Personalized medicine in thrombosis: back to the future

Assessing hypercoagulability and VTE risk using thromboelastography and Khorana score in women with cancers receiving chemotherapy

Venous thromboembolism (VTE) is a common occurrence in cancer and chemotherapy increases thrombosis risk. Current risk assessment models such as the Khorana score (KS) and its modifications have limitations in female cancers. We assessed the coagulation profile of a group of women cancer patients under chemotherapy using thromboelastography (TEG) to determine if this can inform VTE risk assessment. Cancer patients who planned to receive chemotherapy were recruited. Baseline demographics, cancer data, BMI, Khorana Score (KS), and VTE risk factors were recorded and patients were followed for 6 months, for any thrombotic events. A total of 36 patients aged 35-85 (18 breast, 11 endometrial, 7 ovarian cancer) were evaluated. Hypercoagulability was detected in 63% of patients post-chemo cycle 1 and 75% post-cycle 2, with a significant increase in MA (maximum amplitude) and CI (clotting index), reduction in R (reaction time), K (clot kinetics), and LY30 (lysis time after 30 min of MA). KS showed only 7% of patients were high risk, 23% were low, and 70% were intermediate risk. MA and CI significantly increased in patients with intermediate and high-risk KS when compared with the low-risk patients and MA was positively correlated with KS. Five patients developed actual VTE; 100% of the tested ones were hypercoagulable either post-cycle 1 or 2 and 80% were KS intermediate risk. TEG is a hypercoagulability marker and TEG-MA and CI can potentially assess VTE risk. Larger studies are needed to assess the utility of TEG as an adjuvant to KS to better predict VTE in specific female cancers.

Food Compass Score and its association with inflammatory markers and homocysteine in cardiovascular disease-free adults: a cross-sectional analysis of the ATTICA epidemiological study

BACKGROUND/OBJECTIVES

Several nutrient profiling systems have been developed to assist in food choices and policy. Food Compass Score (FCS) is a novel holistic food score assessing 54 parameters. The aim was to assess the relation of FCS with inflammatory and lipid markers in cardiovascular disease-free volunteers.

SUBJECTS/METHODS

Information from the ATTICA epidemiological study participants, with complete data on lipid, inflammatory markers and dietary intake were studied (n = 1018). C-reactive protein (CRP) and amyloid A were determined by immunonephelometry, fibrinogen by nephelometry, homocysteine by fluorometry, while tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), adiponectin and leptin were determined by ELISA in fasting blood samples. Dietary intake was assessed through a semi-quantitative validated food frequency questionnaire. Each food was assigned a FCS value from the published values and then individual's FCS values were calculated.

RESULTS

Mean FCS was 56 (standard deviation: 5.7) and it was similar in men and women. FCS was inversely correlated with age (r = -0.06, p = 0.03). In multiple linear regression models, FCS was inversely associated with CRP (-0.03, 0.01), TNF-a (-0.04, 0.01), amyloid A (-0.10, 0.04) and homocysteine (-0.09, 0.04) (b coefficients, standard errors, all p < 0.05) and was not associated with IL-6, fibrinogen, adiponectin, leptin, or lipids levels (all p > 0.05).

CONCLUSIONS

The inverse correlations of the FCS with inflammatory markers suggest that a diet containing foods with high FCS might be protective against inflammation process. Our results support the usefulness of the FCS, but future studies should evaluate its relation to cardiovascular and other inflammation-related chronic diseases.

A comprehensive review of Rubia cordifolia L.: Traditional uses, phytochemistry, pharmacological activities, and clinical applications

Rubia cordifolia (family: Rubiaceae) L (R. cordifolia) is a perennial botanical drug climbing vine. As the main part of the traditional Chinese medicine, the rhizome has a long history. A great number of literary studies have reported that it can be used for the improvement of blood circulation, hemostasis, activation of collaterals, etc. When it comes to the wide application of R. cordifolia in traditional medicine, we systematically review its traditional uses, phytochemistry and pharmacological effects. Literatures were systematically searched using several scientific databases, including China National Knowledge Infrastructure (CNKI), Baidu Scholar, PubMed, Web of Science, and other professional websites. Kew Botanical Garden and the iPlant were used for obtaining the scientific names and plant images of R. cordifolia. In addition, other information was also gathered from books including traditional Chinese herbal medicine, the Chinese Pharmacopoeia, and Chinese Materia Medica. So far, many prescriptions containing R. cordifolia have been widely used in the clinical treatment of abnormal uterine bleeding, primary dysmenorrhea and other gynecological diseases, allergic purpura, renal hemorrhage and other diseases. The phytochemistry studies have reported that more than 100 compounds are found in R. cordifolia, such as bicyclic peptides, terpenes, polysaccharides, trace elements, flavonoids, and quinones. Among them, quinones and peptides are the types of components with the highest contents in R. cordifolia. The modern pharmacological studies have revealed that R. cordifolia and its derived components have anti-tumor, anti-oxidative, anti-platelet aggregation, and anti-inflammatory effects. However, most studies are preclinical. The pharmacological mechanism of R. cordifolia has not been thoroughly studied. In addition, there are few pharmacokinetic and toxicity studies of R. cordifolia, therefore the clinical safety data for R. cordifolia is lacking. To sum up, this review for the first time summarizes a systemic and integrated traditional uses, chemical compositions, pharmacological actions and clinical applications of R. cordifolia, which provides the novel and full-scale insight for the drug development, medicinal value, and application of R. cordifolia in the future.

High-throughput glycolytic inhibitor discovery targeting glioblastoma by graphite dots-assisted LDI mass spectrometry

Malignant tumors will become vulnerable if their uncontrolled biosynthesis and energy consumption engaged in metabolic reprogramming can be cut off. Here, we report finding a glycolytic inhibitor targeting glioblastoma with graphite dots-assisted laser desorption/ionization mass spectrometry as an integrated drug screening and pharmacokinetic platform (GLMSD). We have performed high-throughput virtual screening to narrow an initial library of 240,000 compounds down to the docking of 40 compounds and identified five previously unknown chemical scaffolds as promising hexokinase-2 inhibitors. The best inhibitor (Compd 27) can regulate the reprogrammed metabolic pathway in U87 glioma cells (median inhibitory concentration ~ 11.3 μM) for tumor suppression. Highly effective therapy against glioblastoma has been demonstrated in both subcutaneous and orthotopic brain tumors by synergizing Compd 27 and temozolomide. Our glycolytic inhibitor discovery can inspire personalized medicine targeting reprogrammed metabolisms of malignant tumors. GLMSD enables large, high-quality data for next-generation artificial intelligence-aided drug development.

Donor genetic variants as risk factors for thrombosis after liver transplantation: A genome-wide association study

Thrombosis after liver transplantation substantially impairs graft- and patient survival. Inevitably, heritable disorders of coagulation originating in the donor liver are transmitted by transplantation. We hypothesized that genetic variants in donor thrombophilia genes are associated with increased risk of posttransplant thrombosis. We genotyped 775 donors for adult recipients and 310 donors for pediatric recipients transplanted between 1993 and 2018. We determined the association between known donor thrombophilia gene variants and recipient posttransplant thrombosis. In addition, we performed a genome-wide association study (GWAS) and meta-analyzed 1085 liver transplantations. In our donor cohort, known thrombosis risk loci were not associated with posttransplant thrombosis, suggesting that it is unnecessary to exclude liver donors based on thrombosis-susceptible polymorphisms. By performing a meta-GWAS from children and adults, we identified 280 variants in 55 loci at suggestive genetic significance threshold. Downstream prioritization strategies identified biologically plausible candidate genes, among which were AK4 (rs11208611-T, p = 4.22 × 10^-05 ) which encodes a protein that regulates cellular ATP levels and concurrent activation of AMPK and mTOR, and RGS5 (rs10917696-C, p = 2.62 × 10^-05 ) which is involved in vascular development. We provide evidence that common genetic variants in the donor, but not previously known thrombophilia-related variants, are associated with increased risk of thrombosis after liver transplantation.

Perioperative Precision Medicine: Where Are We in 2020?

PURPOSE OF REVIEW

The present review examines how targeted approaches to care, based on individual variability in patient characteristics, could be applied in the perioperative setting. Such an approach would enhance individualized risk assessment and allow for targeted preventive and therapeutic decision-making in patients at increased risk for adverse perioperative events.

RECENT FINDINGS

Prior and current studies highlight valuable lessons on how future investigations attempting to link specific patient-related characteristics or treatment modalities with outcomes and adverse drug responses might be designed in the perioperative setting.

SUMMARY

Our review highlights the past, present, and future directions of perioperative precision medicine. Current evidence provides important lessons on how a specific patient and disease tailored approach can help perioperative physicians in delivering the most appropriate and safest perioperative care.

Thrombophilia evaluation in pulmonary embolism

PURPOSE OF REVIEW

Patients with pulmonary embolism commonly undergo thrombophilia evaluation for a variety of reasons including risk stratification for recurrent venous thromboembolism (VTE) and treatment planning. However, the utility of thrombophilia testing in many clinical scenarios remains unclear. This review evaluates current recommendations for thrombophilia testing described in consensus VTE guidelines, recent literature on the clinical application of these recommendations, novel genetic assessments for hereditary thrombophilias, and studies evaluating use of direct oral anticoagulants (DOACs) in VTE patients with thrombophilias.

RECENT FINDINGS

Current VTE guidelines advise limited use of thrombophilia testing, recognizing that testing may be misinterpreted and frequently does not lead to a change in management. Testing and test results are not necessarily benign, are frequently misinterpreted, and can lead to increased anxiety in both patients and clinicians. Recent studies have offered innovative techniques to better align clinical practice with these recommendations as well as expanded genomic assessments to improve the scope and predictive value of thrombophilia testing. There is also emerging literature on the appropriateness of direct oral anticoagulant therapy for VTE patients with hereditary thrombophilias or antiphospholipid syndrome.

SUMMARY

Thrombophilia testing in its current form does not significantly impact clinical management or improve outcomes for most VTE patients. Therefore, it should be employed judiciously and only in patients for whom it is likely to alter clinical management. Novel expanded genomic thrombophilia testing approaches and additional studies evaluating optimal anticoagulant treatment in various thrombophilia subpopulations will make thrombophilia testing more useful for patients moving forward.

Protein biomarkers for incident deep venous thrombosis in critically ill adolescents: An exploratory study

BACKGROUND

There are no tests to identify critically ill children at high risk of deep venous thrombosis (DVT). In this exploratory study, we aimed to identify proteins that are associated with incident DVT in critically ill adolescents.

PROCEDURE

Plasma samples were obtained from critically ill adolescents within 24 hours after initiation of cardiopulmonary support. The adolescents were followed with ultrasound to detect the development of DVT of the lower extremity and clinically for bleeding. Thrombin-antithrombin complex and prothrombin fragment 1+2 were measured using immunosorbent assays, whereas procoagulation and anticoagulation factors were measured using multiplex assays. Plasma samples were also analyzed using SOMAscan, an aptamer-based capture assay. The associations between DVT and the log-transformed level of the proteins were assessed using logistic regression adjusting for the presence of femoral venous catheter and severity of illness. Associations were expressed as odds ratio (OR) for every log-fold increase in level of the protein with 95% confidence interval (CI).

RESULTS

Plasma from 59 critically ill adolescents, of whom 9 developed incident DVT, was analyzed. The median age of the adolescents was 15.1 years (interquartile range, 14.0-16.7 years). Higher levels of thrombin-antithrombin complex (OR: 31.54; 95% CI: 2.09-475.92) and lower levels of factor XIII (OR: 0.03; 95% CI: 0.002-0.44) were associated with DVT. CD36, MIC-1, and EpoR were marginally associated with DVT. Only factor XIII was associated with clinically relevant bleeding (OR: 0.27; 95% CI: 0.08-0.97).

CONCLUSIONS

We identified candidate protein biomarkers for incident DVT. We plan to validate our findings in adequately powered studies.

Therapeutic management of hyperlipoproteinemia (a)

Cardiovascular disease (CVD) has consistently been the leading cause of death worldwide. Several clinical and epidemiological studies have demonstrated that an elevated plasma concentration of lipoprotein (a) [Lp(a)] is a causative and independent major risk factor for the development of CVD, as well as calcific aortic valve stenosis. Thus, the therapeutic management of hyperlipoproteinemia (a) has received much attention, as significant reductions in Lp(a) levels may, potentially, favorably affect cardiovascular risk. Aspirin, niacin, estrogens, and statins, which act on different molecular pathways, may be prescribed to patients with mild or modest elevations of Lp(a) levels. Other therapeutic interventions, such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, Lp(a) apheresis, and the novel antisense oligonucleotides APO(a)-Rx and APO(a)-LRx, which are being evaluated in ongoing clinical trials, have provided some promising results and can potentially be used in severe cases of hyperlipoproteinemia (a). This review aims to present and discuss the current clinical and scientific data pertaining to the therapeutic options for the management of hyperlipoproteinemia (a).

Clinical significance of altered collagen-receptor functioning in platelets with emphasis on glycoprotein VI

Much interest surrounds the receptors α2β1 and glycoprotein VI (GPVI) whose synchronized action mediates the attachment and activation of platelets on collagen, essential for preventing blood loss but also the most thrombogenic component of the vessel wall. Subject to density variations on platelets through natural polymorphisms, the absence of α2β1 or GPVI uniquely leads to a substantial block of hemostasis without causing major bleeding. Specific to the megakaryocyte lineage, GPVI and its signaling pathways are most promising targets for anti-thrombotic therapy. This review looks at the clinical consequences of the loss of collagen receptor function with emphasis on both the inherited and acquired loss of GPVI with brief mention of mouse models when necessary. A detailed survey of rare case reports of patients with inherited disease-causing variants of the GP6 gene is followed by an assessment of the causes and clinical consequences of acquired GPVI deficiency, a more frequent finding most often due to antibody-induced platelet GPVI shedding. Release of soluble GPVI is brought about by platelet metalloproteinases; a process induced by ligand or antibody binding to GPVI or even high shear forces. Also included is an assessment of the clinical importance of GPVI-mediated platelet interactions with fibrin and of the promise shown by the pharmacological inhibition of GPVI in a cardiovascular context. The role for GPVI in platelet function in inflammation and in the evolution and treatment of major illnesses such as rheumatoid arthritis, cancer and sepsis is also discussed.

Laboratory hemostasis: from biology to the bench

Physiological hemostasis is an intricate biological system, where procoagulant and anticoagulant forces interplay and preserves blood fluidity when blood vessels are intact, or trigger clot formation to prevent excessive bleeding when blood vessels are injured. The modern model of hemostasis is divided into two principal phases. The first, defined as primary hemostasis, involves the platelet-vessel interplay, whilst the second, defined as secondary hemostasis, mainly involves coagulation factors, damaged cells and platelet surfaces, where the so-called coagulation cascade rapidly develops. The activation and amplification of the coagulation cascade is finely modulated by the activity of several physiological inhibitors. Once bleeding has been efficiently stopped by blood clot formation, dissolution of the thrombus is essential to restore vessel permeability. This process, known as fibrinolysis, also develops through coordinate action of a vast array of proteins and enzymes. An accurate diagnosis of hemostasis disturbance entails a multifaceted approach, encompassing family and personal history of hemostatic disorders, accurate collection of clinical signs and symptoms, integrated with laboratory hemostasis testing. Regarding laboratory testing, a reasonable approach entails classifying hemostasis testing according to cost, complexity and available clinical information. Laboratory workout may hence initiate with some rapid and inexpensive "screening" tests, characterized by high negative predictive value, then followed by second- or third-line analyses, specifically aimed to clarify the nature and severity of bleeding or thrombotic phenotype. This article aims to provide a general overview of the hemostatic process, and to provide some general suggestions to optimally facilitate laboratory hemostasis testing.

The Impact of Pharmacogenomics in Personalized Medicine

Recent advances in Pharmacogenomics have made it possible to understand the reasons behind the different response of a drug. Discovery of genetic variants and its association with the varying response of drug provide the basis for recommending a drug and its dose to an individual patient. Genetic makeup-based prescription, design, and implementation of therapy not only improve the outcome of treatments but also reduce the risk of toxicity and other adverse effects. A better understanding of individual variations and their effect on drug response, metabolism excretion, and toxicity will replace the trial-and-error approach of treatment. Evidence of the clinical utility of pharmacogenetics testing is only available for a few medications, and FDA labels only require pharmacogenetics testing for a small number of drugs. Although there is a great promise, there are not many examples where Pharmacogenomics impacts clinical utility. Some genetic variants related to different diseases have been reported, and many have not been studied yet. The information related to the outcome of treatment with a particular drug and a genetic variant can be used to release a warning/label for the use of that drug. There are many limitations in the way of implementing the goal of personalized medicine. Future advances in the field of genomics, diagnosis approaches, data analysis, clinical decision-making, and sustainable business model for personalization of therapy can speed up the individualization of therapy based on genetic makeup.

Effects of genetic variation in protease activated receptor 4 after an acute coronary syndrome: Analysis from the TRACER trial

Variation in platelet response to thrombin may affect the safety and efficacy of PAR antagonism. The Thr120 variant of the common single nucleotide polymorphism (SNP) rs773902 in the protease-activated receptor (PAR) 4 gene is associated with higher platelet aggregation compared to the Ala120 variant. We investigated the relationship between the rs773902 SNP with major bleeding and ischemic events, safety, and efficacy of PAR1 inhibition in 6177 NSTE ACS patients in the TRACER trial. There was a lower rate of GUSTO moderate/severe bleeding in patients with the Thr120 variant. The difference was driven by a lower rate in the smaller homozygous group (recessive model, HR 0.13 [0.02-0.92] P = 0.042). No significant differences were observed in the ischemic outcomes. The excess in bleeding observed with PAR1 inhibition was attenuated in patients with the Thr120 variant, but the interactions were not statistically significant. In summary, lower major bleeding rates were observed in the overall TRACER cohort with the hyperreactive PAR4 Thr120 variant. The increase in bleeding with vorapaxar was attenuated with the Thr120 variant, but we could not demonstrate an interaction with PAR1 inhibition. These findings warrant further exploration, including those of African ancestry where the A allele (Thr120) frequency is ~65%.

Advances in predicting venous thromboembolism risk in children

Paediatric venous thromboembolism (VTE) is a rare disorder but a rising incidence has been observed in recent years, due to improved VTE diagnosis and increased use of central venous catheters in the treatment of severe diseases. Risk assessment strategies are well established for adult patients, however, similar guidelines for paediatric patients are largely lacking. Several risk prediction tools have been reported in recent literature, which make use of established risk factors to assess VTE risk in paediatric subgroups, such as hospitalised children, cancer-diagnosed children and paediatric trauma patients. Although these models suffer several limitations regarding their study size and heterogeneous selection of predictor variables, they offer potential for improving the thromboprophylaxis management in these children. Here, we give an overview on recently reported risk prediction models for paediatric VTE.

Whole-exome sequencing in evaluation of patients with venous thromboembolism

Genetics play a significant role in venous thromboembolism (VTE), yet current clinical laboratory-based testing identifies a known heritable thrombophilia (factor V Leiden, prothrombin gene mutation G20210A, or a deficiency of protein C, protein S, or antithrombin) in only a minority of VTE patients. We hypothesized that a substantial number of VTE patients could have lesser-known thrombophilia mutations. To test this hypothesis, we performed whole-exome sequencing (WES) in 64 patients with VTE, focusing our analysis on a novel 55-gene extended thrombophilia panel that we compiled. Our extended thrombophilia panel identified a probable disease-causing genetic variant or variant of unknown significance in 39 of 64 study patients (60.9%), compared with 6 of 237 control patients without VTE (2.5%) (P < .0001). Clinical laboratory-based thrombophilia testing identified a heritable thrombophilia in only 14 of 54 study patients (25.9%). The majority of WES variants were either associated with thrombosis based on prior reports in the literature or predicted to affect protein structure based on protein modeling performed as part of this study. Variants were found in major thrombophilia genes, various SERPIN genes, and highly conserved areas of other genes with established or potential roles in coagulation or fibrinolysis. Ten patients (15.6%) had >1 variant. Sanger sequencing performed in family members of 4 study patients with and without VTE showed generally concordant results with thrombotic history. WES and extended thrombophilia testing are promising tools for improving our understanding of VTE pathogenesis and identifying inherited thrombophilias.

Platelet genomics: the role of platelet size and number in health and disease

Taken together, there is ample evidence of the association of cardiovascular disease, cerebrovascular, and inflammatory disease with single nucleotide variants (SNV) due to their impact on platelet size, number, and function. With the use of electronic medical record (EMR) or other phenotypic-linked bioinformatics sources, the more important "functional" variants are emerging and provide valuable information on their specific role in promoting early onset of disease or poor response to therapeutic measures. This review will focus upon the recognized common polymorphisms or gene variants with small, but functional effects, as it is becoming clear that these contribute to hyper- or hypo-responsive platelet phenotypes. The impact of these gene variants is distinguishable among normal individuals, and they are suspected contributors to increased risk of adverse outcomes in patients with underlying disease. There are thousands of gene variants and environmental factors that may mitigate risk or amplify the potential for disease within each of us. When combined with the environment and epigenetic influences, it is clear that whole-genome sequencing and bioinformatics alone will not be enough to truly predict "risk" or probability, but awareness of their potential influence may be a starting point in selective screening and generating prevention strategies to promote a healthy lifestyle or fine-tune therapeutic choices in the future.

Temporal quantitative phosphoproteomics of ADP stimulation reveals novel central nodes in platelet activation and inhibition

Adenosine diphosphate (ADP) enhances platelet activation by virtually any other stimulant to complete aggregation. It binds specifically to the G-protein-coupled membrane receptors P2Y1 and P2Y12, stimulating intracellular signaling cascades, leading to integrin αIIbβ3 activation, a process antagonized by endothelial prostacyclin. P2Y12 inhibitors are among the most successful antiplatelet drugs, however, show remarkable variability in efficacy. We reasoned whether a more detailed molecular understanding of ADP-induced protein phosphorylation could identify (1) critical hubs in platelet signaling toward aggregation and (2) novel molecular targets for antiplatelet treatment strategies. We applied quantitative temporal phosphoproteomics to study ADP-mediated signaling at unprecedented molecular resolution. Furthermore, to mimic the antagonistic efficacy of endothelial-derived prostacyclin, we determined how Iloprost reverses ADP-mediated signaling events. We provide temporal profiles of 4797 phosphopeptides, 608 of which showed significant regulation. Regulated proteins are implicated in well-known activating functions such as degranulation and cytoskeletal reorganization, but also in less well-understood pathways, involving ubiquitin ligases and GTPase exchange factors/GTPase-activating proteins (GEF/GAP). Our data demonstrate that ADP-triggered phosphorylation occurs predominantly within the first 10 seconds, with many short rather than sustained changes. For a set of phosphorylation sites (eg, PDE3A^Ser312, CALDAG-GEFI^Ser587, ENSA^Ser109), we demonstrate an inverse regulation by ADP and Iloprost, suggesting that these are central modulators of platelet homeostasis. This study demonstrates an extensive spectrum of human platelet protein phosphorylation in response to ADP and Iloprost, which inversely overlap and represent major activating and inhibitory pathways.

Personalized medicine and blood disorders

Personalized medicine has been using genomics approaches to elucidate the etiology of a disease as well as to personalize the management for patients of a particular disease based on that individual's genetic features. It benefits patients across a multitude of therapeutic areas and advancements are particularly evident in hematology/oncology. The importance of genomics discoveries and development in nonmalignant blood disorders generally goes unrecognized, but it becomes critical now due to the global disease burden and a high mortality. This paper focuses on the exploration of personalized medicine applications in hemoglobin diseases, and thrombotic and bleeding disorders. It discusses the challenges which slow down the implementation as well. The available data suggest that the ability to understand the clinical features of a patient's genetic profile and the knowledge of disease mechanisms are the keys to facilitate new diagnosis, new therapies, new prescriptions and better healthcare.