Extensive blood transcriptome analysis reveals cellular signaling networks activated by circulating glycocalyx components reflecting vascular injury in COVID-19.

Background: Degradation of the endothelial protective glycocalyx layer during COVID-19 infection leads to shedding of major glycocalyx components. These circulating proteins and their degradation products may feedback on immune and endothelial cells and activate molecular signaling cascades in COVID-19 associated microvascular injury. To test this hypothesis, we measured plasma glycocalyx components in patients with SARS-CoV-2 infection of variable disease severity and identified molecular signaling networks activated by glycocalyx components in immune and endothelial cells. Methods: We studied patients with RT-PCR confirmed COVID-19 pneumonia, patients with COVID-19 Acute Respiratory Distress Syndrome (ARDS) and healthy controls (wildtype, n=20 in each group) and measured syndecan-1, heparan sulfate and hyaluronic acid. The in-silico construction of signaling networks was based on RNA sequencing (RNAseq) of mRNA transcripts derived from blood cells and of miRNAs isolated from extracellular vesicles from the identical cohort. Differentially regulated RNAs between groups were identified by gene expression analysis. Both RNAseq data sets were used for network construction of circulating glycosaminoglycans focusing on immune and endothelial cells. Results: Plasma concentrations of glycocalyx components were highest in COVID-19 ARDS. Hyaluronic acid plasma levels in patients admitted with COVID-19 pneumonia who later developed ARDS during hospital treatment (n=8) were significantly higher at hospital admission than in patients with an early recovery. RNAseq identified hyaluronic acid as an upregulator of TLR4 in pneumonia and ARDS. In COVID-19 ARDS, syndecan-1 increased IL-6, which was significantly higher than in pneumonia. In ARDS, hyaluronic acid activated NRP1, a co-receptor of activated VEGFA, which is associated with pulmonary vascular hyperpermeability and interacted with VCAN (upregulated), a proteoglycan important for chemokine communication. Conclusions: Circulating glycocalyx components in COVID-19 have distinct biologic feedback effects on immune and endothelial cells and result in upregulation of key regulatory transcripts leading to further immune activation and more severe systemic inflammation. These consequences are most pronounced during the early hospital phase of COVID-19 before pulmonary failure develops. Elevated levels of circulating glycocalyx components may early identify patients at risk for microvascular injury and ARDS. The timely inhibition of glycocalyx degradation could provide a novel therapeutic approach to prevent the development of ARDS in COVID-19.

Brain autopsies of critically ill COVID-19 patients demonstrate heterogeneous profile of acute vascular injury, inflammation and age-linked chronic brain diseases.

BACKGROUND: This study examined neuropathological findings of patients who died following hospitalization in an intensive care unit with SARS-CoV-2. METHODS: Data originate from 20 decedents who underwent brain autopsy followed by ex-vivo imaging and dissection. Systematic neuropathologic examinations were performed to assess histopathologic changes including cerebrovascular disease and tissue injury, neurodegenerative diseases, and inflammatory response. Cerebrospinal fluid (CSF) and fixed tissues were evaluated for the presence of viral RNA and protein. RESULTS: The mean age-at-death was 66.2 years (range: 26-97 years) and 14 were male. The patient's medical history included cardiovascular risk factors or diseases (n = 11, 55%) and dementia (n = 5, 25%). Brain examination revealed a range of acute and chronic pathologies. Acute vascular pathologic changes were common in 16 (80%) subjects and included infarctions (n = 11, 55%) followed by acute hypoxic/ischemic injury (n = 9, 45%) and hemorrhages (n = 7, 35%). These acute pathologic changes were identified in both younger and older groups and those with and without vascular risk factors or diseases. Moderate-to-severe microglial activation were noted in 16 (80%) brains, while moderate-to-severe T lymphocyte accumulation was present in 5 (25%) brains. Encephalitis-like changes included lymphocytic cuffing (n = 6, 30%) and neuronophagia or microglial nodule (most prominent in the brainstem, n = 6, 30%) were also observed. A single brain showed vasculitis-like changes and one other exhibited foci of necrosis with ball-ring hemorrhages reminiscent of acute hemorrhagic leukoencephalopathy changes. Chronic pathologies were identified in only older decedents: 7 brains exhibited neurodegenerative diseases and 8 brains showed vascular disease pathologies. CSF and brain samples did not show evidence of viral RNA or protein. CONCLUSIONS: Acute tissue injuries and microglial activation were the most common abnormalities in COVID-19 brains. Focal evidence of encephalitis-like changes was noted despite the lack of detectable virus. The majority of older subjects showed age-related brain pathologies even in the absence of known neurologic disease. Findings of this study suggest that acute brain injury superimposed on common pre-existing brain disease may put older subjects at higher risk of post-COVID neurologic sequelae.

Circulating Endothelial Cells: A New Possible Marker of Endothelial Damage in Kawasaki Disease, Multisystem Inflammatory Syndrome in Children and Acute SARS-CoV-2 Infection.

BACKGROUND: Kawasaki Disease (KD) and Multisystem Inflammatory Syndrome in Children (MIS-C) are pediatric diseases characterized by systemic inflammation and vascular injury, potentially leading to coronary artery lesions (CALs). Data on vascular injury occurring during acute COVID-19 (AC19) in children are still lacking. The aim of our study was to investigate endothelial injury in KD-, MIS-C- and AC19-dosing circulating endothelial cells (CECs). METHODS: We conducted a multicenter prospective study. CECs were enumerated by CellSearch technology through the immunomagnetic capture of CD146-positive cells from whole blood. RESULTS: We enrolled 9 KD, 20 MIS-C and 10 AC19. During the acute stage, the AC19 and KD patients had higher CECs levels than the MIS-C patients. From the acute to subacute phase, a significant CEC increase was observed in the KD patients, while a mild decrease was detected in the MIS-C patients. Cellular clusters/syncytia were more common in the KD patients. No correlation between CECs and CALs were found in the MIS-C patients. The incidence of CALs in the KD group was too low to investigate this correlation. CONCLUSIONS: Our study suggests a possible role of CECs as biomarkers of systemic inflammation and endothelial dysfunction in KD and MIS-C and different mechanisms of vascular injury in these diseases. Further larger studies are needed.

Treatment preferences of orthopedic surgeons for closed, isolated middle-third diaphyseal long bone fractures without neurovascular injury in children: A cross- sectional survey.

OBJECTIVE: This study aimed to assess the treatment trends and the factors influencing the treatment methods of Orthopaedic Surgeons in closed, isolated, middle-third diaphyseal long bone fractures without any neurovascular injury in children. METHODS: This was a cross-sectional electronic survey of Turkish Orthopaedic Surgeons who were active members of the Turkish Society of Children's Orthopaedics (TSCO) and still managing the children's fractures in their daily clinical practice. An initial e-mail including the electronic survey followed by three reminder e-mails was sent to 110 members, and then reminder telephone calls were made. RESULTS: The survey response rate was 66/110 (60%). In recent years, a definitive trend to surgical treatment was not seen 98%, 77%, 39%, and 88% of the responders in the closed humerus, forearm, femur, and tibia mid-shaft fractures, respectively. Neither the years of expertise nor the intensity of daily pediatric patients of the participants did not affect the treatment trend in any fracture scenarios. The patient's age was the most cited factor influencing the responders' decisions on whether conservative or surgical treatment would be performed in each fracture scenario. The most cited lowest age limits for surgical treatment inclosed mid-shaft fractures of the humerus, forearm, femur, and tibia, were the adolescent age group, 10-12 years, six years, and ten years, respectively. CONCLUSION: This is the first study assessing the daily clinical practice of members of TSCO in the management of closed, isolated, non- complicated middle-third diaphyseal long bone fractures in children just before the covid-19 pandemic started. A marked tendency toward surgical treatment is seen in femur mid-shaft fractures, followed by forearm mid-shaft fractures up to a certain level. The patient's age is the main determinant of the responders' decisions on the type of treatment in closed, isolated, non-complicated middle-third diaphyseal long bone fractures in children.

Vital Signs of Severe COVID-19 Patients During Inter-Hospital Helicopter Transfer (preprint)

Background: During the COVID-19 pandemic in The Netherlands, critically ill ventilated COVID-19 patients were transferred not only between hospitals by ambulance but also by the Helicopter Emergency Medical Service (HEMS). To date, little is known about the impact of helicopter transport on critically ill patients and COVID-19 patients in particular. This study was conducted to explore the impact of inter-hospital helicopter transfer on vital signs of mechanically ventilated severe COVID-19 intensive care patients, with special focus on take-off, midflight, and landing. Methods: : All ventilated critically ill COVID-19 patients who were transported between April 2020 and June 2021 by the Dutch ‘Lifeliner 5’ HEMS team and who were fully monitored, including noninvasive cardiac output, were included in this study. Three 10-minute timeframes (take-off, midflight and landing) were defined for analysis. Continuous data on the vital parameters heart rate, peripheral oxygen saturation, arterial blood pressure, end-tidal CO 2 and noninvasive cardiac output using electrical cardiometry were collected and stored at 1-minute intervals. Data were analydzed for differences over time within the timeframes using 1-way analysis of variance. Significant differences were checked for clinical relevance. Results: : Ninety-eight patients were included in the analysis. During take-off, an increase was noticed in cardiac output (from 6.7 to 8.1 Lmin -1 ; P<0.0001), which was determined by a decrease in systemic vascular resistance (from 1068 to 750 dyne·s·cm −5 , P<0.0001) accompanied by an increase in stroke volume (from 92.0 to 110.2 ml, P<0.0001). Other parameters were unchanged during take-off and mid-flight. During landing, cardiac output and stroke volume slightly decreased (from 7.9 to 7.1 Lmin -1 , P<0.0001 and from 108.3 to 100.6 ml, P<0.0001, respectively), and total systemic vascular resistance increased (P<0.0001). Though statistically significant, the found changes were small and not clinically relevant to the medical status of the patients as judged by the attending physicians. Conclusions: : Interhospital helicopter transfer of ventilated intensive care patients with COVID-19 can be performed safely and does not result in clinically relevant changes in vital signs. This study was assessed by the medical ethical committee Arnhem-Nijmegen, the Netherlands (identifier 2021-7313). The committee waived the need for informed consent. The study was registered at www.trialregister.nl (identifier NL9307).

Mental Health Consequences from COVID-19 Pandemic and Strategies for Community Level Recovery (preprint)

Background: The COVID-19 pandemic has spread across the globe from 2019 affecting millions of people physically, mentally, and socio-economically. The purpose of the study was to map out the mental health consequences of the COVID-19 pandemic and suggest recovery strategies. Methods: : A qualitative inquiry into the mental health aspects of the COVID-19 pandemic using observations from working in busy health clinics, general practices, primary and community care setting, and dedicated COVID acute care wards during the pandemic in Australia, United Kingdom and Sri Lanka; discussions with colleagues worldwide; analyzing social and news media comments; literature survey and experience of dealing with past disasters were used to map out mental health consequences and put forward recovery strategies. Results: : In covid sufferers, neuropsychiatric symptoms lasting months, unrelated to respiratory insufficiency suggested brain damage due to vascular endothelial injury and/or cerebral venous thrombosis (CVT). A third went onto develop or have a relapse of a psychological or neurological conditions. In the general population, common consequences included common mental health disorders; changing patterns of substance abuse including alcohol; increased domestic violence and child abuse. Family relationships, interactions and understanding improved in many but minority had strained dynamics. Vulnerable groups included the elderly, women, youth; children; disabled; frontline and health workers; minorities and severely mentally ill. At the community level, there were signs of collective (mass) hysteria from panic buying to conspiracy theories, public shaming, fake news and disinformation spreading on social media and mass protests. There were also positive effects such as better understanding of bio-knowledge; interventions (rapid vaccine production, contact tracing methods) and discoveries (mRNA Vaccines), health systems improvements (tele-health), online learning, gratitude toward heath care workers, increased social/community/family cohesion, closer international networking, reduction in suicide rates and drop in interstate and civil conflicts, road accidents, crime and communicable diseases with their resultant morbidity, mortality and mental health consequences. Conclusions: : In view of the widespread mental health and psychosocial consequences from the COVID-19 pandemic, a community-based approach is suggested while treating more severe mental disorders at the primary care or specialist level.

Inflammatory Profiles and Clinical Features of Coronavirus 2019 Survivors 3 Months After Discharge in Wuhan, China.

BACKGROUND: Postdischarge immunity and its correlation with clinical features among patients recovered from coronavirus disease 2019(COVID-19) are poorly described. This prospective cross-sectional study explored the inflammatory profiles and clinical recovery of patients with COVID-19 at 3 months after hospital discharge. METHODS: Patients with COVID-19 discharged from 4 hospitals in Wuhan, recovered asymptomatic patients (APs) from an isolation hotel, and uninfected healthy controls (HCs) were recruited. Viral nucleic acid and antibody detection, laboratory examination, computed tomography, pulmonary function assessment, multiplex cytokine assay, and flow cytometry were performed. RESULTS: The72 age-, sex- and body mass index-matched participants included 19 patients with severe/critical COVID-19 (SPs), 20 patients with mild/moderate COVID-19 (MPs), 16 APs, and 17 HCs. At 3 months after discharge, levels of proinflammatory cytokines and factors related to vascular injury/repair in patients recovered from COVID-19 had not returned to those of the HCs, especially among recovered SPs compared with recovered MPs and APs. These cytokines were significantly correlated with impaired pulmonary function and chest computed tomographic abnormalities. However, levels of immune cells had returned to nearly normal levels and were not significantly correlated with abnormal clinical features. CONCLUSION: Vascular injury, inflammation, and chemotaxis persisted in patients with COVID-19 and were correlated with abnormal clinical features 3 months after discharge, especially in recovered SPs.

Application of Ultrasonography in Conservative Treatment of Humeral Shaft Fracture in Children (preprint)

Purpose: Most of humeral shaft fractures in children could be treated satisfactorily by conservative treatment. This study aimed to evaluate the application value of ultrasonography in conservative treatment of humeral shaft fracture in children.Methods : We retrospectively reviewed children admitted to our hospital, for humeral shaft fracture from January 2014 to March 2018. The patients were divided into two groups: ultrasonography group and X-ray group. All patients were instructed to re-examined at 1 week, 2 weeks, 4 weeks, 12 weeks, 24 weeks and 1 year from the injury date for follow-up, and evaluated the prognosis according to the Disabilities of Arm, Shoulder and Hand (DASH) score at 12 months.Results : A total of 37 children were divided into ultrasonography group, 32 children were divided into X-ray group. There was no significant difference in prognosis between the two groups. The mean number of radiation exposures of ultrasonography group was less and ultrasonic examination found radial nerve injury, and using ultrasound reduced the chance of direct or in direct contact with infected peoples. Conclusion: Ultrasound is a non-invasive, non-radioactive test, which could decrease risk of COVID-19 infection and detect the vascular nerve injury caused by fracture. Ultrasonography may be the examination method for follow-up conservative treatment of humeral shaft fracture in children during the epidemic period.

Erythrocytes Induce Vascular Dysfunction in COVID-19 (preprint)

Background: Vascular injury has been implicated as a major cause of clinical complications in patients with coronavirus disease 2019 (COVID-19) based on autopsy studies showing destruction of the endothelial architecture. Red blood cells (RBCs) are affected by COVID-19 with alterations in their structure and function, possibly altering disease progress. Objectives: This study was designed to test the hypothesis of persistent endothelial dysfunction and that RBCs act as mediators of endothelial dysfunction in COVID-19. Methods and results: COVID-19 patients displayed profound endothelial dysfunction in vivo assessed with pulse amplitude tonometry, both in the acute phase and at follow-up four months later. RBCs but not plasma from COVID-19 patients in the acute phase incubated with healthy rat aorta induced severe endothelial dysfunction ex vivo compared to RBCs from healthy subjects. Further, these RBCs induced vascular arginase 1 and oxidative stress. Consequently, inhibition of vascular arginase or superoxide attenuated endothelial dysfunction induced by RBCs from COVID-19 patients. These RBCs were characterized by increased production of reactive oxygen species and reduced export of the nitric oxide metabolite nitrate. RBCs from COVID-19 patients at follow-up did not affect vascular function. Pre-incubation of RBCs from healthy subjects with interferon-γ impaired endothelial function.Conclusions: This study demonstrates the presence of persistent endothelial dysfunction in an otherwise mainly healthy population hospitalized for COVID-19, and implicates a role of RBCs as mediators of endothelial injury. These data shed light on a new pathological mechanism underlying vascular dysfunction in COVID-19 and lay the foundation for future therapeutic developments.

Robotic Resection of a Left Brachiocephalic Vein Aneurysm Mimicking Thymoma.

A 70-year-old man was scheduled for the robotic resection of a 21×16 × 30 mm thymic nodule incidentally detected by a computed tomography scan (CT) for thoracic trauma after a domestic accident. Positron emission tomography (PET) scan confirmed a low [18F]-FDG uptake (SUVmax = 1,9). During the surgery, the mass showed to be a saccular aneurysm of the left brachiocephalic vein (LBCV). A complete tangential resection of the aneurysm, with the use of EndoGIA stapler (Covidien® Endo GIA™) at its origin, was performed. The patient's recovery was uneventful, and postoperative CT with contrast administration confirmed the patency of the vein.

SARS-CoV-2 precipitated Kasabach-Merritt syndrome in a child with Kaposiform Hemangiendothelioma and acute lymphoblastic leukemia (preprint)

Kaposiform hemangiendothelioma usually occurs in children under two years of age and develops thrombocytopenia secondary to sequestration of platelets within (Kasabach-Merritt phenomenon) and is complicated by secondary consumption of fibrinogen and clotting factors. SARS-CoV-2 produces cutaneous endothelitis as a direct effect of the presence of the virus and the host inflammatory response. We describe an 8-month-old boy with leukemia and SARS-CoV-2 infection who developed Kasabach-Merritt phenomenon, coagulopathy, and intestinal involvement. Given the emerging evidence of endothelial and vascular involvement in COVID-19, the development of tests to detect vascular injury may be critical to guide the use of new therapeutic strategies.

Acute Macular Neuroretinopathy as a Manifestation of Coronavirus Disease 2019: a Case Report (preprint)

This is a new case of simultaneous occurrences of AMN and COVID-19 in a previously healthy woman. The importance of the current report lies in increasing the awareness of all physicians about the probable association of COVID-19 with retinal vascular injury and ischemia.

Five-Year Management of Vascular Injuries of the Extremities in the "Real-World" Setting in Northeastern Greece: The Role of Iatrogenic Traumas.

BACKGROUND: Vascular trauma comprises a diagnostic and surgical challenge. Aim of this study was to present the vascular traumas treated in our Tertiary Hospital during the last 5 years. METHODS: We retrospectively reviewed the surgical records of our vascular department and documented the site and type of vascular injuries of the extremities along with the concurrence of musculoskeletal injuries. The type and outcome of surgical interventions were also recorded. RESULTS: Fifty-eight cases of vascular trauma were recorded (39 in the upper and 19 in the lower extremities). Overall, iatrogenic traumas accounted for 41.3% of cases. The arterial injuries of the upper limb were blunt and penetrating in 27% and 67%, respectively. The most affected artery in the upper limb was the radial artery (37.8%), followed by the ulnar artery (27%) and the brachial artery (24.3%). Orthopedic injuries were recorded in 19% of patients. Management involved simple revascularization, bypass operations, patch arterioplasty and endovascular management in 48.7%, 33.3%, 5.1%, and 5.1%, respectively. The most affected site in the lower extremity was the common femoral artery (36.8%) followed by the popliteal artery (21%). Bone fractures were reported in 5 cases (26.3%). The surgical management involved bypass, simple revascularization, patch arterioplasty in 42.1%, 26.3%, and 21%, respectively. Endovascular management was performed in 10.5%. CONCLUSIONS: A considerable percentage of iatrogenic vascular injuries was recorded, affecting both the upper and lower limbs. Despite the trend toward centralization of vascular services, a basic service of vascular surgery should be available in most sites to ensure that patients with vascular injuries receive fast and appropriate care.

Identification of key signaling pathways induced by SARS-CoV2 that underlie thrombosis and vascular injury in COVID-19 patients.

The SARS-CoV-2 pandemic has led to hundreds of thousands of deaths and billions of dollars in economic damage. The immune response elicited from this virus is poorly understood. An alarming number of cases have arisen where COVID-19 patients develop complications on top of the symptoms already associated with SARS, such as thrombosis, injuries of vascular system, kidney, and liver, as well as Kawasaki disease. In this review, a bioinformatics approach was used to elucidate the immune response triggered by SARS-CoV-2 infection in primary human lung epithelial and transformed human lung alveolar. Additionally, examined the potential mechanism behind several complications that have been associated with COVID-19 and determined that a specific cytokine storm is leading to excessive neutrophil recruitment. These neutrophils are directly leading to thrombosis, organ damage, and complement activation via neutrophil extracellular trap release.

What We Learned From COVID 19? Trying to find best approach from pathophysiology to treatment. (preprint)

Introduction: The outbreak of the novel coronavirus 2019 (COVID-19) caused a pandemic that led to death of more than 3 million people globally. COVID-19 may yield a variety of clinical pictures, differing from pneumonitis to Acute Respiratory Distress Syndrome (ARDS) along with vascular damage in the lung tissue, which is named as endotheliitis, To date, no specific treatment was approved by any authority for the prevention or treatment of COVID-19. Materials and Methods: Here, we presented our experience on COVID-19 with evaluating 11,190 COVID-19 patients by presenting the manifestations of endotheliitis in skin, lung, and brain tissues according to different phases of COVID-19. In our perspective, distinctive manifestations in each COVID-19 patient, including non-respiratory conditions in the acute phase and the emerging risk of long-lasting complications, suggest that COVID-19 has an endotheliitis-centred thrombo-inflammatory pathophysiology. Accordingly, our treatment strategy was adopted to prevent both respiratory and vascular distresses, which are categorized according to extent of endotheliitis. (Group A: no or mild pulmonary involvement, Group B: moderate pulmonary involvement with clinical risk of deterioration, Group C: severe pulmonary involvement and respiratory failure). Potential pathophysiological mechanisms contributing to endotheliitis includes cytokine storm and toxic plasma, thromboinflammation and systemic microangiopathy. Results: A total of 11.190 COVID-19 patients that were diagnosed and treated in Samsun VM Medicalpark Hospital, Turkey, between March 2020 and April 2021 were retrospectively evaluated. The mean age was 59.2 years and male to female ratio was 5507/5683. Among these patients, 1896 (16.9%) individuals were hospitalized. While 1220 (64.3%) of the inpatients were hospitalized within the first 10 days after the diagnosis, 676 (35.7%) of them were hospitalized 10 days after their diagnosis. The number of patients who did not respond to group A and B treatments and developed hypoxemic respiratory failure (Group C) was 520 (27.4%). Among hospitalized patients, 146 (7.7%) individuals needed ventilator support (non-invasive/invasive mechanical ventilation) and were followed in the intensive care unit, and 43 (2.2%) patients died. In conclusion; Endotheliitis can also explain the mechanism behind the respiratory failure in COVID-19, and the difference of COVID-19 related ARDS from ARDS seen in other critical conditions. Hence, daily evaluation of momentary changes in clinical, laboratory and radiological findings of patients and deciding appropriate pathophysiological treatment would help to reduce the mortality rate of COVID-19.

The maladaptive vascular response in COVID-19 acute respiratory distress syndrome and recovery (preprint)

ABSTRACT Vascular injury is a menacing element of acute respiratory distress syndrome (ARDS) pathogenesis. To better understand the role of vascular injury in COVID-19 ARDS, we used lung autopsy immunohistochemistry and blood proteomics from COVID-19 subjects at distinct timepoints in disease pathogenesis, including a hospitalized cohort at risk of ARDS development (“ at risk” , N=59), an intensive care unit cohort with ARDS ( “ARDS ”, N=31), and a cohort recovering from ARDS (“ recovery ”, N=12). COVID-19 ARDS lung autopsy tissue revealed an association between vascular injury and platelet-rich microthrombi. This link guided the derivation of a protein signature in the at risk cohort characterized by lower expression of vascular proteins in subjects who died, an early signal of vascular limitation termed the maladaptive vascular response . These findings were replicated in COVID-19 ARDS subjects, as well as when bacterial and influenza ARDS patients (N=29) were considered, hinting at a common final pathway of vascular injury that is more disease (ARDS) then cause (COVID-19) specific, and may be related to vascular cell death. Among recovery subjects, our vascular signature identified patients with good functional recovery one year later. This vascular injury signature could be used to identify ARDS patients most likely to benefit from vascular targeted therapies.

Machine learning-based analysis of alveolar and vascular injury in SARS-CoV-2 acute respiratory failure.

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pneumopathy is characterized by a complex clinical picture and heterogeneous pathological lesions, both involving alveolar and vascular components. The severity and distribution of morphological lesions associated with SARS-CoV-2 and how they relate to clinical, laboratory, and radiological data have not yet been studied systematically. The main goals of the present study were to objectively identify pathological phenotypes and factors that, in addition to SARS-CoV-2, may influence their occurrence. Lungs from 26 patients who died from SARS-CoV-2 acute respiratory failure were comprehensively analysed. Robust machine learning techniques were implemented to obtain a global pathological score to distinguish phenotypes with prevalent vascular or alveolar injury. The score was then analysed to assess its possible correlation with clinical, laboratory, radiological, and tissue viral data. Furthermore, an exploratory random forest algorithm was developed to identify the most discriminative clinical characteristics at hospital admission that might predict pathological phenotypes of SARS-CoV-2. Vascular injury phenotype was observed in most cases being consistently present as pure form or in combination with alveolar injury. Phenotypes with more severe alveolar injury showed significantly more frequent tracheal intubation; longer invasive mechanical ventilation, illness duration, intensive care unit or hospital ward stay; and lower tissue viral quantity (p < 0.001). Furthermore, in this phenotype, superimposed infections, tumours, and aspiration pneumonia were also more frequent (p < 0.001). Random forest algorithm identified some clinical features at admission (body mass index, white blood cells, D-dimer, lymphocyte and platelet counts, fever, respiratory rate, and PaCO2 ) to stratify patients into different clinical clusters and potential pathological phenotypes (a web-app for score assessment has also been developed; https://r-ubesp.dctv.unipd.it/shiny/AVI-Score/). In SARS-CoV-2 positive patients, alveolar injury is often associated with other factors in addition to viral infection. Identifying phenotypical patterns at admission may enable a better stratification of patients, ultimately favouring the most appropriate management. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Excessive matrix metalloproteinase-1 and hyperactivation of endothelial cells occurred in COVID-19 patients and were associated with the severity of COVID-19 (preprint)

COVID-19 starts as a respiratory disease that can progress to pneumonia, severe acute respiratory syndrome (SARS), and multi-organ failure. Growing evidence suggests that COVID-19 is a systemic illness that primarily injures the vascular endothelium, yet the underlying mechanisms remain unknown. SARS-CoV-2 infection is believed to trigger a cytokine storm that plays a critical role in the pathogenesis of endothelialitis and vascular injury, eventually leading to respiratory and multi-organ failure in COVID-19 patients. We used a multiplex immunoassay to systematically profile and compare 65 inflammatory cytokines/chemokines/growth factors in plasma samples from 24 hospitalized (severe/critical) COVID-19 patients, 14 mild/moderate cases, and 13 healthy controls (HCs). Patients with severe/critical and mild/moderate COVID-19 had significantly higher plasma levels of 20 analytes than HCs. Surprisingly, only one cytokine (MIF) was among these altered analytes, while the rest were chemokines and growth factors. In addition, only MMP-1 and VEGF-A were significantly elevated in hospitalized COVID-19 patients when compared to mild/moderate cases. Given that excessive MMP-1 plays a central role in tissue destruction in a wide variety of vascular diseases and that elevated VEGF-A, an EC activation marker, increases vascular permeability, we further studied MMP-1 enzymatic activity and other EC activation markers such as soluble forms of CD146, ICAM-1, and VCAM-1. We found that plasma MMP-1 enzymatic activity and plasma levels of MMP-1 and EC activation markers were highly dysregulated in COVID-19 patients. Some dysregulations were associated with patients’ age or gender, but not with race. Our results demonstrate that COVID-19 patients have distinct inflammatory profiles that are distinguished from the cytokine storms in other human diseases. Excessive MMP-1 and hyperactivation of ECs occur in COVID-19 patients and are associated with the severity of COVID-19.

Strategies to DAMPen COVID-19-mediated lung and systemic inflammation and vascular injury.

Approximately 15%-20% of patients infected with SARS-CoV-2 coronavirus (COVID-19) progress beyond mild and self-limited disease to require supplemental oxygen for severe pneumonia; 5% of COVID-19-infected patients further develop acute respiratory distress syndrome (ARDS) and multiorgan failure. Despite mortality rates surpassing 40%, key insights into COVID-19-induced ARDS pathology have not been fully elucidated and multiple unmet needs remain. This review focuses on the unmet need for effective therapies that target unchecked innate immunity-driven inflammation which drives unchecked vascular permeability, multiorgan dysfunction and ARDS mortality. Additional unmet needs including the lack of insights into factors predicting pathogenic hyperinflammatory viral host responses, limited approaches to address the vast disease heterogeneity in ARDS, and the absence of clinically-useful ARDS biomarkers. We review unmet needs persisting in COVID-19-induced ARDS in the context of the potential role for damage-associated molecular pattern proteins in lung and systemic hyperinflammatory host responses to SARS-CoV-2 infection that ultimately drive multiorgan dysfunction and ARDS mortality. Insights into promising stratification-enhancing, biomarker-based strategies in COVID-19 and non-COVID ARDS may enable the design of successful clinical trials of promising therapies.