Внеклеточные ловушки нейтрофилов (NETs) в патогенезе тромбоза и тромбовоспалительных заболеваний

This article summarizes numerous studies on the relationship of biological processes such as inflammation and thrombosis. The huge role of neutrophils and the extracellular neutrophil traps (NETs) secreted by them has been demonstrated. The discovery of NETs has opened new horizons in the understanding of neutrophil biology and the role of these cells in the body. The use of chromatin in combination with the intracellular proteins, as an effective antimicrobial agent has ancient roots and changes our understanding of chromatin only as a carrier of genetic information. Through NETs, neutrophils can contribute to the development of pathological venous and arterial thrombosis or immunothrombosis, as well as atherosclerosis. NETs release has been shown to be one of the causes of thrombosis in conditions such as sepsis and cancer. The presence of NETs in these diseases and conditions makes it possible to use them or individual components as potential biomarkers. NETs and their components may be attractive as therapeutic targets. Further studies of neutrophils and NETs are needed to develop new approaches to the diagnosis and treatment of inflammatory and thrombotic conditions. Perhaps long-forgotten drugs will find a new area for effective use.В данной статье обобщены многочисленные исследования о взаимосвязи таких биологических процессов как воспаление и тромбообразование. Продемонстрирована огромная роль нейтрофиллов и выделяемых ими внеклеточных ловушек нейтрофилов (Neutrophil Extracellular Traps, NETs). Открытие NETs расширило горизонты в понимании биологии нейтрофилов и роли этих клеток в организме. Использование хроматина в сочетании с внутриклеточными белками в качестве противомикробного средства имеет древнюю историю и меняет наше представление о хроматине только как о носителе генетической информации. Благодаря NETs, нейтрофилы могут способствовать развитию патологического венозного и артериального тромбоза или иммунотромбоза, а также атеросклероза. Высвобождение NETs является, как было показано, одной из причин тромбообразования при таких состояниях как сепсис и рак. Наличие NETs при этих заболеваниях и состояниях дает возможность использовать их или отдельные компоненты в качестве потенциальных биомаркеров. NETs и их компоненты могут быть привлекательны в качестве терапевтических мишеней. Дальнейшие исследования нейтрофилов и NETs необходимы для разработки новых подходов к диагностике и лечению воспалительных и тромботических состояний. Возможно, давно забытые препараты найдут новую сферу для эффективного применения

COVID-19, септический шок и синдром диссеминированного внутрисосудистого свертывания крови. Часть 2

The article discusses the issues of hemostatic system disorders in patients with COVID-19. Strengthening the coagulopathy characteristic of DIC-syndrome, is a key sign of deterioration and an unfavorable prognosis in COVID-19 patients. Data obtained by Chinese colleagues demonstrates that a significantly increased level of D-dimer is one of the predictors of death. The article also highlights the preliminary recommendations of the International society of Thrombosis and Hemostasis (ISTH, 2020) to identify markers such as D-dimer, prothrombin time and platelet count as significant predictive markers in severe COVID-19 patients. The necessity of anticoagulant therapy in hospitalized patients is justified. The article discusses the features of sepsis in pregnant women. Data from a meta-analysis of 19 studies evaluating pregnancy complications and outcomes in patients with various coronavirus infections are presented. Despite the complicated course of pregnancy, there were no cases of vertical transmission of viral infection. In the pathogenesis of severe COVID-19 complications with the formation of severe acute respiratory distress syndrome, multi-organ dysfunction, super inflammation and cytokine storm play a leading role. In connection with viral sepsis, the article discusses the role of hemophagocytic lymphohistiocytosis as a hyperinflammatory syndrome characterized by fulminant and fatal hypercytokinemia with multiple organ failure, the role of hyperferritinemia in predicting the outcomes of severe sepsis. Groups of patients at high risk of death are discussed, as well as the need for anticoagulant and anti-cytokine therapy in patients with COVID-19.В статье рассматриваются вопросы нарушения системы гемостаза у пациентов с COVID-19. Нарастание коагулопатии, характерной для диссеминированного внутрисосудистого свертывания крови (ДВС-синдрома), ― ключевой признак ухудшения состояния и неблагоприятного прогноза у пациентов с COVID-19. Приводятся данные, полученные китайскими коллегами, согласно которым значительно повышенный уровень D-димера является одним из предикторов смерти. Также освещены предварительные рекомендации Международного общества тромбоза и гемостаза (International Society on Thrombosis and Haemostasis, ISTH, 2020) по определению таких маркеров, как D-димер, протромбиновое время и количество тромбоцитов, в качестве значимых прогностических маркеров у тяжелых больных COVID-19. Обосновывается необходимость антикоагулянтной терапии у госпитализированных больных. В статье обсуждаются особенности сепсиса у беременных. Приводятся данные метаанализа 19 исследований, посвященных оценке осложнений и исходов беременности у пациенток с различными коронавирусными инфекциями. Несмотря на осложненное течение беременности, не отмечено ни одного случая вертикальной передачи вирусной инфекции. В патогенезе тяжелых осложнений COVID-19 с формированием тяжелого острого респираторного дистресс-синдрома, полиорганной дисфункции ведущую роль играют супервоспаление и цитокиновый шторм. В статье в связи с вирусным сепсисом обсуждается роль гемофагоцитарного лимфогистиоцитоза как гипервоспалительного синдрома, характеризуемого фульминантной и фатальной гиперцитокинемией с полиорганной недостаточностью, роль гиперферритинемии в прогнозировании исходов тяжелого сепсиса. Обсуждаются группы пациентов высокого риска развития летальных исходов, а также необходимость антикоагулянтной и антицитокиновой терапии у больных COVID-19

Thrombotic storm, hemostasis disorders and thromboinflammation in COVID-19

The rate of thrombosis and disseminated intravascular coagulation (DIC) has been increasing in COVID-19 patients. Key features related to such condition include minimal or no risk of bleeding, moderate thrombocytopenia, high plasma fibrinogen as well as complement components level in the areas of thrombotic microangiopathy. The clinical picture is not typical for classic DIC. This review systematizes the pathogenetic mechanisms of hypercoagulation in sepsis and its extreme forms in patients with COVID-19. The latter consist of the thrombosis-related immune mechanisms, the complement activation, the macrophage activation syndrome, the formation of antiphospholipid antibodies, the hyperferritinemia, and the dysregulation of the renin-angiotensin system. Taking into consideration the pathogenetic mechanisms, the biomarkers had been identified related to the prognosis of the disease development. Patients with pre-existing cardiovascular disease and other risk factors, including obesity, diabetes, hypertension, and aging pose the peak risk of dying from COVID-19. We also summarize new data on platelet and endothelial dysfunction, immunothrombosis, and, as a result, thrombotic storm as essential components of COVID-19 severe features

Double vs single internal thoracic artery harvesting in diabetic patients: role in perioperative infection rate

Background: The aim of this prospective study is to evaluate the role in the onset of surgical site infections of bilateral internal thoracic arteries harvesting in patients with decompensated preoperative glycemia. Methods: 81 consecutive patients with uncontrolled diabetes mellitus underwent elective CABG harvesting single or double internal thoracic arteries. Single left ITA was harvested in 41 patients (Group 1, 50.6%), BITAs were harvested in 40 (Group 2, 49.4%). The major clinical end points analyzed in this study were infection rate, type of infection, duration of infection, infection relapse rate and total hospital length of stay. Results: Five patients developed sternal SSI in the perioperative period, 2 in group 1 and 3 in group 2 without significant difference. All sternal SSIs were superficial with no sternal dehiscence. The development of infection from the time of surgery took 18.5 ± 2.1 and 7.3 ± 3.0 days for Groups 1 and 2 respectively. The infections were treated with wound irrigation and debridement, and with VAC therapy as well as with antibiotics. The VAC system was removed after a mean of 12.8 ± 5.1 days, when sterilization was achieved. The overall survival estimate at 1 year was 98.7%. Only BMI was a significant predictor of SSI using multivariate stepwise logistic regression analysis (Odds Ratio: 1.34; 95%Conficdence Interval: 1.02–1.83; p value: 0.04). In the model, the use of BITA was not an independent predictor of SSI. Conclusion: CABG with bilateral pedicled ITAs grafting could be performed safely even in diabetics with poor preoperative glycaemic control

Shiga Toxin and Lipopolysaccharide Induce Platelet-Leukocyte Aggregates and Tissue Factor Release, a Thrombotic Mechanism in Hemolytic Uremic Syndrome

BACKGROUND: Aggregates formed between leukocytes and platelets in the circulation lead to release of tissue factor (TF)-bearing microparticles contributing to a prothrombotic state. As enterohemorrhagic Escherichia coli (EHEC) may cause hemolytic uremic syndrome (HUS), in which microthrombi cause tissue damage, this study investigated whether the interaction between blood cells and EHEC virulence factors Shiga toxin (Stx) and lipopolysaccharide (LPS) led to release of TF. METHODOLOGY/PRINCIPAL FINDINGS: The interaction between Stx or LPS and blood cells induced platelet-leukocyte aggregate formation and tissue factor (TF) release, as detected by flow cytometry in whole blood. O157LPS was more potent than other LPS serotypes. Aggregates formed mainly between monocytes and platelets and less so between neutrophils and platelets. Stimulated blood cells in complex expressed activation markers, and microparticles were released. Microparticles originated mainly from platelets and monocytes and expressed TF. TF-expressing microparticles, and functional TF in plasma, increased when blood cells were simultaneously exposed to the EHEC virulence factors and high shear stress. Stx and LPS in combination had a more pronounced effect on platelet-monocyte aggregate formation, and TF expression on these aggregates, than each virulence factor alone. Whole blood and plasma from HUS patients (n = 4) were analyzed. All patients had an increase in leukocyte-platelet aggregates, mainly between monocytes and platelets, on which TF was expressed during the acute phase of disease. Patients also exhibited an increase in microparticles, mainly originating from platelets and monocytes, bearing surface-bound TF, and functional TF was detected in their plasma. Blood cell aggregates, microparticles, and TF decreased upon recovery. CONCLUSIONS/SIGNIFICANCE: By triggering TF release in the circulation, Stx and LPS can induce a prothrombotic state contributing to the pathogenesis of HUS

Guidance for the Management of Patients with Vascular Disease or Cardiovascular Risk Factors and COVID-19: Position Paper from VAS-European Independent Foundation in Angiology/Vascular Medicine .

COVID-19 is also manifested with hypercoagulability, pulmonary intravascular coagulation, microangiopathy, and venous thromboembolism (VTE) or arterial thrombosis. Predisposing risk factors to severe COVID-19 are male sex, underlying cardiovascular disease, or cardiovascular risk factors including noncontrolled diabetes mellitus or arterial hypertension, obesity, and advanced age. The VAS-European Independent Foundation in Angiology/Vascular Medicine draws attention to patients with vascular disease (VD) and presents an integral strategy for the management of patients with VD or cardiovascular risk factors (VD-CVR) and COVID-19. VAS recommends (1) a COVID-19-oriented primary health care network for patients with VD-CVR for identification of patients with VD-CVR in the community and patients' education for disease symptoms, use of eHealth technology, adherence to the antithrombotic and vascular regulating treatments, and (2) close medical follow-up for efficacious control of VD progression and prompt application of physical and social distancing measures in case of new epidemic waves. For patients with VD-CVR who receive home treatment for COVID-19, VAS recommends assessment for (1) disease worsening risk and prioritized hospitalization of those at high risk and (2) VTE risk assessment and thromboprophylaxis with rivaroxaban, betrixaban, or low-molecular-weight heparin (LMWH) for those at high risk. For hospitalized patients with VD-CVR and COVID-19, VAS recommends (1) routine thromboprophylaxis with weight-adjusted intermediate doses of LMWH (unless contraindication); (2) LMWH as the drug of choice over unfractionated heparin or direct oral anticoagulants for the treatment of VTE or hypercoagulability; (3) careful evaluation of the risk for disease worsening and prompt application of targeted antiviral or convalescence treatments; (4) monitoring of D-dimer for optimization of the antithrombotic treatment; and (5) evaluation of the risk of VTE before hospital discharge using the IMPROVE-D-dimer score and prolonged post-discharge thromboprophylaxis with rivaroxaban, betrixaban, or LMWH