Coagulation Pathway Research Articles

Platelet in thrombo-inflammation: Unraveling new therapeutic targets.

In the broad range of human diseases, thrombo-inflammation appears as a clinical manifestation. Clinically, it is well characterized in context of superficial thrombophlebitis that is recognized as thrombosis and inflammation of superficial veins. However, it is more hazardous when developed in the microvasculature of injured/inflamed/infected tissues and organs. Several diseases like sepsis and ischemia-reperfusion can cause formation of microvascular thrombosis subsequently leading to thrombo-inflammation. Thrombo-inflammation can also occur in cases of antiphospholipid syndrome, preeclampsia, sickle cell disease, bacterial and viral infection. One of the major contributors to thrombo-inflammation is the loss of normal anti-thrombotic and anti-inflammatory potential of the endothelial cells of vasculature. This manifest itself in the form of dysregulation of the coagulation pathway and complement system, pathologic platelet activation, and increased recruitment of leukocyte within the microvasculature. The role of platelets in hemostasis and formation of thrombi under pathologic and non-pathologic conditions is well established. Platelets are anucleate cells known for their essential role in primary hemostasis and the coagulation pathway. In recent years, studies provide strong evidence for the critical involvement of platelets in inflammatory processes like acute ischemic stroke, and viral infections like Coronavirus disease 2019 (COVID-19). This has encouraged the researchers to investigate the contribution of platelets in the pathology of various thrombo-inflammatory diseases. The inhibition of platelet surface receptors or their intracellular signaling which mediate initial platelet activation and adhesion might prove to be suitable targets in thrombo-inflammatory disorders. Thus, the present review summarizes the concept and mechanism of platelet signaling and briefly discuss their role in sterile and non-sterile thrombo-inflammation, with the emphasis on role of platelets in COVID-19 induced thrombo-inflammation. The aim of this review is to summarize the recent developments in deciphering the role of the platelets in thrombo-inflammation and discuss their potential as pharmaceutical targets.

Strongly-adhesive easily-detachable carboxymethyl cellulose aerogel for noncompressible hemorrhage control

Hemostats that can strongly adhere to wound tissue and are easy to remove when stopping bleeding are favored for the control of noncompressible hemorrhage. Here, we prepared a citric acid (CA)-crosslinked and N-hydroxysuccinimide (NHS) ester-activated carboxymethyl cellulose (CMC-NHS) aerogel for noncompressible hemostasis. CA was used to crosslink CMC to form a strengthened structure. NHS ester was introduced to activate the adhesion of CMC-NHS aerogel to wound tissue and promoted blood coagulation through the formation of amide crosslinks between CMC and erythrocytes and free blood proteins. The plentiful carboxyl groups could also trigger the intrinsic coagulation pathway. Thus, the aerogel could quickly adhere to wound tissue to stop bleeding, and then could be easily removed when fully hydrated as CMC was dissolved at the adhesion interface. The aerogel also had good biocompatibility and antibacterial capability. Overall, CMC-NHS aerogel is a competitive hemostat for the control of noncompressible hemorrhage.

Lupus anticoagulant testing for patients on direct oral anticoagulants

Abstract As use of direct factor Xa inhibitor (direct oral anticoagulant; DOAC) therapy increases, a modified lupus anticoagulant (LAC) testing method was studied to remove interfering DOACs, allowing clinicians to evaluate patients for antiphospholipid syndrome (APS) without altering anticoagulation treatment. We evaluated the use of DOAC-StopTM on our LAC testing panel with two assays: dilute Russell viper venom time (dRVVT), a factor X activator, and Silica Clotting Time (SCT), an intrinsic coagulation pathway activator. The plasma specimens were pretreated with DOAC-STOPTM beads by mixing on a rocking platform for 5 minutes and centrifugation at 5000 rpm for 5 minutes. The treated plasma supernatant was used for each step of the assay including the screen, confirm (addition of phospholipid), 50:50 mix (addition of reagent plasma with coagulation factors) and confirm 50:50 mix. The total ratio (ratio between screen and confirm ratios relative to mean of normal ranges) was calculated and used per the package insert in the positive or negative interpretation of each LAC testing panel. The study included patients with one or more of the following characteristics identified during coagulation sign-out and chart review: no evidence of a LAC (NELAC), evidence of a LAC, and whether on apixaban or rivaroxaban therapy. The effectiveness of DOAC removal was characterized with an apixaban spiking experiment for NELAC and LAC patient specimens which showed no change in LAC testing panel interpretation before and after DOAC-STOPTM treatment. A second experiment with apixaban-spiked NELAC samples demonstrated removal of anti-factor Xa activity upon comparison of pre- and post-treatment with DOAC-STOPTM. Of 10 patients taking rivaroxaban, nine had positive dRVVT interpretations; eight of these specimens changed to negative interpretations after DOAC-STOPTM treatment. For SCT, two positive interpretations remained positive, while two of the remaining eight negatives became positive after treatment. Of nine patients taking apixaban, two had positive dRVVT interpretations, one of which became negative post-treatment. Of the seven negative interpretations, one became positive post-treatment. For SCT, three were positive pre-treatment and seven were negative with no change post-treatment. Providing a LAC testing option for patients on DOACs may be of benefit to patients and clinicians in APS assessment, eliminating the risk of suspending anticoagulation therapy. Our study shows DOAC-STOPTM effectively removes DOAC interference in the majority of patient specimens studied, though LAC testing and interpretation in the setting of a high-complexity patient population on DOAC therapy remains challenging with occasional false positives and false negatives.

Abstract 126: The Association Of Higher Or Lower Mean Arterial Pressure On Kidney Function After Cardiac Arrest: A Post-hoc Analysis Of The Comacare And Neuroprotect Trials

Introduction: Acute kidney injury (AKI) denotes a sudden reduction in kidney function manifested by a rise in S-creatine levels and reduced urine output. Studies have suggested an association between AKI severity and outcomes after OHCA. Various criteria have been used to define AKI, the Kidney Disease Improving Global Outcomes (KDIGO) published in 2012 being the currently used tool. AKI is a feature of post-cardiac arrest syndrome.During post-CA syndrome, possible causes of renal damage are direct renal ischaemic-reperfusion injury and indirect renal damage characterized by the activation of inflammatory and coagulation pathways. Although the overall mortality rate after CA mainly relates to hypoxic-ischaemic brain injury, damage to other organs also has prognostic implications. Methods: Pooled post-hoc analysis of the COMACARE (NCT02698917) and NEUROPROTECT (NCT02541591) trials that randomized patients to lower (MAP 65-70 mmHg) or higher (MAP 80-100 mmHg) targets for the first 36 hours of post-CA intensive care. Kidney function was categorised using the KDIGO classification during the first five days after OHCA. We used Cox regression analysis to identify factors associated with AKI after OHCA. Results: A total of 227 patients were included: 115 in the high MAP group and 112 in the low MAP group. Eighty-six (38%) patients developed AKI during the first five days; 40 (47%) patients had AKI in the high MAP group and 46 (54%) in the low MAP group (p = 0.51). The mean creatinine and mean daily diuresis were 104 (95% CI 94-115) μmol/l and 1989 (95% CI 1829-2150) mL/day in the high MAP group and 111 (95% CI 99-122) μmol/l and 1677 (95% CI 1530-1824) mL/day in the low MAP group. In a Cox regression model, independent AKI predictors were previous hypertension (HR 1.72; 95% CI 1.07-2.78; p = 0.03), bystander cardiopulmonary resuscitation (hazard ratio [HR] 0.46; 95% CI 0.29-0.73; p < 0.01), shockable initial rhythm (HR 0.36; 95% CI 0.21-0.61; p ≤ 0.01), and time to ROSC (HR 1.04; 95% CI 1.02-1.06; p < 0.01) whereas high/low MAP was not an independent predictor of AKI. Conclusions: KDIGO1-staged AKI is common after CA and is associated with previous hypertension and CA factors. Targeting higher MAP after CA does not appear to influence the development of AKI.

Abstract 14391: The Transcriptional Landscape of Liver Sinusoidal Endothelial Cells

Introduction: Human liver endothelial cells (HLEC) are a heterogeneous cell population. Single cell transcriptomics and immunostaining assays have categorized HLEC into two major groups according to their location within the liver lobules (zone 1 or periportal HLEC and zones 2/3 or central venous (CV) HLEC). Hypothesis: Cellular deconvolution of the bulk transcriptome of HLEC will highlight important properties of HLECs and their transcriptional regulators. Methods: We uniformly processed all bulk RNA-seq data from HLECs in Gene Expression Omnibus. We used CIBERSORTx with human liver single cell RNA-seq data to perform cell type deconvolution of bulk HLEC RNA-seq. We compared the transcriptome of HLEC subpopulations to that of HUVEC. We then applied the HOMER motif finding algorithm on the promoters of genes up/downregulated in HLEC compared to HUVEC. Results: We analyzed data from 10 HLEC samples and 107 HUVEC samples from 37 independent experiments. Principal component analysis revealed that 6 of the 10 HLEC samples have robust transcriptional differences compared to HUVEC. CIBERSORTx showed that those 6 HLEC samples correspond to CV HLECs and can be identified by FCGR2B expression. Differential gene expression analysis revealed enrichment of inflammatory and coagulation pathways in CV HLEC and enrichment of proliferation and mitosis pathways in HUVEC. CV HLEC showed increased expression of factors VIII, X, XII, Protein S and antithrombin III. We validated gene expression at the protein level by Western blot. A transcription factor (TF) prioritization approach using HOMER motif enrichment revealed a potential role for E2F, and RXR-RAR TF as primary determinants of the differences between HUVEC and CV HLEC. Conclusions: We identify and characterize CV HLEC as a distinct endothelial subtype relevant to inflammation and coagulation. We also identify downregulation of E2F and upregulation of RXR-RAR TF as potential key regulators of the CV HLEC transcriptome.

Abstract 9252: Risk for Incident Coronary Heart Disease Associated With High Lipoprotein(a) by Levels of Factor VIII and High-Sensitivity C-Reactive Protein

Introduction: Both coagulation and inflammation may contribute to the higher risk for coronary heart disease (CHD) associated with high lipoprotein(a) [Lp(a)]. The association of Lp(a) with CHD is stronger in individuals with high versus low high-sensitivity C-reactive protein (hsCRP), a marker of inflammation. It is unclear if coagulation Factor VIII also modifies the association of Lp(a) with CHD independently of hsCRP. Hypothesis: Lp(a) is associated with incident CHD in adults with high Factor VIII after adjustment for hsCRP but not among those with low Factor VIII. Methods: We analyzed data from 6,495 adults 45 to 84 years of age without a history of cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis (MESA). Lp(a) mass concentration, Factor VIII antigen, and hsCRP were measured using blood collected at baseline (2000-2002). Lp(a), Factor VIII and hsCRP were categorized as high or low (≥75th or <75th percentile of the distribution). Participants were followed for incident CHD through 2015 (median follow-up 14 years). Results: The mean age of participants was 62 years and 47% were male. After log-transformation, the Pearson’s correlation between Factor VIII and hsCRP was 0.15 (p-value <0.001). High Lp(a) was associated with an increased risk for incident CHD in participants with high Factor VIII and high hsCRP, separately, but not among those with low Factor VIII or low hsCRP (Table). The adjusted hazard ratio (95%CI) for CHD associated with high Lp(a) was 1.09 (0.77, 1.53) in participants with low Factor VIII and low hsCRP, 1.49 (0.84, 2.67) in those with low Factor VIII and high hsCRP, 1.54 (0.92, 2.59) in those with high Factor VIII and low hsCRP, and 3.84 (1.85, 7.97) in those with high Factor VIII and high hsCRP (p-value comparing hazard ratios 0.02). Conclusions: High Lp(a) is a risk factor for incident CHD in adults with high Factor VIII or hsCRP. The activation of either the inflammation or coagulation pathway may modify the association of Lp(a) with CHD.

Abstract 13499: Unravelling the Pathophysiology of Right Ventricular Maladaptive Hypertrophy in Chronic Pulmonary Hypertension Through Imaging and Omics

Introduction: Right ventricular (RV) failure is the strongest determinant of survival in chronic pulmonary hypertension (PH), but its pathophysiological mechanisms remain unclear. Hypothesis: In addition to RV pressure overload, compounds liberated from the pulmonary vascular damage (identifiable by omics) may exert a detrimental effect on RV function in PH. Methods: Four different experimental models of RV pressure overload in 48 Yucatan pigs were developed: chronic postcapillary PH by pulmonary veins banding (M1); chronic PH by aorto-pulmonary shunting (M2); RV pressure overload by PA banding (thus without PH) (M3); and sham procedure (M0). Animals were evaluated at 1, 5 and 8 months after surgery by right heart catheterization, cardiac magnetic resonance (CMR), and blood/histological sampling. Unsupervised proteomic and metabolomic analyses were performed and compared among experimental groups and to the severity of RV dysfunction. Results: A total of 33 pigs completed follow-up (M1,n=8; M2,n=6; M3,n=10; and M0,n=9). As expected, M1&M2-animals developed chronic PH, whereas M3-animals had severely increased RV systolic pressure without PH (Table). M3-pigs developed more severe RV hypertrophy (significantly higher mass on CMR and cardiomyocyte area on histology), but maintained normal function. In contrast, M1&M2 animals developed RV systolic disfunction and increased myocardial apoptosis in M1. Plasma metabolomic and proteomic patterns differed among groups, highlighting greater inflammation and taurine/arginine deficiency in PH models (M1&M2), coagulation disturbances in M1, and predominant lipidomic changes in M3. Key proteins/metabolites from coagulation, complement system and apolipoproteins pathways significantly associated with RV performance. Conclusion: Maladaptive RV hypertrophy in PH is associated with significant changes in plasma proteins and metabolites. Their identification may help to identify potential targets.

A prospective, controlled study on the utility of rotational thromboelastometry in surgery for acute type A aortic dissection

To evaluate the hemostatic system with ROTEM in patients undergoing surgery for acute type aortic dissection (ATAAD) using elective aortic procedures as controls. This was a prospective, controlled, observational study. The study was performed at a tertiary referral center and university hospital. Twenty-three patients with ATAAD were compared to 20 control patients undergoing elective surgery of the ascending aorta or the aortic root. ROTEM (INTEM, EXTEM, HEPTEM and FIBTEM) was tested at 6 points in time before, during and after surgery for ATAAD or elective aortic surgery. The ATAAD group had an activated coagulation coming into the surgical theatre. The two groups showed activation of both major coagulation pathways during surgery, but the ATAAD group consistently had larger deficiencies. Reversal of the coagulopathy was successful, although none of the groups reached elective baseline until postoperative day 1. ROTEM did not detect low levels of clotting factors at heparin reversal nor low levels of platelets. This study demonstrated that ATAAD is associated with a coagulopathic state. Surgery causes additional damage to the hemostatic system in ATAAD patients as well as in patients undergoing elective surgery of the ascending aorta or the aortic root. ROTEM does not adequately catch the full coagulopathy in ATAAD. A transfusion protocol in ATAAD should be specifically created to target this complex coagulopathic state and ROTEM does not negate the need for routine laboratory tests.

Prognostic Impact of Systemic Coagulation-Inflammation Index in AcuteType A Aortic Dissection Surgery.

A novel hematologic parameter, systemic coagulation-inflammation (SCI) index reflecting inflammation and coagulation pathways could be easily obtained from clinically routine laboratory findings. We hypothesize that the SCI index has prognostic implication in predicting operative mortality for patients with acute type A aortic dissection (ATAAD). This study aims to investigate the prognostic value of the SCI index and to establish an SCI-adding nomogram for mortality prediction in ATAAD patients. A total of 1,967 ATAAD patients surgically repaired were collected from 12 Chinese cardiovascular centers by the 5A (Additive Anti-inflammatory Action for Aortopathy & Arteriopathy [Multicenter Retrospective Study]) study III (2016-2020). SCI index was calculated as platelet count× fibrinogen/white blood cell count on admission. By adding SCI index, a nomogram was developed and evaluated for 90-day mortality prediction with conventional predictors via the Cox model with 10-fold cross-validation. Patients were stratified with low SCI (<40), middle SCI (40-100), or high SCI (>100). The 90-day survival rates increased with SCI index (low 86.9%; [95%CI: 84.9%-89.0%], middle 92.7% [95%CI: 90.9%-94.9%], and high 96.4% [95%CI: 94.2%-98.6%]; log-rank P< 0.001). SCI index is independently associated with 90-day mortality (adjusted hazard ratio: 0.549; 95%CI: 0.424-0.710; P< 0.001). The addition of SCI index provided significantly incremental prognostic value to base model including age, serum creatinine, DeBakey class, and location of intimal entry (area under the curve: 0.677; 95%CI: 0.641-0.716 vs 0.724; 95%CI: 0.685-0.760; P=0.002), which was confirmed by net reclassification improvement index (0.158; 95%CI: 0.065-0.235; P< 0.001) and integrated discrimination improvement index (0.070; 95%CI: 0.007-0.036; P< 0.001). SCI index is easily obtainable, performs moderately well as a predictor of short-term mortality in ATAAD patients, and may be useful for risk stratification in emergency settings. (Additive Anti-inflammatory Action for Aortopathy & Arteriopathy [Multicenter Retrospective Study] III NCT04918108).

Hereditary angioedema is associated with an increased risk of venous thromboembolism

Hereditary angioedema is associated with an increased risk of venous thromboembolism

Evidence that complement and coagulation proteins are mediating the clinical response to omega-3 fatty acids: A mass spectrometry-based investigation in subjects at clinical high-risk for psychosis

Preliminary evidence indicates beneficial effects of omega-3 polyunsaturated fatty acids (PUFAs) in early psychosis. The present study investigates the molecular mechanism of omega-3 PUFA-associated therapeutic effects in clinical high-risk (CHR) participants. Plasma samples of 126 CHR psychosis participants at baseline and 6-months follow-up were included. Plasma protein levels were quantified using mass spectrometry and erythrocyte omega-3 PUFA levels were quantified using gas chromatography. We examined the relationship between change in polyunsaturated PUFAs (between baseline and 6-month follow-up) and follow-up plasma proteins. Using mediation analysis, we investigated whether plasma proteins mediated the relationship between change in omega-3 PUFAs and clinical outcomes. A 6-months change in omega-3 PUFAs was associated with 24 plasma proteins at follow-up. Pathway analysis revealed the complement and coagulation pathway as the main biological pathway to be associated with change in omega-3 PUFAs. Moreover, complement and coagulation pathway proteins significantly mediated the relationship between change in omega-3 PUFAs and clinical outcome at follow-up. The inflammatory protein complement C5 and protein S100A9 negatively mediated the relationship between change in omega-3 PUFAs and positive symptom severity, while C5 positively mediated the relationship between change in omega-3 and functional outcome. The relationship between change in omega-3 PUFAs and cognition was positively mediated through coagulation factor V and complement protein C1QB. Our findings provide evidence for a longitudinal association of omega-3 PUFAs with complement and coagulation protein changes in the blood. Further, the results suggest that an increase in omega-3 PUFAs decreases symptom severity and improves cognition in the CHR state through modulating effects of complement and coagulation proteins.

Data mining for prothrombin time and international normalized ratio reference intervals in children.

Reference intervals (RIs) help physicians in differentiating healthy from sick individuals. The prothrombin time (PT) and International normalized ratio (INR) fluctuate in coagulation pathway defects and have interlaboratory variability due to the instrument/reagent used. As direct method is difficult in children, we chose an indirect data mining method for the determining PT/INR RIs. The indirect method overcomes the substantial financial and logistic challenges, and ethical restrictions in children, moreover, allows partitioning in more fine-grained age groups. Prothrombin Time/INR measurements performed in patients aged birth-18 years between January 2013 and December 2020, were retrieved from laboratory management system of the Aga Khan Hospital. Reference intervals were computed using an indirect KOSMIC algorithm. The KOSMIC package function on the assumption that the non-pathologic samples follow a Gaussian distribution (after Box-Cox transformation of the data), following an elaborate statistical process to isolate distribution of physiological samples from mixed dataset. A total of 56,712 and 52,245 values were retrieved for PT and INR respectively. After the exclusion of patients with multiple specimens obtained during the study period, RIs were calculated for 37,356 (PT) and 37,192 (INR) children with stratification into 9 age groups. A comparison of 2.5th and 97.5th percentile results with those of established RIs from SickKids Handbook of Pediatric Thrombosis and Hemostasis demonstrated good agreement in between different age groups. This study supports data mining as an alternate approach for establishing PT/INR RIs, specifically in resource-limited settings. The results obtained are specific to studied population and instrument/reagent used. The study also allows understanding of fluctuations in coagulation pathways with increasing age and hence better clinical decision-making based on PT and INR results.

Neuroinflammation Plays a Critical Role in Cerebral Cavernous Malformation Disease.

Cerebral cavernous malformations (CCMs) are neurovascular lesions caused by loss of function mutations in 1 of 3 genes, including KRIT1 (CCM1), CCM2, and PDCD10 (CCM3). CCMs affect ≈1 out of 200 children and adults, and no pharmacologic therapy is available. CCM lesion count, size, and aggressiveness vary widely among patients of similar ages with the same mutation or even within members of the same family. However, what determines the transition from quiescent lesions into mature and active (aggressive) CCM lesions is unknown. We use genetic, RNA-sequencing, histology, flow cytometry, and imaging techniques to report the interaction between CCM endothelium, astrocytes, leukocytes, microglia/macrophages, neutrophils (CCM endothelium, astrocytes, leukocytes, microglia/macrophages, neutrophils interaction) during the pathogenesis of CCMs in the brain tissue. Expression profile of astrocytes in adult mouse brains using translated mRNAs obtained from the purification of EGFP (enhanced green fluorescent protein)-tagged ribosomes (Aldh1l1-EGFP/Rpl10a) in the presence or absence of CCM lesions (Slco1c1-iCreERT2;Pdcd10fl/fl; Pdcd10BECKO) identifies a novel gene signature for neuroinflammatory astrocytes. CCM-induced reactive astrocytes have a neuroinflammatory capacity by expressing genes involved in angiogenesis, chemotaxis, hypoxia signaling, and inflammation. RNA-sequencing analysis on RNA isolated from brain endothelial cells in chronic Pdcd10BECKO mice (CCM endothelium), identified crucial genes involved in recruiting inflammatory cells and thrombus formation through chemotaxis and coagulation pathways. In addition, CCM endothelium was associated with increased expression of Nlrp3 and Il1b. Pharmacological inhibition of NLRP3 (NOD [nucleotide-binding oligomerization domain]-' LRR [leucine-rich repeat]- and pyrin domain-containing protein 3) significantly decreased inflammasome activity as assessed by quantification of a fluorescent indicator of caspase-1 activity (FAM-FLICA [carboxyfluorescein-fluorochrome-labeled inhibitors of caspases] caspase-1) in brain endothelial cells from Pdcd10BECKO in chronic stage. Importantly, our results support the hypothesis of the crosstalk between astrocytes and CCM endothelium that can trigger recruitment of inflammatory cells arising from brain parenchyma (microglia) and the peripheral immune system (leukocytes) into mature active CCM lesions that propagate lesion growth, immunothrombosis, and bleedings. Unexpectedly, partial or total loss of brain endothelial NF-κB (nuclear factor κB) activity (using Ikkbfl/fl mice) in chronic Pdcd10BECKO mice does not prevent lesion genesis or neuroinflammation. Instead, this resulted in a trend increase in the number of lesions and immunothrombosis, suggesting that therapeutic approaches designed to target inflammation through endothelial NF-κB inhibition may contribute to detrimental side effects. Our study reveals previously unknown links between neuroinflammatory astrocytes and inflamed CCM endothelium as contributors that trigger leukocyte recruitment and precipitate immunothrombosis in CCM lesions. However, therapeutic approaches targeting brain endothelial NF-κB activity may contribute to detrimental side effects.

Stable Gastric Pentadecapeptide BPC 157 as Useful Cytoprotective Peptide Therapy in the Heart Disturbances, Myocardial Infarction, Heart Failure, Pulmonary Hypertension, Arrhythmias, and Thrombosis Presentation

In heart disturbances, stable gastric pentadecapeptide BPC 157 especial therapy effects combine the therapy of myocardial infarction, heart failure, pulmonary hypertension arrhythmias, and thrombosis prevention and reversal. The shared therapy effect occurred as part of its even larger cytoprotection (cardioprotection) therapy effect (direct epithelial cell protection; direct endothelium cell protection) that BPC 157 exerts as a novel cytoprotection mediator, which is native and stable in human gastric juice, as well as easily applicable. Accordingly, there is interaction with many molecular pathways, combining maintained endothelium function and maintained thrombocytes function, which counteracted thrombocytopenia in rats that underwent major vessel occlusion and deep vein thrombosis and counteracted thrombosis in all vascular studies; the coagulation pathways were not affected. These appeared as having modulatory effects on NO-system (NO-release, NOS-inhibition, NO-over-stimulation all affected), controlling vasomotor tone and the activation of the Src-Caveolin-1-eNOS pathway and modulatory effects on the prostaglandins system (BPC 157 counteracted NSAIDs toxicity, counteracted bleeding, thrombocytopenia, and in particular, leaky gut syndrome). As an essential novelty noted in the vascular studies, there was the activation of the collateral pathways. This might be the upgrading of the minor vessel to take over the function of the disabled major vessel, competing with and counteracting the Virchow triad circumstances devastatingly present, making possible the recruitment of collateral blood vessels, compensating vessel occlusion and reestablishing the blood flow or bypassing the occluded or ruptured vessel. As a part of the counteraction of the severe vessel and multiorgan failure syndrome, counteracted were the brain, lung, liver, kidney, gastrointestinal lesions, and in particular, the counteraction of the heart arrhythmias and infarction.

Marine Biological Macromolecules and Chemically Modified Macromolecules; Potential Anticoagulants.

Coagulation is a potential defense mechanism that involves activating a series of zymogens to convert soluble fibrinogen to insoluble fibrin clots to prevent bleeding and hemorrhagic complications. To prevent the extra formation and diffusion of clots, the counterbalance inhibitory mechanism is activated at levels of the coagulation pathway. Contrariwise, this system can evade normal control due to either inherited or acquired defects or aging which leads to unusual clots formation. The abnormal formations and deposition of excess fibrin trigger serious arterial and cardiovascular diseases. Although heparin and heparin-based anticoagulants are a widely prescribed class of anticoagulants, the clinical use of heparin has limitations due to the unpredictable anticoagulation, risk of bleeding, and other complications. Hence, significant interest has been established over the years to investigate alternative therapeutic anticoagulants from natural sources, especially from marine sources with good safety and potency due to their unique chemical structure and biological activity. This review summarizes the coagulation cascade and potential macromolecular anticoagulants derived from marine flora and fauna.

Modern Aspects of Anticoagulation System Disorders Diagnosis in Children with Different Polymorphisms in Coagulation Genes. Initial Results

Background. Hemostatic system pathology is topical and poorly studied issue in pediatrics. One of the main causes of coagulation pathway disorders associated with thrombotic events is abnormality in various parts of the hemostatic system. Vascular accidents are commonly caused by anticoagulation system factors deficiency. Conventionally, thrombosis is a common event in adult patients, and there is no adequate attention to disorders of primary physiological anticoagulants system in children. More often acquired anticoagulant proteins deficiency develops in presence of various pathological conditions, especially after the past infectious diseases. All these diseases (thrombophilia, trombotic events, cardiovascular pathology, nervous system diseases, genetic diseases) can occur separately and in association with each other, plus clinical picture of coagulation events may be similar. Objective. The aim of the study is to evaluate changes in the physiological anticoagulants system in children with different pathologies who have polymorphic variants in coagulation genes and who had new coronavirus infection. Methods. The study included 33 children who had severe coronavirus infection in family clusters and had severe chronic pathology potentially associated with disorders of the coagulation system (nervous system damage, hypertrophic cardiomyopathy, hereditary monogenic syndromes, hemato-mesenchymal dysplasia syndrome). All children underwent complete examination including clinical examination, laboratory, and instrumental diagnostics. Results. Preliminary study results indicate significant incidence of polymorphic variants in coagulation genes (one third of children with various diseases from the study). Some children had decreased activity of anticoagulation system glycoproteins (from 6% to 36%) that confirmed the topicality of the examination of anticoagulation system factors deficiency and the need for further dynamic follow-up, as well as revealing of trombophilia predictors in children in selected target groups. Study on revealing anticoagulation system disorders and mutations in coagulation genes will predict the risk of thrombotic disorders. Conclusion. The obtained results have confirmed the significant role of the ongoing study for comprehensive assessment of hemostatic system disorders in children. That will allow us to optimize the approach to diagnosis and personalize the management strategy for patients with different chronic pathologies and disorders of the natural anticoagulants system. The study is currently ongoing.

Cross-Ancestry Investigation of Venous Thromboembolism Genomic Predictors.

Venous thromboembolism (VTE) is a life-threatening vascular event with environmental and genetic determinants. Recent VTE genome-wide association studies (GWAS) meta-analyses involved nearly 30 000 VTE cases and identified up to 40 genetic loci associated with VTE risk, including loci not previously suspected to play a role in hemostasis. The aim of our research was to expand discovery of new genetic loci associated with VTE by using cross-ancestry genomic resources. We present new cross-ancestry meta-analyzed GWAS results involving up to 81 669 VTE cases from 30 studies, with replication of novel loci in independent populations and loci characterization through in silico genomic interrogations. In our genetic discovery effort that included 55 330 participants with VTE (47 822 European, 6320 African, and 1188 Hispanic ancestry), we identified 48 novel associations, of which 34 were replicated after correction for multiple testing. In our combined discovery-replication analysis (81 669 VTE participants) and ancestry-stratified meta-analyses (European, African, and Hispanic), we identified another 44 novel associations, which are new candidate VTE-associated loci requiring replication. In total, across all GWAS meta-analyses, we identified 135 independent genomic loci significantly associated with VTE risk. A genetic risk score of the significantly associated loci in Europeans identified a 6-fold increase in risk for those in the top 1% of scores compared with those with average scores. We also identified 31 novel transcript associations in transcriptome-wide association studies and 8 novel candidate genes with protein quantitative-trait locus Mendelian randomization analyses. In silico interrogations of hemostasis and hematology traits and a large phenome-wide association analysis of the 135 GWAS loci provided insights to biological pathways contributing to VTE, with some loci contributing to VTE through well-characterized coagulation pathways and others providing new data on the role of hematology traits, particularly platelet function. Many of the replicated loci are outside of known or currently hypothesized pathways to thrombosis. Our cross-ancestry GWAS meta-analyses identified new loci associated with VTE. These findings highlight new pathways to thrombosis and provide novel molecules that may be useful in the development of improved antithrombosis treatments.

Role of Thromboelastogram in monitoring the activation of the coagulation pathway and assessing the associated risk factors for hypercoagulable state in transfusion dependent thalassemia patients

BackgroundThromboembolic events are rare but one of the fatal complications in thalassemia. Assessment of the hypercoagulable state is not done regularly, and we have assessed the utility of Thromboelastography (TEG) for monitoring the activation of the coagulation pathway in patients with thalassemia. MethodologyA prospective single-center cohort study was conducted in a tertiary care set-up. Transfusion Dependent Thalassemia patients registered with the pediatric unit were screened for hypercoagulability using TEG during six months of the study period and followed up for three years for the development of thromboembolic events. Patient demographics, history of splenectomy, Serum ferritin levels and annual red cell transfusion requirement (mL/kg/year) were assessed. TEG parameters used were R time, K time, alpha angle, Maximum amplitude, Clot index, and Lysis 30. The thrombin generation test (V Curve) obtained from the first-degree derivate of the TEG velocity curve was also used for analysis. ResultsA total of 34 patients were recruited during the six months study period with an average age of 10.6 years ( ± 5.47). The average pre-transfusion hemoglobin level and the volume of packed red cells received were 7.24 g/dL and 152.82 mL/kg/year respectively. The TEG tracing was suggestive of a hypercoagulable state in 58.82% of patients. The mean values of angle (70.74), MA (64.16), CI (2.65) and TG (774.43) in TDT patients compared to age matched reference range (62.81, 57.99, 0.8, 577.83 respectively) was suggestive of prothrombotic changes. Annual blood transfusion requirement was negatively correlated with hypercoagulable status (‐0.344, CI= -0.68 to 0.08). One out of 34 patients developed corona radiata infarct (with annual blood requirement; 112.7 mL/kg/Year). The risk to develop a hypercoagulable state appeared to be higher when the volume of RBCs transfused was less than 154 mL/kg/Year. ConclusionTDT patients are at risk of developing thromboembolism, and screening with TEG may be useful to identify those at high risk.

Cooperative ETS Transcription Factors Enforce Adult Endothelial Cell Fate and Cardiovascular Homeostasis.

Current dogma dictates that during adulthood, endothelial cells (ECs) are locked in an immutable stable homeostatic state. By contrast, herein we show that maintenance of EC fate and function are linked and active processes, which depend on the constitutive cooperativity of only two ETS-transcription factors (TFs) ERG and Fli1. While deletion of either Fli1 or ERG manifest subtle vascular dysfunction, their combined genetic deletion in adult EC results in acute vasculopathy and multiorgan failure, due to loss of EC fate and integrity, hyperinflammation, and spontaneous thrombosis, leading to death. ERG and Fli1 co-deficiency cause rapid transcriptional silencing of pan- and organotypic vascular core genes, with dysregulation of inflammation and coagulation pathways. Vascular hyperinflammation leads to impaired hematopoiesis with myeloid skewing. Accordingly, enforced ERG and FLI1 expression in adult human mesenchymal stromal cells activates vascular programs and functionality enabling engraftment of perfusable vascular network. GWAS-analysis identified vascular diseases are associated with FLI1/Erg mutations. Constitutive expression of ERG and Fli1 uphold EC fate, physiological function, and resilience in adult vasculature; while their functional loss can contribute to systemic human diseases.

Dual pathway inhibition as compared to acetylsalicylic acid monotherapy in relation to endothelial function in peripheral artery disease, a phase IV clinical trial.

ObjectiveDual pathway inhibition (DPI) by combining acetylsalicylic acid (ASA) with low-dose rivaroxaban has been shown to reduce cardiovascular events in patients with peripheral arterial disease (PAD) when compared to ASA monotherapy. A potential explanation is that inhibition of factor Xa improves endothelial function through crosstalk between coagulation and inflammatory pathways, subsequently attenuating the occurrence of cardiovascular events. We hypothesize that the addition of rivaroxaban to ASA in PAD patients leads to improved endothelial function.DesignAn investigator-initiated, multicentre trial investigating the effect of DPI on endothelial function.MethodsPatients, diagnosed with PAD, were enrolled in two cohorts: cohort A (Rutherford I-III) and cohort B (Rutherford IV-VI). Participants received ASA monotherapy for a 4-weeks run-in period, followed by 12 weeks of DPI. Macro- and microvascular endothelial dysfunction were studied by measuring carotid artery reactivity upon sympathetic stimulus and by measuring plasma endothelin-1 concentrations, respectively. All measurements were performed during the use of ASA (baseline) and after 12 weeks of DPI.Results159 PAD patients (111 cohort A, 48 cohort B) were enrolled. Twenty patients discontinued study drugs early. Carotid artery constriction upon sympathetic stimulation at baseline (ASA) and after 12 weeks of DPI was similar in the total group, 22.0 vs. 22.7% (p = 1.000), and in the subgroups (Cohort A 22.6 vs. 23.7%, p = 1.000; cohort B 20.5 vs. 20.5%, p = 1.000), respectively. The mean concentration of plasma endothelin-1 at baseline and after 12 weeks of DPI did not differ, 1.70 ± 0.5 vs. 1.66 ± 0.64 pmol/L (p = 0.440) in the total group, 1.69 ± 0.59 vs. 1.62 ± 0.55 pmol/L in cohort A (p = 0.202), and 1.73 ± 0.53 vs. 1.77 ± 0.82 pmol/L in cohort B (p = 0.682), respectively.ConclusionMacro- and microvascular endothelial dysfunction, as reflected by carotid artery reactivity and plasma endothelin-1 concentrations, are not influenced in PAD patients by addition of low-dose rivaroxaban to ASA monotherapy for 12 weeks.Trial registrationhttps://clinicaltrials.gov/ct2/show/NCT04218656.