Coagulation Factor XIII in Cerebral Venous Thrombosis

Platelet Phenotype Analysis of COVID-19 Patients Reveals Progressive Changes in the Activation of Integrin αIIbβ3, F13A1, the SARS-CoV-2 Target EIF4A1 and Annexin A5

Background: The fatal consequences of an infection with severe acute respiratory syndrome coronavirus 2 are not only caused by severe pneumonia, but also by thrombosis. Platelets are important regulators of thrombosis, but their involvement in the pathogenesis of COVID-19 is largely unknown. The aim of this study was to determine their functional and biochemical profile in patients with COVID-19 in dependence of mortality within 5-days after hospitalization. Methods: The COVID-19-related platelet phenotype was examined by analyzing their basal activation state via integrin αIIbβ3 activation using flow cytometry and the proteome by unbiased two-dimensional differential in-gel fluorescence electrophoresis. In total we monitored 98 surviving and 12 non-surviving COVID-19 patients over 5 days of hospital stay and compared them to healthy controls (n = 12). Results: Over the observation period the level of basal αIIbβ3 activation on platelets from non-surviving COVID-19 patients decreased compared to survivors. In line with this finding, proteomic analysis revealed a decrease in the total amount of integrin αIIb (ITGA2B), a subunit of αIIbβ3, in COVID-19 patients compared to healthy controls; the decline was even more pronounced for the non-survivors. Consumption of the fibrin-stabilizing factor coagulation factor XIIIA (F13A1) was higher in platelets from COVID-19 patients and tended to be higher in non-survivors; plasma concentrations of the latter also differed significantly. Depending on COVID-19 disease status and mortality, increased amounts of annexin A5 (ANXA5), eukaryotic initiation factor 4A-I (EIF4A1), and transaldolase (TALDO1) were found in the platelet proteome and also correlated with the nasopharyngeal viral load. Dysregulation of these proteins may play a role for virus replication. ANXA5 has also been identified as an autoantigen of the antiphospholipid syndrome, which is common in COVID-19 patients. Finally, the levels of two different protein disulfide isomerases, P4HB and PDIA6, which support thrombosis, were increased in the platelets of COVID-19 patients. Conclusion: Platelets from COVID-19 patients showed significant changes in the activation phenotype, in the processing of the final coagulation factor F13A1 and the phospholipid-binding protein ANXA5 compared to healthy subjects. Additionally, these results demonstrate specific alterations in platelets during COVID-19, which are significantly linked to fatal outcome.

Intraoperative Thrombophilia-Associated Thrombosis of Both Saphenous Veins during Harvesting for Coronary Artery Bypass Grafting

Introduction  Intraoperative thrombosis of saphenous veins (SV) during open harvesting is very rare. Case Report  We present a case of a 60-year-old male patient with multivessel coronary artery disease and a history of a non-ST elevation acute coronary syndrome, and type-2 diabetes mellitus admitted for coronary artery bypass grafting, in whom bilateral intraoperative SV thrombosis occurred during graft harvesting. Routine thrombophilia screening showed no abnormalities and cancer was excluded. Compared with healthy controls, we observed prolonged fibrin clot lysis time and increased thrombin generation reflected by endogenous thrombin potential. Scanning electron microscopy of the thrombosed material revealed compact and thick fibrin layer on the clot surface with a solid mass of unusually compressed platelets and erythrocytes underneath. The patient was tested for fibrinogen and factor (F) XIII polymorphisms, and was found to be heterozygous for β-fibrinogen HaeIII (-455G > A) and FXIII Val34Leu (100G > T). Conclusion  β-fibrinogen HaeIII and FXIII Val34Leu polymorphisms are reflected in reduced clot permeability and susceptibility to lysis, and might contribute to intraoperative SV thrombosis during vascular grafting procedures. Carriers of those are at risk of primary venous graft failure after bypass procedures.

Prothrombogenic polymorphic variants of hemostatic and folate metabolism genes In patients with aseptic cerebral venous thrombosis

Cerebral venous sinus thrombosis (CVT) becomes the cause of stroke in less than 1% of patients. In 20-30% of patients, the cause of thrombosis remains unclear, and thrombosis is considered idiopathic. Inherited hypercoagulable conditions significantly increase the risk of CVT. The aim of the study was to evaluate the frequency of prothrombogenic polymorphic variants of hemostatic and methionine-homocysteine metabolism genes alleles and genotypes in patients with aseptic CVT. Fifty one patients aged 18–75 with aseptic CVT were examined. The control group included 36 healthy volunteers. Neuroimaging methods included brain MRI in standard modes (T1, T2, T2 d-f (FLAIR), DWI) and MR venosinusography. All patients were surveyed to identify carriers of prothrombogenic polymorphic variants of hemostatic and folate metabolism genes alleles and genotypes. Prothrombogenic polymorphic variants of hemostatic genes were detected in 94% of patients, and the variants of the methionine-homocysteine metabolism genes were observed in 86% of patients. The differences between distributions of alleles and genotypes 5G6754G of the PAI-1 gene, G103T of the FXIIIA1 gene, A66G of the MTRR gene, A2756G of the MTR gene in the group of patients with CVT and in the control group were significant. Allele 4G, genotypes 4G/4G and 5G/4G of 5G6754G polymorphism of the PAI-1 gene; allele T of G103Т polymorphism of the FXIIIA1 gene; allele G and genotype A/G of A66G polymorphism of the MTRR gene; allele G and genotype A/G of A2756G polymorphism of the MTR gene correlated with aseptic CVT. It was concluded that the gene polymorphisms 5G6754G (PAI-1), G103T (FXIIIA1), A66G (MTRR) and A2756G (MTR) carriage increased the risk of aseptic CVT and did not affect the thrombosis clinical manifestations.