Lupus Anticoagulant and Abnormal Coagulation Tests in Patients with Covid-19

Worldwide impact of COVID-19 on hospital admissions for non-ST-elevation acute coronary syndromes (NSTACS): a systematic review with meta-analysis of 553 038 cases

BACKGROUND

How coronavirus disease 2019 (COVID-19) impacted non-ST-segment elevation acute coronary syndromes (NSTACS) is an object of controversial reports.

AIM

To systematically review studies reporting NSTACS hospitalizations during the COVID-19 pandemic, and analyse whether differences in COVID-19 epidemiology, methodology of report, or public health-related factors could contribute to discrepant findings.

METHODS

Comprehensive search (Medline, Embase, Scopus, Web of Science, Cochrane Register), of studies reporting NSTACS hospitalizations during the COVID-19 pandemic compared with a reference period, following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Data were independently extracted by multiple investigators and pooled using a random-effects model. Health-related metrics were from publicly available sources, and analysed through multiple meta-regression modelling.

RESULTS

We retrieved 102 articles (553 038 NSTACS cases, 40 countries). During peak COVID-19 pandemic, overall incidence rate ratio (IRR) of NSTACS hospitalizations over reference period decreased (0.70, 95% confidence interval (CI) 0.66-0.75; P < 0.00001). Significant heterogeneity was detected among studies (I2 = 98%; P < 0.00001). Importantly, wide variations were observed among, and within, countries. No significant differences were observed by study quality, whereas comparing different periods within 2020 resulted in greater decrease (IRR: 0.61; CI: 0.53-0.71) than comparing 2020 vs. previous years (IRR: 0.74; CI 0.69-0.79). Among many variables, major predictors of heterogeneity were severe acute respiratory syndrome coronavirus 2 reproduction rate/country, number of hospitals queried, and reference period length; country stringency index and socio-economical indicators did not contribute significantly.

CONCLUSIONS

During the COVID-19 pandemic, NSTACS hospitalizations decreased significantly worldwide. However, substantial heterogeneity emerged among countries, and within the same country. Factors linked to public health management, but also to methodologies to collect results may have contributed to this heterogeneity.

TRIAL REGISTRATION

The protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews (ID: CRD42022308159).

Mechanisms of Pulmonary Vasculopathy in Acute and Long-Term COVID-19: A Review

Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 may predispose patients to thrombotic disease in both venous and arterial circulation, and many cases of severe acute pulmonary embolism have been reported. The demonstrated presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the endothelial cells suggests that direct viral effects, in addition to indirect effects of perivascular inflammation and coagulopathy, may contribute to pulmonary vasculopathy in COVID-19. In this review, we discuss the pathological mechanisms leading to pulmonary vascular damage during acute infection, which appear to be mainly related to thromboembolic events, an impaired coagulation cascade, micro- and macrovascular thrombosis, endotheliitis and hypoxic pulmonary vasoconstriction. As many patients develop post-COVID symptoms, including dyspnea, we also discuss the hypothesis of pulmonary vascular damage and pulmonary hypertension as a sequela of the infection, which may be involved in the pathophysiology of long COVID.

Antiphospholipid antibody-related hepatic vasculitis in a juvenile after non-severe COVID-19: a case report and literature review

Antiphospholipid antibodies (aPL) are both laboratory evidence and causative factors for a broad spectrum of clinical manifestations of antiphospholipid syndrome (APS), with thrombotic and obstetric events being the most prevalent. Despite the aPL-triggered vasculopathy nature of APS, vasculitic-like manifestations rarely exist in APS and mainly appear associated with other concurrent connective tissue diseases like systemic lupus erythematous. Several studies have characterized pulmonary capillaritis related to pathogenic aPL, suggesting vasculitis as a potential associated non-thrombotic manifestation. Here, we describe a 15-year-old girl who develops hepatic infarction in the presence of highly positive aPL, temporally related to prior non-severe COVID-19 infection. aPL-related hepatic vasculitis, which has not been reported before, contributes to liver ischemic necrosis. Immunosuppression therapy brings about favorable outcomes. Our case together with retrieved literature provides supportive evidence for aPL-related vasculitis, extending the spectrum of vascular changes raised by pathogenic aPL. Differentiation between thrombotic and vasculitic forms of vascular lesions is essential for appropriate therapeutic decision to include additional immunosuppression therapy. We also perform a systematic review to characterize the prevalence and clinical features of new-onset APS and APS relapses after COVID-19 for the first time, indicating the pathogenicity of aPL in a subset of COVID-19 patients.

Antiphospholipid syndrome in the era of COVID-19 - Two sides of a coin

In addition to the respiratory symptoms associated with COVID-19, the disease has consistently been linked to many autoimmune diseases such as systemic lupus erythematous and antiphospholipid syndrome (APS). APS in particular was of paramount significance due to its devastating clinical sequela. In fact, the hypercoagulable state seen in patients with acute COVID-19 and the critical role of anticoagulant treatment in affected individuals shed light on the possible relatedness between APS and COVID-19. Moreover, the role of autoimmunity in the assumed association is not less important especially with the accumulated data available regarding the autoimmunity-triggering effect of SARS-CoV-2 infection. This is furtherly strengthened at the time patients with COVID-19 manifested antiphospholipid antibodies of different types following infection. Additionally, the severe form of the APS spectrum, catastrophic APS (CAPS), was shown to have overlapping characteristics with severe COVID-19 such as cytokine storm and multi-organ failure. Interestingly, COVID vaccine-induced autoimmune phenomena described in the medical literature have pointed to an association with APS. Whether the antiphospholipid antibodies were present or de novo, COVID vaccine-induced vascular thrombosis in certain individuals necessitates further investigations regarding the possible mechanisms involved. In our current paper, we aimed to focus on the associations mentioned, their implications, importance, and consequences.

Anticoagulation with argatroban using hemoclot™ targets is safe and effective in CARDS patients receiving venovenous extracorporeal membrane oxygenation: An exploratory bi-centric cohort study

Direct thrombin inhibitors, including argatroban, are increasingly used for anticoagulation during venovenous extracorporeal membrane oxygenation (VV ECMO). In many centers activated partial thromboplastin time (aPTT) is used for monitoring, but it can be affected by several confounders. The aim of this study was to evaluate the safety and efficacy of anticoagulation with argatroban titrated according to diluted thrombin time targets (hemoclot™ assay) compared to anti-Xa guided anticoagulation with unfractionated heparin (UFH).

METHODS

This cohort study included adults at two tertiary care centers who required VV ECMO for severe COVID-19-related acute respiratory distress syndrome (CARDS). Patients received center-dependent argatroban or UFH for anticoagulation during ECMO. Argatroban was guided following a hemoclot™ target range of 0.4-0.6 μg/ml. UFH was guided by anti-factor Xa (antiXa) levels (0.2-0.3 IU/ml). The primary outcome was safety of argatroban compared to UFH, assessed by time to first clinically relevant bleeding event or death during ECMO. Secondary outcomes included efficacy (time to thromboembolism) and feasibility (proportion of anticoagulation targets within range).

RESULTS

From 2019 to 2021 57 patients were included in the study with 27 patients (47 %) receiving argatroban and 30 patients (53 %) receiving UFH. The time to the first clinically relevant bleeding or death during ECMO was similar between groups (HR (argatroban vs. UFH): 1.012, 95 % CI 0.44-2.35, p = 0.978). Argatroban was associated with a decreased risk for thromboembolism compared to UFH (HR 0.494 (95 % CI 0.26-0.95; p = 0.034)). The overall proportion of anticoagulation within target ranges was not different between groups (46 % (23-54 %) vs. 46 % (37 %-57 %), p = 0.45).

CONCLUSION

Anticoagulation with argatroban according to hemoclot™ targets (0.4-0.6 μg/ml) compared to antiXa guided UFH (0.2-0.3 IU/ml) is safe and may prolong thromboembolism-free time in patients with severe ARDS requiring VV ECMO.

The laboratory parameters in predicting the severity and death of COVID-19 patients: Future pandemic readiness strategies

The range of clinical manifestations associated with the infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encompasses a broad spectrum, ranging from flu-like symptoms to the occurrence of multiple organ failure and death. The severity of the coronavirus disease 2019 (COVID-19) is categorized based on clinical presentation and is divided into three distinct levels of severity identified as non-severe, severe, and critical. Although individuals of all age groups are susceptible to SARS-CoV-2 infection, middle-aged and older adults are more frequently impacted, with the latter being more likely to develop severe illness. Various laboratory characteristics observed in hospitalized COVID-19 patients have been correlated with adverse outcomes. These include elevated levels of D-dimer, liver enzymes, lactate dehydrogenase, C-reactive protein, ferritin, prothrombin time, and troponin, as well as decreased lymphocyte and platelets counts. This review investigated the relationship between baseline clinical characteristics, initial laboratory parameters upon hospital admission, and the severity of illness and mortality rates among COVID-19 patients. Although the COVID-19 pandemic has concluded, understanding the laboratory predictors of virus severity and mortality remains crucial, and examining these predictors can have long-term effects. Such insights can help healthcare systems manage resources more effectively and deliver timely and appropriate care by identifying and targeting high-risk individuals. This knowledge can also help us better prepare for future pandemics. By examining these predictors, we can take steps to protect public health and mitigate the impact of future pandemics.

Are Antiphospholipid Antibodies a Surrogate Risk Factor for Thrombosis in Sepsis?

Antiphospholipid syndrome (APS) is a hypercoagulable state caused by antiphospholipid antibodies (aPL). APS clinically manifests with arterial or venous or microvascular thrombi and/or pregnancy complications. It is well-known that the development of aPL can be a transient phenomenon and thus the current diagnostic criterion for APS requires repeat laboratory testing several weeks apart before a definitive diagnosis is made. However, transient presence of aPL may also be pathogenic. In this article, we attempt to give historical and clinical evidence for the importance of these antibodies, even when transient, and call for further research into mechanisms by which these antibodies may promote thrombosis and pregnancy morbidities.

Acute neutrophilic vasculitis (leukocytoclasia) in 36 COVID-19 autopsy brains

BACKGROUND

Hypercytokinemia, the renin-angiotensin system, hypoxia, immune dysregulation, and vasculopathy with evidence of immune-related damage are implicated in brain morbidity in COVID-19 along with a wide variety of genomic and environmental influences. There is relatively little evidence of direct SARS-CoV-2 brain infection in COVID-19 patients.

METHODS

Brain histopathology of 36 consecutive autopsies of patients who were RT-PCR positive for SARS-CoV-2 was studied along with findings from contemporary and pre-pandemic historical control groups. Immunostaining for serum and blood cell proteins and for complement components was employed. Microcirculatory wall complement deposition in the COVID-19 cohort was compared to historical control cases. Comparisons also included other relevant clinicopathological and microcirculatory findings in the COVID-19 cohort and control groups.

RESULTS

The COVID-19 cohort and both the contemporary and historical control groups had the same rate of hypertension, diabetes mellitus, and obesity. The COVID-19 cohort had varying amounts of acute neutrophilic vasculitis with leukocytoclasia in the microcirculation of the brain in all cases. Prominent vascular neutrophilic transmural migration was found in several cases and 25 cases had acute perivasculitis. Paravascular microhemorrhages and petechial hemorrhages (small brain parenchymal hemorrhages) had a slight tendency to be more numerous in cohort cases that displayed less acute neutrophilic vasculitis. Tissue burden of acute neutrophilic vasculitis with leukocytoclasia was the same in control cases as a group, while it was significantly higher in COVID-19 cases. Both the tissue burden of acute neutrophilic vasculitis and the activation of complement components, including membrane attack complex, were significantly higher in microcirculatory channels in COVID-19 cohort brains than in historical controls.

CONCLUSIONS

Acute neutrophilic vasculitis with leukocytoclasia, acute perivasculitis, and associated paravascular blood extravasation into brain parenchyma constitute the first phase of an immune-related, acute small-vessel inflammatory condition often termed type 3 hypersensitivity vasculitis or leukocytoclastic vasculitis. There is a higher tissue burden of acute neutrophilic vasculitis and an increased level of activated complement components in microcirculatory walls in COVID-19 cases than in pre-pandemic control cases. These findings are consistent with a more extensive small-vessel immune-related vasculitis in COVID-19 cases than in control cases. The pathway(s) and mechanism for these findings are speculative.

COVID-19 and cardiovascular disease in patients with chronic kidney disease

Millions of people worldwide have chronic kidney disease (CKD). Affected patients are at high risk for cardiovascular (CV) disease for several reasons. Among various comorbidities, CKD is associated with the more severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This is particularly true for patients receiving dialysis or for kidney recipients. From the start of the SARS-CoV-2 pandemic, several CV complications have been observed in affected subjects, spanning acute inflammatory manifestations, CV events, thrombotic episodes and arrythmias. Several pathogenetic mechanisms have been hypothesized, including direct cytopathic viral effects on the myocardium, endothelial damage and hypercoagulability. This spectrum of disease can occur during the acute phase of the infection, but also months after recovery. This review is focussed on the CV complications of coronavirus disease 2019 (COVID-19) with particular interest in their implications for the CKD population.

The outcome and risk factors associated with central and peripheral nervous system involvement in hospitalized COVID-19 patients: a retrospective cohort study

Introduction

SARS-CoV-2 infection can affect any organ, including both the central nervous system (CNS) and peripheral nervous system (PNS). The aim of this study was to explore the outcome and risk factors associated with the involvement of either CNS or PNS in a cohort of hospitalized COVID-19 patients.

Methods

We performed a retrospective observational cohort study of hospitalized adult patients with COVID-19, between May 2020 and December 2022, presenting with new onset neurological disabilities any time after admission.

Results

We included 115 patients, 72 with CNS manifestations and 43 with PNS involvement. The CNS manifestations were COVID-19-associated encephalopathy, headache, neurovascular events, and seizures in 80.5, 43, 31.9, and 11.1% of patients, respectively. The neurovascular events were ischemic stroke in 17 (23.6%) patients, hemorrhagic stroke in 6 (8.3%) patients, venous thrombosis in 1 (1.4%) patient, and subarachnoid hemorrhage in 1 (1.4%) patient. Cranial nerve involvement was the most frequent PNS manifestation in 34 (79%) cases, followed by mononeuritis in 5 (11.6%) patients and polyneuropathy in 4 (9.3%) patients. The affected cranial nerves were the vestibulocochlear nerve in 26 (60.5%) patients, the olfactory nerve in 24 (55.8%) patients, the oculomotor nerves in 5 (11.6%) patients, and the facial nerve in 1 (2.3%) patient. Two patients (9.3%) presented with polyneuritis cranialis. Older age (HR = 1.02, 95% CI: 1.003-1.037, p = 0.01), COVID severity (HR = 2.53, 95% CI: 1.42-4.5, p = 0.002), ischemic cardiac disease (HR = 2.42, 95% CI: 1.05-5.6, p = 0.03), and increased D-dimers (HR = 1.00, 95% CI: 1.00-1.00, p = 0.02) were independently associated with the development of CNS manifestations. The factors associated with in-hospital mortality were age (HR = 1.059, 95% CI: 1.024-1.096, p = 0.001), C-reactive protein (HR = 1.006, 95% CI: 1.00-1.011, p = 0.03), CNS involvement (HR = 9.155, 95% CI: 1.185-70.74, p = 0.03), and leucocyte number (HR = 1.053, 95% CI: 1.026-1.081, p < 0.001).

Conclusion

COVID-19-associated encephalopathy was the most common CNS manifestation in our study, but neurovascular events are also important considering the overlap between inflammatory and prothrombotic pathways, especially in severe cases. CNS involvement was associated with in-hospital all-cause mortality. PNS findings were various, involving mostly the cranial nerves, especially the vestibulocochlear nerve.

Thrombotic Markers in Pregnant Patients with and without SARS-CoV-2 Infection

BACKGROUND

 Coronavirus disease 2019 (COVID-19) is associated with coagulation abnormalities and increased risk for venous and arterial thrombi. This study aimed to evaluate D-dimer levels and lupus anticoagulant (LAC) positivity in pregnant individuals with and without Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

STUDY DESIGN

 This was a prospective cohort study of pregnant individuals delivering at a single academic institution from April 2020 to March 2022. Individuals with a positive SARS-CoV-2 result during pregnancy were compared with a convenience sample of those without a positive SARS-CoV-2 result. For individuals with SARS-CoV-2 infection, severity was assessed based on the National Institutes of Health classification system. The primary outcome was D-dimer level measured during delivery admission. The secondary outcomes were LAC positivity and thromboembolic events. Outcomes were compared between individuals with and without a positive SARS-CoV-2 result, and further by disease severity.

RESULTS

 Of 98 participants, 77 (78.6%) were SARS-CoV-2 positive during pregnancy. Among individuals with SARS-CoV-2 infection, severity was asymptomatic in 20 (26.0%), mild in 13 (16.9%), moderate in 4 (5.2%), severe in 38 (49.4%), and critical in 2 (2.6%). The D-dimer concentration at delivery did not significantly differ between those with a SARS-CoV-2 positive result compared with those without (mean 2.03 µg/mL [95% confidence interval {CI} 1.72-2.40] vs. 2.37 µg/mL [95% CI 1.65-3.40]; p = 0.43). Three individuals (4%) with SARS-CoV-2 infection and none (0%) without infection were LAC positive (p = 0.59). There were no clinically apparent thromboses in either group. D-dimer concentrations and LAC positive results did not differ by COVID-19 severity.

CONCLUSION

 Thrombotic markers did not differ in pregnant individuals by SARS-CoV-2 infection; however, high rates of LAC positivity were detected.

KEY POINTS

· Thrombotic markers did not differ in pregnant individuals by SARS-CoV-2 infection.. · Higher than expected rates of LAC positivity were detected.. · There were no clinically apparent thromboses..

Epidemiology, pathogenesis, and management of Coronavirus disease 2019-associated stroke

The Coronavirus disease 2019 (COVID-19) epidemic has triggered a huge impact on healthcare, socioeconomics, and other aspects of the world over the past three years. An increasing number of studies have identified a complex relationship between COVID-19 and stroke, although active measures are being implemented to prevent disease transmission. Severe COVID-19 may be associated with an increased risk of stroke and increase the rates of disability and mortality, posing a serious challenge to acute stroke diagnosis, treatment, and care. This review aims to provide an update on the influence of COVID-19 itself or vaccines on stroke, including arterial stroke (ischemic stroke and hemorrhagic stroke) and venous stroke (cerebral venous thrombosis). Additionally, the neurovascular mechanisms involved in SARS-CoV-2 infection and the clinical characteristics of stroke in the COVID-19 setting are presented. Evidence on vaccinations, potential therapeutic approaches, and effective strategies for stroke management has been highlighted.

It's in the blood: a review of the hematological system in SARS-CoV-2-associated COVID-19

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global healthcare crisis. While SARS-CoV-2-associated COVID-19 affects primarily the respiratory system, patients with COVID-19 frequently develop extrapulmonary manifestations. Notably, changes in the hematological system, including lymphocytopenia, neutrophilia and significant abnormalities of hemostatic markers, were observed early in the pandemic. Hematological manifestations have since been recognized as important parameters in the pathophysiology of SARS-CoV-2 and in the management of patients with COVID-19. In this narrative review, we summarize the state-of-the-art regarding the hematological and hemostatic abnormalities observed in patients with SARS-CoV-2-associated COVID-19, as well as the current understanding of the hematological system in the pathophysiology of acute and chronic SARS-CoV-2-associated COVID-19.

Antithrombotic Therapy in Arterial Thrombosis and Thromboembolism in COVID-19: An American College of Chest Physicians Expert Panel Report

BACKGROUND

Evidence increasingly shows that the risk of thrombotic complications in COVID-19 is associated with a hypercoagulable state. Several organizations have released guidelines for the management of COVID-19-related coagulopathy and prevention of VTE. However, an urgent need exists for practical guidance on the management of arterial thrombosis and thromboembolism in this setting.

RESEARCH QUESTION

What is the current available evidence informing the prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19?

STUDY DESIGN AND METHODS

A group of approved panelists developed key clinical questions by using the Population, Intervention, Comparator, and Outcome (PICO) format that address urgent clinical questions regarding prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19. Using MEDLINE via PubMed, a literature search was conducted and references were screened for inclusion. Data from included studies were summarized and reviewed by the panel. Consensus for the direction and strength of recommendations was achieved using a modified Delphi survey.

RESULTS

The review and analysis of the literature based on 11 PICO questions resulted in 11 recommendations. Overall, a low quality of evidence specific to the population with COVID-19 was found. Consequently, many of the recommendations were based on indirect evidence and prior guidelines in similar populations without COVID-19.

INTERPRETATION

The existing evidence and panel consensus do not suggest a major departure from the management of arterial thrombosis according to recommendations predating the COVID-19 pandemic. Data on the optimal strategies for prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19 are sparse. More high-quality evidence is needed to inform management strategies in these patients.

Hematological and Biochemical Laboratory Parameters in COVID-19 Patients: A Retrospective Modeling Study of Severity and Mortality Predictors

Background

It is well known that laboratory markers could help in identifying risk factors of severe illness and predicting outcomes of diseases. Here, we performed a retrospective modeling study of severity and mortality predictors of hematological and biochemical laboratory parameters in Iranian COVID-19 patients.

Methods

Data were obtained retrospectively from medical records of 564 confirmed Iranian COVID-19 cases. According to the disease severity, the patients were categorized into two groups (severe or nonsevere), and based on the outcome of the disease, patients were divided into two groups (recovered or deceased). Demographic and laboratory data were compared between groups, and statistical analyses were performed to define predictors of disease severity and mortality in the patients.

Results

The study identified a panel of hematological and biochemical markers associated with the severe outcome of COVID-19 and constructed different predictive models for severity and mortality. The disease severity and mortality rate were significantly higher in elderly inpatients, whereas gender was not a determining factor of the clinical outcome. Age-adjusted white blood cells (WBC), platelet cells (PLT), neutrophil-to-lymphocyte ratio (NLR), red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), erythrocyte sedimentation rate (ESR), mean corpuscular hemoglobin (MCHC), blood urea nitrogen (BUN), and creatinine (Cr) also showed high accuracy in predicting severe cases at the time of hospitalization, and logistic regression analysis suggested grouped hematological parameters (age, WBC, NLR, PLT, HGB, and international normalized ratio (INR)) and biochemical markers (age, BUN, and lactate dehydrogenase (LDH)) as the best models of combined laboratory predictors for severity and mortality.

Conclusion

The findings suggest that a panel of several routine laboratory parameters recorded on admission could be helpful for clinicians to predict and evaluate the risk of disease severity and mortality in COVID-19 patients.

Incidence and Risk Factors Associated with Thromboembolic Events among Patients with COVID-19 Inpatients: A Retrospective Study

Aims and objectives

Despite thromboprophylaxis, some severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients develop thrombotic complications with poor prognosis. Our goal is to comprehensively assess the incidence, risk factors, and clinical outcomes associated with thromboembolic events (TE) among adult patients presenting with coronavirus disease-2019 (COVID-19).

Materials and methods

The study was conducted as an observational and retrospective study across COVID-19 patients (n = 207) in a tertiary care hospital in the Middle East and North Africa (MENA) region. Electronic health records were collected from the COVID-19 Database from April 2020 to December 2020 which included clinical history and TE.

Results

Fifty-six (27.05%) out of 207 patients (age: 54.42 ± 15.01 years) developed TE despite the anticoagulant therapy. The incidence of venous thromboembolism (VTE) was significantly higher for patients aged >50 years compared to <50 years (73.21% vs 26.79%, p < 0.05). There were no differences in the incidence of VTE between genders (p = 0.561). 165 patients (79.71%) received anticoagulant therapy, yet 48 (29%) developed TE. The most commonly used anticoagulant was low-molecular-weight heparin (LMWH, 47.34%). In spite of efficient treatment and medical management, the majority of patients with TE (45 out of 56 patients, 80.35%) experienced mortality. The comorbidities that significantly increase the risk of TE include hypertension (HTN) and ischemic heart disease (IHD). The laboratory parameters that were associated with an increased risk of VTE include ferritin, lactate dehydrogenase (LDH), and creatinine.

Conclusion

The COVID-19 patients develop thrombotic complications. Future studies should clarify the underlying mechanisms of TE and optimize the antithrombotic regimens in COVID-19 patients.

How to cite this article

Tashkandi WA. Incidence and Risk Factors Associated with Thromboembolic Events among Patients with COVID-19 Inpatients: A Retrospective Study. Indian J Crit Care Med 2023;27(11):830-836.

Thyroid Autoimmunity and SARS-CoV-2 Infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological culprit of COronaVIrus Disease 19 (COVID-19), can enter the cells via the angiotensin-converting enzyme 2 (ACE2) receptor, which has been found in several tissues including in endocrine organs, such as the ovaries, testes, pancreas, and thyroid. Several thyroid disorders have been associated with SARS-CoV-2 infection [subacute thyroiditis (SAT), thyrotoxicosis, and non-thyroidal illness syndrome (NTIS)] and, in part, they are believed to be secondary to the local virus replication within the gland cells. However, as documented for other viruses, SARS-CoV-2 seems to interfere with several aspects of the immune system, inducing the synthesis of autoantibodies and triggering latent or new onset autoimmune disease (AID), including autoimmune thyroid disease (AITD), such as Hashimoto Thyroiditis (HT) and Graves' disease (GD). Several mechanisms have been hypothesized to explain this induction of autoimmunity by SARS-CoV-2 infection: the immune system hyper-stimulation, the molecular mimicry between the self-antigens of the host and the virus, neutrophils extracellular traps, and finally, the virus induced transcriptional changes in the immune genes; nonetheless, more evidence is needed especially from large, long-term cohort studies involving COVID-19 patients, to establish or reject this pathogenetic relationship.

Long COVID-19 Pathophysiology: What Do We Know So Far?

Long COVID-19 is a recognized entity that affects millions of people worldwide. Its broad clinical symptoms include thrombotic events, brain fog, myocarditis, shortness of breath, fatigue, muscle pains, and others. Due to the binding of the virus with ACE-2 receptors, expressed in many organs, it can potentially affect any system; however, it most often affects the cardiovascular, central nervous, respiratory, and immune systems. Age, high body mass index, female sex, previous hospitalization, and smoking are some of its risk factors. Despite great efforts to define its pathophysiology, gaps remain to be explained. The main mechanisms described in the literature involve viral persistence, hypercoagulopathy, immune dysregulation, autoimmunity, hyperinflammation, or a combination of these. The exact mechanisms may differ from system to system, but some share the same pathways. This review aims to describe the most prevalent pathophysiological pathways explaining this syndrome.

Crosstalk between Platelets and SARS-CoV-2: Implications in Thrombo-Inflammatory Complications in COVID-19

The SARS-CoV-2 virus, causing the devastating COVID-19 pandemic, has been reported to affect platelets and cause increased thrombotic events, hinting at the possible bidirectional interactions between platelets and the virus. In this review, we discuss the potential mechanisms underlying the increased thrombotic events as well as altered platelet count and activity in COVID-19. Inspired by existing knowledge on platelet-pathogen interactions, we propose several potential antiviral strategies that platelets might undertake to combat SARS-CoV-2, including their abilities to internalize the virus, release bioactive molecules to interfere with viral infection, and modulate the functions of immune cells. Moreover, we discuss current and potential platelet-targeted therapeutic strategies in controlling COVID-19, including antiplatelet drugs, anticoagulants, and inflammation-targeting treatments. These strategies have shown promise in clinical settings to alleviate the severity of thrombo-inflammatory complications and reduce the mortality rate among COVID-19 patients. In conclusion, an in-depth understanding of platelet-SARS-CoV-2 interactions may uncover novel mechanisms underlying severe COVID-19 complications and could provide new therapeutic avenues for managing this disease.

Thromboembolic Presentations among Patients Hospitalized to the Intensive Care Unit for Coronavirus Disease 2019 (COVID-19) - A Northern Taiwan Single Center Experience

Coronavirus Disease 2019 (COVID-19) has been associated with a high thromboembolic risk among patients in intensive care units. Asian populations may share a similar thromboembolic risk, but with a higher prevalence of arterial thromboembolism than venous thromboembolism. To clarify this risk in Taiwan, this single-center retrospective study collected 27 consecutive intensive care unit patients with COVID-19 confirmed by polymerase chain reaction, with a median age of 67.6 years (male 81.5%). Twenty-three patients received prophylactic anticoagulation (85.2%), and there were four bleeding events (14.8%). Nine patients had thromboembolism (33.3%), including three with deep vein thrombosis, two with peripheral artery thromboembolism, and four with ischemic stroke. There were no significant clinical differences between the patients with or without thromboembolism. Initial serum ferritin [adjusted odds ratio (OR): 13.19, 95% confidence interval (CI): 1.01-172.07] and peak serum procalcitonin (adjusted OR: 18.93, 95% CI: 1.08-330.91) were associated with a higher risk of thromboembolism. Furthermore, prophylactic anticoagulation (adjusted OR: 0.01, 95% CI: < 0.001-0.55) was associated with a lower risk of thromboembolism. All cases of deep vein thrombosis and one peripheral artery thromboembolism occurred at intravascular catheter locations. No association between thromboembolism and survival was found (age-adjusted hazard ratio: 0.55, 95% CI: 0.10-2.95). In conclusion, the prevalence of COVID-19 thromboembolism among Taiwanese patients in intensive care units was high, even with prophylactic anticoagulation. Serum ferritin and procalcitonin may identify high-risk populations. Prophylactic anticoagulation may reduce the risk of thromboembolism with a manageable bleeding risk. Larger prospective studies are needed to clarify the risk of COVID-19 thromboembolism and its risk factors in the post-Omicron era.

Incidence of factor XII deficiency in critically ill patients with a prolonged activated partial thromboplastin time: a prospective observational study

Limited data is available on factor XII deficiency in critically ill patients with prolonged activated partial thromboplastin time (aPTT). The association of factor XII deficiency with an increased risk of thromboembolism is unclear. This prospective observational study assessed the incidence of factor XII deficiency among critically ill patients with prolonged aPTT (>40 s), whether factor XII deficiency manifesting as prolonged aPTT was associated with an increased risk of thromboembolism, and clotting time on a viscoelastic (ROTEM) test was useful to predict factor XII deficiency. Of the 40 included patients, 48% [95% confidence interval (CI) 33-63) had a factor XII deficiency (mean ± standard deviation of factor XII level of all patients: 54% ± 29%). Factor XII levels were not significantly correlated with the measured aPTT ( r  = -0.163, P  = 0.315). Factor XII deficiency was significantly more common in patients who were less critically ill ( P  = 0.027), but it was not significantly related to Disseminated Intravascular Coagulation scores ( P  = 0.567). The incidence of symptomatic venous thromboembolism ( P  = 0.246), allogeneic blood transfusion ( P  = 0.816), and hospital mortality ( P  = 0.201) were not significantly different between those with and without factor XII deficiency. The clotting time on the viscoelastic test was not predictive of factor XII deficiency (area under the receiver-operating characteristic = 0.605, P  = 0.264). Factor XII deficiency was common in critically ill patients with a prolonged aPTT. There was no association between factor XII deficiency and risk of thromboembolism. The clotting time on ROTEM was not predictive of the presence of factor XII deficiency.

Inhibiting NINJ1-dependent plasma membrane rupture protects against inflammasome-induced blood coagulation and inflammation

Systemic blood coagulation accompanies inflammation during severe infection like sepsis and COVID. We've previously established a link between pyroptosis, a vital defense mechanism against infection, and coagulopathy. During pyroptosis, the formation of gasdermin-D (GSDMD) pores on the plasma membrane leads to the release of tissue factor (TF)-positive microvesicles (MVs) that are procoagulant. Mice lacking GSDMD release fewer TF MVs. However, the specific mechanisms leading from activation of GSDMD to MV release remain unclear. Plasma membrane rupture (PMR) in pyroptosis was recently reported to be actively mediated by the transmembrane protein Ninjurin-1 (NINJ1). Here we show that NINJ1 promotes procoagulant MV release during pyroptosis. Haploinsuffciency or glycine inhibition of NINJ1 limited the release of procoagulant MVs and inflammatory cytokines and protected against blood coagulation and lethality triggered by bacterial flagellin. Our findings suggest a crucial role for NINJ1-dependent PMR in inflammasome-induced blood coagulation and inflammation.

Deficiency in the production of antibodies to lipids correlates with increased lipid metabolism in severe COVID-19 patients

Background

Antibodies to lipids are part of the first line of defense against microorganisms and regulate the pro/anti-inflammatory balance. Viruses modulate cellular lipid metabolism to enhance their replication, and some of these metabolites are proinflammatory. We hypothesized that antibodies to lipids would play a main role of in the defense against SARS-CoV-2 and thus, they would also avoid the hyperinflammation, a main problem in severe condition patients.

Methods

Serum samples from COVID-19 patients with mild and severe course, and control group were included. IgG and IgM to different glycerophospholipids and sphingolipids were analyzed using a high-sensitive ELISA developed in our laboratory. A lipidomic approach for studying lipid metabolism was performed using ultra-high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS).

Results

Mild and severe COVID-19 patients had higher levels of IgM to glycerophosphocholines than control group. Mild COVID-19 patients showed higher levels of IgM to glycerophosphoinositol, glycerophosphoserine and sulfatides than control group and mild cases. 82.5% of mild COVID-19 patients showed IgM to glycerophosphoinositol or glycerophosphocholines plus sulfatides or glycerophosphoserines. Only 35% of severe cases and 27.5% of control group were positive for IgM to these lipids. Lipidomic analysis identify a total of 196 lipids, including 172 glycerophospholipids and 24 sphingomyelins. Increased levels of lipid subclasses belonging to lysoglycerophospholipids, ether and/or vinyl-ether-linked glycerophospholipids, and sphingomyelins were observed in severe COVID-19 patients, when compared with those of mild cases and control group.

Conclusion

Antibodies to lipids are essential for defense against SARS-CoV-2. Patients with low levels of anti-lipid antibodies have an elevated inflammatory response mediated by lysoglycerophospholipids. These findings provide novel prognostic biomarkers and therapeutic targets.

COVID-19 and Cerebrovascular Disease

COVID-19 has been associated with numerous neurological complications, with acute cerebrovascular disease being one of the most devastating complications. Ischemic stroke is the most common cerebrovascular complication of COVID-19, affecting between 1 and 6% of all patients. Underlying mechanisms for COVID-related ischemic strokes are thought to be due to vasculopathy, endotheliopathy, direct invasion of the arterial wall, and platelet activation. Other COVID-19-associated cerebrovascular complications include hemorrhagic stroke, cerebral microbleeds, posterior reversible encephalopathy syndrome, reversible cerebral vasoconstriction syndrome, cerebral venous sinus thrombosis, and subarachnoid hemorrhage. This article discusses the incidence of these cerebrovascular complications, risk factors, management strategies, prognosis and future research directions, as well as considerations in pregnancy-related cerebrovascular events in the setting of COVID-19.

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.

Lupus anticoagulants as a prospective independent predictor in COVID-19 patients

OBJECTIVE

Lupus anticoagulant (LA) are commonly detected during SARS-CoV-2 infection. However, the relationship between LA and clinical significance is still unclear.

METHODS

A retrospective chart analysis was performed on COVID-19 patients who were tested for LA at our hospital from March 2020 to November 2021. We analyzed the patient's characteristics based on the result of the LA test. In addition, subgroup analysis performed the LA-positive group who had undergone serial LA tests.

RESULTS

A total of 219 COVID-19 patients were enrolled in the study, 148 patients (67.6%) were positive for LA test. The LA-positive group received more treatment of high flow nasal cannula (LA-positive 73.0%, LA-negative 57.7%, p = 0.024). The LA-positive group showed prolonged aPTT, higher levels of CRP and fibrinogen (all p's < 0.05). Among 148 LA-positive patients, 127 patients (86.5%) were found to be LA-positive within 10 days of SARS-CoV-2 positive, and LA-positive group confirmed a median time to LA loss of 10 days. However, there was a group that was negative for LA in the early stages of infection and became positive about 13 days later. A subgroup analysis showed that these patients had different characteristics due to their longer hospital stays and higher D-dimer levels.

CONCLUSIONS

In COVID-19 patients, LA is expected to be associated to disease severity. Since the clinical significance of LA is different depending on the onset time of LA positivity, the LA test is suggested to be done at diagnosis of SARS-CoV-2 infection, even if LA is negative, follow-up test should be considered within 10 days.

Cellular and molecular features of COVID-19 associated ARDS: therapeutic relevance

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can be asymptomatic or cause a disease (COVID-19) characterized by different levels of severity. The main cause of severe COVID-19 and death is represented by acute (or acute on chronic) respiratory failure and acute respiratory distress syndrome (ARDS), often requiring hospital admission and ventilator support.The molecular pathogenesis of COVID-19-related ARDS (by now termed c-ARDS) is still poorly understood. In this review we will discuss the genetic susceptibility to COVID-19, the pathogenesis and the local and systemic biomarkers correlated with c-ARDS and the therapeutic options that target the cell signalling pathways of c-ARDS.

Symptomatic arterial thrombosis associated with novel coronavirus disease 2019 (COVID-19): report of two cases

Since December 2019, the outbreak of the novel coronavirus disease (COVID-19) in China has rapidly spread throughout the world. During the course of the COVID-19 pandemic, thrombotic complications have emerged as an important issue. We present two cases of symptomatic arterial thrombosis in patients with confirmed COVID-19. The first patient presented with digital ischemia due to distal embolization from a floating thrombus in the proximal left subclavian artery, and the second one with bilateral acute limb ischemia due to thrombosis of the right popliteal artery and left tibioperoneal trunk. This case report illustrates that arterial thrombosis associated with COVID-19 can occur even in the absence of severe respiratory disease and clinically relevant peripheral arterial disease.

Computational modeling of hypercoagulability in COVID-19

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 100 million people worldwide and claimed millions of lives. While the leading cause of mortality in COVID-19 patients is the hypoxic respiratory failure from acute respiratory distress syndrome, there is accumulating evidence that shows excessive coagulation also increases the fatalities in COVID-19. Thus, there is a pressing demand to understand the association between COVID-19-induced hypercoagulability and the extent of formation of undesired blood clots. Mathematical modeling of coagulation has been used as an important tool to identify novel reaction mechanisms and to identify targets for new drugs. Here, we employ the coagulation factor data of COVID-19 patients reported from published studies as inputs for two mathematical models of coagulation to identify how the concentrations of coagulation factors change in these patients. Our simulation results show that while the levels of many of the abnormal coagulation factors measured in COVID-19 patients promote the generation of thrombin and fibrin, two key components of blood clots, the increased level of fibrinogen and then the reduced level of antithrombin are the factors most responsible for boosting the level of fibrin and thrombin, respectively. Altogether, our study demonstrates the potential of mathematical modeling to identify coagulation factors responsible for the increased clot formation in COVID-19 patients where clinical data is scarce.

COVID-19 vaccine affects neither prothrombotic antibody profile nor thrombosis in primary anti-phospholipid syndrome: a prospective study

OBJECTIVE

To explore whether inactivated coronavirus disease 2019 vaccine influences the profile of prothrombotic autoantibodies and induces thrombotic events in primary APS patients.

METHODS

We enrolled 39 primary APS patients who received two doses of inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (BBIBPCorV, Sinopharm, Beijing, China) voluntarily in this prospective cohort. Prothrombotic autoantibodies were determined before vaccination and 4 weeks after the second dose of vaccination. Thrombotic disorders were evaluated via hospital site visits and assessments.

RESULTS

There was no significant difference in the presence of all 11 autoantibodies detected before and 4 weeks after vaccination: for aCL, IgG (14 vs 16, P = 0.64), IgM (13 vs 19, P = 0.34), IgA (2 vs 3, P = 0.64); anti-β2GP1, IgG (12 vs 12, P = 1.00), IgM (5 vs 8, P = 0.36), IgA (4 vs 3, P = 0.69); anti-PS/PT IgG (13 vs 16, P = 0.48), IgM (17 vs 22, P = 0.26); LAC (22 vs 28, P = 0.16); aPF4-heparin (0 vs 0, P = 1.00) and ANA (23 vs 26, P = 0.48). Notably, the distribution of the aPL profile in the pre- and post-vaccination cohorts was not affected by SARS-CoV-2 vaccination: for patients with a low-risk aPL profile (11 vs 10, P = 0.799) and patients with a high-risk aPL profile (28 vs 29, P = 0.799), respectively. Furthermore, no case exhibited symptoms of the thrombotic disorder during a minimum follow-up period of 12 weeks. There was no adjustment to the ongoing treatment regimens following SARS-CoV-2 vaccination.

CONCLUSION

Inactivated SARS-CoV-2 vaccine does not influence the profile of anti-phospholipid antibodies and anti-PF4-heparin antibodies nor induces thrombotic events in primary APS patients.

The prevalence of deep vein thrombosis and associated risk factors among patients with COVID-19 in the North of Iran

Aim: We aimed to investigate the associated risk factors of deep vein thrombosis (DVT) among COVID-19 patients. Materials & methods: In this cross-sectional study the demographical data and clinical characteristics of 382 COVID-19 patients were collected and analyzed. Results: The DVT was observed in 53 patients (14.1%). The rate of death was significantly associated with the incidence of DVT, 48.1 versus 32.2% in non-DVT cases; p = 0.034). Also, BMI (p = 0.0001), renal failure (p = 0.001), lower-limb edema (p = 0.0001) and intubation (p = 0.004) were associated with the risk of DVT. Conclusion: COVID-19 patients with a higher BMI, renal failure, lower-limb edema and need for intubation were at a higher risk of DVT.

Outcomes associated with antiphospholipid antibodies in COVID-19: A prospective cohort study

Background

The significance of antiphospholipid antibodies (aPL) in COVID-19 remains uncertain.

Objectives

We determined whether aPL are associated with COVID-19 and/or thrombosis or adverse outcomes during hospitalization for COVID-19.

Methods

Symptomatic adults tested for SARS-CoV-2 for clinical reasons (March-July 2020) with either ≥1 positive polymerase chain reaction (COVID-19+) or all negative (non-COVID-19) results were recruited to a biobank collecting plasma, clinical data, and outcomes. We tested baseline plasma samples (days 0-7) of all subjects (and day-30 samples in the COVID-19+ subjects, when available) for aPL (anticardiolipin immunoglobulin [Ig]M/IgG, anti-β2-glycoprotein I IgM/IgG, antiphosphatidylserine/prothrombin IgM/IgG, and lupus anticoagulant). We compared the baseline prevalence of aPL between the COVID-19+ and non-COVID-19 subjects. Among hospitalized COVID-19+ subjects, multivariable logistic regression was used to evaluate the association of aPL (and their subtypes) with arterial or venous thromboembolic events, acute kidney injury, intensive care unit admission, mechanical ventilation, and death after adjusting for potential confounders.

Results

At baseline, 123 of 289 (43%) COVID+ subjects had ≥1 aPL versus 116 of 261 (32%) non-COVID-19 subjects (difference, 10%; 95% CI, 3%-18%). Among 89 COVID+ subjects with repeated samples, aPL persisted on day 30 in 15 of 34 (44%) subjects with baseline aPL positivity, and half of those without aPL at baseline developed one or more new aPL. In hospitalized COVID-19 subjects (n = 241), baseline aPL positivity was associated with acute kidney injury (odds ratio [OR], 1.8; 95% CI, 1.1-3.2) and mechanical ventilation (OR, 3.2; 95% CI, 1.5-6.8) but not death (OR, 1.2; 95% CI, 0.6-2.5). In secondary analyses, medium-to-high titers of anticardiolipin IgG (>40) were associated with thromboembolic events (OR, 7.3; 95% CI, 1.8-30.1).

Conclusion

In patients with COVID-19, aPL may help identify an increased risk of thrombosis and other adverse outcomes.

Evaluating the Relationship Between Antiphospholipid Antibodies and COVID-19 Severity

Coronavirus 2 (COVID-19) has emerged as a new global pandemic, causing severe acute respiratory syndrome. Furthermore, the existence of antiphospholipid (APL) antibodies (Abs) and ultimately patient death may be linked to the occurrence of thrombotic events in patients with COVID-19. We aimed to investigate if there was a link between the presence of APL Abs and the severity of COVID-19 disease in patients at the Vali-Asr Hospital in Zanjan from June to July 2021. Real-time PCR was used to diagnose COVID-19 in 76 hospitalized patients. A total of 38 patients were hospitalized in the internal medicine ward and another 38 people were admitted to the intensive care unit of the Vali-Asr Educational Hospital in Iran's Zanjan region. Lupus anticoagulant (LAC) detection was done using the dilute Russell viper venom time method, and tests for anticardiolipin (ACL) Abs, IgG and IgM, and anti-beta2 glycoprotein 1 Abs, IgG and IgM, were done on blood and plasma samples of linked patients using the enzyme-linked immunosorbent assay technique. SPSS 24 was used to analyze data. Our findings showed that the presence of LAC was associated with disease severity in COVID-19 patients (p = 0.001). However, there was no significant relationship between APL Abs and mortality in patients affected with COVID-19. The evaluation of APL Abs, particularly LAC, in COVID-19 patients appears to be helpful in predicting the severity of the disease.

In-stent Thrombosis and COVID-19 Infection: Current Insights on the Mechanistic Relationship

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been demonstrated as a major risk factor in inducing coronary stent thrombosis due to its propensity to create a pro-thrombotic state. This review explores the mechanisms that may contribute to the increased thrombosis risk seen in COVID-19. Furthermore, we discuss the patient and haematological factors that predispose to an increased risk of stent thrombosis, as well as the role of certain antiplatelet and anticoagulation therapies, including ticagrelor and enoxaparin, that may reduce the likelihood and severity of in-stent thrombosis, in SARS-CoV-2 infection. To counter the proinflammatory and pro-thrombotic state shown in COVID-19, anti-thrombotic therapy in the future may be optimised using point-of-care platelet inhibition testing and inflammation-modifying therapies. Large-scale randomised trials with long-term follow-up are increasingly necessary to assess the intersection of COVID-19 and stent optimisation as well as the reduction of stent thrombosis after drug-eluting stent (DES) implantation.

Fibrinogen, Coagulation, and Ageing

The World Health Organization estimates that the world's population over 60 years of age will nearly double in the next 30 years. This change imposes increasing demands on health and social services with increased disease burden in older people, hereafter defined as people aged 60 years or more. An older population will have a greater incidence of cardiovascular disease partly due to higher levels of blood fibrinogen, increased levels of some coagulation factors, and increased platelet activity. These factors lead to a hypercoagulable state which can alter haemostasis, causing an imbalance in appropriate coagulation, which plays a crucial role in the development of cardiovascular diseases. These changes in haemostasis are not only affected by age but also by gender and the effects of hormones, or lack thereof in menopause for older females, ethnicity, other comorbidities, medication interactions, and overall health as we age. Another confounding factor is how we measure fibrinogen and coagulation through laboratory and point-of-care testing and how our decision-making on disease and treatment (including anticoagulation) is managed. It is known throughout life that in normal healthy individuals the levels of fibrinogen and coagulation factors change, however, reference intervals to guide diagnosis and management are based on only two life stages, paediatric, and adult ranges. There are no specific diagnostic guidelines based on reference intervals for an older population. How ageing relates to alterations in haemostasis and the impact of the disease will be discussed in this chapter. Along with the effect of anticoagulation, laboratory testing of fibrinogen and coagulation, future directions, and implications will be presented.

De Novo Autoimmune Hepatitis after COVID-19 Infection in an Unvaccinated Patient

Liver test abnormalities have been described during severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infection causing coronavirus disease 2019. Most of them consist of elevation of the aminotransferases that resolve once the infection subsides. There are several reports of autoimmune hepatitis developing after vaccination against COVID-19 and one case of autoimmune hepatitis following COVID-19 infection. We present a patient that was not vaccinated against COVID-19 and developed resistant de novo autoimmune hepatitis following COVID-19 infection requiring aggressive immunosuppression.

The Presence of Antineutrophil Cytoplasmic Antibodies and Antiphospholipid Antibodies in Patients with Severe Acute Respiratory Syndrome Coronavirus 2: A Case-Control Study among Sudanese Patients

Patients infected with COVID-19 are at an increased risk for thrombosis, suggesting a possible role of COVID-19 in the induction of coagulopathy. This study aimed to investigate the presence of prothrombotic antineutrophil cytoplasmic antibodies (ANCA) and antiphospholipid antibodies (aPLs) in the course of COVID-19 infection and to correlate these markers with severity and fatality, suggesting that COVID-19-induced autoimmune thrombosis is a possible axis in the inflammatory circuit of this infection. To investigate this, we conducted a case-control study which included patients with a positive reverse transcription-polymerase chain reaction (RT-PCR) test of COVID-19 and a control group with negative COVID-19 PCR and antibody (IgG-IgM and IgA nucleoprotein) ELISA results. An indirect immunofluorescence assay using granulocyte biochips (Aesku slides from AESKU DIAGNOSTICS, Germany) was used to detect ANCA (IgG), as well as multiplex ELISA for the detection of antiphospholipid antibodies for all patients with COVID-19 and for the control group. The results revealed the detection of antiphospholipid antibodies (IgG) in one patient out of the 45 patients in the case group. 1/45(2.2%) and 7/45(15.6%) tested positive for ANCA. Five were men and two were females, with one case revealed to be positive for both aPL and ANCA. A cytoplasmic reaction on the eosinophil granulocytes was observed in 2 cases; both were positive for ANCA. Other markers (CRP, APTT, PT, INR, ESR, and neutrophil and lymphocyte counts) were included in the study, along with demographic data. No aPL or ANCA reactions were detected for any of the control groups. These findings suggest that aPL and ANCA may be induced during the course of inflammation in COVID-19 and possibly contribute to the disease's severity and mortality.

Cardiovascular, Pulmonary, and Neuropsychiatric Short- and Long-Term Complications of COVID-19

Beginning with the various strategies of the SARS-CoV-2 virus to invade our bodies and manifest infection, and ending with the recent long COVID, we are witnessing the evolving course of the disease in addition to the pandemic. Given the partially controlled course of the COVID-19 pandemic, the greatest challenge currently lies in managing the short- and long-term complications of COVID-19. We have assembled current knowledge of the broad spectrum of cardiovascular, pulmonary, and neuropsychiatric sequelae following SARS-CoV-2 infection to understand how these clinical manifestations collectively lead to a severe form of the disease. The ultimate goal would be to better understand these complications and find ways to prevent clinical deterioration.

COVID-19 and the antiphospholipid syndrome

Coronavirus disease 2019 (COVID-19) has resulted in a global pandemic. Most COVID-19 patients are asymptomatic or have flu-like symptoms. However, around 15% of the patients may have severe disease, including unilateral or bilateral pneumonia with acute respiratory distress syndrome and progressive hypoxemia that may require mechanical ventilation assistance. A systemic inflammatory response syndrome occurs in the most severe forms of COVID-19, with multiorgan involvement which can be life threatening caused by a cytokine storm. Although what best characterizes COVID-19 are the manifestations of the respiratory system, it has been shown that it also acts at the cardiovascular level, producing coagulation abnormalities, which causes thrombotic events mainly in the arteries/arterioles, microcirculation and venous system, and potentially increased mortality risk. This multiorgan vascular disease overlaps with other known microangiopathies, such as thrombotic microangiopathy or paroxysmal nocturnal hemoglobinuria, where complement overactivation plays an important role in the pathophysiology of thrombosis. Furthermore, coagulopathy secondary to COVID-19 occurs in the context of an uncontrolled inflammatory response, reminiscent of APS, especially in its catastrophic form. This review summarizes the current knowledge regarding the relationship between COVID-19 and the APS.

Severe Thrombocytopenia, Thrombosis and Anti-PF4 Antibody after Pfizer-BioNTech COVID-19 mRNA Vaccine Booster-Is It Vaccine-Induced Immune Thrombotic Thrombocytopenia?

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a serious and life-threatening complication occurring after adenovirus-vector COVID-19 vaccines, and is rarely reported after other vaccine types. Herein, we report a case of possible VITT after the Pfizer-BioNTech mRNA vaccine booster, who presented with extensive lower limb deep vein thrombosis, severe thrombocytopenia, markedly elevated D-dimer and positive anti-PF4 antibody occurring 2 weeks post-vaccination, concurrent with a lupus anticoagulant. A complete recovery was made after intravenous immunoglobulin, prednisolone and anticoagulation with the oral direct Xa inhibitor rivaroxaban. The presenting features of VITT may overlap with those of antiphospholipid syndrome associated with anti-PF4 and immune thrombocytopenia. We discuss the diagnostic considerations in VITT and highlight the challenges of performing VITT confirmatory assays in non-specialized settings. The set of five diagnostic criteria for VITT is a useful tool for guiding initial management, but may potentially include patients without VITT. The bleeding risks of severe thrombocytopenia in the face of thrombosis, requiring anticoagulant therapy, present a clinical challenge, but early recognition and management can potentially lead to favorable outcomes.

A Review Pertaining to SARS-CoV-2 and Autoimmune Diseases: What Is the Connection?

Coronavirus disease 2019 (COVID-19) is an infectious viral disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). It is known that infection with SARS-CoV-2 can lead to various autoimmune and autoinflammatory diseases. There are few reports in the literature on the association between SARS-CoV-2 and autoimmune diseases, and the number of reports has been increasing since 2020. Autoimmune diseases and SARS-CoV-2 infections are intertwined in several ways. Both conditions lead to immune-mediated tissue damage, the immune response is accompanied by the increased secretion of inflammatory cytokines and both conditions can be treated using immunomodulatory drugs. Patients with certain autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, cardiac sarcoidosis, idiopathic pulmonary fibrosis, autoimmune hepatitis, multiple sclerosis and others, are more susceptible to SARS-CoV-2 infection, either because of the active autoimmune disease or because of the medications used to treat it. Conversely, SARS-CoV-2 infection can also cause certain autoimmune diseases. In this paper, we describe the development of autoimmune diseases after COVID-19 and the recovery from COVID-19 in people with autoimmune diseases.

Haematological predictors of poor outcome among COVID-19 patients admitted to an intensive care unit of a tertiary hospital in South Africa

Background

Studies from Asia, Europe and the USA indicate that widely available haematological parameters could be used to determine the clinical severity of Coronavirus disease 2019 (COVID-19) and predict management outcome. There is limited data from Africa on their usefulness in patients admitted to Intensive Care Units (ICUs). We performed an evaluation of baseline haematological parameters as prognostic biomarkers in ICU COVID-19 patients.

Methods

Demographic, clinical and laboratory data were collected prospectively on patients with confirmed COVID-19, admitted to the adult ICU in a tertiary hospital in Cape Town, South Africa, between March 2020 and February 2021. Robust Poisson regression methods and receiver operating characteristic (ROC) curves were used to explore the association of haematological parameters with COVID-19 severity and mortality.

Results

A total of 490 patients (median age 54.1 years) were included, of whom 237 (48%) were female. The median duration of ICU stay was 6 days and 309/490 (63%) patients died. Raised neutrophil count and neutrophil/lymphocyte ratio (NLR) were associated with worse outcome. Independent risk factors associated with mortality were age (ARR 1.01, 95%CI 1.0–1.02; p = 0.002); female sex (ARR 1.23, 95%CI 1.05–1.42; p = 0.008) and D-dimer levels (ARR 1.01, 95%CI 1.002–1.03; p = 0.016).

Conclusions

Our study showed that raised neutrophil count, NLR and D-dimer at the time of ICU admission were associated with higher mortality. Contrary to what has previously been reported, our study revealed females admitted to the ICU had a higher risk of mortality.

Is there an interplay between the SARS-CoV-2 spike protein and Platelet-Activating factor?

Previous publications have reported a potent effect of COVID-19 on platelet function and that the Spike protein enhances washed human platelet aggregation induced by various agonists. This study aims to evaluate whether mRNA vaccination for COVID-19 affects human platelet-rich plasma (hPRP) aggregation response, whether a recombinant Spike protein modulates PAF-induced aggregation in hPRP and in washed rabbit platelets (WRP), and to investigate the effect of recombinant Spike protein on the PAF production in the U-937 cell line. Our results showed that PRP from vaccinated individuals exhibited ex vivo lower EC₅₀ values in response to PAF, ADP, and collagen. Platelet incubation with the Spike protein alone did not induce aggregation either in hPRP or in WRP, but resulted in augmentation of in vitro PAF-induced aggregation in hPRP from non-vaccinated individuals and in WRP. When PRP from vaccinated individuals was incubated with the Spike protein and PAF was subsequently added, elimination of the secondary wave of the biphasic aggregation curve was recorded compared with the aggregation induced by PAF alone. Collagen-induced in vitro aggregation was dose-dependently reduced when platelets were pre-incubated with the Spike protein in all tested aggregation experiments. Stimulation of U-937 by the Spike protein induced an increase in intracellular PAF production accompanied by elevation of the activities of all three PAF biosynthetic enzymes. In conclusion, since the Spike protein appears to modulate PAF production and activity, the use of compounds that act as PAF inhibitors, could be considered at least in mild cases of patients infected with SARS-CoV-2.

Coagulation Profile of COVID-19 Patients

Coronavirus disease is a viral infection that can affect multiple systems and be expressed with many-or no-symptoms. The viral infection begins when the virus binds to the host's receptor and from that point on, it is transmitted to the rest of the body, where it causes inflammatory reactions. Among other tissues and systems, SARS-CoV-2 impacts the coagulation system, where it triggers the immunothrombotic response. Its effects are rather intense and can lead to many complications. COVID-19-associated coagulopathy is frequently observed in hospitalized patients, especially ICU patients, and can be proven detrimental. It is usually accompanied by other complications, such as sepsis-induced coagulopathy, disseminated intravascular coagulation and venous thromboembolism. Since all these conditions lead to poor prognosis for severely ill patients, thromboprophylaxis and coagulopathy prognosis are just as important as the therapeutic handling of these patients. Since the beginning of the pandemic, many biomarkers have been considered useful when trying to assess the thrombotic risk of hospitalized patients or evaluate the severity of their situation. At the same time, many drugs have already been tested-while others are still being trialed-in order to find the optimal therapy for each urgent situation.

Multiple ischemic stroke with pulmonary embolism revealing severe COVID-19 infection in a young healthy patient

Coronavirus 2019 (COVID-19) disease has caused significant morbidity and mortality worldwide since its emergence in December 2019. Despite its respiratory tropism; there is a nontrivial relationship between this virus and the neurovascular system exposing patients to higher morbidity and mortality. We report the case of a young patient admitted for hemiplegia with acute respiratory failure, in whom imaging found multiple ischemic strokes with pulmonary embolism and severe involvement suggestive of COVID-19 pneumopathy. Stroke in the context of COVID-19 infection has distinct characteristics in terms of disease mechanism, patient demographics, but also clinical, biological, and neuroradiological specificities. The pathogenesis and optimal management of COVID-19-associated ischemic stroke remain unclear, but the coagulopathy and endotheliopathy triggered by the cytokine storm represent possible target mechanisms.

SARS-CoV-2 in immunocompromised individuals

Immunocompromised individuals and particularly those with hematologic malignancies are at increased risk for SARS-CoV-2-associated morbidity and mortality due to immunologic deficits that limit prevention, treatment, and clearance of the virus. Understanding the natural history of viral infections in people with impaired immunity due to underlying conditions, immunosuppressive therapy, or a combination thereof has emerged as a critical area of investigation during the COVID-19 pandemic. Studies focused on these individuals have provided key insights into aspects of innate and adaptive immunity underlying both the antiviral immune response and excess inflammation in the setting of COVID-19. This review presents what is known about distinct states of immunologic vulnerability to SARS-CoV-2 and how this information can be harnessed to improve prevention and treatment strategies for immunologically high-risk populations.

Co-infection associated with SARS-CoV-2 and their management

SARS-CoV-2 was discovered in Wuhan, China and quickly spread throughout the world. This deadly virus moved from person to person, resulting in severe pneumonia, fever, chills and hypoxia. Patients are still experiencing problems after recovering from COVID-19. This review covers COVID-19 and associated issues following recovery from COVID-19, as well as multiorgan damage risk factors and treatment techniques. Several unusual illnesses, including mucormycosis, white fungus infection, happy hypoxia and other systemic abnormalities, have been reported in recovered individuals. In children, multisystem inflammatory syndrome with COVID-19 (MIS-C) is identified. The reasons for this might include uncontrollable steroid usage, reduced immunity, uncontrollable diabetes mellitus and inadequate care following COVID-19 recovery.

Coagulation parameters predict COVID-19-related thrombosis in a neural network with a positive predictive value of 98%

Thrombosis is a major clinical complication of COVID-19 infection. COVID-19 patients show changes in coagulation factors that indicate an important role for the coagulation system in the pathogenesis of COVID-19. However, the multifactorial nature of thrombosis complicates the prediction of thrombotic events based on a single hemostatic variable. We developed and validated a neural net for the prediction of COVID-19-related thrombosis. The neural net was developed based on the hemostatic and general (laboratory) variables of 149 confirmed COVID-19 patients from two cohorts: at the time of hospital admission (cohort 1 including 133 patients) and at ICU admission (cohort 2 including 16 patients). Twenty-six patients suffered from thrombosis during their hospital stay: 19 patients in cohort 1 and 7 patients in cohort 2. The neural net predicts COVID-19 related thrombosis based on C-reactive protein (relative importance 14%), sex (10%), thrombin generation (TG) time-to-tail (10%), α₂-Macroglobulin (9%), TG curve width (9%), thrombin-α₂-Macroglobulin complexes (9%), plasmin generation lag time (8%), serum IgM (8%), TG lag time (7%), TG time-to-peak (7%), thrombin-antithrombin complexes (5%), and age (5%). This neural net can predict COVID-19-thrombosis at the time of hospital admission with a positive predictive value of 98%-100%.

Hemostatic system and COVID-19 crosstalk: A review of the available evidence

Since the discovery of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resultant coronavirus disease 2019 (COVID-19) pandemic, respiratory manifestations have been the mainstay of clinical diagnosis, laboratory evaluations, and radiological investigations. As time passed, other pathological aspects of SARS-CoV-2 have been revealed. Various hemostatic abnormalities have been reported since the rise of the pandemic, which was sometimes superficial, transient, or fatal. Mild thrombocytopenia, thrombocytosis, venous, arterial thromboembolism, and disseminated intravascular coagulation are among the many hemostatic events associated with COVID-19. Venous thromboembolism necessitating therapeutic doses of anticoagulants is more frequently seen in severe cases of COVID-19, especially in patients admitted to intensive care units. Hemorrhagic complications rarely arise in COVID-19 patients either due to a hemostatic imbalance resulting from severe disease or as a complication of over anticoagulation. Although the pathogenesis of coagulation disturbance in SARS-CoV-2 infection is not yet understood, professional societies recommend prophylactic antithrombotic therapy in severe cases, especially in the presence of abnormal coagulation indices. The review article discusses the various available evidence on coagulation disorders, management strategies, outcomes, and prognosis associated with COVID-19 coagulopathy, which raises awareness about the importance of anticoagulation therapy for COVID-19 patients to guard against possible thromboembolic events.