Search Results (563)

Background: COVID-19 is associated with coagulopathy and increased mortality. The ABO blood group system has been implicated in modulating susceptibility to SARS-CoV-2 infection and disease severity, but its relationship with viral RNAemia, spike gene mutations, and thrombosis remains underexplored. Methods: We analyzed 446 hospitalized COVID-19 patients between 2021 and 2022. SARS-CoV-2 RNAemia was assessed via RT-qPCR on whole blood, and spike gene mutations were identified through whole-genome sequencing in RNAemia-positive samples. ABO blood groups were determined by agglutination testing, and thrombotic events were evaluated using coagulation markers. Statistical analyses included chi-square tests and Kruskal–Wallis tests, with significance set at p < 0.05. Results: RNAemia was detected in 26.9% of patients, with no significant association with ABO blood group (p = 0.175). Omicron was the predominant variant, especially in blood group A (62.5%). The N501Y mutation was the most prevalent in group O (53.2%), and K417N was most prevalent in group B (36.9%), though neither reached statistical significance. Thrombotic events were significantly more common in blood group A (OR = 2.08, 95% CI = 1.3–3.4, p = 0.002), particularly among RNAemia-positive patients. Conclusions: ABO blood group phenotypes, particularly group A, may influence thrombotic risk in the context of SARS-CoV-2 RNAemia. While no direct association was found between blood group and RNAemia or spike mutations, the observed trends suggest potential host–pathogen interactions. Integrating ABO typing and RNAemia screening may enhance risk stratification and guide targeted thromboprophylaxis in COVID-19 patients. Full article

Background: Studies have suggested a synergism between lenalidomide (LEN) and ibrutinib (IBR) in multiple myeloma (MM). Both downregulate IRF4, a key target and master transcriptional factor regulating myeloma cell survival. Method: A 3 + 3 phase I trial was conducted to determine the maximum tolerated dose (MTD) of IBR in combination with LEN + dexamethasone (DEX) in patients with relapsed/refractory (RR) MM who had at least one prior line of therapy. Three dose levels (DLs) were planned. The cycle length was 28 days. IBR was administered orally daily in doses of 560 mg on DL1-2 and 840 mg on DL3, LEN was administered orally on days 1–21 in doses of 15 mg on DL1 and 25 mg on DL2-3, and DEX was administered orally on days 1, 8, 15, and 22 in a dose of 40 mg if age < 75 years or in a dose of 20 mg if it was ≥75 years for DL1-3. Patients with a glomerular filtration rate (GFR) <60 but ≥30 mL/min were treated in accordance with the manufacturer’s instructions with LEN 10 mg. Dose-limiting toxicities (DLTs) included the following: grade 4 neutropenia lasting more than 5 days, thrombocytopenia, febrile neutropenia, nausea, vomiting or diarrhea; grade 3 thrombocytopenia with bleeding or platelet transfusion; and grade 3–4 hyperglycemia or a thrombotic/embolic event, and other nonhematologic toxicities. The overall response rate (ORR) was defined as the percentage of patients with a partial response (PR), very good partial response (VGPR), or complete response (CR) according to IMWG criteria on two consecutive evaluations at least 4 weeks apart. The clinical benefit rate (CBR) was defined as the percentage of patients with stable disease (SD) or a better outcome on two consecutive evaluations at weeks apart. Results: Fourteen patients (DL1: six patients; DL2: three patients; DL3: five patients) were registered for the study from March 2019 to May 2023, prior to its closure due to limited accrual. Thirteen patients are included in the summary of toxicities and response as one patient on DL3 halted participation prior to the start of the treatment. Two patients on DL3 were excluded from the determination of MTD: one having discontinued cycle 1 treatment due to COVID-19 infection and the another having mistakenly taken 280 mg/day of IBR instead of the assigned 840 mg/day dose during cycle 1. Only one patient developed a DLT, on DL1 with grade 3 non-viral hepatitis. The median number of cycles administered was 4 (range: 1–56). Severe toxicities reported included grade 4 lymphocytopenia (1), grade 4 thrombocytopenia (1), and grade 5 sepsis in the setting of PD (1). Disease responses included a VGPR on DL1 and CR on DL3. Thus, the ORR was 15.4% (90% CI: 2.8–41.0%). One patient on DL1 maintained SD for 4.6 years before discontinuing the treatment to undergo an alternative therapy. Another five patients maintained SD for ≥ 2 consecutive cycles. Thus, the CBR was 61.5% (90% CI: 35.5–83.4%). Conclusions: The combination of LEN with IBR in RR MM proved feasible, with manageable toxicities and the majority of discontinuations being due to disease progression. Full article

Background: Pancreatic Ductal Adenocarcinoma (PDAC) is one of the most common malignancies associated with thrombotic events. While there is research present on various techniques of portal vein reconstruction, there is limited published data on the techniques and/or considerations of reconstruction in the setting of complete portal vein occlusion. We therefore sought to analyze and present our experience of this clinical scenario. Methods: This was a retrospective analysis of a prospectively collected database. All patients who underwent portal vein resection and/or reconstruction during a pancreatic resection were included. Post-operatively, all patients underwent a contrast-enhanced CT scan on post-operative day 1 to assess for any portal vein thrombus. Results: Pancreatic resection with portal vein reconstruction was performed in 183 patients. Complete PV occlusion was seen in 12 patients at the time of surgery. In those patients with an occluded PV, reconstruction options included primary repair with end-end anastomosis (n = 2) or use of an interposition graft (n = 9). Interposition graft conduits included the left renal vein (n = 6), tubularized bovine pericardium (n = 3), and femoral vein (n = 1). Post-operative portal vein thrombus was seen in 4/12 patients. The majority of patients (n = 7) were discharged on therapeutic anticoagulation, 4 were discharged on an antiplatelet, and 1 patient received neither. Conclusions: Based on our series, we would recommend attempting PV reconstruction in these patients with an interposition graft (with autologous left renal vein or bovine pericardium). We believe that with this technique, the post-operative thrombosis risk is similar to PV reconstructions in non-occluded patients. Full article

Myeloproliferative neoplasms (MPNs) are chronic blood cancers characterized by overproduction of blood cells, leading to increased thrombotic and ischemic risk. Patients frequently experience symptoms including fatigue, abdominal discomfort, and complications from thrombotic events, which significantly impact the quality of life (QoL). Many patients inquire about complementary and integrative medicine (CIM) approaches, including nutritional interventions and supplements, creating opportunities for healthcare providers to engage in meaningful discussions guided by the principle of safety. This review examines the current evidence for integrative approaches in MPN management, focusing on nutrition, microbiota, supplements, mind–body techniques, and acupuncture. We analyze the available data on anti-inflammatory interventions, QoL improvement strategies, and treatment tolerance enhancement. The review provides clinicians with evidence-based guidance for safely integrating complementary therapeutic approaches with conventional MPN treatment. This integrative approach represents an opportunity to develop more comprehensive and personalized therapeutic paradigms in hematology while ensuring that complementary interventions serve as adjuncts to evidence-based medical treatment. Full article

Myeloproliferative neoplasms (MPNs) are clonal hematopoietic disorders characterized by excessive proliferation of one or more myeloid lineages, frequently accompanied by an elevated risk of thrombotic events. Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, are implicated in numerous inflammatory and vascular pathophysiological processes. In this study, we analyzed the association between selected MMP polymorphisms, rs1799750, rs243865, rs3025058, rs3918242, and rs17576, and thrombotic risk as well as clinical characteristics in patients with MPNs. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Among the polymorphisms analyzed, a statistically significant association was identified between the MMP-9 rs3918242 CT genotype and an increased risk of arterial thrombosis (OR = 4.206, CI 1.337–13.234, p = 0.014). Moreover, rs3918242 CT was associated with thrombotic events (both arterial and venous thrombosis combined), suggesting a potential contributory role in the prothrombotic phenotype observed in MPNs (OR = 3.200, CI 1.110–9.258, p = 0.031). These findings indicate that genetic variation in MMP-9, particularly rs3918242, may serve as a predictive marker for vascular complications in MPN patients. Further studies with larger cohorts are warranted to confirm these associations and to elucidate the molecular mechanisms underlying the contribution of MMP polymorphisms to thrombosis in MPNs. Full article

Background: Retinal vascular occlusion (RVO) and retinal artery occlusion (RAO) have been reported as rare adverse events following COVID-19 vaccination, raising concerns about vaccine safety. This review synthesizes cohort and case–control studies assessing the association between COVID-19 vaccines and RVO/RAO, while exploring potential pathophysiological mechanisms. Methods: We analyzed large-scale population-based studies from South Korea, Europe, and the TriNetX database, focusing on odds ratios (OR), hazard ratios (HR), and relative risks (RR) across mRNA and adenoviral vector vaccines. Pathological processes were hypothesized based on molecular and clinical evidence. Results: Studies investigating the association between COVID-19 vaccination and retinal vascular occlusion show conflicting results; some studies report no association (e.g., OR 0.93, 95% CI 0.60–1.45), others suggest reduced risk (e.g., OR 0.80, 95% CI 0.64–0.99), and one indicates increased risk over two years (HR 2.19, 95% CI 2.00–2.39). Adenoviral vector vaccines, particularly ChAdOx1, show higher RAO incidence in specific cohorts. Proposed mechanisms include vaccine-induced immune thrombotic thrombocytopenia (VITT) via anti-PF4 antibodies, spike protein-mediated endothelial dysfunction, and adjuvant-driven inflammation. Conclusions: While causality remains unproven, temporal heterogeneity and vaccine type-specific risks warrant further investigation. Longitudinal studies with robust controls are needed to clarify these associations in the post-pandemic context. Full article

Background/Objectives: Immature platelet fraction (IPF) and reticulated platelets (RPs) are biomarkers reflecting the youngest and most metabolically active platelets in circulation. RPs, a subset of immature platelets, contain residual RNA and have been associated with increased thrombotic potential. Elevated IPF levels indicate enhanced platelet production, commonly observed during elevated platelet turnover, such as in autoimmune reactions, consumption, and thrombotic events. This systematic review aims to evaluate the potential role of IPF and RPs in the context of cerebrovascular events, specifically ischemic and hemorrhagic stroke, as well as transient ischemic attacks (TIAs), and to assess their clinical utility in stroke monitoring and management. Methods: A comprehensive literature search was conducted in PubMed, Scopus, Cochrane Library, and Web of Science for studies published between 2000 and 2024, which focused on IPF and RPs in human subjects with cerebrovascular events. Results: Six studies met the inclusion criteria. Findings suggest that elevated levels of IPF and RP are associated with the acute and chronic phases of ischemic stroke and TIA and may reflect increased platelet turnover and thrombotic activity. Some evidence supports their role in predicting stroke severity, recurrence, and underlying etiology, although results are not yet consistent across all studies. Conclusions: IPF and RPs are emerging biomarkers with potential applications in acute ischemic stroke and risk stratification. While current evidence is promising, further research is needed to standardize measurement techniques and validate their routine use in clinical practice. Full article

Reactive nitrogen species (RNS), particularly peroxynitrite (ONOO⁻), play a central role in post-translational modifications (PTMs) of proteins, including fibrinogen, a key component of the coagulation cascade. This review explores the structural and functional consequences of fibrinogen nitration, with a focus on its impact on clot formation, morphology, mechanical stability, and fibrinolysis. Nitration, primarily targeting tyrosine residues within functional domains of the Aα, Bβ, and γ chains, induces conformational changes, dityrosine crosslinking, and aggregation into high molecular weight species. These modifications result in altered fibrin polymerization, the formation of porous and disorganized clot networks, reduced mechanical resilience, and variable susceptibility to fibrinolysis. Moreover, nitrated fibrinogen may affect interactions with platelets and endothelial cells, although current evidence remains limited. Emerging clinical studies support its role as both a prothrombotic mediator and a potential biomarker of oxidative stress in cardiovascular and inflammatory diseases. Finally, we explore both pharmacological interventions, such as NOX inhibitors, and natural antioxidant strategies at counteracting fibrinogen nitration. Overall, fibrinogen nitration emerges as a critical molecular event linking oxidative stress to thrombotic risk. Full article

Objectives: We wished to evaluate the safety profile of the Janus kinase (JAK) inhibitors used in the Spanish population; to study the onset of major adverse cardiovascular events (MACEs) and thrombotic events (arterial and venous); and to analyze the factors associated with the onset of these events. Methods: We conducted a retrospective observational study of a cohort of patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), and psoriatic arthritis (PsA) included in the biological therapy registry of the Rheumatology Department of Virgen Macarena University Hospital (HUVM), Seville, Spain, who started targeted treatment between 2019 and late 2024. We collected data on disease activity, traditional cardiovascular risk factors, the Charlson comorbidity index, previous synthetic or biologic drug therapy, the use of corticosteroids (and their dose), severity data (structural damage, extra-articular manifestations), and adverse events at the end of follow-up (e.g., MACEs, infections, neoplasms, and herpes zoster). We performed a descriptive bivariate analysis and a multivariate logistic regression analysis (dependent variable: MACEs) to identify factors that were independently associated with MACEs. Results: The study population comprised 137 patients (110 with RA, 18 with PsA, and 9 with SpA) who were followed up for a mean of 3.9 (2.6) years. Most patients had received JAK inhibitors as their second-line or subsequent treatment. At the end of the follow-up, 82 patients (66.7%) continued their treatment. Nine patients (6.6%) experienced a MACE, and five experienced a heart attack. All of these patients had RA. We found no differences between JAK inhibitors in terms of the incidence of the adverse events studied. Patients who experienced MACEs were more often male and smokers (current or former) and more often had hypertension and diabetes. No significant differences were found in the association with disease activity or previous or concomitant treatment. The factors that were independently associated with MACEs were a previous cardiovascular event (OR, 10.74; 95%CI, 1.05–113.7; p = 0.036), male sex (OR, 9.7; 95%CI, 1.6–76.5; p = 0.016), diabetes mellitus (OR, 10.3; 95%CI, 1.75–83; p = 0.013), and the duration of treatment with JAK inhibitors (OR, 1.47; 95%CI, 1.13–2.01; p = 0.005). Conclusions: We found no differences in the onset of adverse events, specifically MACEs, between the different JAK inhibitors analyzed. These events are more common in patients who already have cardiovascular risk factors, such as diabetes mellitus, or who have already experienced a cardiovascular event. JAK inhibitors broadly suppress cytokines in patients whose disease is refractory to other treatments. However, we must continue to evaluate their long-term safety in real-world studies. Full article

Background/Objectives: Apixaban is favored over warfarin for atrial fibrillation (Afib) and venous thromboembolism (VTE) due to its effectiveness, safety, and lack of routine monitoring. However, managing anticoagulation in hospitalized patients with acute kidney injury (AKI) is challenging due to altered pharmacokinetics and limited safety data. This study assesses the safety and efficacy of apixaban versus warfarin in these patients. Methods: This retrospective chart review at King Abdulaziz Medical City in Riyadh included adult patients (≥18 years) with AKI, as defined by the Kidney Disease Improving Global Outcome (KDIGO) guideline. Primary outcomes were rates of major and minor bleeding within 30 days, as defined by the International Society on Thrombosis and Haemostasis (ISTH), and thrombotic events. Secondary outcomes included 30-day rates of all-cause mortality and hospital readmissions. Results: Among 513 patients, 294 received apixaban and 219 received warfarin. Major bleeding within 30 days was significantly lower in the apixaban group (3.4%) compared to warfarin (7.3%) (p = 0.0461). Minor bleeding rates were similar (6.5% apixaban vs. 5.5% warfarin; p = 0.616). Thrombotic events occurred in 6.8% of patients, with no significant difference between apixaban (6.5%) and warfarin (7.3%) (p = 0.739). Mortality rates were 8.0%, with no significant difference (8.8% apixaban vs. 6.8% warfarin; p = 0.3846). Readmission rates were comparable (38.8% for apixaban vs. 39.7% for warfarin; p = 0.9499). Conclusions: In hospitalized AKI patients, apixaban was associated with a lower major bleeding risk compared to warfarin, with similar rates of thrombotic events, mortality, and readmissions, suggesting apixaban may be a safer option, warranting further research. Full article

Background and Clinical Significance: Hereditary Fibrinogen Disorders (HFDs) are a group of rare, inherited coagulation disorders with a wide spectrum of clinical presentations, ranging from asymptomatic cases to severe bleeding or thrombotic events. Among these, hereditary hypofibrinogenemia (HH) poses particular challenges in obstetric care due to its unpredictable course and limited evidence-based guidelines. Case Presentation: This case report describes the novel obstetrical management of a 37 years old multiparous woman with severe HH (SHH) guided not only by fibrinogen levels but also by rotational thromboelastometry (ROTEM^®), a global test of hemostasis using specific parameters such as FIBTEM^® and NATEM^® assays. Despite persistent low fibrinogen levels during labor and peripartum (<100 mg/dL), favorable maternal and neonatal outcomes were achieved by relying on ROTEM^®-based parameters to guide clinical decisions. Conclusions: Current recommendations for managing pregnancies in women with HFDs are largely based on expert consensus and exclusively use fibrinogen levels. This case supports the use of specific assays (FIBTEM^® and NATEM^®) of the ROTEM^® global test of hemostasis as valuable tools in the obstetric management of women with HH. The use of FIBTEM^® and NATEM^® assays could provide individualized perinatal care, avoiding unnecessary therapeutic interventions and aiming for optimal perinatal outcomes. Full article

Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare thrombotic disorder first identified in 2021 as a catastrophic syndrome associated with anti-SARS-CoV-2 adenoviral vector (AdV)-vaccine administration. It is characterized by the presence of oligo- or monoclonal anti-PF4 antibodies able to induce in vitro platelet activation in the presence of PF4. In addition to this immune-based pathomechanism, random splicing events of the Adv-vector DNA encoding for SARS-CoV-2 spike protein resulting in the secretion of soluble spike variants have been postulated as a possible pathophysiological mechanism. More recently, some novel clinical-pathological anti-PF4-associated entities also characterized by thrombosis, thrombocytopenia, and VITT-like antibodies but independent from heparin or AdV-vaccine administration have been identified. To date, these VITT-like disorders have been reported following the administration of vaccines different from anti-SARS-CoV-2 AdV-vaccines, like human papillomavirus (HPV) and mRNA-based COVID-19 vaccines, following a bacterial or viral respiratory infection, and in patients with a monoclonal gammopathy of undetermined significance. The purpose of this review is to provide an update on the knowledge on VITT pathogenesis, focusing on recent findings on anti-PF4 antibodies, on a possible genetic predisposition to VITT, on VITT-antibody intracellular activated pathways, on lipid metabolism alterations, and on new VITT-like disorders. Full article

Background: Chronic kidney disease (CKD) and its advanced stage, end-stage renal disease (ESRD), affect millions worldwide and are associated with a paradoxical hemostatic imbalance—marked by both increased thrombotic and bleeding risks—which complicates anticoagulant use and demands clearer, evidence-based clinical guidance. Design: This study is a critical review synthesizing the current literature on anticoagulant therapy in CKD and ESRD, with emphasis on altered pharmacokinetics, clinical complications, and therapeutic adjustments. Data Sources: PubMed, Scopus, and Google Scholar were searched for articles discussing anticoagulation in CKD/ESRD, focusing on pharmacokinetics, clinical outcomes, and dosing recommendations. Study Selection: Studies examining the safety, efficacy, and pharmacokinetics of anticoagulants—including heparin, low-molecular-weight heparin (LMWH), warfarin, and direct oral anticoagulants (DOACs)—in CKD and ESRD populations were included. Data Extraction and Synthesis: Key findings were summarized to highlight the dose modifications, therapeutic considerations, and clinical challenges in managing anticoagulation in CKD/patients with ESRD. Emphasis was placed on balancing thrombotic and bleeding risks and identifying gaps in existing guidelines. Results: Patients with CKD and ESRD exhibit a paradoxical hypercoagulable state marked by platelet dysfunction, altered coagulation factors, and vascular endothelial damage. This condition increases the risk of thrombotic events, such as deep vein thrombosis (DVT) and pulmonary embolism (PE), while simultaneously elevating bleeding risks. Hemodialysis and CKD-associated variables further complicate the management of coagulation. Among anticoagulants, unfractionated heparin (UFH) is preferred due to its short half-life and adjustability based on activated partial thromboplastin time (aPTT). Low-molecular-weight heparins (LMWHs) offer predictable pharmacokinetics but require dose adjustments in CKD stages 4 and 5 due to reduced clearance. Warfarin necessitates careful dosing based on the estimated glomerular filtration rate (eGFR) to maintain an international normalized ratio (INR) ≤ 4, minimizing bleeding risks. Direct oral anticoagulants (DOACs), particularly Apixaban, are recommended for patients with eGFR < 15 mL/min or those on dialysis, although data on other DOACs in CKD remain limited. The lack of comprehensive guidelines for anticoagulant use in CKD and ESRD highlights the need for individualized, patient-centered approaches that account for comorbidities, genetics, and clinical context. Conclusions: Managing anticoagulation in CKD/ESRD is challenging due to complex coagulation profiles and altered pharmacokinetics. Judicious dosing, close monitoring, and patient-centered care are critical. High-quality randomized controlled trials are needed to establish clear guidelines and optimize therapy for this vulnerable population. Full article

Cryofibrinogenemia (CF) may be secondary to COVID-19. To establish this relationship, in PRECOVID-19 and COVID-19 periods we assess: (a) frequency and clinical features in patients with CF; (b) study of CF syndrome. We study all cryofibrinogen tests performed in a single university hospital in Northern Spain, comparing two periods: PRECOVID-19 (July 2017–February 2020) and COVID-19 (March 2020–October 2022). CF syndrome was established with two positive cryofibrinogen tests plus compatible cutaneous manifestations and/or thrombotic events (TE). CF was found in 129/279 patients. In the COVID-19 period, they had more positive tests (50.2% vs. 28%; p = 0.0047), younger age (33 vs. 55 years, p = 0.054) and fewer cardiovascular (CV) risk factors (39.1% vs. 78.6%, p = 0.005). Cutaneous manifestations were the most frequent in both periods (81.4%), particularly purpuric macules (29.5%). Skin ulcers showed statistically significant differences, being more frequent in the PRECOVID-19 era (35.7% vs. 7.8%, p = 0.008). Thrombotic CV events were also observed (13.2%), particularly venous thromboembolisms (12.2%). Severe complications were more frequent in the PRECOVID-19 era, although this difference did not reach statistical significance (35.7% vs. 19.1%; p = 0.169). CF was secondary in 68/129 cases, mainly to SARS-CoV-2 (n = 45). CF syndrome was found in 27.9% of patients. After one year, most patients were clinically stable or in remission. Mild dermatological lesions were the most frequent manifestations, and most patients recovered. Full article

Severe COVID-19 is often associated with coagulopathy and thrombotic complications. The underlying mechanisms are complex and multifactorial, involving platelet activation, dysregulation of the complement cascade, fibrinolytic imbalance, release of pro-inflammatory cytokines, immunothrombosis, antiphospholipid antibodies, and alterations in the von Willebrand factor (vWF)/ADAMTS13 axis. These pathways are also implicated in thrombotic microangiopathies (TMAs), characterized by endothelial injury and widespread microvascular thrombosis. In this prospective monocentric observational study, we investigated whether COVID-19-associated coagulopathy meets the criteria for TMA and evaluated the roles of complement activation and vWF/ADAMTS13 imbalance in disease severity. Forty-three hospitalized COVID-19 patients were enrolled and stratified by disease severity. Blood samples collected at admission were analyzed for hematologic, coagulation, inflammatory, and complement parameters. A 30-day follow-up recorded survival and thrombotic events. All patients showed elevated vWF and factor VIII levels; however, only vWF collagen-binding activity (vWF-CBA) significantly correlated with disease severity. ADAMTS13 activity remained above 60% in all cases, and no schistocytes were detected, arguing against a diagnosis of classical TMA. Nevertheless, the vWF-CBA/ADAMTS13 ratio was significantly higher in severe cases, particularly in unvaccinated individuals, suggesting endothelial dysregulation. Complement analysis revealed increased C5a levels and decreased C3b/iC3b ratios in severe disease, consistent with complement activation and consumption. C2 levels were also lower in these patients. Although complement activation and vWF/ADAMTS13 imbalance did not directly correlate, both pathways showed a similar trend according to disease severity. Overall, our findings indicate that COVID-19-related coagulopathy does not fulfill the criteria for classical TMA but shows features of complement-mediated endothelial injury and vWF dysregulation. The vWF-CBA may serve as a rapid, standardized tool for assessing endothelial dysfunction. Activation of the complement system, particularly via the lectin and alternative pathways, appears central to the prothrombotic state in severe COVID-19. Full article