Increased fibrinaloid microclot counts in platelet-poor plasma are associated with Long COVID (preprint)

Outcomes following SARS-CoV-2 infection are variable; whilst the majority of patients recover without serious complications, a subset of patients develop prolonged illness termed Long COVID or post-acute sequelae of SARS-CoV-2 infection (PASC). The pathophysiology underlying Long COVID remains unclear but appears to involve multiple mechanisms including persistent inflammation, coagulopathy, autoimmunity, and organ damage. Studies suggest that microclots, also known as fibrinaloids, play a role in Long COVID. In this context, we developed a method to quantify microclots and investigated the relationship between microclot counts and Long COVID. We show that as a cohort, platelet-poor plasma from Long COVID samples had a higher microclot count compared to control groups but retained a wide distribution of counts. Recent COVID-19 infections were also seen to be associated with microclot counts higher than the control groups and equivalent to the Long COVID cohort, with a subsequent time-dependent reduction of counts. Our findings suggest that microclots could be a potential biomarker of disease and/or a treatment target in some Long COVID patients.

The Aftermath of COVID-19: Exploring Long-Term Effects on the Organ Systems (preprint)

Background: Post-acute sequelae of SARS-CoV-2 infection (PASC) is a complicated disease that affects millions of people all over the world. Previous studies have shown that PASC impacts 10% of SARS-CoV-2 infected patients of which 50-70% are hospitalized. It has also been shown that 10-12% of those vaccinated against COVID-19 were affected with PASC and its complications. The severity and the later development of PASC symptoms is positively associated with the early intensity of the infection. Results: The generated health complications caused by PASC involve a vast variety of organ systems. Patients affected by PASC have been diagnosed with neuropsychiatric and neurological symptoms. Cardiovascular system also has been involved and several diseases such as myocarditis, pericarditis, and coronary artery diseases were reported. Chronic hematological problems such as thrombotic endothelialitis and hypercoagulability were described as a condition that could increase the risk of clotting disorders and coagulopathy in PASC patients. Chest pain, breathlessness, and cough in PASC patients were associated with respiratory system in long COVID-19 causing respiratory distress syndrome. The observed immune complications were notable, involving several diseases. Renal system also was impacted and result in raising the risk of diseases such as thrombotic issues, fibrosis, and sepsis. Endocrine gland malfunction can lead to diabetes, thyroiditis, and male infertility. Symptoms such as diarrhea, nausea, loss of appetite and taste were also among reported observations due to several gastrointestinal disorders. Skin abnormalities might be an indication of infection and long-term implications such as persistent cutaneous complaints were linked to PASC. Conclusions: Long COVID is a multidimensional syndrome with considerable public health implications, affecting several physiological systems and demanding thorough medical therapy as well as more study to address its underlying causes and long-term effects.

COVID-19-associated acute renal failure in critically ill patients correlates with microthrombosis and renal loss of thrombomodulin (preprint)

Critically ill COVID-19 patients have a high degree of acute kidney injury which develops in up to 85% of patients. We have previously shown that circulating levels of angiopoietin-2 increased in critically ill COVID-19 patients correlated to kidney injury, coagulopathy, and mortality. Furthermore, our experiments showed a causal effect on coagulopathy from angiopoietin-2 binding and inhibition of thrombomodulin mediated anticoagulation. In the current study we hypothesize that renal microthrombi may be a mechanism for reduced renal function in critically ill COVID-19 patients, and that local dysregulation of thrombomodulin and angiopoietin-2 may be involved. To investigate our hypothesis, we utilized postmortem kidney tissue from seven COVID-19 patients treated at the intensive care unit. We evaluated kidney function, thrombosis, tubular injury, fibrosis, glomerulosclerosis, glomerular size as well as renal expression of thrombomodulin and angiopoietin-2. Proximity ligation assay was utilized to evaluate the presence of angiopoietin-2 binding to thrombomodulin. Normal kidney tissue came from the healthy part of six nephrectomies due to cancer. Our experiments show renal thrombosis in 6/7 COVID-19 patients, on average 14.7 (6.9-22.5) thrombi per mm2. Most COVID-19 kidneys had extensive kidney injury, especially tubular necrosis, but also glomerular enlargement, glomerulosclerosis, and tubulointerstitial fibrosis which in some cases most likely resulted from underlying disease. Thrombomodulin expression was reduced in glomeruli and peritubular capillaries in kidneys from COVID-19 patients, whereas no change was found for angiopoietin-2. In summary, our study describes a high degree of acute renal failure, renal microthrombosis, and loss of thrombomodulin in postmortem tissue from critically ill COVID-19 patients.

Targeting G9a translational mechanism of SARS-CoV-2 pathogenesis for multifaceted therapeutics of COVID-19 and its sequalae (preprint)

By largely unknown mechanism(s), SARS-CoV-2 hijacks the host translation apparatus to promote COVID-19 pathogenesis. We report that the histone methyltransferase G9a noncanonically regulates viral hijacking of the translation machinery to bring about COVID-19 symptoms of hyperinflammation, lymphopenia, and blood coagulation. Chemoproteomic analysis of COVID-19 patient peripheral mononuclear blood cells (PBMC) identified enhanced interactions between SARS-CoV-2-upregulated G9a and distinct translation regulators, particularly the N6-methyladenosine (m6A) RNA methylase METTL3. These interactions with translation regulators implicated G9a in translational regulation of COVID-19. Inhibition of G9a activity suppressed SARS-CoV-2 replication in human alveolar epithelial cells. Accordingly, multi-omics analysis of the same alveolar cells identified SARS-CoV-2-induced changes at the transcriptional, m6A-epitranscriptional, translational, and post-translational (phosphorylation or secretion) levels that were reversed by inhibitor treatment. As suggested by the aforesaid chemoproteomic analysis, these multi-omics-correlated changes revealed a G9a-regulated translational mechanism of COVID-19 pathogenesis in which G9a directs translation of viral and host proteins associated with SARS-CoV-2 replication and with dysregulation of host response. Comparison of proteomic analyses of G9a inhibitor-treated, SARS-CoV-2 infected cells, or ex vivo culture of patient PBMCs, with COVID-19 patient data revealed that G9a inhibition reversed the patient proteomic landscape that correlated with COVID-19 pathology/symptoms. These data also indicated that the G9a-regulated, inhibitor-reversed, translational mechanism outperformed G9a-transcriptional suppression to ultimately determine COVID-19 pathogenesis and to define the inhibitor action, from which biomarkers of serve symptom vulnerability were mechanistically derived. This cell line-to-patient conservation of G9a-translated, COVID-19 proteome suggests that G9a inhibitors can be used to treat patients with COVID-19, particularly patients with long-lasting COVID-19 sequelae.

Clot Twist - D-dimer analysis of healthy adults receiving heterologous or homologous booster COVID-19 vaccine after a single prime dose of Ad26.COV2.S in a phase II randomised open-label trial, BaSiS. (preprint)

BaSiS (Booster After Sisonke Study) is a prospectively enrolled open-label trial in which healthy adults, with controlled co-morbidities and no prior thrombosis, who received a single Ad26.COV2.S prime vaccination primarily through the Sisonke phase IIIB open label implementation study in South Africa. An exploratory objective evaluated the clotting profiles of participants who were enrolled across 4 sites in South Africa and randomised 1:1:1:1 to receive one of full-dose Ad26.COV2.S, half-dose Ad26.COV2.S, full-dose Comirnaty or half-dose Comirnaty booster. D-dimer testing (INNOVANCE D-Dimer Assay), as a coagulopathy marker, was conducted pre-booster (baseline) and 2 weeks post-booster. The median age among 285 participants was 42.2 years (IQR:35.5-48.7), 235/285 (82.5%) were female, 269/285 (94.4%) were Black African. Of the 40.4% (115/285) people living with HIV (PLHIV), 79.1% (91/115) were well-controlled on antiretroviral therapy. At baseline, 39.3% (112/285) had elevated d-dimers; all asymptomatic. Females and obese participants were significantly more likely to have elevated baseline d-dimers (OR=4.17; 95% CI:1.88 to 9.26 and OR=2.64; 95% CI:1.57 to 4.43, respectively). Of 169 with normal baseline d-dimers, 29 (17.2%) became elevated 2 weeks post-booster: median increase 0.23ug/ml (IQR:0.15-0.42); those receiving full-dose Comirnaty exhibited lower risk of d-dimer elevation post vaccination, compared to other booster vaccination arms (OR:0.26; 95% CI:0.07 to 0.98). PLHIV experienced significantly higher median increases compared to HIV uninfected participants (0.43 vs 0.17, p=0.004). Elevated d-dimers in asymptomatic, low-risk adults were unexpectedly common but were not associated with thromboembolism, supporting the rationale of using d-dimers only if clinically indicated. Trial Registration: South African Clinical Trails Register number DOH-27-012022-7841.

Beneficial Effects of novel Aureobasidium Pullulans strains produced Beta-1,3-1,6 Glucans on Interleukin-6 and D-Dimer levels in COVID-19 patients; results of a randomized multiple-arm pilot clinical study (preprint)

Objective: Cytokine storm and Coagulopathy have been implicated as major causes of morbidity and mortality in COVID-19 patients. A black yeast Aureobasidium pullulans AFO-202 strain produced beta 1,3-1,6 glucan has been reported to offer potential immune enhancement and metabolism balancing, as well as mitigation of coagulopathy risks. The N-163 strain produced beta glucan is an efficient anti-inflammatory immune modulator. In this pilot clinical study, we report the beneficial effects of these two beta glucans on the biomarkers for cytokine storm and coagulopathy in COVID-19 patients. Methods: : A total of 24 RT-PCR positive COVID-19 patients were recruited (Age range: 18~62; 17 males and 7 females). Patients were randomly divided into three groups (Gr): Gr. 1 control (n=8); Gr. 2: AFO-202 beta glucan (n=8); and Gr. 3, a combination of AFO-202 and N-163 beta glucans (n=8). All three groups received the standard care while groups 2 and 3 received additional supplementation of beta glucans for 30 days. In addition to basic clinical parameters, we periodically evaluated D-Dimer, IL-6, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the neutrophil to lymphocyte ratio (NLR), the lymphocyte to CRP ratio (LCR) and the leukocyte-CRP ratio (LeCR). Results: : The duration of hospital stay for all three groups was nearly equivalent. There was no mortality of the subjects in any of the groups. Intermittent oxygen was administered from day of admission for up to four to five days with mask (two to four Lpm) to two subjects in Gr. 2 and one subject in Gr. 3. None of the subjects required ventilation. The D-Dimer values in Gr. 1, which was on average 751 ng/ml at baseline, decreased to 143.89 ng/ml on day 15, but increased to 202.5 ng/ml on day 30, which in groups 2 and 3 decreased on day 15 and continued to remain at normal levels until day 30. IL-6 levels decreased on day 15 from an average of 7.395 pg/ml to 3.16 pg/ml in the control, 26.18 pg/ml to 6.94 pg/ml in Gr. 2 and 6.25 pg/ml to 5.22 pg/ml in Gr. 3. However, when measured on day 30, in Gr. 1, the IL-6 increased to 55.37 pg/ml while there was only slight marginal increase in Gr. 2 but within normal range, and the levels further decreased to less than 0.5 pg/ml in Gr. 3. The same trend was observed with ESR. LCR and LeCR increased significantly in Gr. 3. NLR decreased significantly in groups 2 and 3. There was no difference in CRP within the groups. Conclusion: In this exploratory study, consumption of Aureobasidium pullulans produced beta glucans for thirty days, results in a significant control of IL6, D-Dimer and NLR, a significant increase in LCR, LeCR and marginal control of ESR in COVID-19 patients. As these beta glucans are well known food supplements with decades of a track record for safety, based on these results, we recommend larger multi-centric clinical studies to validate their use as an adjunct in the management of COVID-19 and the ensuing long COVID-19 syndrome.

Prospective Study of Sars-cov2 Associated Coagulopathy and Role of Complement Activation (preprint)

Sars-CoV2 associated coagulopathy is a complex entity. Platelets, coagulation factors, fibrinolysis, inflammatory cytokines, immunothrombosis, antiphospholipd antibodies, von Willebrand factor/ADAMTS13 axis, complement system have all been demonstrated to be actively involved in the determination of thrombotic events. Til now retrospective studies have analyzed the activaction of vWF/ADAMTS13 axis and complement involvement. We performed a prospective study with the aim of describing clinical and laboratoristic features of Sars-CoV2 associated coagulopathy and its relationship with complement activation. Biochemical variables, vWF/ADAMTS13 axis, complement factors of the enrolled patients have been analyzed. These variables have been correlated to clinical outcome of the disease. Covid associated coagulopathy is neither a Trombotic Trombocitopenc Purpura (TTP) nor and atypical hemolytic uremic syndrome (aSEU). Nevertheless, imbalance of vWF/Adamts13 axis and complement activation simultaneously occurre and are significantly higher in the severe form of disease.

Xenosialylation: Role in SARS/CoV-2 Post-infectious and Post-vaccination Complications and Common Cause of Hyperimmune/Autoimmune Diseases (preprint)

The host glycosylation mechanism synthesizes the carbohydrates of glycoproteins of viral envelopes. Due to the loss of the Cytidine Monophospho-N-Acetylneuraminic Acid Hydroxylase gene by some mammalian species, including humans (negative-CMAH), Neu5Gc is no longer synthesized. Uptake of Neu5Gc by negative-CMAH species, through the intake of food products derived from positive-CMAH mammals, leads to incorporating Neu5Gc-glycans in the glycocalyx (xenosialylation). Neu5Gc, being a Mammalian-associated Carbohydrate Antigen (MCA), acts as a non-self-antigen, inducing an inflammatory reaction (Xenosialitis), and triggering the production of circulating antiNeu5Gc antibodies to attack/remove all incorporated Neu5Gc. In the state of Xenosialitis, the virus-neutralizing antibodies produced by a heavily xenosialylated patient following exposure to viral infection (including SarsCoV2) or anti SarsCoV2 vaccination cross-react against all incorporated non-self Neu5Gc-MCA glycans due to their resemblance with viral envelope antigens synthesized by the host glycosylation mechanism. In addition, the circulating anti-XeSias antibodies determine the massive removal of the circulating neutralizing FC-xeno-contaminated antibodies by the serum, living only the hyper-inflammatory agalattosylated antiviral IgG antibodies. Therefore, we hypothesize that the combination of antibody cross-reaction against non-self Neu5Gc-MCA glycans and the massive removal of the xeno-contaminated newly formed neutralizing antibodies in favor of hyper reactive antibodies, could be the cause of the massive inflammatory reaction (cytokine storm, coagulopathies, neuropathies) observed in Covid 19 patients or after anti-SarsCoV2 vaccination. This analysis is an invitation to investigate the post-infectious and/or post-vaccination adverse phenomena in the light of xenosialization as a key to understanding the severe post viral and post vaccine complications, including SARS-CoV2 infection or related vaccination.

Intracardiac Thrombus in COVID-19 Inpatients: A Nationwide Study of Incidence, Predictors and Outcomes (preprint)

Background: COronaVIrus Disease 2019 (COVID-19) has been observed to be associated with a hypercoagulable state. Intracardiac thrombosis is a serious complication but has seldom been evaluated in COVID-19 patients. We assessed the incidence, associated factors, and outcomes of COVID-19 patients with intracardiac thrombosis. Methods: COVID-19 inpatients during 2020 were retrospectively identified from the national inpatient sample (NIS) database, and data retrieved regarding clinical characteristics, intracardiac thrombosis, and adverse outcomes. Multivariable logistic regression was performed to identify the clinical factors associated with intracardiac thrombosis and in-hospital mortality and morbidities. Results: A total of 1,683,785 COVID-19 inpatients were identified in 2020 from NIS, with a mean age of 63.8 {+/-} 1.6 years, and 32.2% females. Intracardiac thrombosis was present in 0.001% (1,830) patients. Overall, in-hospital outcomes include all-cause mortality 13.2% (222,695/1,683,785), cardiovascular mortality 3.5%, cardiac arrest 2.6%, acute coronary syndrome (ACS) 4.4%, heart failure 16.1%, stroke 1.3% and acute kidney injury (AKI) 28.3%. The main factors associated with intracardiac thrombosis were a history of congestive heart failure and coagulopathy. Intracardiac thrombosis was independently associated with a higher risk of in-hospital all-cause mortality (OR: 3.32, 95% CI: 2.42-4.54, p<0.001), cardiovascular mortality (OR: 2.95, 95% CI: 1.96-4.44, p<0.001), cardiac arrest (OR: 2.04, 95% CI: 1.22-3.43, p=0.006), ACS (OR: 1.62, 95% CI: 1.17-2.22, p=0.003), stroke (OR: 3.10, 95% CI: 2.11-4.56, p<0.001), and AKI (OR: 2.13 95% CI: 1.68-2.69, p<0.001), but not incident heart failure (p=0.27). Conclusion: Although intracardiac thrombosis is rare in COVID-19 inpatients, its presence was independently associated with higher risks of in-hospital mortality and most morbidities. Prompt investigations and treatments for intracardiac thrombosis are warranted when there is a high index of suspicion and a confirmed diagnosis respectively.

Hematological changes as a consequence of COVID-19 and its vaccines / Alteraciones hematológicas como consecuencia de COVID-19 y sus vacunas

El virus SARS-CoV-2 continúa infectando a millones de individuos en el mundo. Aunque los síntomas más frecuentes observados en los pacientes con COVID-19 son fiebre, fatiga y tos, en los casos severos la hipercoagulabilidad y la inflamación son dos condiciones que pueden producir complicaciones y causar daño en órganos, poniendo en riesgo la vida del paciente. Con el fin de clasificar a los pacientes durante el triaje, se han explorado diferentes marcadores hematológicos, incluidos el recuento de plaquetas, linfocitos y eosinófilos, y la relación neutrófilos/ linfocitos, entre otros. Por su parte, para la evaluación de las coagulopatías, se vienen determinando marcadores como el dímero D y el fibrinógeno. En esta revisión se abordan las coagulopatías y los parámetros hematológicos en pacientes con COVID-19, al igual que las anormalidades en la coagulación como la trombocitopenia trombótica inmune inducida por las vacunas contra el SARS-CoV-2

The SARS-CoV-2 virus continues to infect millions of individuals around the world. Although the most frequent symptoms observed in patients with COVID-19 are fever, fatigue and cough, in severe cases hypercoagulability and inflammation are two conditions that can cause complications and organ failure, putting the patient's life at risk. In order to classify patients during triage, different hematological markers have been explored, including platelet, lymphocyte, and eosinophil counts, and the neutrophil/lymphocyte ratio, among others. Furthermore, for the evaluation of coagulopathies, markers such as D-dimer and fibrinogen are being evaluated. This review addresses the coagulopathies and hematological parameters in patients with COVID-19, as well as coagulation abnormalities such as immune thrombotic thrombocytopenia induced by SARS-CoV-2 vaccines

Interrelationship between COVID-19 and Coagulopathy: Pathophysiological and Clinical Evidence.

Since the first description of COVID-19 infection, among clinical manifestations of the disease, including fever, dyspnea, cough, and fatigue, it was observed a high incidence of thromboembolic events potentially evolving towards acute respiratory distress syndrome (ARDS) and COVID-19-associated-coagulopathy (CAC). The hypercoagulation state is based on an interaction between thrombosis and inflammation. The so-called CAC represents a key aspect in the genesis of organ damage from SARS-CoV-2. The prothrombotic status of COVID-19 can be explained by the increase in coagulation levels of D-dimer, lymphocytes, fibrinogen, interleukin 6 (IL-6), and prothrombin time. Several mechanisms have been hypothesized to explain this hypercoagulable process such as inflammatory cytokine storm, platelet activation, endothelial dysfunction, and stasis for a long time. The purpose of this narrative review is to provide an overview of the current knowledge on the pathogenic mechanisms of coagulopathy that may characterize COVID-19 infection and inform on new areas of research. New vascular therapeutic strategies are also reviewed.

Molecular Mimicry of the Viral Spike in the SARS-CoV-2 Vaccine Possibly Triggers Transient Dysregulation of ACE2, Leading to Vascular and Coagulation Dysfunction Similar to SARS-CoV-2 Infection.

The benefits of SARS-CoV-2 spike mRNA vaccines are well known, including a significant decline in COVID-19 morbidity and a decrease in the mortality rate of SARS-CoV-2 infected persons. However, pharmacovigilance studies have revealed the existence of rare cases of cardiovascular complications after mass vaccination using such formulations. Cases of high blood pressure have also been reported but were rarely documented under perfectly controlled medical supervision. The press release of these warning signals triggered a huge debate over COVID-19 vaccines' safety. Thereby, our attention was quickly focused on issues involving the risk of myocarditis, acute coronary syndrome, hypertension and thrombosis. Rare cases of undesirable post-vaccine pathophysiological phenomena should question us, especially when they occur in young subjects. They are more likely to occur with inappropriate use of mRNA vaccine (e.g., at the time when the immune response is already very active during a low-noise infection in the process of healing), leading to angiotensin II (Ang II) induced inflammation triggering tissue damage. Such harmful effects observed after the COVID-19 vaccine evoke a possible molecular mimicry of the viral spike transiently dysregulating angiotensin converting enzyme 2 (ACE2) function. Although the benefit/risk ratio of SARS-CoV-2 spike mRNA vaccine is very favorable, it seems reasonable to suggest medical surveillance to patients with a history of cardiovascular diseases who receive the COVID-19 vaccine.

Effects of COVID-19 infection in healthy subjects on cardiac function and biomarker of oxygen transport, blood coagulation and inflammation (preprint)

Background: The manifestations, severity, and mortality of COVID-19 are considered to be associated with the changes in various hematological parameters and in immunity. Associations of immunoglobulin G antibodies against severe acute respiratory syndrome-linked coronavirus (IgG-SARS)-positive status with cardiac function and hematological and biochemical parameters in apparently health subjects are poorly understood. Methods: The present cross-sectional study included 307 healthy volunteers (24-69 years of age; 44.8±8.6 years; 80.4% men) and was initiated in 2019 before the COVID-19 pandemic. COVID-19 episodes were confirmed by detection of IgG-SARS against SARS-CoV-2 S1 RBD to reveal 70 IgG-SARS-positive and 237 negative participants. Numerous ultrasound characteristics were assessed by echocardiography, and 15 hematological and biochemical parameters were assayed in the blood. Descriptive and comparative analysis was based on the IgG-SARS status of the participants. Results: The left ventricular mass index, mitral ratio of peak early to late diastolic filling velocity or flow velocity across the mitral valve, and deceleration time of early mitral inflow were decreased (P<0.05) in IgG-SARS-positive participants versus those in IgG-SARS-negative participants according to multivariate logistic regression analysis. Erythrocyte sedimentation rate and platelet count were slightly increased, and blood hemoglobin was decreased in IgG-SARS-positive participants compared with those in IgG-SARS-negative participants. Conclusions: LV filling, inflammation, blood coagulation, and hemoglobin appear to be influenced by COVID-19 infection in healthy participants. These observations contribute to the development of a population recovery strategy after the episodes of COVID-19.

Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights Into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges (preprint)

Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; chronic, low grade inflammatory response; immune dysregulation and defective immune response; reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal dysregulation, mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; as well as cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers or their link to etiopathogenetic mechanisms, and the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on main LC symptomatology in the frame of the epidemiological and pathogenetic aspects of the syndrome, and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions.

SARS-CoV-2 induced coagulopathy and potential role of anticoagulation: Scoping review of literature.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can vary on a spectrum of asymptomatic disease to rarer manifestations like hypercoagulability especially among elderly patients admitted in the intensive care unit (ICU) and those with preexisting comorbidities. The exact mechanism behind this phenomenon is still unclear, however studies have shown an association with elevated cytokines and severe inflammatory response which encompasses this disease. Hypercoagulability can be limited to the lungs, or present as systemic manifestations of arterial and venous thrombosis leading to mortal outcomes. Thus, careful evaluation of risk factors should be performed by physicians and treatment with anticoagulants should be modified accordingly. All Coronavirus Disease 2019 (COVID-19) in-patients should receive thromboprophylactic therapy, with increased dosages administered to patients with increased disease severity or those with a high risk. D-dimer levels and sepsis-induced coagulopathy (SIC) score aid in identifying high risk patients and predicting outcome. This article highlights the pathophysiology behind hypercoagulability, its clinical associations and discusses therapeutic modalities to combat this fatal consequence of SARS-CoV-2.

Long COVID is primarily a Spike protein Induced Thrombotic Vasculitis (preprint)

Long COVID describes an array of often debilitating symptoms in the aftermath of SARS-CoV-2 infection, with similar symptomatology affecting some people post-vaccination. With an estimated > 200 million Long COVID patients worldwide and cases still rising, the effects on quality of life and the economy are significant, thus warranting urgent attention to understand the pathophysiology. Herein we describe our perspective that Long COVID is a continuation of acute COVID-19 pathology, whereby coagulopathy is the main driver of disease and can cause or exacerbate other pathologies common in Long COVID, such as mast cell activation syndrome and dysautonomia. Considering the SARS-CoV-2 spike protein can independently induce fibrinaloid microclots, platelet activation, and endotheliitis, we predict that persistent spike protein will be a key mechanism driving the continued coagulopathy in Long COVID. We discuss several treatment targets to address the coagulopathy, and predict that (particularly early) treatment with combination anticoagulant and antiplatelet drugs will bring significant relief to many patients, supported by a case study. To help focus attention on such treatment targets, we propose Long COVID should be referred to as Spike protein Induced Thrombotic Vasculitis (SITV). These ideas require urgent testing, especially as the world tries to co-exist with COVID-19.

A Literature Review of Pathophysiology, Clinical Manifestations, Medications and Optimal Dosage, Outpatient, and Post-hospitalization Use of Anticoagulation in COVID-19 Patients.

Since severe acute respiratory syndrome coronavirus 2 led to a world pandemic, extensive research has been conducted to identify its characteristics and form an appropriate management plan. One recognized complication of COVID-19 is coagulation defects that can lead to thromboembolic events. We have reviewed the literature to summarize and present the latest research about the pathophysiology, clinical manifestations, anticoagulation use and appropriate dose in COVID-19 patients, as well as the effect of anticoagulation in outpatient and post-hospital settings. The pathophysiology of coagulation abnormalities in COVID-19 is not fully understood yet, but multiple mechanisms appear to be involved, such as a direct viral attack, hyperinflammation, increased immune response, blood stasis, and endothelial injury. Clinical manifestations are mainly venous thromboembolism (deep vein thrombosis and pulmonary embolism), arterial thromboembolism, ischemic stroke, central venous sinus thrombosis, and central retinal vein occlusion. Anticoagulation is widely used in hospitalized patients with COVID-19, unless it is contraindicated. Heparinoid is the main anticoagulant used. However, the appropriate dosage is still debated as research is trying to find a balance between benefits and risks. In outpatients, it appears that anticoagulation has no benefit in contrast to post-hospitalization use, where benefit could be observed in severely affected patients. We concluded that thromboprophylaxis should be used in treating hospitalized COVID-19 patients, but the dosage is still a matter of debate. More research needs to be done on outpatient and post-hospitalized patients to derive accurate conclusions.

BLOOD COAGULATION DISORDERS IN PATIENTS WITH LIVER CIRRHOSIS INFECTED COVID-19.

OBJECTIVE: The aim: To investigate the features of coagulation homeostasis in patients with liver cirrhosis (LC) in COVID-19 infection. PATIENTS AND METHODS: Materials and methods: At the clinical base of the Department of Propaedeutics of Internal Medicine, 32 patients with LC infected with COVID-19 were examined - 1 Group of patients. The study also included 30 patients with LC who were not infected with COVID-19 (2 Group of patients). RESULTS: Results: The analysis of the obtained data indicates disorders of the hemostasis system in patients with LC without the COVID-19 infection (Group 2), as well as in patients with LC at the time of being infected with COVID-19. The violation of the protein synthesis function of the liver is manifested through a decrease in the level of fibrinogen in blood serum (up to 2.0±0.5 gr/l in patients of Group 1 at the time of admission for inpatient care) and up to 21.9±0.5 gr/l in patients of group ІІ - р<0.05. This was accompanied by an acceleration of prothrombin time, thrombin time and activated partial thromboplastic time in patients with LC, as well as an increase in the level of antithrombin III. The level of D-dimer was reduced both in patients of group II and in patients of group I at the time of being infected with COVID-19. CONCLUSION: Conclusions: Changes in coagulation homeostasis characteristic of hypocoagulation syndrome have been established in patients with LC. COVID-19 infection in patients with LC leads to hypercoagulation, especially in patients with complicated stage of LC (ascites, encephalopathy, hepatorenal syndrome).

Status of major hemostatic components in the setting of COVID-19: the effect on endothelium, platelets, coagulation factors, fibrinolytic system, and complement.

The coagulation, fibrinolytic, anticoagulation, and complement systems are in delicate balance with the vessel wall endothelium ensuring appropriate hemostasis. Coagulopathy in coronavirus disease 2019 (COVID-19) is not a simple disorder of one hemostatic component but a complicated process affecting most of the hemostasis system. COVID-19 disturbs the balance between the procoagulant systems and the regulatory mechanisms. Here, we investigate the effect of COVID-19 on key hemostatic components, including platelets, endothelial cells, coagulation factors, fibrinolytic system, anticoagulant protein system, and complement system, to improve our understanding of the pathophysiological processes underlying COVID-19 coagulopathy based on evidence.