Intravascular Thrombosis Research Articles

Immunohistochemical evaluation of fibrin/fibrinogen, d-dimers, and intravascular thrombosis in brains of dogs with meningoencephalitis of unknown origin

Granulomatous meningoencephalitis (GME) and necrotizing encephalitides (NE) are the most common immune-mediated inflammatory diseases of the central nervous system in dogs. Activation of the fibrinolytic system in multiple sclerosis, a similar immune-mediated disease affecting the central nervous system in humans, seems to be related to disease progression. The aim of this study was to identify fibrin/fibrinogen and D-dimer deposition, as well as presence of intravascular thrombosis (IVT) in brains of dogs with a diagnosis of GME or NE. Immunohistochemical studies using antibodies against fibrin/fibrinogen and D-dimers were performed. Statistical analyses were performed to determine whether there were differences in the presence and location of fibrin/fibrinogen, D-dimers deposits, and IVT between GME and NE. Samples from sixty-four dogs were included in the study: 32 with a diagnosis of GME and 32 with a diagnosis of NE. Fibrin/fibrinogen depositions were detected in all samples and d-dimers were detected in 43/64 samples. IVT was present in 29/64 samples, with a significantly higher score in samples from dogs with NE than in samples from dogs with GME (P = 0.001). These data support hemostatic system activation in both diseases, especially NE. This finding might be related to the origin of the necrotic lesions seen in NE, which could represent chronic ischemic lesions. Further studies are needed to investigate the association between vascular lesions and the histopathological differences between GME and NE and the hemostatic system as a potential therapeutic target.

Isolation and Optimal Fermentation Conditions of Bacillus licheniformis SFD-Y5 for a New Douchi Fibrinolytic Enzyme Producer

Cardiovascular disease (CVD) has become the leading cause of death, and it is critical to develop new functional foods to prevent intravascular thrombosis, the key cause of CVD. Fermented soy-based food is a good choice because of its native fibrinolytic enzyme (FE) activity. In this study, a strain that can produce a new type of fibrinolytic enzyme was selected from Chinese Douchi and identified as Bacillus licheniformis SFD-Y5 by molecular biology experiments and physiological and biochemical experiments. Single factor experiments combined with statistical experiments, including Plackett–Burman experiment, steepest ascent experiment and RSM (Box–Behnken design), were used to optimize the fermentation of FE by B. licheniformis SFD-Y5. The final FE activity was 2434.45 ± 28.49 IU/mL under optimal conditions, which is the highest FE activity produced by wild B. licheniformis so far. Further studies showed that Y5 FE is a serine metalloproteinase with good stability at alkaline pHs (pH 8.0–11.0). The results of our study could lay a foundation for the future production, molecular modification and further application in functional foods of Y5 FE.

Investigational Workout for the Diagnosis of Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired rare disease that affects both males and females characterized by the triad of intravascular hemolytic anemia, thrombosis, and bone marrow failure. Flow cytometry is the gold standard for the final diagnosis. This is a PNH case of a 42-year-old Indonesian woman who presented to the emergency department with sustained generalized fatigability, pallor, and jaundice with a history of multiple recurrent previous events managed by blood transfusions. The diagnosis was reached by laboratory studies that revealed hemolytic anemia and erythroid hyperplasia, which was confirmed by a clonal deficiency of CD59 red blood cells (RBCs) using flow cytometry. She was prescribed eculizumab. Hemolytic anemia and jaundice in patients with PNH can be caused by RBCs hemolysis due to the absence of CD55 and CD59 proteins caused by a genetic defect (PIG-A) on the X chromosome. That is why flow cytometry must be made for each patient suspected of having PNH.

Non-invasive in vivo thrombus imaging in patients with ischaemic stroke or transient ischaemic attack

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Life Molecular Imaging provide reagents for GP1 production free of charge. Background and Purpose 18F-GP1 is a novel positron-emitting radiotracer that has high and specific binding affinity for the activated glycoprotein IIb/IIIa receptor, a key receptor in platelet activation and thrombus formation. Preliminary studies 18F-GP1 demonstrated excellent in vivo binding properties which enabled detection of intravascular thrombosis in a range of conditions including coronary thrombosis, left ventricular thrombus, pulmonary thromboembolism, and deep vein thrombosis. In a pilot proof-of-concept study, we aimed to determine its potential clinical application in establishing the role and origin of thrombus in stroke . Methods Autoradiography of 18F-GP1 uptake was performed on post-mortem samples of infarcted brain tissue following an acute ischaemic stroke and from control brain tissue without stroke. Eleven patients with recent ischaemic stroke (n=9) or transient ischaemic attack (n=2) underwent 18F-GP1 positron emission tomography and computed tomography angiography at median of 11 (absolute range 2–21) days from symptom onset. 18F-GP1 uptake (quantified by maximum target-to-background ratio, TBRmax) was assessed in the carotid arteries and brain. Results Ex vivo autoradiography of post-mortem infarcted brain tissue showed focal uptake corresponding to intraluminal thrombus within the culprit vessel and downstream microvasculature. There was also evidence of lower diffuse uptake within some of the infarcted brain tissue reflecting microthrombi within regions of reperfusion haemorrhage. In vivo 18F-GP1 uptake was identified in 9 of 11 patients: 3 in the carotid arteries only, 3 in the brain only and 3 in both the brain and carotid arteries. In those with carotid uptake, 3 participants had >50% stenosis and 3 had non-stenotic disease. One case had bilateral stenotic disease (>70%) but only the culprit carotid artery demonstrated 18F-GP1 uptake. The average uptake was higher in the culprit (median TBRmax 1.55 [interquartile range 1.26–1.82]) compared with the contralateral non-culprit carotid artery (TBRmax 1.22 [1.19–1.6]). In those with brain 18F-GP1 uptake (TBRmax 6.45 [4.89–7.65]), areas of acute infarction on computed tomography correlated with brain 18F-GP1 uptake in 6 cases. There was no brain 18F-GP1 uptake in the 7 cases without CT-defined acute cerebral infarction. Conclusions 18F-GP1 positron emission tomography and computed tomography angiography is a novel non-invasive method of identifying in vivo cerebrovascular thrombosis which holds major promise in understanding the role and origin of thrombosis in stroke.

Lessons Learnt from the Management of Severe COVID-19 Disease in a 93-year-old with Chronic Co-Morbidities at a Resource-constrained Centre in Nigeria – A Retrospective Single Case Study

Introduction: Severe COVID-19 infection is associated with significant mortality in the elderly. This is even more so, when the elderly patient with the disease also has multiple chronic co-morbidities, and is resident in a resource-constrained area.
 Aims/ Objectives: To outline management strategies employed, and important lessons learnt from the successful management of a case of severe COVID-19 disease in a 93-year-old with chronic co-morbidities in a resource-limited setting.
 Methods: We utilized a simple COVID-19 severity categorization algorithm on presentation, to assign the index patient to the appropriate COVID-19 disease severity class and subsequently employed patient’s serial, weekly clinical and laboratory parameters to guide a multi-specialty management protocol.
 Results: A 93-year-old man was referred to a tertiary hospital in Enugu during the second wave of the COVID-19 pandemic, with a 5-day-history of high grade fever, severe fatigue, and altered sensorium. He had been living with diabetes for 48years; recently had worsening glycemic control, and was yet to pass urine in the previous 12hours. He was also being managed conservatively for prostate carcinoma. Examination revealed signs of severe pneumonia and he was drowsy, dehydrated, and had asterixis. A diagnosis of acute kidney injury from septicemia, following community acquired pneumonia and possibly urinary tract infection was made, with COVID-19 infection as a differential. Samples were collected for laboratory investigations while he was recommended for intensive care unit admission for further care. Para-enteral broad spectrum antibiotics, intravenous fluid therapy, intranasal oxygen therapy, basal-bolus-insulin-regimen, and anti-coagulation prophylaxis were instituted. Following laboratory investigation results which included a positive COVID-19 test (clinically categorized as severe disease), severe systemic inflammation, evidence of uro-tract infection, intravascular thrombosis and severe renal impairment, the Nephrology, Infectious disease, Urology teams were invited to co-manage the patient alongside the Endocrinologists. After 27days of collaborative care, patient was discharged with resolution of his symptoms and signs.
 Conclusion: Multi-specialty collaborative care improves patients’ outcome even in the face of severe COVID-19 with associated co-morbidities in elderly patients. Severity stratification ensures life-saving timely care for severe COVID-19 disease.

Expression of eIF6 and its relationship with cell proliferation in colorectal adenocarcinoma

Abstract Objectives Eukaryotic translation initiation factors (eIFs) are genes related to tumor formation. They selectively translate some mRNAs, regulate protein synthesis, promote cell proliferation, and effectively control the progression of some tumors. As a member of this family, eukaryotic translation initiation factor 6 (eIF6) plays a crucial role in tumor formation and progression. Exploring the expression characteristics of eIF6 and proliferating cell nuclear antigen (PCNA), a proliferation-associated factor, in colorectal adenocarcinoma (CRAC) and analyzing their correlation and clinical significance can provide a theoretical basis for the study of CRAC and objective biological indicators for the clinical judgment of tumor formation and progression. Methods The GEPIA database was used to predict the trend of eIF6 and PCNA in CRAC. Sixty-four patients diagnosed with CRAC and undergoing surgical treatment were selected from January 2017 to November 2022. CRAC tissues and normal mucous tissues (>3 cm away from the tumor margin) were retained. The expression of eIF6 and PCNA was detected by immunohistochemistry (IHC). Colon cancer cell lines SW480, HCT15, and SW620 and normal colon cell line NCM460 were selected, and the expression of eFI6 and PCNA in these cells was detected by Western blot. Results A trend of elevated expression of eIF6 and PCNA was predicted in CRAC by the GEPIA database. The expression levels of eIF6 (65.63 % vs. 9.38 %, X2=43.2000, p<0.0001) and PCNA (84.38 % vs. 46.88 %, X2=19.9481, p<0.0001) were higher in CRAC tissues than that in normal mucosa as indicated by IHC. Significant difference in eIF6 and PCNA expression was found among different maxim tumor diameters and depths of infiltration in colon adenocarcinoma (p<0.05). No statistical difference in eIF6 and PCNA expression was observed among different genders, ages, degrees of differentiation, LNMets, intravascular cancer thrombosis, TNM stages, and numbers of lymph node metastases (p>0.05). A positive correlation was found between eIF6 and PCNA in CRAC (X2=5.05, r=0.77, p=0.0283). Their expression was significantly higher in SW480, HCT15, and SW620 than in NCM460 (p<0.05). Conclusions eIF6 is highly expressed in CRAC, participates in tumor formation and progression, and has a positive correlation with PCNA.

Abstract #1407180: Drug Induced Acute Pancreatitis Secondary to Ezetimibe

Drug induced acute pancreatitis (DIAP) is a rare clinical entity with incidence of <2% in general population. Most cases are typically mild and have excellent prognosis but prompt diagnosis and cessation of offending drug is important to avoid adverse outcomes. A 58-year-old female former smoker with history of COPD and hyperlipidemia presented to the hospital with sudden onset abdominal pain radiating to the back associated with nausea and vomiting for 12 hours. On arrival vitals were normal and physical examination showed epigastric tenderness with negative murphy’s sign. Labs showed normal CBC and CMP with elevated serum lipase (2469 U/L – Normal 16 - 61 U/L) concerning for acute pancreatitis. CT abdomen and pelvis showed normal biliary tract. US of the abdomen showed no evidence of gall stone or biliary sludge. Serum lipid panel showed total cholesterol of 193, HDL of 66, LDL of 111 and triglyceride of 87. Serum Calcium was normal. Detailed history revealed no alcohol but that patient recently started ezetimibe 10 mgs daily 8 weeks prior to present due to history of statin intolerance. Her only other medication was inhaled Albuterol taken as needed. Immune panel include IgG-4 was negative. Patient was diagnosed with drug induced acute pancreatitis secondary to ezetimibe, and was managed conservatively cessation of ezetimibe, pain meds and bowel rest. Her overall condition improved in 48 hours and diet was progressed. She was discharged with outpatient follow up. Serum lipase dropped to 74 U/L prior to discharge. Drug induced pancreatitis account for ∼ 5% of all cases of pancreatitis. There is limited data on the exact mechanism by which drugs can induce pancreatitis as most evidence is bases on case reports or meta-analysis. On the basis of these case reports drugs are classified from class I-IV depending on the probability to cause pancreatitis. Some proposed mechanisms include immunologic reactions, direct toxic effect, accumulation of a toxic metabolite, ischemia, intravascular thrombosis, and an increased viscosity of pancreatic juice. Though most cases are mild the identification of the offending drug is crucial to prevent ongoing damage and recurrence. However, in most instances the diagnosis of drug induced pancreatitis and identification of offending drug can be challenging due to the presence of multiple agents. Current proposed criteria for identification include: 1) Pancreatitis develops during treatment with the drug, 2) Other likely causes of pancreatitis are not present 3) Pancreatitis resolves upon discontinuation of the drug and 4) Pancreatitis usually recurs upon re-administration of the drug. Our patient fulfilled 3 of the above criteria which suggest Ezetimibe induced Pancreatitis. Prior to this case there is one more case reported cases of Ezetimibe induced Pancreatitis but in both the cases there is no re-challenge of Ezetimibe which makes it a Class IV drug to cause pancreatitis.

Diagnosis of the right atrial myxoma after treatment of COVID‐19: A case report

Atrial myxoma is a rare disease but has a broad clinical presentation and complication that involves several systems- heart, lungs, brain, and systemic. An interdisciplinary approach is very important to optimize the outcome in patients with atrial myxomas. A thorough examination by primary care providers is crucial. Then radiologists or cardiologists can help with imaging modalities that can help diagnose and characterize the tumor. Prior to surgical resection by cardiothoracic surgeons, patients need to be evaluated by pulmonologists, cardiologists, and anesthesiologists for preoperative risk stratifications. In patients with neurological complications, pulmonary complications, or infectious endocarditis, input from neurologists, hematologists, infectious disease specialists is essential for patient care. In case antiplatelet/anticoagulation therapy or antibiotic treatment is warranted, pharmacists can provide valuable recommendations. Myxoma is the most common benign cardiac primary tumor, occurring in the right atrium in only 15%-20% of cases. This disease is asymptomatic initially depending upon size of the tumor, and symptoms develop as the tumor spreads. Atrial myxomas are associated with a triad of complications, including obstruction, emboli, and constitutional symptoms (such as fever and weight loss). This regard, embolization of the pulmonary circulation system is a complication of right myxoma. The patient was a 40-year-old male who presented to the emergency department complaining of fever and confusion. He had been previously hospitalized due to COVID-19 and treated with Remdesivir and plasmapheresis. He had tachycardia, tachypnea, thrombocytopenia, and increased liver enzymes. Chest imaging showed nodular lesions with necrotic areas and cavitary lesions in both lungs and the right atrium infected clot was seen in echocardiography. He was treated with intravenous antibiotics and finally underwent heart surgery due to the diagnosis of pulmonary septic embolism. The patient was finally diagnosed with right atrial myxoma according to heart mass histopathology. It is worth noting that the patient's thrombosis had already developed on the right atrial myxoma, which delayed the diagnosis in this patient. This thrombus formation was due to the hypercoagulability state of COVID-19 and following the insertion of a central venous catheter to perform plasmapheresis as a complication of treatment. Special attention should be paid to thromboprophylaxis and the early diagnosis of intravascular and intracardiac thrombosis in COVID-19 patients. Furthermore, the use of imaging modalities is recommended to differentiate thrombus from myxoma.

Prevention and Treatment of Acute Coronary Artery Syndrome

Acute coronary syndrome(ACS) refers to a group of clinical symptoms caused by acute myocardial ischemia, including unstable angina pectoris, acute myocardial infarction, and sudden ischemic death. In recent years, studies have shown that the main mechanism of its occurrence is the rupture of plaque and the consequent intravascular thrombosis. Multiple factors may lead to the occurrence of the disease. However, the mechanism of the histomorphological change from pre-fragmentation to post-fragmentation is still unclear. Vasospasm may also play an important role. Prevention of plaque formation and rupture or prevention of thrombosis by antithrombotic therapy is effective in reducing the incidence of acute coronary syndrome, and coronary intervention also reduces the mortality of acute coronary syndrome. Some new therapies, such as gene therapy, are still in the experimental stage. At the same time, people should improve the awareness of disease prevention, and the most active prevention is the best means of disease treatment.

Effect of ischemic preconditioning on skeletal tissue tolerance after warm venous ischemia

Free muscular flaps are commonly used in plastic surgery. The main reason of failure is thrombosis induced by a phenomenon called ischemia reperfusion. Preconditioning showed an interest to prevent ischemia reperfusion injury in transplantation surgery. The aim of the study is to evaluate the effect of ischemic preconditioning on skeletal tissue tolerance after warm venous ischemia. We realized an experimental study with latissimus dorsi flaps of 12 pigs, divided in 6 groups in function of their time of preconditioning and duration of warm venous ischemia. A morphologic analysis was performed measuring cell's diameter and interstitial tissue area and notifying the presence or absence of neutrophils, necrosis or intravascular thrombosis. To detect inflammation, necrosis or hypoxia, immunohistochemistry was effectuated using the follow primary antibodies, AIF, HIF1 alpha, caspase 3, SOD 1 and PKC epsilon. TUNEL assay showed apoptosis cells, were realized. One way Anova test was performed to compare the quantitative evolution over time of histological parameters and rate of apoptosis. Preconditioning of 40min or 1hour allowed to reduced ischemia reperfusion lesions: no cellular or interstitial oedema, reduction of neutrophils infiltrate and intravascular thrombus. TUNEL assay showed a higher rate of apoptosis nucleus for the control group E compared to preconditioning group C and D. Immunohistochemistry results were no relevant. We showed a diminution of lesions of ischemia reperfusion for experimental groups with preconditioning: diminution of interstitial oedema, of cellular oedema, diminution of neutrophils infiltrated and level of apoptosis cells. Preconditioning of 40minutes were as efficient as one hour.

STING activation in platelets aggravates septic thrombosis by enhancing platelet activation and granule secretion

Sepsis is a dysregulated inflammatory consequence of systemic infection. As a result, excessive platelet activation leads to thrombosis and coagulopathy, but we currently lack sufficient understanding of these processes. Here, using the cecal ligation and puncture (CLP) model of sepsis, we observed septic thrombosis and neutrophil extracellular trap formation (NETosis) within the mouse vasculature by intravital microscopy. STING activation in platelets was a critical driver of sepsis-induced pathology. Platelet-specific STING deficiency suppressed platelet activation and granule secretion, which alleviated sepsis-induced intravascular thrombosis and NETosis in mice. Mechanistically, sepsis-derived cGAMP promoted the binding of STING to STXBP2, the assembly of SNARE complex, granule secretion, and subsequent septic thrombosis, which probably depended on the palmitoylation of STING. We generated a peptide, C-ST5, to block STING binding to STXBP2. Septic mice treated with C-ST5 showed reduced thrombosis. Overall, platelet activation via STING reveals a potential strategy for limiting life-threatening sepsis-mediated coagulopathy.

Study of Coagulation Disorders and the Prevalence of Their Related Symptoms among COVID-19 Patients in Al-Jouf Region, Saudi Arabia during the COVID-19 Pandemic

The coronavirus (COVID-19) has affected millions of people around the world. COVID-19 patients, particularly those with the critical illness, have coagulation abnormalities, thrombocytopenia, and a high prevalence of intravascular thrombosis. This work aims to assess the prevalence of coagulation disorders and their related symptoms among COVID-19 patients in the Al-Jouf region of Saudi Arabia. We conducted a retrospective study on 160 COVID-19 patients. Data were collected from the medical records department of King Abdulaziz Specialist Hospital, Sakaka, Al-Jouf, Saudi Arabia. The socio-demographic data, risk factors, coagulation profile investigation results, symptom and sign data related to coagulation disorders, and disease morbidity and mortality for COVID-19 patients were extracted from medical records, and the data were stored confidentially. Males represented the highest prevalence of COVID-19 infection at 65%; 29% were aged 60 or over; 28% were smokers; and 36% were suffering from chronic diseases, with diabetes mellitus representing the highest prevalence. Positive D-dimer results occurred in 29% of cases, with abnormal platelet counts in 26%. Our findings confirm that the dysregulation of the coagulation cascade and the subsequent occurrence of coagulation disorders are common in coronavirus infections. The results show absolute values, not increases over normal values; thus, it is hard to justify increased risk and presence based on the presented data.

Acute limb ischemia due to diclofenac sodium iatrogenic intra-arterial injection: a case report

We report the case of accidental intra-arterial injection of diclofenac sodium in the brachial artery leading to acute limb ischemia. Iatrogenic intra-arterial injection is rarely reported in the literature; however, it is toxic and can lead to limb amputation. Only two cases of intra-arterial injection of diclofenac have been reported in the literature. The proposed pathophysiological mechanism is vasospasm, intravascular thrombosis, and chemical endoarteritis. The most common anatomical location in accidental intra-arterial injection is the antecubital fossa, where branches of the ulnar and brachial arteries are more superficial. The injection of medication must be as careful as possible, since the intra-arterial injection can affect the functional prognosis of the organ.

Management of purpura fulminans skin loss at a regional burns centre: Sixteen-year experience

Purpura fulminans (PF) is a rare syndrome of cutaneous purpura which is the consequence of severe circulatory shock causing intravascular thrombosis, haemorrhagic necrosis, and consequent tissue loss. The aim of this study was to present our 16-year experience of managing PF in a regional burns centre. We performed a single-centre retrospective case series of all patients admitted to the St Andrews Burns Centre at Broomfield Hospital, Chelmsford, Essex, UK, between June 2006 and July 2022 with a diagnosis of PF. Data were extracted by retrospectively searching hospital case notes. Thirteen individuals were identified [five children (mean age 5, range 1-14) and eight adults (mean age 39, range 24-54)]. The total body surface area of cutaneous necrosis ranged from 5% to 80%, with a mean of 27.2%. Patients were treated with an established surgical sequence of total wound debridement and immediate coverage with a cadaveric allograft, followed by staged wound autografting. The mean time from disease onset to wound autografting was 37.3 days (range 20-64 days). Eight individuals (61.6%) required major amputation of at least one limb (proximal to the ankle or wrist joint). Only one mortality (of 80% total body surface area skin loss) was observed in the identified cohort. The large body surface areas often involved in PF cases make management of these wounds well suited for burns centres, wherein established facilities and multidisciplinary teams exist that are familiar with managing large cutaneous burns. We provide a suggested algorithm to aid the management of PF.

Cell-autonomous requirement for ACE2 across organs in lethal mouse SARS-CoV-2 infection.

Angiotensin-converting enzyme 2 (ACE2) is the cell-surface receptor for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). While its central role in Coronavirus Disease 2019 (COVID-19) pathogenesis is indisputable, there remains significant debate regarding the role of this transmembrane carboxypeptidase in the disease course. These include the role of soluble versus membrane-bound ACE2, as well as ACE2-independent mechanisms that may contribute to viral spread. Testing these roles requires in vivo models. Here, we report humanized ACE2-floxed mice in which hACE2 is expressed from the mouse Ace2 locus in a manner that confers lethal disease and permits cell-specific, Cre-mediated loss of function, and LSL-hACE2 mice in which hACE2 is expressed from the Rosa26 locus enabling cell-specific, Cre-mediated gain of function. Following exposure to SARS-CoV-2, hACE2-floxed mice experienced lethal cachexia, pulmonary infiltrates, intravascular thrombosis and hypoxemia-hallmarks of severe COVID-19. Cre-mediated loss and gain of hACE2 demonstrate that neuronal infection confers lethal cachexia, hypoxemia, and respiratory failure in the absence of lung epithelial infection. In this series of genetic experiments, we demonstrate that ACE2 is absolutely and cell-autonomously required for SARS-CoV-2 infection in the olfactory epithelium, brain, and lung across diverse cell types. Therapies inhibiting or blocking ACE2 at these different sites are likely to be an effective strategy towards preventing severe COVID-19.

Rare germline complement factor H variants in patients with paroxysmal nocturnal hemoglobinuria

AbstractPatients with paroxysmal nocturnal hemoglobinuria (PNH) are susceptible to complement-mediated intravascular hemolysis and thrombosis. Factor H (FH) is the main regulator of the complement alternative pathway, which protects cells from unwanted complement-mediated damage. Although FH is not a glycosylphosphatidylinositol-linked molecule, it may play a role in PNH. We sought to determine if rare germline variants in complement factor H (CFH) affect the PNH course, screening 84 patients with PNH treated with eculizumab for rare variants in CFH, CFI, and C3 genes. We compared the allelic frequencies with populational data and a geographically-matched control group, looking for an association between presence of the variants and treatment response (transfusion independence by 6 months). Sixteen patients presented rare variants, 9 in CFH (10.7%). Germline CFH variants were more frequent among patients with PNH than among controls (P = .02) or public data (P < .001) and were more likely to be transfusion-dependent at 6 months after eculizumab initiation (P = .015). With a median follow-up of 5.8 years, 8 of 9 patients with the CFH variant received transfusions, and 2 developed thromboses. None of the patients with the CFH variant had severe aplastic anemia from eculizumab initiation until 6 months. We demonstrated for the first time that rare CFH variants are over-represented among patients with PNH and that germline genetic background may affect the response to eculizumab.

Application of decellularized vascular matrix in small-diameter vascular grafts.

Coronary artery bypass grafting (CABG) remains the most common procedure used in cardiovascular surgery for the treatment of severe coronary atherosclerotic heart disease. In coronary artery bypass grafting, small-diameter vascular grafts can potentially replace the vessels of the patient. The complete retention of the extracellular matrix, superior biocompatibility, and non-immunogenicity of the decellularized vascular matrix are unique advantages of small-diameter tissue-engineered vascular grafts. However, after vascular implantation, the decellularized vascular matrix is also subject to thrombosis and neoplastic endothelial hyperplasia, the two major problems that hinder its clinical application. The keys to improving the long-term patency of the decellularized matrix as vascular grafts include facilitating early endothelialization and avoiding intravascular thrombosis. This review article sequentially introduces six aspects of the decellularized vascular matrix as follows: design criteria of vascular grafts, components of the decellularized vascular matrix, the changing sources of the decellularized vascular matrix, the advantages and shortcomings of decellularization technologies, modification methods and the commercialization progress as well as the application prospects in small-diameter vascular grafts.

Historical Review and Future of Cardiac Xenotransplantation.

Along with the development of immunosuppressive drugs, major advances on xenotransplantation were achieved by understanding the immunobiology of xenograft rejection. Most importantly, three predominant carbohydrate antigens on porcine endothelial cells were key elements provoking hyperacute rejection: α1,3-galactose, SDa blood group antigen, and N-glycolylneuraminic acid. Preformed antibodies binding to the porcine major xenoantigen causes complement activation and endothelial cell activation, leading to xenograft injury and intravascular thrombosis. Recent advances in genetic engineering enabled knock-outs of these major xenoantigens, thus producing xenografts with less hyperacute rejection rates. Another milestone in the history of xenotransplantation was the development of co-stimulation blockaded strategy. Unlike allotransplantation, xenotransplantation requires blockade of CD40-CD40L pathway to prevent T-cell dependent B-cell activation and antibody production. In 2010s, advanced genetic engineering of xenograft by inducing the expression of multiple human transgenes became available. So-called 'multi-gene' xenografts expressing human transgenes such as thrombomodulin and endothelial protein C receptor were introduced, which resulted in the reduction of thrombotic events and improvement of xenograft survival. Still, there are many limitations to clinical translation of cardiac xenotransplantation. Along with technical challenges, zoonotic infection and physiological discordances are major obstacles. Social barriers including healthcare costs also need to be addressed. Although there are several remaining obstacles to overcome, xenotransplantation would surely become the novel option for millions of patients with end-stage heart failure who have limited options to traditional therapeutics.

АНАЛИЗ ВОЗМОЖНОСТЕЙ ПРИМЕНЕНИЯ НОВОГО МЕТОДА ОПРЕДЕЛЕНИЯ УРОВНЯ D-ДИМЕРА В ПЛАЗМЕ КРОВИ У БОЛЬНЫХ С COVID-19 НА ГОСПИТАЛЬНОМ ЭТАПЕ

Introduction. The outbreak of the novel viral infection SARS-CoV-2 and its associated pandemic has generated significant interest among professionals regarding the role of D-dimer as a marker. D-dimer not only reflects the intensity of hemostatic and fibrinolytic reactions but also holds prognostic value. However, the standardization of D-dimer determination remains elusive, as the findings are known to depend on the completeness of fibrinolysis in the vasculature. Objective. This study aims to investigate the objective values of D-dimer levels, taking into consideration the concentration of its terminal fragments in plasma, specifically in patients with intravascular thrombosis associated with coronavirus infection. Materials and Methods. The study involved the examination of sodium citrate-stabilized plasma from 90 patients with severe COVID-19 who required respiratory support upon admission to the intensive care unit (ICU). The ICU mortality rate was 50% within 14 days. Additionally, a control group of 78 healthy individuals was included. The quantitative determination of D-dimer in human plasma was conducted using the Auto Red D-Dimer 700 (Helena Bioscience) and Sysmex CA1500 coagulation analyzer (Sysmex Corporation). Fibrinolysis was stimulated in vitro by streptokinase during sample preparation. The assessment was based on the analysis of blood plasma before and after the administration of the fibrinolysis activator. Results. Using the classical method of determination, D-dimer levels exceeded the cut-off value (300 ng/ml) in 61 out of 90 patients (67.8%). After fibrinolysis stimulation with streptokinase, this number increased to 66 (73.3%). Compared to the survival group, the fatal outcome group exhibited a 143.6% higher D-dimer level using the classical approach (p=0.2355). With the new approach involving streptokinase, the increase was 181.2% (p=0.0257). In one-fifth of fatal cases, the streptokinase-induced D-dimer concentration was more than twice the baseline obtained through the classical approach. Conclusion. The proposed approach for quantitatively determining D-dimer, which incorporates the use of streptokinase, provides more accurate data regarding the plasma concentration of D-dimer neoantigens. These findings establish a potential direction for standardizing such studies in clinical practice, particularly for determining treatment strategies for patients with COVID-19.

COVID-19 as an independent predictor of aspiration thrombectomy in STEMI. National data from the ORPKI register in the years 2020-2022.

Coronavirus disease 2019 (COVID-19) exacerbates intravascular thrombosis that occurs in the coronary artery in ST-elevation myocardial infarction (STEMI). To analyze the impact of COVID-19 on the application and effect of thrombectomy in STEMI patients. 29915 STEMI patients were analyzed, of whom 3139 (10.5%) underwent thrombectomy. COVID-19 (+) was reported in 311 (10.8%). The clinical characteristics and management of STEMI in COVID-19 (+) and COVID-19 (-) patients were compared. A multivariable logistic regression analysis was performed in search of factors influencing thrombectomy. COVID-19 (+) patients had higher Killip class (IV class; n = 33 (12.31%) vs. n = 138 (5.84%); p < 0.0001) and cardiac arrest at baseline was more frequent in this group (n = 25 (8.04%) vs. n = 137 (4.84%); p = 0.016). Thrombolysis in myocardial infarction (TIMI) 3 after percutaneous coronary intervention was less frequent (n = 248 (80.52%) vs. n = 2388 (87.19%); p = 0.001) in the COVID-19 (-) group. Periprocedural mortality was similar in both groups (n = 28 (0.99%) vs. n = 4 (1.29%); p = 0.622). In multivariable regression analysis COVID-19 increased the risk of thrombectomy (OR = 1.23; 97.5% CI: 1.05-1.43; p = 0.001). STEMI patients undergoing aspiration thrombectomy who were COVID-19 (+) were more likely to be in a severe clinical condition (higher Killip class, more frequent cardiac arrest before the procedure) than COVID-19 (-) patients. Despite more intensive antiplatelet and anticoagulant treatment, PCI procedures were less likely to result in an optimal TIMI 3 effect. COVID-19 is an independent strong predictor of patient qualification for aspiration thrombectomy in STEMI.