The Personalization of Clopidogrel Antiplatelet Therapy: The Role of Integrative Pharmacogenetics and Pharmacometabolomics

Association of genetic variations of 3'-UTR in clopidogrel pharmacokinetic-relevant genes with clopidogrel response in Han Chinese patients with coronary artery disease

Dual antiplatelet therapy with aspirin and clopidogrel has reduced ischemic vascular events significantly. Genetic influence, especially those in clopidogrel pharmacokinetic-relevant genes partially accounts for interindividual pharmacodynamic variability of clopidogrel. However, most studies have concentrated on the genetic variations in introns, exons, or promoters of the candidate genes, and the association between genetic variations in 3'-UTR in clopidogrel pharmacokinetic-relevant genes and clopidogrel response is unknown. In our study, ten different algorithms were applied to pick potential miRNAs targeting the clopidogrel pharmacokinetic-relevant genes. Furthermore, the correlation between miRNA expression profiles and mRNA expression of corresponding clopidogrel pharmacokinetic-relevant genes was analyzed. Through comprehensive analysis, including bioinformatics prediction and correlation analysis of miRNA and mRNA expression profiles, miR-218-5p and miR-506-5p were supposed to regulate the expression of PON1 via binding with its 3'-UTR. Moreover, PON1 rs854551 and rs854552 were located in miRNA recognizing sequences and may serve as potential miRSNPs possibly affecting PON1 expression. The rs854552 polymorphism was genotyped and platelet reactivity index (PRI) indicative of clopidogrel response was measured in 341 Chinese coronary artery disease (CAD) patients 24 h after administration of 300 mg clopidogrel. Our results showed that PON1 rs854552 had a significant influence on PRI in CAD patients, especially in patients with CYP2C19 extensive metabolic phenotype. In conclusion, PON1 rs854552 polymorphisms may affect clopidogrel response. Bioinformatics prediction followed by functional validation could aid in decoding the contribution of unexplained variations in the 3'-UTR in drug-metabolizing enzymes on clopidogrel response.

The association between abcb1 gene polymorphism and clopidogrel response variability in stroke ischemic: a cross sectional study

BACKGROUND

Clopidogrel has been the primary choice of antiplatelet in ischemic stroke that inhibits adenosine diphosphate (ADP)-induced platelet aggregation. P-glycoprotein (P-gp) multidrug resistance-1 (MDR1) is a transmembrane efflux transporter in intestinal cells that plays a significant role in clopidogrel absorption, therefore may affect platelet aggregation. P-gp is encoded by the ABCB1 gene. This study aims to evaluate the effect of ABCB1 polymorphism on clopidogrel response variability in ischemic stroke patients and its genotype frequency.

METHODS

A cross-sectional study was conducted in ischemic stroke patients who received clopidogrel between 2020 and 2023 in RSUI/RSCM. All subjects were assessed for ABCB1 polymorphisms C3435T and C1236T. Platelet aggregation were measured using VerifyNow PRU. Clopidogrel response variability was classified into unresponsive (> 208 PRU), responsive (95-208 PRU), and bleeding risk (< 95 PRU).

RESULTS

124 subjects enrolled in this study, with 12,9% of subjects classified as non-responsive/resistant, 49,5% as responsive, and 41,9% as bleeding risk. ABCB1 C1236T homozygote wildtype (CC) was associated with 3,76 times higher bleeding risk than other variants (p = 0,008; 95%CI 1,41 - 10,07). Genotype frequency of ABCB1 C3435T homozygote wildtype, heterozygote, and homozygote variants were 35,9%, 43,5% and 16,9%, respectively; while the genotype frequency of ABCB1 C1236T were 17,8%, 39,5%, and 42,7%, respectively.

CONCLUSION

ABCB1 C1236T homozygote wildtype was associated with 3,76 times higher bleeding risk than other variants. The most common genotype frequency of ABCB1 C1236T was homozygote variant; while for ABCB1 C3435T was heterozygote.

Investigation of smoking on the antiplatelet response to clopidogrel: Unravelling the smoker's paradox

The intricate relationship between smoking and the effects of the antiplatelet drug clopidogrel has been termed the "smoker's paradox". This paradox details the enhanced efficacy of clopidogrel in smokers compared to non-smokers. This review begins with an exploration of the proposed mechanisms of the smoker's paradox, particularly drawing attention to the induction of cytochrome P450 (CYP) isoenzymes via tobacco smoke, specifically the enzymes CYP1A2 and CYP2C19. Moreover, an investigation of the effects of genetic variability on the smoker's paradox was undertaken from both clinical and molecular perspectives, delving into the effects of ethnicity and genetic polymorphisms. The intriguing role of CYP1A2 genotypes and the response to clopidogrel in smoking and non-smoking populations was examined conferring insight into the individuality rather than universality of the smoker's paradox. CYP1A2 induction is hypothesised to elucidate the potency of smoking in exerting a counteracting effect in those taking clopidogrel who possess CYP2C19 loss of function polymorphisms. Furthermore, we assess the comparative efficacies of clopidogrel and other antiplatelet agents, namely prasugrel and ticagrelor. Studies indicated that prasugrel and ticagrelor provided a more consistent effect and further reduced platelet reactivity compared to clopidogrel within both smoking and non-smoking populations. Personalised dosing was another focus of the review considering patient comorbidities, genetic makeup, and smoking status with the objective of improving the antiplatelet response of those taking clopidogrel. In summation, this review provides insight into multiple areas of research concerning clopidogrel and the smoker's paradox taking into account proposed mechanisms, genetics, other antiplatelet agents, and personalised dosing.

Pharmacokinetics in Pharmacometabolomics: Towards Personalized Medication

Indiscriminate drug administration may lead to drug therapy results with varying effects on patients, and the proposal of personalized medication can help patients to receive effective drug therapy. Conventional ways of personalized medication, such as pharmacogenomics and therapeutic drug monitoring (TDM), can only be implemented from a single perspective. The development of pharmacometabolomics provides a research method for the realization of precise drug administration, which integrates the environmental and genetic factors, and applies metabolomics technology to study how to predict different drug therapeutic responses of organisms based on baseline metabolic levels. The published research on pharmacometabolomics has achieved satisfactory results in predicting the pharmacokinetics, pharmacodynamics, and the discovery of biomarkers of drugs. Among them, the pharmacokinetics related to pharmacometabolomics are used to explore individual variability in drug metabolism from the level of metabolism of the drugs in vivo and the level of endogenous metabolite changes. By searching for relevant literature with the keyword "pharmacometabolomics" on the two major literature retrieval websites, PubMed and Web of Science, from 2006 to 2023, we reviewed articles in the field of pharmacometabolomics that incorporated pharmacokinetics into their research. This review explains the therapeutic effects of drugs on the body from the perspective of endogenous metabolites and pharmacokinetic principles, and reports the latest advances in pharmacometabolomics related to pharmacokinetics to provide research ideas and methods for advancing the implementation of personalized medication.

A metabolomics study: Could plasma metabolites be a guide for the prevention of tamsulosin side effects?

BACKGROUND

The understanding of precision medicine, which aims for high efficacy and low toxicity in treatments, has gained more importance with omics technologies. In this study, it was aimed to reach new suggestions for low-toxicity treatment by clarifying the relationship between tamsulosin side effects and metabolome profiles.

MATERIALS AND METHODS

Plasma samples of control and tamsulosin-treated rats were analyzed by LC-Q-TOF/MS/MS. MS/MS data was processed in XCMS software for the identification of metabolite and metabolic pathway analysis. Data were classified with MATLAB 2019b for multivariate data analysis. 34m/z values were found to be significantly different between the drug and control groups (P≤0.01 and fold analysis≥1.5) and identified by comparing METLIN and HMDB databases.

RESULTS

According to multivariate data analysis, α-Linolenic Acid, Thiamine, Retinoic acid, 1.25-Dihydroxyvitamin D3-26.23-Lactone, L-Glutamine, L-Serine, Retinaldehyde, Sphingosine 1-phosphate, L-Lysine, 23S.25-Dihydroxyvitamin D3, Sphinganine, L-Cysteine, Uridine 5'-diphosphate, Calcidiol, L-Tryptophan, L-Alanine levels changed significantly compared to the control group. Differences in the metabolisms of Retinol, Sphingolipid, Alanine-Aspartate-Glutamate, Glutathione, Fatty Acid, Tryptophan, and biosynthesis of Aminoacyl-tRNA, and Unsaturated Fatty Acid have been successfully demonstrated by metabolic pathway analysis. According to our study, vitamin A and D supplements can be recommended to prevent side effects such as asthenia, rhinitis, nasal congestion, dizziness and IFIS in the treatment of tamsulosin. Alteration of aminoacyl-tRNA biosynthesis and sphingolipid metabolism pathways during tamsulosin treatment is effective in the occurrence of nasal congestion.

CONCLUSIONS

Our study provides important information for tamsulosin therapy with high efficacy and low side effects in precision medicine.

Correlation P2Y12 Genetic Polymorphism As Risk Factor of Clopidogrel Resistance in Indonesian Stroke Patients

Background

Stroke is one of the highest causes of disability and mortality in several countries worldwide. Secondary prevention is important in the management of stroke. Clopidogrel is widely used in Asia as secondary prevention for ischemic stroke, even though several studies in Western show limited data related to clopidogrel resistance in Asia. This study aims to determine the correlation between P2Y12 genetic polymorphism and clopidogrel resistance in Indonesia.

Methods

This study was conducted on one-year duration, the subjects were chosen through the consecutive sampling method, all subjects were examined for genetics and resistance to clopidogrel. The data were analyzed through statistical analysis, a bivariate analysis was conducted to determine the correlation between several variables and the resistance variable. This study employed resistance diagnostic methods with VerifyNow. Polymorphism of receptor P2Y12 was tested with the Polymerase Chain Reaction method (PCR) and analysis of restriction fragment length polymorphism (RFLP). The genes tested in this study were G52T and C34T.

Results

The number of participants in this study was 112. Examination of gene P2Y12 showed that the majority was homozygote, wild-type C34T allele (67%), and G52T (66.1%). There was no significant correlation between clopidogrel resistance and gene G52T and C34T of P2Y12 (p > 0.05). Hb levels significantly correlated with P2Y12 G52T (p = 0.024). Meanwhile, Fatty Liver significantly correlated with P2Y12 C34T (p = 0.037).

Conclusion

Indonesia showed a low clopidogrel resistance rate and a very low C34T and G52T allele P2Y12 gene mutation, meaning that Indonesia had low mutations in the P2Y12. This is the cause of clopidogrel resistance in this study only 15%. Therefore, in a region with less clopidogrel resistance, examination of the P2Y12 gene would not give significant results.

The Therapeutic Potential of Anticoagulation in Organ Fibrosis

Fibrosis, also known as organ scarring, describes a pathological stiffening of organs or tissues caused by increased synthesis of extracellular matrix (ECM) components. In the past decades, mounting evidence has accumulated showing that the coagulation cascade is directly associated with fibrotic development. Recent findings suggest that, under inflammatory conditions, various cell types (e.g., immune cells) participate in the coagulation process causing pathological outcomes, including fibrosis. These findings highlighted the potential of anticoagulation therapy as a strategy in organ fibrosis. Indeed, preclinical and clinical studies demonstrated that the inhibition of blood coagulation is a potential intervention for the treatment of fibrosis across all major organs (e.g., lung, liver, heart, and kidney). In this review, we aim to summarize our current knowledge on the impact of components of coagulation cascade on fibrosis of various organs and provide an update on the current development of anticoagulation therapy for fibrosis.

Dosage optimization of clopidogrel via a precision medicine approach: the way forward

Clopidogrel is a prodrug chiefly metabolized by the hepatic isoenzyme CYP2C19 to its active metabolite that inhibits the platelet aggregation. It has been proven in many populations that the genetic polymorphism of CYP2C19 has influence on the pharmacokinetic and or pharmacodynamics of this drug and resulting in high inter-individual variability in the treatment outcomes. As CYP2C19 genetic polymorphism is highly prevalent among the Asian population, the influence of the same on the pharmacokinetics and; thereby, the pharmacodynamics of clopidogrel needs more attention. Using the pharmacogenetic information for drug therapy could help overcome these issues and to optimize the dosage regimen of clopidogrel, this review advocates the precision medicine approach for reducing the clopidogrel resistance and adverse cardiovascular events.

Relationship between platelet aggregation and stroke risk after percutaneous coronary intervention: a PENDULUM analysis

In patients undergoing percutaneous coronary intervention (PCI) with a stent, high on-treatment platelet reactivity may be associated with an increased risk of stroke. This post hoc analysis of the PENDULUM registry compared the risk of post-PCI stroke according to on-treatment P2Y₁₂ reaction unit (PRU) values. Patients aged ≥ 20 years who underwent PCI were stratified by baseline PRU (at 12 and 48 h post-PCI) as either high (HPR, > 208), optimal (OPR, > 85 to ≤ 208), or low on-treatment platelet reactivity (LPR, ≤ 85). The incidences of non-fatal ischemic and non-ischemic stroke through to 12 months post-PCI were recorded. Almost all enrolled patients (6102/6267 [97.4%]) had a risk factor for ischemic stroke, and most were receiving dual antiplatelet therapy. Of the 5906 patients with PRU data (HPR, n = 2227; OPR, n = 3002; LPR, n = 677), 47 had a non-fatal stroke post-PCI (cumulative incidence: 0.68%, ischemic; 0.18%, non-ischemic stroke). Patients with a non-fatal ischemic stroke event had statistically significantly higher post-PCI PRU values versus those without an event (P = 0.037). The incidence of non-fatal non-ischemic stroke was not related to PRU value. When the patients were stratified by PRU ≤ 153 versus > 153 at 12–48 h post-PCI, a significant difference was observed in the cumulative incidence of non-fatal stroke at 12 months (P = 0.044). We found that patients with ischemic stroke tended to have higher PRU values at 12–48 h after PCI versus those without ischemic stroke.

Clinical trial registration: UMIN000020332.

Pharmacokinetics, mass balance, and metabolism of [14C]vicagrel, a novel irreversible P2Y12 inhibitor in humans

Vicagrel, a novel irreversible P2Y₁₂ receptor inhibitor, is undergoing phase III trials for the treatment of acute coronary syndromes in China. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of vicagrel in six healthy male Chinese subjects after a single oral dose of 20 mg [¹⁴C]vicagrel (120 µCi). Vicagrel absorption was fast (T_max = 0.625 h), and the mean t_1/2 of vicagrel-related components was ~38.0 h in both plasma and blood. The blood-to-plasma radioactivity AUC_inf ratio was 0.55, suggesting preferential distribution of drug-related material in plasma. At 168 h after oral administration, the mean cumulative excreted radioactivity was 96.71% of the dose, including 68.03% in urine and 28.67% in feces. A total of 22 metabolites were identified, and the parent vicagrel was not detected in plasma, urine, or feces. The most important metabolic spot of vicagrel was on the thiophene ring. In plasma pretreated with the derivatization reagent, M9-2, which is a methylated metabolite after thiophene ring opening, was the predominant drug-related component, accounting for 39.43% of the radioactivity in pooled AUC_0-8 h plasma. M4, a mono-oxidation metabolite upon ring-opening, was the most abundant metabolite in urine, accounting for 16.25% of the dose, followed by M3-1, accounting for 12.59% of the dose. By comparison, M21 was the major metabolite in feces, accounting for 6.81% of the dose. Overall, renal elimination plays a crucial role in vicagrel disposition, and the thiophene ring is the predominant metabolic site.

Risk of stroke in CYP2C19 LoF polymorphism carrier coronary artery disease patients undergoing clopidogrel therapy: An ethnicity-based updated meta-analysis

BACKGROUND

Antiplatelet agent clopidogrel has been widely used for stroke management for many years, although resistance to clopidogrel may increase the chance of stroke recurrence. CYP2C19 loss-of-function (LoF) polymorphism is assumed to be responsible for the poor metabolism of clopidogrel that ultimately turns to resistance. Previous publications could not provide firm evidence due to highly conflicting and heterogeneous outcomes.

AIM

To get clear evidence from an updated meta-analysis on CYP2C19 LoF polymorphism association with stroke risk in clopidogrel treated patients, this study has been performed.

METHODS

We conducted a meta-analysis with 72 selected studies from authentic databases, including 40,035 coronary artery disease patients treated with clopidogrel.

RESULTS

This analysis showed that the worldwide carrier of one or more CYP2C19 LoF alleles had a significantly higher risk of stroke and composite events than the non-LoF carriers (RR=1.78, 95% CI=1.52-2.07, p<0.00001 and RR=1.39, 95% CI=1.26-1.54, p<0.00001, respectively). Besides, subgroup analysis showed that Asian CYP2C19 LoF carriers had a significantly increased risk of stroke (RR=1.91, 95% CI=1.60-2.28, p<0.00001) while the risk of composite events was significantly higher in all ethnic populations (Asian: RR=1.58, 95% CI=1.32-1.89, p<0.00001; Caucasian: RR=1.27, 95% CI=1.08-1.50, p=0.003; Hispanic and others: RR=1.21, 95% CI=1.09-1.34, p=0.0003).

CONCLUSION

Our meta-analysis confirmed that the presence of CYP2C19 LoF alleles increases the risk of stroke and composite events recurrence in the worldwide population, especially in Asians undergoing clopidogrel treatment. Alternative antiplatelet therapy should be investigated thoroughly for the intermediate and poor metabolizers.

The Role of Platelets in the Stimulation of Neuronal Synaptic Plasticity, Electric Activity, and Oxidative Phosphorylation: Possibilities for New Therapy of Neurodegenerative Diseases

The central nervous system (CNS) is highly vascularized where neuronal cells are located in proximity to endothelial cells, astroglial limitans, and neuronal processes constituting integrated neurovascular units. In contrast to many other organs, the CNS has a blood-brain barrier (BBB), which becomes compromised due to infection, neuroinflammation, neurodegeneration, traumatic brain injury, and other reasons. BBB disruption is presumably involved in neuronal injury during epilepsy and psychiatric disorders. Therefore, many types of neuropsychological disorders are accompanied by an increase in BBB permeability leading to direct contact of circulating blood cells in the capillaries with neuronal cells in the CNS. The second most abundant type of blood cells are platelets, which come after erythrocytes and outnumber ~100-fold circulating leukocytes. When BBB becomes compromised, platelets swiftly respond to the vascular injury and become engaged in thrombosis and hemostasis. However, more recent studies demonstrated that platelets could also enter CNS parenchyma and directly interact with neuronal cells. Within CNS, platelets become activated by recognizing major brain gangliosides on the surface of astrocytes and neurons and releasing a milieu of pro-inflammatory mediators, neurotrophic factors, and neurotransmitters. Platelet-derived factors directly stimulate neuronal electric and synaptic activity and promote the formation of new synapses and axonal regrowth near the site of damage. Despite such active involvement in response to CNS damage, the role of platelets in neurological disorders was not extensively studied, which will be the focus of this review.

Therapeutic Dilemma in personalized medicine

The practice of medicine depends over a long time on identifying therapies that target an entire population. The increase in scientific knowledge over the years has led to the gradual change towards individualization and personalization of drug therapy. The hope of this change is to achieve a better clinical response to given medications and reduction of their adverse effects. Tailoring of medicine on the road of personalized medicine considers molecular and genetic mapping of the individual. However, many factors still impede the smooth application of personalized medicine and represent challenges or limitations in its achievement. In this article, we put some clinical examples that show dilemmas in the application of personalized medicine such as opioids in pain control, fluoropyrimidines in malignancy, clopidogrel as antiplatelet therapy and oral hypoglycemic drugs in Type2 diabetes in adults. Shaping the future of medicine through the application of personalized medicine for a particular patient needs to put into consideration many factors such as patient's genetic makeup and life style, pathology of the disease and dynamic changes in its course as well as interactions between administered drugs and their effects on metabolizing enzymes. We hope in the coming years, the personalized medicine will foster changes in health care system in the way not only to treat patients but also to prevent diseases.

A Pharmacogenetic Study of CYP2C19 in Acute Coronary Syndrome Patients of Colombian Origin Reveals New Polymorphisms Potentially Related to Clopidogrel Therapy

Clopidogrel, an oral platelet P2Y₁₂ receptor blocker, is used in the treatment of acute coronary syndrome. Interindividual variability in treatment response and the occurrence of adverse effects has been attributed to genetic variants in CYP2C19. The analysis of relevant pharmacogenes in ethnically heterogeneous and poorly studied populations contributes to the implementation of personalized medicine. We analyzed the coding and regulatory regions of CYP2C19 in 166 patients with acute coronary syndrome (ACS) treated with clopidogrel. The allele frequencies of CYP2C19 alleles *1, *2, *4, *17, *27 and *33 alleles were 86.1%, 7.2%, 0.3%, 10.2%, 0.3% and 0.3%, respectively. A new potentially pathogenic mutation (p.L15H) and five intronic variants with potential splicing effects were detected. In 14.4% of the patients, a new haplotype in strong linkage disequilibrium was identified. The clinical outcome indicated that 13.5% of the patients presented adverse drugs reactions with a predominance of bleeding while 25% of these patients were carriers of at least one polymorphic allele. We propose that new regulatory single-nucleotide variants (SNVs) might potentially influence the response to clopidogrel in Colombian individuals.

Platelet aggregometry for hip fracture surgery in patients treated with clopidogrel: a pilot study

Surgery for hip fractures should be performed within 48 h from patient's admission. However, several factors including chronic antiplatelet therapy could delay operation. Among the totality of patients taking clopidogrel, up to 30% are resistant to the drug and have a normal platelets reactivity. We propose thromboelastography (TEG) with an ADP Platelet Mapping assay kit to assess platelet aggregation, a safe tool that could help to avoid surgery delay in those patients treated with antiplatelet therapy. A patient's blood sample was collected for aggregometry. If MA-ADP and platelets aggregation (%) were within normal values, the patient was fit for immediate surgery with neuraxial anesthesia and ultrasound-guided nerve block. If one of the two parameters or both were deranged, a mortality risk assessment was estimated. In the low risk category, the patients waited till normalization of the parameters, whereas in the high-risk group a general anesthesia and peripheral antalgic block was carried out. Nine patients were enrolled. Four of them showed normal aggregometry and surgery was performed within 24 h from admission. Two patients were classified as high mortality risk and surgery was carried out under general anesthesia. Three patients awaited operation till normalization of parameters. No peri or post-operative complications were reported. An aggregometry-guided protocol can safely expedite hip fracture surgery in patients taking clopidogrel. Nonetheless, in presence of a normal platelets function, clinician can opt for a neuraxial instead of general anesthesia reducing the incidence of postoperative delirium and cognitive dysfunction.Trial registration: prospectively registered at clinicaltrials.gov (NCT04642209; date of registration: 23rd November 2020).

Identification of biomarkers to diagnose diseases and find adverse drug reactions by metabolomics

Metabolomics has been widely used for investigating the biological functions of disease expression and has the potential to discover biomarkers in circulating biofluids or tissue extracts that reflect in phenotypic changes. Metabolic profiling has advantages because of the use of unbiased techniques, including multivariate analysis, and has been applied in pharmacological studies to predict therapeutic and adverse reactions of drugs, which is called pharmacometabolomics (PMx). Nuclear magnetic resonance (NMR)- and mass spectrometry (MS)-based metabolomics has contributed to the discovery of recent disease biomarkers; however, the optimal strategy for the study purpose must be selected from many established protocols, methodologies and analytical platforms. Additionally, information on molecular localization in tissue is essential for further functional analyses related to therapeutic and adverse effects of drugs in the process of drug development. MS imaging (MSI) is a promising technology that can visualize molecules on tissue surfaces without labeling and thus provide localized information. This review summarizes recent uses of MS-based global and wide-targeted metabolomics technologies and the advantages of the MSI approach for PMx and highlights the PMx technique for the biomarker discovery of adverse drug effects.

Pharmacokinetic, pharmacodynamic, and pharmacogenetic assays to monitor clopidogrel therapy

Clopidogrel is the most common and widely used antiplatelet agent for patients with coronary artery disease following confirmation by electrocardiographic studies. The nonresponsiveness of patients to clopidogrel and the possibility of testing for clopidogrel resistance by platelet function assays (PFA) are contentious issues. Light transmission aggregometry (LTA) is considered as the gold standard test among all PFA. In this review, the most commonly used PFA used for monitoring the effect of clopidogrel, LTA, vasodilator-stimulated phosphoprotein assay phosphorylation, rotational thromboelastometry (ROTEM) delta and ROTEM platelet, thromboelastography, PFA-100, VerifyNow P2Y12 assay, Multiplate analyzer, Plateletworks assay and pharmacogenetic studies, are comparatively discussed including their principles of action, advantages, and disadvantages. VerifyNow P2Y12 assay can be accepted as the ideal point of care test out of the discussed assays. However, modified assays are required which could overcome the limitations associated with currently available assays.

Association of FMO3 rs1736557 polymorphism with clopidogrel response in Chinese patients with coronary artery disease

PURPOSE

Dual antiplatelet therapy with aspirin and clopidogrel is commonly used for coronary artery disease (CAD) patients undergoing percutaneous coronary intervention to prevent stent thrombosis and ischemic events. However, some patients show high on-treatment platelet reactivity (HTPR) during clopidogrel therapy. Genetic factors such as loss-of-function variants of CYP2C19 are validated to increase the risk of HTPR. Flavin-containing monooxygenase 3 (FMO3) is reported to be associated with potency of platelet responsiveness and thrombosis. This study aimed to explore the association between FMO3 rs1736557 polymorphism and clopidogrel response.

METHODS

Five hundred twenty-two Chinese CAD patients treated with dual antiplatelet therapy were recruited from Xiangya Hospital. After oral administration of 300 mg loading dose (LD) clopidogrel for 12-24 h or 75 mg daily maintenance dose (MD) clopidogrel for at least 5 days, the platelet reaction index (PRI) was determined by vasodilator-stimulated phosphoprotein-phosphorylation assay. FMO3 rs1736557, CYP2C19*2, and CYP2C19*3 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Mean PRI value was significantly higher in CYP2C19 poor metabolizers (PMs) and intermediate metabolizers (IMs) than the extensive metabolizers (EMs) (p < 0.001). In addition, FMO3 rs1736557 AA homozygotes showed significantly lower PRI as compared with carriers of the major rs1736557 G allele in the entire cohort and in the MD cohort (p = 0.011, p = 0.008, respectively). The risk of HTPR was decreased significantly in carriers of the rs1736557 A allele (AA vs GG: OR = 0.316, 95% CI: 0.137-0.726, p = 0.005; AA vs GA: OR = 0.249, 95% CI: 0.104-0.597, p = 0.001; AA vs GG+GA: OR = 0.294, 95% CI: 0.129-0.669, p = 0.002), and the association was observed mainly in patients carrying the CYP2C19 LOF allele and in those administered with MD.

CONCLUSION

The FMO3 rs1736557 AA genotype was related to an increased the antiplatelet potency of clopidogrel in Chinese CAD patients. Additional studies are required to verify this finding.

Metabolomics applications in coronary artery disease personalized medicine

Coronary artery disease (CAD), the most common cardiovascular disease (CVD), contributes to significant mortality worldwide. CAD is a multifactorial disease wherein various factors contribute to its pathogenesis often complicating management. Biomarker based personalized medicine may provide a more effective way to individualize therapy in multifactorial diseases in general and CAD specifically. Systems' biology "Omics" biomarkers have been investigated for this purpose. These biomarkers provide a more comprehensive understanding on pathophysiology of the disease process and can help in identifying new therapeutic targets and tailoring therapy to achieve optimum outcome. Metabolomics biomarkers usually reflect genetic and non-genetic factors involved in the phenotype. Metabolomics analysis may provide better understanding of the disease pathogenesis and drug response variation. This will help in guiding therapy, particularly for multifactorial diseases such as CAD. In this chapter, advances in metabolomics analysis and its role in personalized medicine will be reviewed with comprehensive focus on CAD. Assessment of risk, diagnosis, complications, drug response and nutritional therapy will be discussed. Together, this chapter will review the current application of metabolomics in CAD management and highlight areas that warrant further investigation.

Integration analysis of metabolites and single nucleotide polymorphisms improves the prediction of drug response of celecoxib

INTRODUCTION

Pharmacogenetics and pharmacometabolomics are the common methods for personalized medicine, either genetic or metabolic biomarkers have limited predictive power for drug response.

OBJECTIVES

In order to better predict drug response, the study attempted to integrate genetic and metabolic biomarkers for drug pharmacokinetics prediction.

METHODS

The study chose celecoxib as study object, the pharmacokinetic behavior of celecoxib was assessed in 48 healthy volunteers based on UPLC-MS/MS platform, and celecoxib related single nucleotide polymorphisms (SNPs) were also detected. Three mathematic models were constructed for celecoxib pharmacokinetics prediction, the first one was mainly based on celecoxib-related SNPs; the second was based on the metabolites selected from a pharmacometabolomic analysis by using GC-MS/MS method, the last model was based on the combination of the celecoxib-related SNPs and metabolites above.

RESULTS

The result proved that the last model showed an improved prediction power, the integration model could explain 71.0% AUC variation and predict 62.3% AUC variation. To facilitate clinical application, ten potential celecoxib-related biomarkers were further screened, which could explain 68.3% and predict 54.6% AUC variation, the predicted AUC was well correlated with the measured values (r = 0.838).

CONCLUSION

This study provides a new route for personalized medicine, the integration of genetic and metabolic biomarkers can predict drug response with a higher accuracy.

Metabolomics technology and bioinformatics for precision medicine

Precision medicine is rapidly emerging as a strategy to tailor medical treatment to a small group or even individual patients based on their genetics, environment and lifestyle. Precision medicine relies heavily on developments in systems biology and omics disciplines, including metabolomics. Combination of metabolomics with sophisticated bioinformatics analysis and mathematical modeling has an extreme power to provide a metabolic snapshot of the patient over the course of disease and treatment or classifying patients into subpopulations and subgroups requiring individual medical treatment. Although a powerful approach, metabolomics have certain limitations in technology and bioinformatics. We will review various aspects of metabolomics technology and bioinformatics, from data generation, bioinformatics analysis, data fusion and mathematical modeling to data management, in the context of precision medicine.

Clinical outcomes and predictive model of platelet reactivity to clopidogrel after acute ischemic vascular events

BACKGROUND

High on-treatment platelet reactivity (HTPR) has been suggested as a risk factor for patients with ischemic vascular disease. We explored a predictive model of platelet reactivity to clopidogrel and the relationship with clinical outcomes.

METHODS

A total of 441 patients were included. Platelet reactivity was measured by light transmittance aggregometry after receiving dual antiplatelet therapy. HTPR was defined by the consensus cutoff of maximal platelet aggregation >46% by light transmittance aggregometry. CYP2C19 loss-of-function polymorphisms were identified by DNA microarray analysis. The data were compared by binary logistic regression to find the risk factors. The primary endpoint was major adverse clinical events (MACEs), and patients were followed for a median time of 29 months. Survival curves were constructed with Kaplan-Meier estimates and compared by log-rank tests between the patients with HTPR and non-HTPR.

RESULTS

The rate of HTPR was 17.2%. Logistic regression identified the following predictors of HTPR: age, therapy regimen, body mass index, diabetes history, CYP2C192, or CYP2C193 variant. The area under the curve of receiver operating characteristic for the HTPR predictive model was 0.793 (95% confidence interval: 0.738-0.848). Kaplan-Meier analysis showed that patients with HTPR had a higher incidence of MACE than those with non-HTPR (21.1% vs. 9.9%; χ = 7.572, P = 0.010).

CONCLUSIONS

Our results suggest that advanced age, higher body mass index, treatment with regular dual antiplatelet therapy, diabetes, and CYP2C192 or CYP2C193 carriers are significantly associated with HTPR to clopidogrel. The predictive model of HTPR has useful discrimination and good calibration and may predict long-term MACE.

Genetic and Nongenetic Implications of Racial Variation in Response to Antiplatelet Therapy

Race has been identified as an independent risk factor for poor prognosis and an independent predictor of survival in coronary artery disease. Race-related dissimilarities have been identified in cardiovascular patients in terms of age of presentation, co-morbidities, socioeconomic status, and treatment approach as well as genetically driven race-related disparities in responsiveness to medications. Antiplatelet therapy represents a fundamental component of therapy in cardiovascular patients, especially in patients presenting with acute coronary syndromes. It has been argued that the different level of platelet reactivity and varying response to antiplatelet therapy among races may account in part for worse outcomes in certain populations. The purpose of this review is to describe genotypic and phenotypic race-related differences in platelet reactivity and responsiveness to cardiovascular treatment, focusing on antiplatelet therapy to highlight the need establish a more effective and targeted antithrombotic strategy.

Clopidogrel Pharmacogenetics in Iranian Patients Undergoing Percutaneous Coronary Intervention

Clopidogrel is used in patients with coronary syndromes and at risk of thrombotic events or receiving percutaneous coronary intervention (PCI) for reducing heart attack and stroke. Here we present genotype and phenotype study of Iranian patients undergoing PCI treated with clopidogrel during a 6-month period of follow-up; common variants of CYP2C19, CYP3A5, CYP3A4, and ABCB1 genes were determined as well as the patients' cardiovascular outcomes to find out the effect of these variants individually and in combination. 388 individuals receiving PCI were enrolled in this study. Different pretreatment doses of clopidogrel were prescribed under the interventional cardiologists' guidance. The patients were followed for a duration of 1 month, and 6 months. Six SNPs were selected for genotyping including CYP2C19*2 (c.681G > A), CYP2C19*3 (c.636G > A), CYP2C19*17 allele (c.-806C > T), ABCB1 (c.3435C > T), CYP3A5 (c.6986A > G), and CYP3A4 (c.1026 + 12G > A). The mean loading dose was 600 mg/day in 267 (68.8%) individuals, 300 mg/day in 121 (31.2%). 8 patients had cardiovascular events such as thrombosis, unstable angina, and non-STEMI. The studied alleles and genotypes were in Hardy-Weinberg equilibrium. None of the SNPs individually were significantly associated with outcome events. Our results indicate that combinations of different alleles of genes are involved in pharmacokinetic variability and joint factors are important; this means that genotyping and analysis of an individual variant may not be as straightforward in risk assessment and pharmacogenetics. This highlights the importance of personalized medicine in risk assessment and treatment.

Association of N6AMT1 rs2254638 Polymorphism With Clopidogrel Response in Chinese Patients With Coronary Artery Disease

Dual antiplatelet treatment with aspirin and clopidogrel is the standard therapy for patients undergoing percutaneous coronary intervention (PCI). However, a portion of patients suffer from clopidogrel resistance (CR) and consequently with recurrence of cardiovascular events. Genetic factors such as loss-of-function variants of CYP2C19 contribute a lot to CR. Recently, the N-6-adenine-specific DNA methyltransferase 1 (N6AMT1) rs2254638 polymorphism is reported to be associated with clopidogrel response. To validate the association between N6AMT1 rs2254638 polymorphism and clopidogrel response, 435 Chinese CAD patients receiving aspirin and clopidogrel were recruited. N6AMT1 rs2254638 and CYP2C19^*2/^*3 polymorphisms were genotyped. Platelet reaction index (PRI) was measured by VASP-phosphorylation assay after treated with a 300 mg loading dose (LD) clopidogrel or 75 mg daily maintenance dose (MD) clopidogrel for at least 5 days. There was a significant difference in PRI between LD cohort and MD cohort. Carriers of CYP2C19^*2 allele showed significantly increased PRI in the entire cohort and in respective of the MD and LD cohorts (p < 0.001, p = 0.003, p < 0.001, respectively). However, carriers of CYP2C19^*3 allele exhibited significantly higher PRI only in the entire cohort and LD cohort (p = 0.023, p = 0.023 respectively). PRI value was significantly higher in CYP2C19 PM genotyped patients as compared with those carrying the IM genotypes and EM genotype (p < 0.001). Besides, carriers of the rs2254638 C allele showed significantly higher PRI in entire cohort and in the LD cohort (p = 0.023, p = 0.008, respectively). When the patients were grouped into clopidogrel resistance (CR) and non-clopidogrel resistance (non-CR) groups, CYP2C19^*2 was associated with increased risk of CR in the entire cohort, the LD cohort and the MD cohort (p < 0.001, p < 0.001, and p = 0.019, respectively). Carriers of the rs2254638 C allele also showed increased risk of CR in the entire cohort and the LD cohort (p = 0.024, and p = 0.028, respectively). N6AMT1 rs2254638 remained as a strong predictor for CR (TC vs. TT: OR = 1.880, 95% CI = 1.099–3.216,p = 0.021; CC vs. TT: OR = 1.930, 95% CI = 1.056-3.527, p = 0.032; TC + CC vs. TT: OR = 1.846, 95%CI = 1.126–3.026, p = 0.015) after adjustment for confounding factors. Our study confirmed the influence of CYP2C19^*2 and rs2254638 polymorphisms on clopidogrel resistance in Chinese CAD patients. Both CYP2C19^*2 and N6AMT1 rs2254638 polymorphism may serve as independent biomarkers to predict CR.

Clopidogrel Pharmacokinetics in Malaysian Population Groups: The Impact of Inter-Ethnic Variability

Malaysia is a multi-ethnic society whereby the impact of pharmacogenetic differences between ethnic groups may contribute significantly to variability in clinical therapy. One of the leading causes of mortality in Malaysia is cardiovascular disease (CVD), which accounts for up to 26% of all hospital deaths annually. Clopidogrel is used as an adjunct treatment in the secondary prevention of cardiovascular events. CYP2C19 plays an integral part in the metabolism of clopidogrel to the active metabolite clopi-H4. However, CYP2C19 genetic polymorphism, prominent in Malaysians, could influence target clopi-H4 plasma concentrations for clinical efficacy. This study addresses how inter-ethnicity variability within the Malaysian population impacts the attainment of clopi-H4 target plasma concentration under different CYP2C19 polymorphisms through pharmacokinetic (PK) modelling. We illustrated a statistically significant difference (P < 0.001) in the clopi-H4 C_max between the extensive metabolisers (EM) and poor metabolisers (PM) phenotypes with either Malay or Malaysian Chinese population groups. Furthermore, the number of PM individuals with peak clopi-H4 concentrations below the minimum therapeutic level was partially recovered using a high-dose strategy (600 mg loading dose followed by a 150 mg maintenance dose), which resulted in an approximate 50% increase in subjects attaining the minimum clopi-H4 plasma concentration for a therapeutic effect.

Possible Molecular Targets of Novel Ruthenium Complexes in Antiplatelet Therapy

In oncotherapy, ruthenium (Ru) complexes are reflected as potential alternatives for platinum compounds and have been proved as encouraging anticancer drugs with high efficacy and low side effects. Cardiovascular diseases (CVDs) are mutually considered as the number one killer globally, and thrombosis is liable for the majority of CVD-related deaths. Platelets, an anuclear and small circulating blood cell, play key roles in hemostasis by inhibiting unnecessary blood loss of vascular damage by making blood clot. Platelet activation also plays a role in cancer metastasis and progression. Nevertheless, abnormal activation of platelets results in thrombosis under pathological settings such as the rupture of atherosclerotic plaques. Thrombosis diminishes the blood supply to the heart and brain resulting in heart attacks and strokes, respectively. While currently used anti-platelet drugs such as aspirin and clopidogrel demonstrate efficacy in many patients, they exert undesirable side effects. Therefore, the development of effective therapeutic strategies for the prevention and treatment of thrombotic diseases is a demanding priority. Recently, precious metal drugs have conquered the subject of metal-based drugs, and several investigators have motivated their attention on the synthesis of various ruthenium (Ru) complexes due to their prospective therapeutic values. Similarly, our recent studies established that novel ruthenium-based compounds suppressed platelet aggregation via inhibiting several signaling cascades. Our study also described the structure antiplatelet-activity relationship (SAR) of three newly synthesized ruthenium-based compounds. This review summarizes the antiplatelet activity of newly synthesized ruthenium-based compounds with their potential molecular mechanisms.

Pharmacogenomic Impact of CYP2C19 Variation on Clopidogrel Therapy in Precision Cardiovascular Medicine

Variability in response to antiplatelet therapy can be explained in part by pharmacogenomics, particularly of the CYP450 enzyme encoded by CYP2C19. Loss-of-function and gain-of-function variants help explain these interindividual differences. Individuals may carry multiple variants, with linkage disequilibrium noted among some alleles. In the current pharmacogenomics era, genomic variation in CYP2C19 has led to the definition of pharmacokinetic phenotypes for response to antiplatelet therapy, in particular, clopidogrel. Individuals may be classified as poor, intermediate, extensive, or ultrarapid metabolizers, based on whether they carry wild type or polymorphic CYP2C19 alleles. Variant alleles differentially impact platelet reactivity, concentration of plasma clopidogrel metabolites, and clinical outcomes. Interestingly, response to clopidogrel appears to be modulated by additional factors, such as sociodemographic characteristics, risk factors for ischemic heart disease, and drug-drug interactions. Furthermore, systems medicine studies suggest that a broader approach may be required to adequately assess, predict, preempt, and manage variation in antiplatelet response. Transcriptomics, epigenomics, exposomics, miRNAomics, proteomics, metabolomics, microbiomics, and mathematical, computational, and molecular modeling should be integrated with pharmacogenomics for enhanced prediction and individualized care. In this review of pharmacogenomic variation of CYP450, a systems medicine approach is described for tailoring antiplatelet therapy in clinical practice of precision cardiovascular medicine.

Pathogenesis of thrombosis: cellular and pharmacogenetic contributions

Our understanding of thrombosis formation has evolved significantly ever since physician Rudolf Virchow proposed his "triad" theory in 1856. Modern science has elucidated the mechanisms of stasis, hypercoagulability, and endothelial dysfunction. Today, we have a firm understanding of the key molecular factors involved in the coagulation cascade and fibrinolytic system, as well as the underlying genetic influences. This knowledge of cellular and genetic contributors has been translated into diverse pharmaceutical interventions. Here, we examine the molecular and cellular mechanisms of thrombosis and its associated pathologies. We also review the current state of pharmacologic interventions, including pro- and anti-thrombotics, direct oral anticoagulants, and anti-platelet therapies. The pharmacogenetic factors that guide clinical decision making and prognosis are described in detail. Finally, we explore new approaches to thrombosis drug discovery, repurposing, and diagnostics. We argue that network biology tools will enable a systems pharmacology revolution in the next generation of interventions, facilitating precision medicine applications and ultimately leading to improved patient outcomes.