis

Background: There is emerging evidence of microvascular thrombosis and thrombotic microangiopathy (TMA) induced by COVID-19, presumably from endothelial injury or endotheliopathy . Thrombomodulin (TM) is an endothelial glycoprotein that plays a crucial role as a natural anticoagulant, binding thrombin to activate protein C (PC). TM is shed from endothelial surface during injury. We hypothesize SARS-CoV-2 spike proteins cause direct microvascular endothelial injury, leading to TM shedding, decreased activation of PC, and consequently, microvascular thrombosis in COVID-19. Aim(s): To assess: 1) endothelial injury (by soluble TM [sTM] levels) in a cohort of critically-ill COVID-19 pediatric patients;2) endothelial injury (TM shedding) in vitro by SARS-CoV-2 spike proteins and the subsequent functional consequence in activated PC (APC) levels. Method(s): STM in plasma samples from SARS-CoV-2 positive patients admitted to Texas Children's Hospital Pediatric Intensive Care Unit (n = 34) and healthy controls (n = 38) were measured by ELISA. IRB approval and waiver of informed consent were obtained. In vitro, confluent glomerular microvascular endothelial cells (GMVECs) were incubated for 24 hours in the presence or absence (control) of purified SARS-CoV-2 spike proteins, S1 and S2. In some experiments, cell lysates were collected, and TM was measured by ELISA;in others, GMVECs were further supplemented with PC and thrombin for 1 hour, followed by supernatant collection for APC measurement by ELISA. Result(s): STM levels were significantly higher in the COVID-19 pediatric patients (p < 0.01) (Fig. 1). In vitro, surface bound TM (Fig 2a) and soluble APC (Fig 2b) were significantly lower in GMVECs after addition of spike proteins (p < 0.05). Conclusion(s): We provide evidence of endothelial injury in COVID-19 patients and demonstrate a potential pathway of SARS-CoV-2 induced thrombosis. Decreased surface-bound TM results in lower amount of thrombin-TM complex, hence lesser activation of PC, likely leading to a pro-thrombotic state. These findings in GMVECs could explain the vulnerability of kidneys to COVID-19-induced TMA.

Role of the Complement System and Vascular Endothelium in COVID-19 Pathogenesis

Background: Coronavirus Disease 2019 (COVID-19) caused by SARS-CoV-2 infection has become a global pandemic, presenting with varying degrees of severity from respiratory distress to multi-organ damage. Kidneys are of several organs affected in COVID-19, with acute kidney injury (AKI) being a common consequence, occurring in more than 30% of patients with severe COVID-19. While the underlying mechanisms of COVID-19 pathogenesis remain poorly understood, there is evidence linking complement system overactivation and endothelial injury to organ damage that increases the risk of mortality in COVID-19. Evidence from previous coronavirus epidemics also suggest direct involvement of inflammation, complement dysregulation, and endothelial cell dysfunction. Thus, we hypothesize that vascular endothelial injury resulting from complement overactivation contributes to COVID-19-associated organ injury. Method(s): Clinical information and sera from SARS-CoV-2+ patients with mild (n=7) and severe COVID-19 (n=7) diseases were obtained from the Canadian COVID-19 Prospective Cohort Study (CANCOV). Complement activation on ECs was evaluated via immunofluorescence assays, measuring the deposition of complement products C3b and C5b-9 on Human Umbilical Vein Endothelial Cells exposed to control or patient sera. In addition, a permeability assay using a transwell model was used to measure the integrity of the endothelial monolayer exposed to patient sera. Result(s): Complement was found to be overactivated on ECs treated with SARSCoV-2+ patient sera compared to those treated with normal human serum as evidenced by significantly increased C3b and C5b-9 deposition. While ECs treated with sera from patients with mild COVID-19 seemed to have higher C3b deposition, ECs treated with sera from patients with severe COVID-19 disease were associated with higher C5b-9 deposition. In addition, increased permeability of the monolayer incubated with SARSCoV-2+ patient sera was seen over time regardless of disease severity. However, ECs tretaed with severe COVID-19 patient sera had signficiantly increased vascular leakiness as evidenced by increased permeability of the treated monolayer. Conclusion(s): Thus, we conclude that complement is overactivated in SARS-CoV-2+ patients and use of anti-complement therapies may be an effective strategy in treating COVID-19 associated vascular injury, hyperinflammation, and organ damage.

THAT BLOODY CLOT DOES NOT ALWAYS NEED A TUNNEL TO MIGRATE: A CASE OF MULTIPLE ARTERIAL AND VENOUS THROMBOSIS IN A COVID-19 PATIENT

SESSION TITLE: Rare Cases of Nervous System and Thrombotic Complication Posters SESSION TYPE: Case Report Posters PRESENTED ON: 10/17/2022 12:15 pm - 01:15 pm INTRODUCTION: Covid 19 virus has impacted nearly 450 million people across the globe;ranging from an asymptomatic carrier state to respiratory symptoms, cardiovascular symptoms, hematologic manifestations and multiorgan failure to death. Thrombotic events are one of its devastating complications. CASE PRESENTATION: A 66 year old man with a history of diabetes mellitus, hypertension and 30 pack years smoking history presented to the emergency room with hypoxia and altered mental status. On exam, his GCS was 8/15 and oxygen saturation was 85% on room air. He was subsequently intubated. CTA chest demonstrated bilateral diffuse ground glass opacities and left pulmonary embolism (PE). CT abdomen and pelvis showed multifocal infarcts in the right kidney with findings suggestive of renal artery thrombosis. Initial platelet count was 80,000/ul with creatinine of 3.9 mg/dl and creatine kinase (CK) of 3977 u/l. His INR was 1.4. Patient was not a candidate for thrombolysis given his thrombocytopenia. He was started on intravenous (IV) heparin and given IV hydration. On day 3 of his admission, he developed dry gangrene of the toes. Ankle brachial index of the right lower extremity (LE) was 1.16 and left LE was 0. Duplex ultrasonography of left LE showed mid to distal popliteal artery thrombus occluding below knee popliteal and tibial arteries. Echocardiogram showed ejection fraction of 55% and bubble study was negative for any intra atrial or pulmonary shunting. On day 4 of his admission, he developed oliguria and his gangrene got worse. His platelet counts decreased to 36,000/ul. Other pertinent labs showed INR 1.2, PT 15.3, PTT 34, D dimer 14.82, fibrinogen 498, CK 6434 mg/dl, hemoglobin 13.2 g/dl, haptoglobin 243 mg/dl and LDH 1041 U/l. Given his poor prognosis in the setting of ventilator dependent respiratory failure, multiple thrombosis and kidney failure requiring hemodialysis, the family decided to withdraw care. DISCUSSION: There are multiple hypotheses of thrombus formation in Covid 19 infection such as interleukin 6 and other cytokines induced endothelial injury, angiogenesis and elevated prothrombotic factors such as factor VIII and fibrinogen. Our patient had PE, renal artery thrombosis and popliteal artery thrombosis. Despite being on full dose anticoagulation, he developed gangrene of the toes. His lab results were not consistent with disseminated intravascular coagulation, thrombotic thrombocytopenic purpura and he was not known to have any baseline hypercoagulable disorder. He did not have any intra cardiac shunts. Hence, it is most likely Covid 19 induced multiple arterial and venous thrombosis. CONCLUSIONS: The treatment of Covid 19 related thrombosis has become very challenging especially in the setting of multiple clots. It is crucial to have large multicenter studies to investigate vascular complications of Covid-19 and to formulate management strategies to ensure good patient outcomes. Reference #1: https://www.nejm.org/doi/full/10.1056/nejmoa2015432 Reference #2: https://journal.chestnet.org/article/S0012-3692(21)01126-0/fulltext DISCLOSURES: No relevant relationships by Devashish Desai No relevant relationships by Swe Swe Hlaing no disclosure on file for Jean Marie Koka;No relevant relationships by Hui Chong Lau No relevant relationships by Subha Saeed No relevant relationships by Anupam Sharma No relevant relationships by Muhammad Moiz Tahir

LONG-TERM SURVEY STUDY of the IMPACT of COVID-19 on SYSTEMIC AUTOIMMUNE DISEASES. LOW DEATH RATE DESPITE the INCREASED PREVALENCE of SYMPTOMATIC INFECTION. ROLE of PRE-EXISTING INTERSTITIAL LUNG DISEASE and ONGOING TREATMENTS

Background: Patients with autoimmune systemic diseases (ASDs) can be counted among frail populations as regards the predisposition to COVID-19 due to the frequent visceral organ involvement and comorbidities, as well as the ongoing immunomodulating treatments. Objectives: Our long-term multicenter telephone survey prospectively investigated the prevalence, prognostic factors, and outcomes of COVID-19 in Italian ASD patients during the frst 3 pandemic waves. Methods: A large series of 3,918 ASD patients (815 M, 3103 F;mean age 59±12SD years) was consecutively recruited at the 36 referral centers of COVID-19 & ASD Italian Study Group. In particular, ASD series encompassed the following conditions: rheumatoid arthritis (n: 981), psoriatic arthritis (n: 471), ankylosing spondylitis (n: 159), systemic sclerosis (n: 1,738), systemic lupus (172), systemic vasculitis (n: 219), and a miscellany of other ASDs (n: 178). The development of COVID-19 was recorded by means of telephone survey using standardized symptom-assessment questionnaire (1). Results: A signifcantly increased prevalence of COVID-19 (8.37% vs 6.49%;p<0.0001) was observed in our ASD patients, while the cumulative death rate revealed statistically comparable to the Italian general population (3.65% vs 2.95%;p: ns). In particular, among the 328 ASD patients complicated by COVID-19, 57 (17%) needed hospitalization, while mild-moderate manifestations were observed in the large majority of individuals (83%). In addition, 12/57 hospitalized patients died due to severe interstitial pneumonia and/or cardiovascular manifestations. Interestingly, a signifcantly higher COVID-19-related death rate was observed in systemic sclerosis patients compared to the Italian general population (6.29% vs 2.95%;p=0.018). Other adverse prognostic factors to develop COVID-19 were the patients' older age, male gender, pre-existing ASD-related interstitial lung involvement, and chronic steroid treatment. Conversely, patients treated with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) showed a signifcantly lower prevalence of COVID-19 compared to those without (3.58% vs 46.99%;p=0.000), as well as the chronic administration of low dose aspirin in a subgroup of SSc patients (with 5.57% vs without 27.84%;p=0.000). Conclusion: The cumulative impact of COVID-19 on ASD patients after the frst 3 pandemic waves revealed less severe than that observed during the frst phase of pandemic (1), especially with regards to the death rate that was comparable to the Italian general population in spite of the increased prevalence of complicating COVID-19 in the same ASD series. Ongoing long-term treatments, mainly csDMARDs, might usefully contribute to generally positive outcomes of in this frail patients' population. Of note, a signifcantly increased COVID-19-related mortality was recorded in only SSc patients' subgroup, possibly favored by pre-existing lung fbrosis. Among different ASD, SSc deserves special attention, since it shares the main pathological alterations with COVID-19, namely the interstitial lung involvement and the endothelial injury responsible for diffuse microangiopathy. Besides SSc, the patients' subgroups characterized by older age, chronic steroid treatment, pre-existing interstitial lung disease, and/or impaired COVID-19 vaccine response (1-3), may deserve well-designed prevention and management strategies.

Immune-mediated Acute Limb Ischemia: A Rare Complication of SARS-CoV-19 Infection

Occurrence of acute limb ischaemia (ALI) in patients with SARS-CoV-2 is an uncommon complication. COVID-19 has been associated with thrombotic disease secondary to a hypercoagulable state. COVID-19 appears to cause a hypercoagulable state through mechanisms unique to SARS-CoV-2 and centres on the cross-talk between thrombosis and inflammation. The proposed hypothesis includes a severely heightened inflammatory response that leads to thrombotic inflammation, through a mechanism such as cytokine storm, complement activation, and endothelitis. The innate and adaptive immune responses result in immunemediated thrombosis, leading to thrombotic complications, such as myocardial infarction, pulmonary embolism, deep vein thrombosis, and stroke. The activation of coagulation (D-dimer) and thrombocytopenia are important prognostic markers in SARSCoV- 19 infections. At our institution, we found six patients to have ALI and reviewed their characteristics and outcomes. Our findings showed that in severe COVID-19 disease, the association of ALI had high mortality. Materials and methods: It is a retrospective observational study performed at Bangalore Baptist hospital during the COVID-19 pandemic (August 2020 to August 2021). We report a case series of 6 ALI patients aged between 30 and 55 years. All the patients were tested positive for SARS-CoV-2 disease. All our patients received standard treatment care as per institution protocol for SARS-CoV-2 disease. They were all commenced on therapeutic anticoagulation at admission to ICU. Baseline coagulation profile and inflammatory markers and their trends were followed in all patients. The diagnosis of ALI in all ventilated patients was done clinically by the presence of pallor, pulselessness, acrocyanosis, blisters, and dry care unit with SARS-CoV-2 disease, 6 patients had developed limb ischemia (1.4%). Male and female preponderance was equal. Among 6 patients, 1 was newly detected diabetes mellitus, 2 were diabetic and hypertensive of which one had right upper limb post-polio paralytic sequelae, and the rest had no co-morbidities. The mean duration of ICU stay and mechanical ventilation days was 22 days and 17.8 days, respectively. All the patients had lower limb ischemia of which 3 were unilateral. Discoloration extended up to the ankle joint in almost all cases. As these patients were on the ventilator secondary to severe hypoxemia or vasopressor support, they were managed conservatively. Two patients presented with stroke, pyelonephritis with acute kidney injury, and septic shock requiring high vasopressor support. 5 of 6 patients died during the course of treatment (mortality 83%). All patients showed high inflammatory markers especially D-dimer during the initial development phase of limb ischemia. 1 survived patient required bilateral foot amputation due to dry gangrene. Conclusion: Limb ischemia with tissue necrosis is a dreadful complication and is associated with high mortality. High incidence of thrombosis despite therapeutic anticoagulation raises a question about pathophysiology unique to COVID-19. Evidence of inflammatory-mediated thrombosis and endothelial injury are possible explanations which would support the use of immunotherapy in addition to anticoagulation for the treatment of thrombotic events. Further insight into the cause and management of thrombosis is needed.

ENDOTHELIAL CELLS AND BLOOD VESSELS – CRITICAL TARGETS FOR COVID-19-INDUCED TISSUE INJURY AND SPREAD TO DISTANT ORGANS. UNDERLYING MECHANISMS INCLUDE ENDOTHELIAL DYSFUNCTION AND INJURY

Endothelial cells (ECs) lining the blood vessels of all organs express the SARS-CoV2 receptor. In the absence of preexisting tissue damage, the virus would need to pass through the ECs to blood vessels to infect other tissues. Thus, EC are a target for SARS-CoV-2 infection and a conduit for viral dissemination to distant organs. We hypothesized that ECs infection and/ or injury are the mechanisms of COVID-19 pathology and multi-organ dissemination and injury. Methods: Human studies: We used lung, heart, kidney, and small bowel specimens obtained during autopsies (n=5) from COVID-19 patients and uninfected subjects. Studies: 1) histologic evaluation of endothelial damage and endotheliitis, 2) immunohistochemistry for vWF, PAI-1, VCAM-1, & ICAM-1. Studies in cultured human microvascular ECs (HMVECs): We cultured lung and cardiac HMVECs in the presence or absence of SARSCoV- 2 S1 and/or S2 protein (10 ng/ml) for 0 - 24 hr. Studies:1) cell viability and proliferation;2) angiogenesis on Matrigel and cell migration;3) mitochondrial membrane potential (MMP);4) RNA seq analysis;5) Western blotting for vWF, PAI-1, VCAM-1, and ICAM-1. We examined the protective effect of melatonin, Coenzyme Q10 and nerve growth factor on S1/S2 protein induced HMVEC cell damage. Results: Histopathologic examination revealed presence of endothelial abnormalities and endotheliitis with marked presence of inflammatory cells in vessel wall & lumen, and fibrinous microthrombi) in lung, heart & kidney in autopsy specimens of COVID-19 patients. Immunostaining visualized increased vWF, PAI-1, VCAM- 1, & ICAM-1 in COVID-19. In in vitro study, S1 and S2 proteins induced endothelial injury, reduced angiogenesis and phosphorylated/activated Erk and Akt proteins in cultured HMVECs. Treatment of HMVECs for 1 & 4 hours with S2 but not S1 protein increased ICAM-1 levels by 1.4- to 1.8-fold (P < 0.001). RNA Seq analysis showed that treatment of HMVECs with S1 and S2 proteins upregulated VCAM-1, ICAM-1 and E-selectin mRNA in cultured HMVECs. Melatonin, Coenzyme Q10 and NGF stimulated angiogenesis in HMVECs by 2.4-, 1.3-&1.4-fold (all P < 0.001). Conclusions: 1) Significant endothelial abnormalities, blood vessel damage and endotheliitis are present in lung, heart and kidney autopsy specimens of COVID-19 patients, 2) There is increased expression of vWF, PAI-1, VCAM-1, and ICAM- 1 in lung, heart, and kidney specimens of COVID-19 patients, 3) Treatment of cultured HMVECs with SARS-CoV-2 S1 and S2 proteins upregulates VCAM-1, ICAM-1 and Eselectin expression, 4) SARS-CoV-2 S1 and S2 proteins induce endothelial injury in cultured HMVECs, and 5) melatonin, Coenzyme Q10 and NGF stimulated EC function. These studies uncovered novel mechanism – endothelial dysfunction underlying SARS-CoV-2 and identified melatonin, Coenzyme Q10 and NGF as potential drugs for treatment of COVID- 19-induced EC injury

Inflammatory and Endothelial Plasma Biomarkers in Patients with Acute Respiratory Distress Syndrome Due to Covid-19 Treated with Systemic Steroids

RATIONALE Immune dysregulation and endothelial injury are implicated in the pathobiology of acute respiratory distress syndrome (ARDS) due to COVID-19. Circulating biomarkers of immune and endothelial dysfunction are variably associated with outcomes in COVID-19 ARDS, with most studies conducted before routine use of systemic corticosteroids. We therefore evaluated the association of baseline inflammatory and endothelial biomarkers with mortality in a recent cohort of critically ill COVID-19 patients. METHODS We prospectively enrolled an observational cohort of COVID-19 ARDS patients from the intensive care unit (ICU) of an urban, academic hospital in Boston, Massachusetts from January 1 to March 1, 2021 (N=100). Patients were aged ≥ 18 years, had confirmed COVID-19 by polymerase chain reaction, and had a diagnosis of ARDS adjudicated by board-certified pulmonary and critical care physicians. Plasma samples were collected on day 1 of ICU admission. Clinical course was followed for 60 days post-enrollment or until discharge. Recorded clinical data included demographics, comorbidities, modified sequential organ failure assessment (mSOFA) score, hospital and ICU length of stay (LOS), and ventilator days. Eleven plasma analytes were measured using a Luminex Discovery Assay (R and D Systems) and Creactive protein (CRP) was measured by the hospital core laboratory. RESULTS Of 100 ICU patients with severe COVID-19 with acute respiratory failure, 74 were intubated and 68 had a plasma sample from day 1 of their ICU admission. Of those intubated (n=74), all met ARDS criteria, mean age (± standard deviation) was 64 ± 15 years, 39 (40%) were female, mean BMI was 30 ± 8, median mSOFA was 6 (IQR 4-8), median PaO2 was 105 mmHg (IQR 83-131 mmHg), and median PaO2/FiO2 was 174 (IQR 132- 235). Seventy patients (95%) received systemic corticosteroids. Median ventilator days was 15 (IQR 8-21), median ICU LOS was 17 days (IQR 10-27), and median hospital LOS was 22 days (IQR 16-32). At 30 days, 29 (40%) patients died, and at 60 days, 33 (45%) patients died. A total of 12 prespecified analytes were profiled (Figure). Only the endothelial biomarker von Willebrand factor (vWF) was associated with mortality at day 30 (∗P=0.003) and day 60 (P=0.002) using logistic regression adjusted for age, mSOFA, and multiple comparisons (P<0.004 significant by Bonferroni). CONCLUSION In a cohort of patients with ARDS due to COVID-19 receiving systemic corticosteroids, there was no association between inflammatory markers and mortality. However, the endothelial protein vWF remained associated with mortality suggesting endothelial injury is incompletely mitigated by systemic corticosteroids.

Thromboembolism in COVID -19 patients on ECMO

Venous thromboembolism (VTE) is a common complication of COVID-19 (coronavirus disease 2019), which often leads to sudden deterioration and death. There are multiple mechanisms contributing to this phenomenon. Endothelial injury from COVID-19 triggers platelet activation and adhesion, leucocyte aggregation, cytokine storm and complement activation. Cytokine storm triggers coagulation activation and thrombin generation. Complement activation is also thought to trigger the formation of systemic thrombus through recruiting inflammatory cytokines and possible complement-mediated thrombotic microangiopathy. Patients on extracorporeal membrane oxygenation (ECMO) are at risk of developing thromboembolism. Thrombus formation within the extracorporeal circuit is the main reason for systemic thromboembolism. Possibly that by contacting blood and nonendothelial surfaces, ECMO triggers activation of coagulation pathway and inflammatory response. Thromboembolic prophylaxis is critical in managing COVID-19 patients on ECMO. Anticoagulation is recommended to all hospitalised COVID-19 patients unless there are contraindications. However, patients are still found to develop VTE while on anticoagulation and the prevalence of VTE in COVID-19 patients on ECMO is still unclear. We aim to investigate the VTE incidence and contribute to anticoagulation strategy and management in this specific population. We retrospectively reviewed the data of 23 patients who were diagnosed with COVID-19 and managed with ECMO. All patients received thromboembolic prophylaxis since admission. We report our findings of the incidences of thromboembolism. Twenty-three adult patients who were diagnosed with COVID-19 received ECMO support. Sixteen patients were minorities, and seven patients were Caucasians. The mean age of patients was 44.8-year old. Seventeen patients were males, and 11 patients had at least one of the following pre-ECMO comorbidity: ten (43.5%) patients had hypertension, 11 (47.8%) patients had type 2 diabetes and four (17.3%) patients had hyperlipidaemia. None of the patients were active smokers or had chronic lung disease. During the hospital course, all patients received heparin for thromboembolic prophylaxis. The overall VTE rate was 34.7%. Six patients developed deep vein thrombosis (DVT) (26%) with lower extremities induration. Two patients were found to have pulmonary embolism (PE) (8.7%). Four patients had clotted circuit that requiring exchange. No stroke or myocardial infarction (MI) was diagnosed in these patients. Heparin-induced thrombocytopenia (HIT) was excluded in all cases. Based on our study, the overall VTE rate of COVID-19 patients on ECMO was 34.7% with 26% incidence of DVT and 8.7% incidence of PE. According to Jenner's recent systemic review of 28 studies, 34% of 2928 ICU-managed COVID-19 patients developed VTE. PE was found in 12.6% of patients and DVT was detected in 16.1% of patients. 529 patients (18.0%) received ECMO in the cohort. When compared with our study, there were no statistically significant differences of the incidences of VTE, DVT or PE between these two studies, although all our patients were on ECMO support. Further investigation into the prevalence, implications and management of thromboembolism in COVID-19 patients on ECMO will lead to significantly improved outcomes for this specific patient population..

Transient endothelial injury and release of lupus anticoagulant in COVID-19

Introduction: Coronavirus disease 2019 (COVID-19) has been described as an endothelial disease associated with a procoagulant state and a high prevalence of lupus anticoagulant (LA). No study has so far evaluated the persistence of endothelial injury after recovery. Purpose: We report the results of a systematic biologic assessment more than 12 weeks after the acute phase of COVID-19. Methods: Patients hospitalized for COVID-19 at Strasbourg university hospital, France, and tested positive for LA were included in the microparticles in COVID-19 (MICO) study. During the prospective follow-up, blood samples were obtained at least 12 weeks after COVID-19 diagnosis. Results: Between March 3 and May 5, 2020, 56 COVID-19 patients with positive LA were included in the study. Five patients were excluded from the analysis because of direct oral anticoagulant treatment at the time of follow-up. A total of 51 patients were included in the final analysis. The mean age was 61 years. During the acute phase of COVID-19, 38 patients (74.5%) required mechanical ventilation, 10 patients (19.7%) presented a venous thrombotic event and mean von Willebrand factor antigen (vWF:Ag) level was 409.5%. Follow-up visit was performed at a median of 144 (interquartile range 129–179) days after COVID-19 diagnosis. LA detection was positive only in three patients (5.9%) and mean level of vWF:Ag was 158.0% at the time of follow-up. No thrombotic event was observed during the follow-up phase (Fig. 1, Table 1). Conclusions: We showed disappearance of LA in a large majority of patients and a drastic decrease of vWF:Ag levels, clinically translated by the absence of thrombosis event during the follow-up. Our results suggest that endothelial dysfunction is transient in COVID-19 patients and therefore associated to a potential temporary and limited pathophysiological effect.

Sars-Cov-2 Induced Endotheliopathy and the Impact on Clinical Outcomes in Critically Ill Pediatric Patients

Background: Coronavirus disease-19 (COVID-19) is an acute respiratory illness caused by the SARS-COV-2 virus. Patients with COVID-19 infection can present with thrombosis in the setting of inflammation (thromboinflammation), presumably from endothelial dysfunction, or “endotheliopathy”. Yu et al demonstrated in vitro that the spike protein subunit of SARS-COV2 acts as a potent activator of the alternative complement pathway (AP), one of three complement pathways within the innate immune system. Satyam et alreported the deposition of complement components on lung tissue of patients who succumbed to COVID-19, consistent with activation of classical and alternate pathways. These studies suggest complement dysregulation potentially causing endotheliopathy in COVID-19 patients. Thrombomodulin (TM) is an endothelial glycoprotein that plays two crucial roles in maintaining a healthy endothelium - as a natural anticoagulant and a negative regulator of complement. TM shed into the circulation due to endothelial injury can be measured in the plasma as soluble TM (sTM). Goshua et al showed elevated sTM in an adult cohort of patients with COVID-19. However, it is yet to be demonstrated if there is any correlation between endothelial injury and AP activation in COVID-19, or if either play a role in clinical outcome in the pediatric population. Objective: To 1) assess endothelial injury and AP activation in a cohort of critically ill pediatric patients with COVID-19 by measuring sTM and Ba (an AP activation product);2) determine the correlation between endothelial injury and AP activation;and 3) analyze the utility of sTM and Ba in predicting pediatric clinical outcomes. Methods: We collected plasma samples of patients admitted to the Pediatric Intensive Care Unit and found to be positive for SARS-CoV-2 between Dec 2, 2020 and Jan 22, 2021 at Texas Children's Hospital. For controls, we collected plasma samples from pediatric patients undergoing preoperative clearance, all at their baseline state of health. sTM levels and Ba levels were measured in plasma samples using commercially available TM and Ba ELISA kits. sTM greater than 7.6 ng/ml (based on the assay range in adults) and Ba greater than 1080 ng/ml (based on data from adult healthy controls) were considered elevated. Data regarding demographics, length of ICU stay, clinical indicators of end organ damage- mechanical ventilation, dialysis, use of vasopressors, ECMO, mortality were obtained retrospectively via chart review. Inclusion criteria included all patients with a positive SARS-COV2 PCR admitted to the ICU. Exclusion criteria was age greater than 21 years, pregnant female, patients with known inflammatory or complement-mediated disorders. Statistical analysis: For sTM and Ba levels between control and COVID-19 patients, mean +/- standard deviation was calculated and significance determined with an unpaired t-test. Fischer exact test, Wilcoxon rank sum and Pearson product-moment correlation tests were used for statistical analysis of clinical outcomes as appropriate. A p-value <0.05 was considered statistically significant. Results: A total of 38 control patients and 33 COVID-19 patients were enrolled. Ba and sTM levels were both significantly higher in the COVID-19 pediatric patients compared to the controls (Fig. 1). Within the COVID-19 patient cohort, 61% (n=20) had elevated sTM and 42% (n=14) had elevated Ba levels. There was a moderately positive correlation between sTM and plasma Ba levels in the COVID-19 cohort (Fig. 2). Within the COVID-19 patients' cohort, though higher Ba levels were not associated with an increased rate of intubation, they were associated with an increased duration of mechanical ventilation (p=.039) for those intubated (Table 1). Elevated sTM was associated with increased vasopressor use (p=.011). Although other clinical outcome variables did not reach statistical significance likely owing to small numbers, overall trend indicated worse outcomes in patients with elevated sTM. Conclusions: Our findings are consistent with the hypothesi that SARS-COV-2 activates AP and causes endothelial injury in children. The positive correlation between sTM and Ba suggest interplay between inflammation, coagulation and endotheliopathy supporting thromboinflammation in COVID-19. Higher sTM and Ba levels indicated worse clinical outcomes in children, but larger studies are needed to confirm our findings. [Formula presented] Disclosures: Sartain: Alexon Pharamaceuticals: Membership on an entity's Board of Directors or advisory committees.

Respiratory symptoms of the 2019 novel coronavirus when the source of the symptoms is intra-cardiac thrombus not the pneumonia

Case Report The 2019 Novel Coronavirus (COVID-19) is currently causing a global pandemic. Common symptoms are fever, cough, myalgia, fatigue, headache, dyspnea, sore throat, vomiting, and diarrhea. Patients may present with end-organ failure, ARDS, shock, acute kidney injury, or even death. We present a case of COVID-19 with shortness of breath caused by an intra-cardiac thrombus. Case presentation An 84-year-old woman with COPD and diastolic heart failure presented with shortness of breath. She had hypoxemia on room air upon presentation. Lungs were clear on physical examination. COVID-19 PCR was positive. Her chest radiograph demonstrated no pulmonary infiltrates. Transthoracic echocardiography (TTE) demonstrated a large, irregularly shaped echogenic mass in both the right atrium and right ventricle consistent with a large thrombus. The mass in the right atrium was 3.9∗3.6 cm;the portion in the ventricle was 3.2∗2.2 cm. A previous TTE study in this patient did not reveal an intra-cardiac thrombus. No deep venous thrombosis was found. She was begun on anticoagulation and refused catheter-directed therapy. She improved and was discharged to her home. Discussion Thromboembolic complications of COVID-19 have been described in the literature. The most common are deep venous thrombosis and pulmonary embolism in critically ill patients despite the use of prophylactic anticoagulation. Several studies have reported post-mortem biopsies with widespread microthrombi. Arterial thrombosis with stroke and limb ischemia has also been described. Our case had an unusual presentation since the cause of her shortness of breath was the intra-cardiac thrombus. The pathogenesis beyond the hypercoagulability in COVID is not well understood. Some studies propose direct endothelial injury by the COVID-19 virus, causing microvascular inflammation, endothelial exocytosis, and endothelitis. Some experts propose a hypercoagulable state in COVID-19 patients based on elevated factor VIII, elevated fibrinogen, circulating prothrombotic microparticles, and neutrophil extracellular traps (NETs). Yet, no definitive mechanism has been identified. (Figure Presented).

Impaired coronary flow reserve in athletes with long-term cardiovascular symptoms after COVID-19

Introduction: Cardiovascular symptoms post-acute sequelae of SARS-CoV-2 infection (CV-PASC) have been increasingly recognized, but the underlying pathobiology is unclear. Endothelial and cardiac pericyte ACE2 receptors are important targets of SARS-CoV-2, resulting in virally-induced endothelial activation, which may adversely affect the coronary microvasculature and impair myocardial performance. We hypothesized that athletes with CV-PASC have microvascular and subclinical myocardial dysfunction. Methods: We compared 15 athletes with CV-PASC with 7 control athletes without prior COVID-19 using regadenoson stress cardiac magnetic resonance (CMR). All athletes participated in >6 hours of endurance activities per week. We analyzed CMR volumes, function, global circumferential strain (GCS), late gadolinium enhancement (LGE), and coronary flow reserve (CFR) by coronary sinus method. Values presented as median [IQR]. Results: CMR in CV-PASC athletes occurred 102 [66,123] days post-SARS-CoV-2 infection. There were no differences in chamber volumes, function, or LGE between groups. One CV-PASC athlete had acute myocarditis (7%). CVPASC athletes had decreased CFR compared with control athletes (Figure 1). Multiple CV-PASC participants had CFR below the 95% CI of the controls and reported normal values from the literature (2.9 and 2.5, respectively). GCS was worse in CV-PASC athletes at the base (-23.7% [-21.6,-26.4] vs -31.1% [-27.3,-33.0], p=0.01), mid-LV (-21.5% [-18.5,-22.8] vs -28.5 [-25.4,-29.9], p=0.008), and apex (-27.1% [-24.1,-29.9] vs -30.6% [-27.8,-38], p=0.07), though the apex did not reach statistical significance. Conclusions: This pilot case-control study found CV-PASC athletes had reduced CFR and associated subclinical myocardial dysfunction as assessed by GCS compared to control athletes. These findings suggest coronary microvascular dysfunction related to endothelial injury may mediate CV-PASC symptoms.

An engineered high-affinity ACE2 peptide therapeutically alleviates lung vascular endothelial injury and mortality induced by distinct SARS-CoV-2 variants

Introduction: Vaccine hesitancy and the continuous emergence of SARS-CoV-2 variants of concern that partially escape vaccine-induced immune responses highlight the urgent need for the development of effective therapeutics for COVID-19 patients. Hypothesis: The Engineered high-affinity ACE2 peptide has a therapeutic effect for SARS-CoV-2 and its variant-induced acute lung vascular injury. Methods: K18-hACE2 transgenic mice were inoculated with SARS-CoV-2 WA-1/2020 or P.1 variant of concerns to induce acute lung injury. The sACE22.v2.4-IgG1 was injected once a day for consecutively 7 days starting from 12 hours at 10 mg/kg/day or 24 hours at 15 mg/kg/day postSARS-CoV-2 inoculation. Results: We demonstrated that the higher binding affinity of sACE22.v2.4-IgG1 to S proteins of the original SARS-CoV-2 WA-1/2020 isolate and the B.1.1.7 (Alpha, UK isolate), B.1.351 (Beta, South Africa isolate), P.1 (Gamma, Brazil isolate), and B.1.617.2 (Delta, India isolate) SARS-CoV-2 variants of concern compared to wild-type soluble ACE2. Using humanized K18-hACE2 mice, we found that both SARS-CoV-2 isolate WA-1/2020 and the P.1 variant of concern induced severe acute lung endothelial injury, which resulted in the severe transvascular leak, lung edema, and death. The P.1 variant induced severe lung vascular leak and death at an earlier time point at Day 5 compared to WA-1 at Day 7, consistent with increased viral entry and replication. Treatment with sACE22.v2.4-IgG1 decoy peptide could be initiated as late as 24h after inoculation with a lethal dose of the SARS-CoV-2 WA-1/2020 isolate and profoundly reduces lung vascular injury and mortality For the P.1 variant of concern, ACE22.v2.4-IgG1 decoy peptide markedly improved survival and reduced lung vascular injury if administered early at 12 hours post-inoculation. Conclusion: sACE22.v2.4-IgG1 has an exceptional therapeutic efficacy to SARS-CoV-2 WA-1/2020 and variant P.1 -induced acute lung vascular injury.