Revisiting the activated protein C-protein S-thrombomodulin ternary pathway: Impact of new understanding on its laboratory investigation

The Molecular Mechanisms of Portal Vein Thrombosis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) represents the sixth most diagnosed cancer worldwide and is the second leading cause of cancer-related death in the world. The association of HCC and portal vein thrombosis (PVT) represents an advanced stage of the tumor. PVT has a prevalence of about 25-50% in HCC, determining poor prognosis and a remarkable reduction in therapeutic perspectives in these patients, leading to severe complications such as ascites, metastasis, an increase in portal hypertension and potentially fatal gastrointestinal bleeding. The aim of this review is to evaluate the molecular mechanisms that are at the basis of PVT development, trying to evaluate possible strategies in the early detection of patients at high risk of PVT.

Haemostatic Gene Expression in Cancer-Related Immunothrombosis: Contribution for Venous Thromboembolism and Ovarian Tumour Behaviour

Ovarian cancer (OC) is the deadliest gynaecological malignancy. Identifying new prognostic biomarkers is an important research field. Haemostatic components together with leukocytes can drive cancer progression while increasing the susceptibility to venous thromboembolism (VTE) through immunothrombosis. Unravelling the underlying complex interactions offers the prospect of uncovering relevant OC prognostic biomarkers, predictors of cancer-associated thrombosis (CAT), and even potential targets for cancer therapy. Thus, this study evaluated the expression of F3, F5, F8, F13A1, TFPI1, and THBD in peripheral blood cells (PBCs) of 52 OC patients. Those with VTE after tumour diagnosis had a worse overall survival (OS) compared to their counterparts (mean OS of 13.8 ± 4.1 months and 47.9 ± 5.7 months, respectively; log-rank test, p = 0.001). Low pre-chemotherapy F3 and F8 expression levels were associated with a higher susceptibility for OC-related VTE after tumour diagnosis (χ2, p < 0.05). Regardless of thrombogenesis, patients with low baseline F8 expression had a shorter progression-free survival (PFS) than their counterparts (adjusted hazard ratio (aHR) = 2.54; p = 0.021). Among those who were not under platelet anti-aggregation therapy, low F8 levels were also associated with a shorter OS (aHR = 6.16; p = 0.006). Moving forward, efforts should focus on external validation in larger cohorts.

Crosstalk between Circulating Tumor Cells and Plasma Proteins-Impact on Coagulation and Anticoagulation

Cancer metastasis is a complex process. After their intravasation into the circulation, the cancer cells are exposed to a harsh environment of physical and biochemical hazards. Whether circulating tumor cells (CTCs) survive and escape from blood flow defines their ability to metastasize. CTCs sense their environment with surface-exposed receptors. The recognition of corresponding ligands, e.g., fibrinogen, by integrins can induce intracellular signaling processes driving CTCs' survival. Other receptors, such as tissue factor (TF), enable CTCs to induce coagulation. Cancer-associated thrombosis (CAT) is adversely connected to patients' outcome. However, cancer cells have also the ability to inhibit coagulation, e.g., through expressing thrombomodulin (TM) or heparan sulfate (HS), an activator of antithrombin (AT). To that extent, individual CTCs can interact with plasma proteins, and whether these interactions are connected to metastasis or clinical symptoms such as CAT is largely unknown. In the present review, we discuss the biological and clinical relevance of cancer-cell-expressed surface molecules and their interaction with plasma proteins. We aim to encourage future research to expand our knowledge of the CTC interactome, as this may not only yield new molecular markers improving liquid-biopsy-based diagnostics but also additional targets for better cancer therapies.

Activity of anticoagulant proteins on the polymer-coated and heparin-coated membranes in an extracorporeal circulation circuit

INTRODUCTION

We performed in vitro experiments using whole human blood without anticoagulants to clarify the activity of anticoagulant proteins on membranes coated with acrylate-copolymer (ACP) with a hydrophilic blood-contacting layer compared to those coated by immobilizing heparin (IHP) in extracorporeal circulation.

METHODS

Whole human blood from healthy volunteers was recirculated in two types of experimental circuits with an ACP-coated reservoir and tubes and an ACP-coated or IHP-coated membrane. To compare the fluctuation of anticoagulant proteins, the circuit pressure at the inlet and outlet of the membrane was measured every 5 min; antithrombin antigen (ATQ), antithrombin activity, protein-C quantitation (PCQ), protein-C activity, protein-S free antigen (PSQ), and protein-S activity were measured at 0, 30, 60, 120, and 180 min in each experiment (n = 5).

RESULTS

The time taken to achieve high circuit pressure (> 300 mmHg) at the inlet of the membrane was significantly shorter in the ACP-coated membrane circuit (28 ± 2.7 min) than in the IHP-coated membrane circuit (54 ± 24 min); however, the ATQ, PCQ, and PSQ at 180 min of recirculation were significantly higher in the former than in the latter (all p < .05).

CONCLUSIONS

ACP-coated membranes can prevent the consumption of anticoagulant proteins but cannot delay circuit thrombogenicity compared to IHP-coated membranes. Considering patient care during the post-extracorporeal circulation period, the use of ACP coating, which can preserve anticoagulant protein, is better in extracorporeal circulation circuits.

Hematology and coagulation preanalytics for clinical chemists: Factors intrinsic to the sample and extrinsic to the patient

In hematology and coagulation, diligence in the preanalytical phase of testing is of critical importance to obtaining reliable test results. If the sample used for testing is unsuitable, even outstanding analytical procedures and technology cannot produce a clinically-reliable result. Therefore, the intent of this manuscript is to review preanalytical factors intrinsic to the sample that affect the hematology and coagulation testing. Factors intrinsic to the sample (excluding in vivo anomalies) can be controlled, theoretically, by phlebotomists (including nurses) and laboratorians in the preanalytical phase of testing. Furthermore, the management and prevention of such factors is highlighted. Erroneous control of preanalytical factors can produce laboratory errors.

Interaction between Antiphospholipid Antibodies and Protein C Anticoagulant Pathway: A Narrative Review

Thrombotic antiphospholipid syndrome (APS) is a condition in which thrombosis in venous, arterial, and/or small vessels is ascribed to the presence of antiphospholipid antibodies (aPL). Among the various proposed pathogenic theories to explain thrombotic APS, those involving the interaction between aPL and the protein C system have gained much consensus. Indeed, robust data show an acquired activated protein C resistance (APC-R) in these patients. The role of aPL in this impairment is clear, but the mechanism of action is uncertain, as the type of aPL and to what extent aPL are involved remains a gray area. Lupus anticoagulant (LA) is often associated with APC-R, but antibodies generating LA comprise those directed to β2-glycoprotein I and antiphosphatidylserine/prothrombin. Moreover, the induction of APC-R by aPL requires the presence of phospholipids and is suppressed by the presence of an excess of phospholipids. How phospholipids exposed on the cell membranes work in the system in vivo is unknown. Interestingly, acquired APC-R due to aPL might explain the clinical phenotypes of thrombotic APS. Indeed, the literature reports cases of both venous and arterial thromboembolism as well as skin necrosis, the latter observed in the severe form of protein C deficiency and in catastrophic APS.

Monocyte activation and acquired autoimmune protein S deficiency promote disseminated intravascular coagulation in a patient with primary antiphospholipid syndrome

Autoimmune protein S (PS) deficiency is a highly thrombotic, potentially life-threatening disorder. Its pathophysiological relevance in the context of primary antiphospholipid syndrome (APS) is unclear. Here, we report the case of a 76-year-old woman, who presented with a painful reticular skin erythema caused by microvascular thromboses. Disseminated intravascular coagulation (DIC) with consumptive coagulopathy was controlled only by continuous anticoagulation. While significantly elevated IgM antibodies to cardiolipin and β2-glycoprotein-I were consistent with primary APS, a function-blocking PS autoantibody of the IgG isotype was detected. Robust microvesicle (MV)-associated tissue factor (TF) procoagulant activity (PCA) was isolated from patient plasma. Moreover, patient IgG, but not IgM, induced expression of TF PCA and release of TF-bearing MVs by peripheral blood mononuclear cells from healthy donors. In primary APS, induction of monocyte TF in combination with an acquired PS inhibitor may provoke a deleterious imbalance of procoagulant and anticoagulant pathways with evolution of thrombotic DIC.

The effect of activated protein C in the experimental disseminated intravascular coagulation model formed by lipopolysaccharide infusion

Purpose:

In this experimental study, activated protein C (APC), which has anticoagulant, antithrombotic, profibrinolytic, anti-inflammatory and antiapoptotic properties, was used to prevent coagulopathy in a disseminated intravascular coagulation (DIC) model formatted with lipopolysaccharide (LPS) infusion.

Methods:

Twenty-five Wistar albino rats weighting 280 – 320 g each were used. They were randomly divided into three groups: sham, control and study groups. To sham group (n = 5), only normal saline was infused. To control (n = 10) and study groups (n = 10), 30 mg/kg LPS was infused for 4 h from femoral vein. After LPS infusion, 100 µg/kg recombinant APC was given during 4 h in study group. Eight hours later, blood samples were taken from abdominal aorta and the animals sacrificed. From these samples, platelet, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer levels were studied.

Results:

Platelet counts and fibrinogen levels were significantly lower in control and study groups than sham group (p < 0.05). The PT, aPTT and D-dimer levels were significantly higher in control and study groups than in sham group (p < 0.05). When comparing control and study groups, platelet counts were not statistically different (p = 0.36). However, the difference of the fibrinogen levels was significant between these groups (p = 0.0001). While PT and aPTT were longer in the study group compared to the control group (p < 0.05), D-dimer levels were lower in the study group than in control (p = 0.0001).

Conclusion:

Use of APC can prevent hypercoagulation and consumption coagulopathy in the DIC as a result of correcting hematological parameters other than prolongation of coagulation time.

COVID-19 Severity and Stroke: Correlation of Imaging and Laboratory Markers

BACKGROUND AND PURPOSE

Coronavirus disease 2019 (COVID-19) appears to be an independent risk factor for stroke. We hypothesize that patients who develop stroke while hospitalized for severe COVID-19 will have higher inflammatory markers and distinct stroke imaging patterns compared with patients positive for COVID-19 with out-of-hospital stroke onset and milder or no COVID-19 symptoms.

MATERIALS AND METHODS

This is a retrospective case series of patients positive for COVID-19 on polymerase chain reaction testing with imaging-confirmed stroke treated within a large health care network in New York City and Long Island between March 14 and April 26, 2020. Clinical and laboratory data collected retrospectively included complete blood counts and creatinine, alanine aminotransferase, lactate dehydrogenase, C-reactive protein, ferritin, and D-dimer levels. All CT and MR imaging studies were independently reviewed by 2 neuroradiologists who recorded stroke subtype and patterns of infarction and intracranial hemorrhage.

RESULTS

Compared with patients with COVID-19 with outside-of-hospital stroke onset and milder or no COVID-19 symptoms (n = 45, 52.3%), patients with stroke already hospitalized for severe COVID-19 (n = 41, 47.7%) had significantly more frequent infarctions (95.1% versus 73.3%, P = .006), with multivascular distributions (56.4% versus 33.3%, P = .022) and associated hemorrhage (31.7% versus 4.4%, P = .001). Patients with stroke admitted with more severe COVID-19 had significantly higher C-reactive protein and ferritin levels, elevated D-dimer levels, and more frequent lymphopenia and renal and hepatic injury (all, P < .003).

CONCLUSIONS

Patients with stroke hospitalized with severe COVID-19 are characterized by higher inflammatory, coagulopathy, and tissue-damage biomarkers, supporting proposed pathogenic mechanisms of hyperinflammation activating a prothrombotic state. Cautious balancing of thrombosis and the risk of hemorrhagic transformation is warranted when considering anticoagulation.

Esophagectomy for Esophageal Cancer in a Patient with Protein C Deficiency: A Case Report

A 63-year-old man with protein C deficiency underwent thoracoscopic esophagectomy and digestive reconstruction using a gastric tube for thoracic esophageal cancer. On postoperative day 3, the gastric tube was removed because of anastomotic leakage and gastric tube necrosis. Digestive reconstruction using a free jejunal graft was attempted 140 days after the first surgery. However, thrombus formation in the artery and vein of the jejunal graft resulted in a failed reconstruction. Ten days after this surgery, digestive reconstruction using the colon was performed with intraoperative heparin administered for anticoagulation control. The surgery was successful, with no thrombus formation afterward. When performing digestive reconstruction in patients with conditions predisposing to thrombus formation, perioperative management should be completed with careful attention toward preventing thrombus formation. In particular, appropriate anticoagulation control, such as the administration of intraoperative heparin, is recommended in patients with protein C deficiency because necrosis of the reconstructed organ is likely.

Central nervous system complications associated with SARS-CoV-2 infection: integrative concepts of pathophysiology and case reports

Coronavirus disease 2019 (COVID-19) is a highly infectious pandemic caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It frequently presents with unremitting fever, hypoxemic respiratory failure, and systemic complications (e.g., gastrointestinal, renal, cardiac, and hepatic involvement), encephalopathy, and thrombotic events. The respiratory symptoms are similar to those accompanying other genetically related beta-coronaviruses (CoVs) such as severe acute respiratory syndrome CoV (SARS-CoV) and Middle East Respiratory Syndrome CoV (MERS-CoV). Hypoxemic respiratory symptoms can rapidly progress to Acute Respiratory Distress Syndrome (ARDS) and secondary hemophagocytic lymphohistiocytosis, leading to multi-organ system dysfunction syndrome. Severe cases are typically associated with aberrant and excessive inflammatory responses. These include significant systemic upregulation of cytokines, chemokines, and pro-inflammatory mediators, associated with increased acute-phase proteins (APPs) production such as hyperferritinemia and elevated C-reactive protein (CRP), as well as lymphocytopenia. The neurological complications of SARS-CoV-2 infection are high among those with severe and critical illnesses. This review highlights the central nervous system (CNS) complications associated with COVID-19 attributed to primary CNS involvement due to rare direct neuroinvasion and more commonly secondary CNS sequelae due to exuberant systemic innate-mediated hyper-inflammation. It also provides a theoretical integration of clinical and experimental data to elucidate the pathogenesis of these disorders. Specifically, how systemic hyper-inflammation provoked by maladaptive innate immunity may impair neurovascular endothelial function, disrupt BBB, activate CNS innate immune signaling pathways, and induce para-infectious autoimmunity, potentially contributing to the CNS complications associated with SARS-CoV-2 infection. Direct viral infection of the brain parenchyma causing encephalitis, possibly with concurrent neurovascular endotheliitis and CNS renin angiotensin system (RAS) dysregulation, is also reviewed.