Platelet aggregates, a marker of severe COVID-19 disease

SARS-CoV-2 Infection Is an Independent Risk Factor for Decompensation in Cirrhosis Patients

BACKGROUND

SARS-CoV-2 causes varied gastrointestinal symptoms. Cirrhosis patients face higher mortality rates from it, especially those with decompensated cirrhosis. This study examines SARS-CoV-2's impact on decompensation in previously compensated cirrhotic patients.

METHODS

We analyzed the Global Collaborative Network, comprising 98 healthcare organizations across sixteen countries, using TriNetX's deidentified research database. Compensated cirrhosis patients were split into two groups: one with SARS-CoV-2-positive patients and another testing negative. Using a 1:1 propensity score matching model based on baseline characteristics and comorbidities, we created comparable cohorts. We then assessed decompensation, mortality, and GI bleed at 1 and 3 months.

RESULTS

Out of 252,631 identified compensated cirrhosis patients, 27.3% (69,057) tested SARS-CoV-2-positive, while 72.6% (183,574) remained negative. Post PSM, 61,963 patients were in each group. SARS-CoV-2-positive patients showed significantly higher decompensation rates (4.4% vs. 1.9% at 1 month; 6% vs. 2.6% overall). Rates of complications, like ascites, SBP, HE, and HRS, increased notably. Mortality (2.5% vs. 1.7% at 1 month; 3.6% vs. 2.7% at 3 months) and GI bleed (1.3% vs. 0.9% at 1 month; 1.9% vs. 1.2% at 3 months) were also elevated in SARS-CoV-2 patients.

CONCLUSIONS

SARS-CoV-2 increases decompensation over 2-fold in compensated cirrhosis patients and raises mortality and increases rates of complications at 1 and 3 months.

An early warning indicator of mortality risk in patients with COVID-19: the neutrophil extracellular traps/neutrophilic segmented granulocyte ratio

Background

Neutrophil extracellular traps (NETs) play a key role in thrombus formation in patients with coronavirus disease 2019 (COVID-19). However, the existing detection and observation methods for NETs are limited in their ability to provide quantitative, convenient, and accurate descriptions of in situ NETs. Therefore, establishing a quantitative description of the relationship between NETs and thrombosis remains a challenge.

Objective

We employed morphological observations of blood cells and statistical analyses to investigate the correlation between the NETs/neutrophilic segmented granulocyte ratio and mortality risk in patients with COVID-19.

Methods

Peripheral blood samples were collected from 117 hospitalized patients with COVID-19 between November 2022 and February 2023, and various blood cell parameters were measured. Two types of smudge cells were observed in the blood and counted: lymphatic and neutral smudge cells. Statistical data analysis was used to establish COVID-19 mortality risk assessment indicators.

Results

Morphological observations of neutrophilic smudge cells revealed swelling, eruption, and NETs formation in the neutrophil nuclei. Subsequently, the NETs/neutrophilic segmented granulocyte ratio (NNSR) was calculated. A high concentration of NETs poses a fatal risk for thrombus formation in patients. Statistical analysis indicated that a high NNSR was more suitable for evaluating the risk of death in patients with COVID-19 compared to elevated fibrinogen (FIB) and D-dimer (DD) levels.

Conclusion

Observing blood cell morphology is an effective method for the detection of NETs, NNSR are important markers for revealing the mortality risk of patients with COVID-19.

Platelet aggregates detected using quantitative phase imaging associate with COVID-19 severity

BACKGROUND

The clinical spectrum of acute SARS-CoV-2 infection ranges from an asymptomatic to life-threatening disease. Considering the broad spectrum of severity, reliable biomarkers are required for early risk stratification and prediction of clinical outcomes. Despite numerous efforts, no COVID-19-specific biomarker has been established to guide further diagnostic or even therapeutic approaches, most likely due to insufficient validation, methodical complexity, or economic factors. COVID-19-associated coagulopathy is a hallmark of the disease and is mainly attributed to dysregulated immunothrombosis. This process describes an intricate interplay of platelets, innate immune cells, the coagulation cascade, and the vascular endothelium leading to both micro- and macrothrombotic complications. In this context, increased levels of immunothrombotic components, including platelet and platelet-leukocyte aggregates, have been described and linked to COVID-19 severity.

METHODS

Here, we describe a label-free quantitative phase imaging approach, allowing the identification of cell-aggregates and their components at single-cell resolution within 30 min, which prospectively qualifies the method as point-of-care (POC) testing.

RESULTS

We find a significant association between the severity of COVID-19 and the amount of platelet and platelet-leukocyte aggregates. Additionally, we observe a linkage between severity, aggregate composition, and size distribution of platelets in aggregates.

CONCLUSIONS

This study presents a POC-compatible method for rapid quantitative analysis of blood cell aggregates in patients with COVID-19.

Liver Damage and Impaired Coagulation in COVID-19 Patients: A Case Series

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has generated an unprecedented challenge for healthcare systems worldwide. Currently, the scientific community wonders if liver injury in patients suffering from severe forms is a direct consequence of the virus or secondary manifestations of systemic inflammation. The liver plays an essential role in the development of the inflammatory storm typical of this disease, and its involvement is associated with worse clinical outcomes and a higher risk of morbidity and mortality from Coronavirus disease 2019 (COVID-19).

METHODS

Ten patients suffering from severe COVID-19 disease who died between January 2020 and December 2021 were included in the present analysis. These subjects underwent a post mortem examination with a focused evaluation of the hepatic injury. Also, several laboratory parameters have been evaluated, with a primary focus on prothrombin time, partial thromboplastin time, fibrinogen, antithrombin III, and D-dimers to detect coagulative changes.

RESULTS

The main cause of death was represented by pulmonary thromboembolism events (50%). The analysis of coagulation laboratory parameters and liver biomarkers revealed a statistically significant rise in aPTT and ALP, and a decrease in albumin, when comparing the blood value at admission and death. We also found high levels of D-dimers in most of the subjects at the time of hospitalization. Interestingly, the post mortem analysis of the liver showed ample morphologic variability, with several disease features. In detail, the liver histology revealed the following: the presence of a variable degree of micro- and macrovacuolar steatosis, inflammation (also, hepato-cholangitis), and variable fibrosis. Of mention, we were also able to detect organized fibrinous material.

CONCLUSIONS

Our results indicate that in subjects with a severe form of COVID-19, liver disease is related to changes in coagulative and fibrinolytic pathways. In particular, we noted low fibrinogen levels and high D-dimer levels with histological liver findings. Our data suggest that fibrinogen and D-dimers may be used as prognostic markers to detect the severity of liver disease in patients with COVID-19. Finally, we underline the crucial role of coagulation balance in subjects with severe forms of COVID-19.

Current knowledge of thrombocytopenia in sepsis and COVID-19

Thrombocytopenia, characterized by a decrease in platelet count, is commonly observed in sepsis and COVID-19. In sepsis, thrombocytopenia can result from various mechanisms, including impaired platelet production in the bone marrow, accelerated platelet destruction due to increased inflammation, sequestration of platelets in the spleen, immune-mediated platelet destruction, or dysregulated host responses. Similarly, thrombocytopenia has been reported in COVID-19 patients, but the immune-related mechanisms underlying this association remain unclear. Notably, interventions targeting thrombocytopenia have shown potential for improving outcomes in both sepsis and COVID-19 patients. Understanding these mechanisms is crucial for developing effective treatments.

Preliminary Study of sCD14 and sCD163 as Predictors of Disease Severity and ICU Admission in COVID-19: Relation to Hematological Parameters, Blood Morphological Changes and Inflammatory Biomarkers

Background and Objectives

Research supports the role of monocyte/macrophage activation in COVID-19 immunopathology. This study aimed to evaluate sCD14 and sCD163 - the monocyte activation markers - and to investigate their relation to hematological parameters and blood morphology in COVID-19 infection.

Methods

This is a case-control study that included 70 COVID-19 patients. Patients were subdivided into two groups: 23 severely diseased ICU-admitted patients and another group of 47 non-ICU-admitted patients. sCD163 and sCD14 levels were determined using ELISA.

Results

sCD163 and sCD14 showed significantly higher levels in sera of patients compared to the control group, with significantly higher levels of sCD163 in ICU-admitted patients than non-ICU admitted patients. Receiver operating characteristic curve analysis demonstrated the usefulness of sCD163 with a cut-off value of 734 ng/mL as a potential marker to discriminate between ICU and non-ICU admitted COVID-19 patients (sensitivity of 81.16%; specificity of 96.67% and positive predictive value of 98% with area under the curve of 0.930). sCD163 levels showed a positive correlation with total white blood cells, absolute neutrophilic count, Neutrophil/Lymphocyte ratio, and a negative correlation with platelet count. sCD14 levels positively correlated with D-dimer values associated with a shift to the left and neutrophilic toxic granulations in blood morphology.

Conclusion

High sCD163 and sCD14 levels, hematological parameters, and blood morphology reflect monocyte activation in COVID-19 infection. sCD163 is a potential marker of disease severity. These findings support further study of therapeutics targeting macrophage activity in COVID-19 patients with high sCD163 levels.

Platelet Activation and Thrombosis in COVID-19

Although thrombosis frequently occurs in infectious diseases, the coagulopathy associated with COVID-19 has unique characteristics. Compared with bacterial sepsis, COVID-19-associated coagulopathy presents with minimal changes in platelet counts, normal prothrombin times, and increased D-dimer and fibrinogen levels. These differences can be explained by the distinct pathophysiology of the thromboinflammatory responses. In sepsis-induced coagulopathy, leukocytes are primarily responsible for the coagulopathy by expressing tissue factor, releasing neutrophil extracellular traps, multiple procoagulant substances, and systemic endothelial injury that is often associated with vasoplegia and shock. In COVID-19-associated coagulopathy, platelet activation is a major driver of inflammation/thrombogenesis and von Willebrand factor and platelet factor 4 are deeply involved in the pathogenesis. Although the initial responses are localized to the lung, they can spread systemically if the disease is severe. Since the platelets play major roles, arterial thrombosis is not uncommon in COVID-19. Despite platelet activation, platelet count is usually normal at presentation, but sensitive biomarkers including von Willebrand factor activity, soluble P-selectin, and soluble C-type lectin-like receptor-2 are elevated, and they increase as the disease progresses. Although the role of antiplatelet therapy is still unproven, current studies are ongoing to determine its potential effects.

Alterations in platelet proteome signature and impaired platelet integrin αIIbβ3 activation in patients with COVID-19

BACKGROUND

Patients with COVID-19 are at increased risk of thrombosis, which is associated with altered platelet function and coagulopathy, contributing to excess mortality.

OBJECTIVES

To characterize the mechanism of altered platelet function in COVID-19 patients.

METHODS

The platelet proteome, platelet functional responses, and platelet-neutrophil aggregates were compared between patients hospitalized with COVID-19 and healthy control subjects using tandem mass tag proteomic analysis, Western blotting, and flow cytometry.

RESULTS

COVID-19 patients showed a different profile of platelet protein expression (858 altered of the 5773 quantified). Levels of COVID-19 plasma markers were enhanced in the platelets of COVID-19 patients. Gene ontology pathway analysis demonstrated that the levels of granule secretory proteins were raised, whereas those of platelet activation proteins, such as the thrombopoietin receptor and protein kinase Cα, were lowered. Basally, platelets of COVID-19 patients showed enhanced phosphatidylserine exposure, with unaltered integrin α_IIbβ₃ activation and P-selectin expression. Agonist-stimulated integrin α_IIbβ₃ activation and phosphatidylserine exposure, but not P-selectin expression, were decreased in COVID-19 patients. COVID-19 patients had high levels of platelet-neutrophil aggregates, even under basal conditions, compared to controls. This association was disrupted by blocking P-selectin, demonstrating that platelet P-selectin is critical for the interaction.

CONCLUSIONS

Overall, our data suggest the presence of 2 platelet populations in patients with COVID-19: one of circulating platelets with an altered proteome and reduced functional responses and another of P-selectin-expressing neutrophil-associated platelets. Platelet-driven thromboinflammation may therefore be one of the key factors enhancing the risk of thrombosis in COVID-19 patients.

Liver injury in COVID-19: Clinical features, potential mechanisms, risk factors and clinical treatments

The coronavirus disease 2019 (COVID-19) pandemic has been a serious threat to global health for nearly 3 years. In addition to pulmonary complications, liver injury is not uncommon in patients with novel COVID-19. Although the prevalence of liver injury varies widely among COVID-19 patients, its incidence is significantly increased in severe cases. Hence, there is an urgent need to understand liver injury caused by COVID-19. Clinical features of liver injury include detectable liver function abnormalities and liver imaging changes. Liver function tests, computed tomography scans, and ultrasound can help evaluate liver injury. Risk factors for liver injury in patients with COVID-19 include male sex, preexisting liver disease including liver transplantation and chronic liver disease, diabetes, obesity, and hypertension. To date, the mechanism of COVID-19-related liver injury is not fully understood. Its pathophysiological basis can generally be explained by systemic inflammatory response, hypoxic damage, ischemia-reperfusion injury, and drug side effects. In this review, we systematically summarize the existing literature on liver injury caused by COVID-19, including clinical features, underlying mechanisms, and potential risk factors. Finally, we discuss clinical management and provide recommendations for the care of patients with liver injury.

Parameters and Morphological Changes of Erythrocytes and Platelets of COVID-19 Subjects: A Longitudinal Cohort Study

Purpose

Information about dynamic changes occurring in the parameters and morphology of erythrocytes and platelets during the coronavirus disease 2019 (COVID-19) infection and convalescence is scarce. To explore potential associations between dynamic erythrocyte and platelet parameters, morphological changes, and the course or severity of the disease is essential.

Patients and Methods

From January 17th, 2020, to February 20th, 2022, we followed up on 35 patients with non-severe and 11 patients with severe COVID-19 following their discharge. We collected clinical features, dynamic complete blood count (CBC), and peripheral blood smears (PBS) and analyzed parameter and morphological changes of erythrocytes and platelets depending on the course or severity of the disease. The course of the disease included four periods, namely onset (T1), discharge (T2), 1-year follow-up (T3), and 2-year follow-up (T4).

Results

Red blood cell (RBC) counts and hemoglobin were the lowest in T2, followed by T1, and lower in T1 and T2 than in T3 and T4. Inversely, the red blood cell distribution width (RDW) was the highest in T2, followed by T1, and higher than in T3 and T4. Compared to non-severe patients, the platelet of severe patients was lower in T1 and T2. In contrast, the mean platelet volume (MPV) and platelet distribution width (PDW) tended to be higher in severe patients. Similarly, anisocytosis was more common in peripheral blood smears at early stages and in severe patients. Finally, large platelets were more common in severe patients.

Conclusion

Anisocytosis of erythrocytes and large platelets are found in patients with severe COVID-19, these changes may help primary hospitals to identify patients with a high risk of severe COVID-19 at an early stage.

Clinical and Inflammatory Profile of COVID-19 Infection at a Tertiary Care Centre in Northern Part of Tamil Nadu – A Retrospective Study

Introduction

The coronavirus disease (COVID-19) pandemic has incurred high costs for the entire planet. The complex interactions between the host, virus, and environment have resulted in various clinical outcomes. It is crucial to comprehend sickness severity and outcome predictors to provide early preventative measures for a better outcome. The current study aimed to determine the association of clinical and inflammatory profiles with the outcome of COVID-19 infection in patients admitted to the intensive care unit.

Methods

This retrospective study was done in patients admitted to intensive care units for COVID-19 with a positive reverse transcriptase polymerase chain reaction (RTPCR) assay. A total of 125 patients above 18 years were included in the study. The patient’s age, gender, and co-morbidities like type 2 diabetes mellitus, hypertension, respiratory illness, and coronary artery disease were noted. The patient’s symptomatology, vital signs, oxygen saturation (Spo2), need for inotropes, and non-invasive positive pressure ventilator support (NIPPV) were observed. Computed tomography severity score (CTSS) and hematological and inflammatory parameters at the time of admission were noticed. Patient’s management and treatment outcomes as survivors and non-survivors were noted.

Results

The mean age was significantly greater in non-survivors. The common symptoms were fever, respiratory distress, cough, muscle pain, and sore throat. The leucocyte count, C-reactive protein (CRP), urea, creatinine, interleukin-6 (IL-6), and lactate dehydrogenase (LDH) were greater, and platelet counts were lower significantly in the non-survivors group. On multivariable logistic regression, CT severity score, NIPPV, and IL-6 had an odds ratio of 1.17, 0.052, and 1.03, respectively. IL-6 had a sensitivity of 81.5% and a specificity of 81.8% with a cut-off value of 37.5.

Conclusion

Vigilant monitoring of leucocyte count, CRP, urea, creatinine, IL-6, LDH, platelet count, and CT severity score is essential for managing COVID-19 infection. IL-6 was found to be a significant marker as a predictor of outcome in our study.

Cytokine patterns in cystic fibrosis patients with different microbial infections in oropharyngeal samples

BACKGROUND

Cytokines play a crucial role in the immune system's regulation by mediating protective responses to infections. anti-inflammatory and pro-inflammatory cytokines are in equilibrium. Therefore, any alteration in cytokine production or cytokine receptor expression might result in pathological illnesses and health issues. Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane regulator (CFTR) gene. Lung infection in these patients is related to chronic bacterial airway infection and inflammation, which is triggered by some inflammatory cytokines. Our goal was to compare the cytokine patterns in CF patient's serum and PBMCs caused by microbial pathogens that colonized their airways to controls.

METHODS

ELISA and Real-time PCR were used to determine the levels of IL-10, IFN-γ, IL-4, TGF-β, IL-8, and IL-17 in serum and PBMC cells. Blood parameters in both patients and healthy people were studied.

RESULTS

An increase in IL-10, IFN-γ, IL-4 (p-v = 0.03, 0.024 and 0.003) levels and a decrease in IL-17 (p-v = 0.004) was found in Pseudomonas aeruginosa positive patients. There were no different in TGF-β and IL-8 (p-value = 0.778 and 0.903) in this patients. IL-10, IFN-γ, and IL-4 (p-value = 0.023, 0.001 and 0.002) levels were high in Staphylococcus aureus positive patients and TGF-β, IL-17, and IL-8 (p-value = 0.085, 0.167 and 0.362) were not significantly different in the patient and control groups. IFN-γ and IL-4 levels were higher in patients without infection who had normal microbiota (p-v = 0.002 and 0.024). In patients with P. aeruginosa, WBC and platelets increased, and MCH and MCV decreased. Patients with normal microbiota had less MCV.

CONCLUSION

According to our research, patients with P. aeruginosa, S. aureus, and normal microbiota are exposed to cytokine alterations and changes in blood factors. The link between the CF patient's airway microbiota and the kind of generated cytokines might lead to the modulation of inflammatory cytokines alone or in combination with antibiotics, reducing disease-causing effects while avoiding drug resistance.

Proteomic Profile of Procoagulant Extracellular Vesicles Reflects Complement System Activation and Platelet Hyperreactivity of Patients with Severe COVID-19

Background

Extracellular vesicles (EVs) are a valuable source of biomarkers and display the pathophysiological status of various diseases. In COVID-19, EVs have been explored in several studies for their ability to reflect molecular changes caused by SARS-CoV-2. Here we provide insights into the roles of EVs in pathological processes associated with the progression and severity of COVID-19.

Methods

In this study, we used a label-free shotgun proteomic approach to identify and quantify alterations in EV protein abundance in severe COVID-19 patients. We isolated plasma extracellular vesicles from healthy donors and patients with severe COVID-19 by size exclusion chromatography (SEC). Then, flow cytometry was performed to assess the origin of EVs and to investigate the presence of circulating procoagulant EVs in COVID-19 patients. A total protein extraction was performed, and samples were analyzed by nLC-MS/MS in a Q-Exactive HF-X. Finally, computational analysis was applied to signify biological processes related to disease pathogenesis.

Results

We report significant changes in the proteome of EVs from patients with severe COVID-19. Flow cytometry experiments indicated an increase in total circulating EVs and with tissue factor (TF) dependent procoagulant activity. Differentially expressed proteins in the disease groups were associated with complement and coagulation cascades, platelet degranulation, and acute inflammatory response.

Conclusions

The proteomic data reinforce the changes in the proteome of extracellular vesicles from patients infected with SARS-CoV-2 and suggest a role for EVs in severe COVID-19.

Red Blood Cell Morphologic Abnormalities in Patients Hospitalized for COVID-19

Peripheral blood smear is a simple laboratory tool, which remains of invaluable help for diagnosing primary and secondary abnormalities of blood cells despite advances in automated and molecular techniques. Red blood cells (RBCs) abnormalities are known to occur in many viral infections, typically in the form of mild normo-microcytic anemia. While several hematological alterations at automated complete blood count (including neutrophilia, lymphopenia, and increased red cell distribution width—RDW) have been consistently associated with severity of COVID-19, there is scarce information on RBCs morphological abnormalities, mainly as case-reports or small series of patients, which are hardly comparable due to heterogeneity in sampling times and definition of illness severity. We report here a systematic evaluation of RBCs morphology at peripheral blood smear in COVID-19 patients within the first 72 h from hospital admission. One hundred and fifteen patients were included, with detailed collection of other clinical variables and follow-up. A certain degree of abnormalities in RBCs morphology was observed in 75 (65%) patients. Heterogenous alterations were noted, with spiculated cells being the more frequent morphology. The group with >10% RBCs abnormalities had more consistent lymphopenia and thrombocytopenia compared to those without abnormalities or <10% RBCs abnormalities (p < 0.018, and p < 0.021, respectively), thus underpinning a possible association with an overall more sustained immune-inflammatory “stress” hematopoiesis. Follow-up analysis showed a different mortality rate across groups, with the highest rate in those with more frequent RBCs morphological alterations compared to those with <10% or no abnormalities (41.9%, vs. 20.5%, vs. 12.5%, respectively, p = 0.012). Despite the inherent limitations of such simple association, our results point out towards further studies on erythropoiesis alterations in the pathophysiology of COVID-19.

Current and novel biomarkers of thrombotic risk in COVID-19: a Consensus Statement from the International COVID-19 Thrombosis Biomarkers Colloquium

Coronavirus disease 2019 (COVID-19) predisposes patients to thrombotic and thromboembolic events, owing to excessive inflammation, endothelial cell activation and injury, platelet activation and hypercoagulability. Patients with COVID-19 have a prothrombotic or thrombophilic state, with elevations in the levels of several biomarkers of thrombosis, which are associated with disease severity and prognosis. Although some biomarkers of COVID-19-associated coagulopathy, including high levels of fibrinogen and D-dimer, were recognized early during the pandemic, many new biomarkers of thrombotic risk in COVID-19 have emerged. In this Consensus Statement, we delineate the thrombotic signature of COVID-19 and present the latest biomarkers and platforms to assess the risk of thrombosis in these patients, including markers of platelet activation, platelet aggregation, endothelial cell activation or injury, coagulation and fibrinolysis as well as biomarkers of the newly recognized post-vaccine thrombosis with thrombocytopenia syndrome. We then make consensus recommendations for the clinical use of these biomarkers to inform prognosis, assess disease acuity, and predict thrombotic risk and in-hospital mortality. A thorough understanding of these biomarkers might aid risk stratification and prognostication, guide interventions and provide a platform for future research.

Baseline Thrombocytopenia and Disease Severity Among COVID-19 Patients, Tibebe Ghion Specialized Hospital COVID-19 Treatment Center, Northwest Ethiopia

Background

Thrombocytopenia and platelet indices in COVID-19 patients were important for prompt treatment and management of the disease. Therefore, the main objective of this study was to assess the prevalence of thrombocytopenia, platelet indices, and its association with disease severity among COVID-19 patients at the Tibebe Ghion Specialized Hospital, COVID-19 treatment center, Northwest Ethiopia.

Methods

A cross-sectional study was conducted among 117 conveniently recruited COVID-19 patients from March to June 2021. Socio-demographic and clinical data were collected using a structured questionnaire and checklist, respectively. The platelet parameters were analyzed by the Mindray-BC 5800 automated hematological analyzer. ANOVA and Kruskal-Wallis tests were used to compare the difference between parametric and non-parametric continuous variables, respectively. Binary logistic regression was used to identify the factors associated with thrombocytopenia. A P-value < 0.05 was defined as statistically significant for all statistical tests.

Results

Among COVID-19 patients, 45, 43 and 29 were mild, moderate and severe, respectively. 65.8% of the patients were males and 34.2% were alcohol drinkers with a mean age of 50.6 ± 15.4. Moreover, 44.4% of the patients had co-morbidity. Thrombocytopenia was presented in 23.9% of the patients. It was 4.57 (95% CI: 1.30-16.07) and 6.10 (95% CI: 1.54-24.08) times more likely in the moderate and severe cases compared to mild cases, respectively. Disease severity was also associated with PDW (P-value = 0.001).

Conclusion

Even though thrombocytopenia was not presented in most moderate and severe COVID-19 patients, thrombocytopenia and PDW were associated with disease severity.

Implications of COVID-19 on Thrombotic Profile of Severely Affected Patients

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is a novel viral disease that spread as a global pandemic in 2020 by infecting millions of people across the world. Its clinical prognosis is dependent on various coagulatory parameters since thrombotic events are frequently associated with infection severity.

METHODS

A total of 383 COVID-19 patients enrolled in Rajiv Gandhi Super Specialty Hospital, Delhi, India, were included in the present retrospective study. Patients were divided into three categories, severe (n = 141), moderate (n = 138), and mild (n = 104) based on infection severity. Various thrombotic parameters and anticoagulant levels were measured in 70 patients and further analyzed.

RESULTS

Coagulopathy is seen in COVID-19 patients (n = 70) with a significant increase in fibrinogen, D-dimer levels, and prothrombin time in patients with severe and moderate disease compared to patients with a mild infection. Approximately, 70% of patients with severe and moderate disease demonstrated fibrinogen levels higher than the standard reference range. 60.41% of patients with severe disease showed significantly higher D-dimer levels. Thrombotic parameters were notably elevated in the nonsurvivors group compared to COVID-19 survivors. Nearly, 91% of patients with severe infection had anticoagulant protein S levels below the reference range.

CONCLUSION

COVID-19 infection severely impacts the blood coagulation cascade, which might lead to the manifestation of severe symptoms and increased mortality in patients.

Integrated miRNA/cytokine/chemokine profiling reveals severity-associated step changes and principal correlates of fatality in COVID-19

Inflammatory cytokines and chemokines (CC) drive COVID-19 pathology. Yet, patients with similar circulating CC levels present with different disease severity. Here, we determined 171 microRNAomes from 58 hospitalized COVID-19 patients (Cohort 1) and levels of 25 cytokines and chemokines (CC) in the same samples. Combining microRNA (miRNA) and CC measurements allowed for discrimination of severe cases with greater accuracy than using miRNA or CC levels alone. Severity group-specific associations between miRNAs and COVID-19-associated CC (e.g., IL6, CCL20) or clinical hallmarks of COVID-19 (e.g., neutrophilia, hypoalbuminemia) separated patients with similar CC levels but different disease severity. Analysis of an independent cohort of 108 patients from a different center (Cohort 2) demonstrated feasibility of CC/miRNA profiling in leftover hospital blood samples with similar severe disease CC and miRNA profiles, and revealed CCL20, IL6, IL10, and miR-451a as key correlates of fatal COVID-19. These findings highlight that systemic miRNA/CC networks underpin severe COVID-19.

Long-term perturbation of the peripheral immune system months after SARS-CoV-2 infection

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious respiratory virus which is responsible for the coronavirus disease 2019 (COVID-19) pandemic. It is increasingly clear that recovered individuals, even those who had mild COVID-19, can suffer from persistent symptoms for many months after infection, a condition referred to as "long COVID", post-acute sequelae of COVID-19 (PASC), post-acute COVID-19 syndrome, or post COVID-19 condition. However, despite the plethora of research on COVID-19, relatively little is known about the molecular underpinnings of these long-term effects.

METHODS

We have undertaken an integrated analysis of immune responses in blood at a transcriptional, cellular, and serological level at 12, 16, and 24 weeks post-infection (wpi) in 69 patients recovering from mild, moderate, severe, or critical COVID-19 in comparison to healthy uninfected controls. Twenty-one of these patients were referred to a long COVID clinic and > 50% reported ongoing symptoms more than 6 months post-infection.

RESULTS

Anti-Spike and anti-RBD IgG responses were largely stable up to 24 wpi and correlated with disease severity. Deep immunophenotyping revealed significant differences in multiple innate (NK cells, LD neutrophils, CXCR3+ monocytes) and adaptive immune populations (T helper, T follicular helper, and regulatory T cells) in convalescent individuals compared to healthy controls, which were most strongly evident at 12 and 16 wpi. RNA sequencing revealed significant perturbations to gene expression in COVID-19 convalescents until at least 6 months post-infection. We also uncovered significant differences in the transcriptome at 24 wpi of convalescents who were referred to a long COVID clinic compared to those who were not.

CONCLUSIONS

Variation in the rate of recovery from infection at a cellular and transcriptional level may explain the persistence of symptoms associated with long COVID in some individuals.

Nuts and bolts of COVID-19 associated coagulopathy: the essentials for management and treatment

INTRODUCTION

COVID-19-associated coagulopathy (CAC) is a well-recognized hematologic complication among patients with severe COVID-19 disease, where macro- and micro-thrombosis can lead to multiorgan injury and failure. Major societal guidelines that have published on the management of CAC are based on consensus of expert opinion, with the current evidence available. As a result of limited studies, there are many clinical scenarios that are yet to be addressed, with expert opinion varying on a number of important clinical issues regarding CAC management.

METHODS

In this review, we utilize current societal guidelines to provide a framework for practitioners in managing their patients with CAC. We have also provided three clinical scenarios that implement important principles of anticoagulation in patients with COVID-19.

CONCLUSION

Overall, decisions should be made on acase by cases basis and based on the providers understanding of each patient's medical history, clinical course and perceived risk.

Platelets in the perspective of COVID-19; pathophysiology of thrombocytopenia and its implication as prognostic and therapeutic opportunity

Despite endorsed and exponential research to improve diagnostic and therapeutic strategies, efforts have not yet converted into a better prospect for patients infected with the novel coronavirus (2019nCoV), and still, the name of SARS-CoV-2 is coupled with numerous unanswered questions. One of these questions is concerning how this respiratory virus reduces the number of platelets (PLTs)? The results of laboratory examinations showed that about a quarter of COVID-19 cases experience thrombocytopenia, and more remarkably, about half of these patients succumb to the infection due to coagulopathy. These findings have positioned PLTs as a pillar in the management as well as stratifying COVID-19 patients; however, not all the physicians came into a consensus about the prognostic value of these cells. The current review aims to unravel the contributory role of PLTs s in COVID-19; and alsoto summarize the original data obtained from international research laboratories on the association between COVID-19 and PLT production, activation, and clearance. In addition, we provide a special focus on the prognostic value of PLTs and their related parameters in COVID-19. Questions on how SARS-CoV-2 induces thrombocytopenia are also responded to. The last section provides a general overview of the most recent PLT- or thrombocytopenia-related therapeutic approaches. In conclusion, since SARS-CoV-2 reduces the number of PLTs by eliciting different mechanisms, treatment of thrombocytopenia in COVID-19 patients is not as simple as it appears and serious cautions should be considered to deal with the problem through scrutiny awareness of the causal mechanisms.

COVID-19 susceptibility variants associate with blood clots, thrombophlebitis and circulatory diseases

Epidemiological studies suggest that individuals with comorbid conditions including diabetes, chronic lung, inflammatory and vascular disease, are at higher risk of adverse COVID-19 outcomes. Genome-wide association studies have identified several loci associated with increased susceptibility and severity for COVID-19. However, it is not clear whether these associations are genetically determined or not. We used a Phenome-Wide Association (PheWAS) approach to investigate the role of genetically determined COVID-19 susceptibility on disease related outcomes. PheWAS analyses were performed in order to identify traits and diseases related to COVID-19 susceptibility and severity, evaluated through a predictive COVID-19 risk score. We utilised phenotypic data in up to 400,000 individuals from the UK Biobank, including Hospital Episode Statistics and General Practice data. We identified a spectrum of associations between both genetically determined COVID-19 susceptibility and severity with a number of traits. COVID-19 risk was associated with increased risk for phlebitis and thrombophlebitis (OR = 1.11, p = 5.36e-08). We also identified significant signals between COVID-19 susceptibility with blood clots in the leg (OR = 1.1, p = 1.66e-16) and with increased risk for blood clots in the lung (OR = 1.12, p = 1.45 e-10). Our study identifies significant association of genetically determined COVID-19 with increased blood clot events in leg and lungs. The reported associations between both COVID-19 susceptibility and severity and other diseases adds to the identification and stratification of individuals at increased risk, adverse outcomes and long-term effects.

Intelligent Platelet Morphometry

Technological advances in image-based platelet analysis or platelet morphometry are critical for a better understanding of the structure and function of platelets in biological research as well as for the development of better clinical strategies in medical practice. Recently, the advent of high-throughput optical imaging and deep learning has boosted platelet morphometry to the next level by providing a new set of capabilities beyond what is achievable with traditional platelet morphometry, shedding light on the unexplored domain of platelet analysis. This Opinion article introduces emerging opportunities in 'intelligent' platelet morphometry, which are expected to pave the way for a new class of diagnostics, pharmacometrics, and therapeutics.