Decreased platelet responsiveness to clopidogrel correlates with CYP2C19 and PON1 polymorphisms in atherosclerotic patients

The effects of CYP2C19 genotype polymorphism and clopidogrel resistance on ischemic event occurrence in patients with peripheral arterial disease undergoing revascularization: A prospective cohort study

INTRODUCTION

Peripheral arterial disease (PAD) affects approximately 236 million people worldwide. Therefore, this study aimed to investigate the relationship between CYP2C19 genotype polymorphisms and clopidogrel resistance (CR) following revascularization in patients with PAD.

MATERIALS AND METHODS

In total, 345 patients who underwent PAD revascularization were monitored for five years and risk factors for ischemic events were identified. Platelet reactivity and CYP2C19 genotypes were measured, and patients were classified as normal, intermediate, or poor metabolizers based on their genotypes. The study endpoint was defined as an ischemic event, that encompassed major adverse cardiovascular or limb events, or all-cause death.

RESULTS

In this study, ischemic events following PAD revascularization were associated with patient age, prior minor amputation, the Rutherford category before revascularization, indications for revascularization, index ankle-branchial index before revascularization, CYP2C19 phenotypes, and CR. Intermediate and poor metabolism, the Rutherford category before revascularization, and CR were independent risk factors for ischemic events in patients after PAD revascularization. Similarly, intermediate and poor metabolism, the Rutherford category before revascularization, and CR were independent risk factors for ischemic events in patients with PAD after revascularization within five years. Intermediate and poor metabolizers had a higher platelet reactivity and risk of CR than normal metabolizers. However, poor metabolizers had a higher platelet reactivity and risk of CR than intermediate metabolizers. Furthermore, the hazard ratio for ischemic events increased with platelet reactivity. This effect was more prevalent in intermediate and poor metabolizers than in normal metabolizers.

CONCLUSIONS

Ischemic events in patients after PAD revascularization were affected by independent risk factors. Decreased clopidogrel metabolism increased the platelet reactivity and CR in patients after PAD revascularization. Furthermore, high platelet reactivity was associated with an increased risk of ischemic events in patients with intermediate and poor metabolism.

Clopidogrel-Related High Residual Platelet Reactivity Associated with Estimated Glomerular Filtration Rate in Patients with Acute Ischemic Stroke

INTRODUCTION

There are few studies on the relationship between the occurrence of clopidogrel-related high residual platelet reactivity (HRPR) and estimated glomerular filtration rate (eGFR) at admission in patients with ischemic stroke. The aim of this study was to investigate the possible relationship between the two.

METHODS

Patients who were hospitalized and diagnosed with acute ischemic stroke were recruited from July 1, 2017, to June 30, 2018, at Shanghai TCM-Integrated Hospital. Renal function was measured within 24 h of enrollment and eGFR was calculated. Patients were tested for platelet reactivity using the VerifyNow system after 7 days of antiplatelet therapy with clopidogrel 75 mg/d alone, and patients with P2Y12 reaction unit values ≥230 were diagnosed with HRPR. The association between HRPR and eGFR was analyzed.

RESULTS

A total of 274 patients were enrolled in the study, of whom 91 (33.21%) had HRPR. Multivariate logistic regression analysis suggested that an increased risk of HRPR was independently associated with female sex and reduced eGFR (female sex: OR = 2.24, 95% CI: 1.26-3.99, p = 0.006; mild chronic kidney disease [CKD]: OR = 2.95, 95% CI: 1.47-5.93, p = 0.002; moderate CKD: OR = 3.07, 95% CI: 1.08-8.75, p = 0.04).

CONCLUSION

Decreased eGFR is an independent risk factor for the occurrence of HRPR in patients with ischemic stroke.

Lower paraoxonase 1 paraoxonase activity is associated with a worse prognosis in patients with non-ST-segment elevation myocardial infarction in long-term follow-up

BACKGROUND

Acute coronary syndrome (ACS) is one of the main manifestations of coronary artery disease, with a higher prevalence and worst prognosis. Oxidative stress is important in atherosclerosis and ACS, and paraoxonase 1 (PON1) is directly related to reducing the effects of oxidative stress on lipoproteins. The present study evaluated the prognostic value of PON1 activity in patients with non-ST-segment elevation ACS [non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA)], included in the ERICO study.

METHODS

PON1 paraoxonase activity was determined in serum samples from 485 patients collected on admission. The prognostic value in the follow-up of up to 5 years was evaluated according to cutoff points established by tertiles. Kaplan-Meier curves and Cox regression were used for the analysis of all-cause mortality and cardiovascular mortality.

RESULTS

The sample consisted mainly of elderly patients with a high frequency of cardiovascular risk factors. At follow-up of up to 5 years, there were 126 deaths from all causes (80 deaths from CVD). The lowest tertile of PON1 paraoxonase activity was associated with a higher risk of death in patients with NSTEMI, but not in patients with UA.

CONCLUSION

PON1 paraoxonase activity has potential prognostic value in patients with NSTEMI.

Cardiovascular Pharmacogenomics: An Update on Clinical Studies of Antithrombotic Drugs in Brazilian Patients

Anticoagulant and antiplatelet drugs effectively prevent thrombotic events in patients with cardiovascular diseases, ischemic stroke, peripheral vascular diseases, and other thromboembolic diseases. However, genetic and non-genetic factors affect the response to antithrombotic therapy and can increase the risk of adverse events. This narrative review discusses pharmacogenomic studies on antithrombotic drugs commonly prescribed in Brazil. Multiple Brazilian studies assessed the impact of pharmacokinetic (PK) and pharmacodynamic (PD) gene variants on warfarin response. The reduced function alleles CYP2C9*2 and CYP2C9*3, and VKORC1 rs9923231 (c.-1639G>A) are associated with increased sensitivity to warfarin and a low dose requirement to prevent bleeding episodes, whereas CYP4F2 rs2108622 (p.Val433Met) carriers have higher dose requirements (warfarin resistance). These deleterious variants and non-genetic factors (age, gender, body weight, co-administered drugs, food interactions, and others) account for up to 63% of the warfarin dose variability. Few pharmacogenomics studies have explored antiplatelet drugs in Brazilian cohorts, finding associations between CYP2C19*2, PON1 rs662 and ABCC3 rs757421 genotypes and platelet responsiveness or clopidogrel PK in subjects with coronary artery disease (CAD) or acute coronary syndrome (ACS), whereas ITGB3 contributes to aspirin PK but not platelet responsiveness in diabetic patients. Brazilian guidelines on anticoagulants and antiplatelets recommend the use of a platelet aggregation test or genotyping only in selected cases of ACS subjects without ST-segment elevation taking clopidogrel, and also suggest CYP2C9 and VKORC1 genotyping before starting warfarin therapy to assess the risk of bleeding episodes or warfarin resistance.

The effects of polymorphisms in CYP2C19, ATP-binding cassette transporter B1, and paraoxonase-1 on clopidogrel treatment of Uygur patients following percutaneous coronary intervention

BACKGROUND

Acute coronary syndrome (ACS) carries a high mortality in Uygur populations. Percutaneous coronary intervention (PCI) is a safe treatment for patients with ACS. Clopidogrel reduces the risk for recurrent cardiovascular events after PCI; however, its activity is influenced by cytochrome P450 (CYP450), ATP-binding cassette transporter B1 (ABCB1), and paraoxonase-1 (PON1).

OBJECTIVES

To assess the effects of genetic polymorphisms CYP2C19*2, *3, *17, ABCB1 C3435T, and PON1 Q192R along with clinical and demographic factors on variations in responses in Uygur patients following PCI.

METHODS

We enrolled 281 patients with PCI who were treated with clopidogrel and aspirin for at least 12 months and recorded major adverse cardiovascular events (MACE) or bleeding within 1 year. Approximately, 2 mL of peripheral venous blood samples were used for genotype detection. Binary logistic regression with likelihood ratio forward stepwise analysis and redundancy analysis were carried out to identify factors associated with MACE. We analyzed risk factors including age, body mass index, smoking, hypertension, dyslipidemia, gender, alcohol consumption, diabetes mellitus, carriers of ABCB1 C3435T T allele, carriers of PON1 Q192R A allele, metabolizer phenotype of CYP2C19, number of targeted vessels, and number of stents.

RESULTS

The CYP2C19 IMs (OR 3.546, 95% CI 1.972-6.375, P = 0.001), CYP2C19 PMs (OR 7.038, 95% CI 1.658-29.880, P = 0.008), and number of targeted vessels (OR 2.033, 95% CI 1.078-3.648, P = 0.026) were significantly associated with MACE.

CONCLUSION

The CYP2C19 IMs, PMs, and the number of targeted vessels are essential factors associated with MACE risk in dual clopidogrel-treated Uygur population with ACS following PCI. These data provide valuable insights into the genetic polymorphisms affecting clopidogrel response among minority groups in China.

Distribution of CYP2C19, ABCB1 and PON1 polymorphisms in Chinese Han, Hui, Uygur and Kazak patients with coronary atherosclerotic heart disease

CYP2C19, ABCB1 and PON1 polymorphisms involve in the metabolism and absorption of clopidogrel, which may be associated with interethnic variability of clopidogrel response. In our study, we evaluated the prevalence of CYP2C19, ABCB1 and PON1 single nucleotide polymorphisms (SNP) in patients with coronary atherosclerotic heart disease (CHD) of Chinese Han, Hui, Uygur and Kazak ethnic groups. Five SNPs were detected [CYP2C19 ∗2 (rs4244285), CYP2C19 ∗3 (rs4986893), CYP2C19 ∗17 (rs12248560), ABCB1 (rs1045642) and PON1 (rs662)]. The analysis was performed in 1,337 patients with CHD, including 831 Han, 85 Hui, 352 Uygur and 69 Kazak. The results revealed the differential distribution of the five SNPs. Frequencies of CYP2C19 no function variants in Uygur and Kazak were lower than those in Han and Hui groups (P < .05). CYP2C19 variants with increased function were more common in Uygur (13.6%) and Kazak (10.9%) groups (P < .05). Compared with Han and Hui groups, distribution of ABCB1 allele T was more prevalent in Uygur and Kazak groups (53.8% and 50.7%, respectively, P < .05). PON1 allele A frequencies of 55.7% and 58.7% in Uygur and Kazak showed higher prevalence than in the Han (38.4%) and Hui (43.5%) groups (P < .05). In conclusion, CYP2C19 *2 and *3 alleles are prevalent in Chinese Han and Hui groups, whereas CYP2C19 *17, ABCB1 T and PON1 A variants are relatively frequent in Chinese Uygur and Kazak ethnic groups. Our findings may provide a theoretical basis for the explanation of ethnic differences in determining clinical therapy strategies and predicting adverse effects.

CYP2C19, PON1, and ABCB1 gene polymorphisms in Han and Uygur populations with coronary artery disease in Northwestern Xinjiang, China, From 2014 Through 2019

The morbidity of coronary artery disease (CAD) in the Uygur population of Xinjiang was much higher than the national average. Clopidogrel is the most commonly used medication worldwide in dual antiplatelet therapy for CAD, and the response of clopidogrel is affected by CYP2C19, PON1, and ABCB1 genetic polymorphisms. The distribution of CYP2C19*17, ABCB1, and PON1 genetic polymorphisms in Han and Uygur populations with CAD of Xinjiang has not been investigated.This study aimed to investigate the frequencies of CYP2C19, PON1, and ABCB1 genetic polymorphisms, and to identify the metabolizer phenotype of CYP2C19 in Han and Uygur populations with CAD in Northwestern Xinjiang, China. We identified 602 Han and 527 Uygur patients from 2014 through 2019 and studied genotypes for selected allele polymorphisms using sequencing by hybridization.There were significantly different allele frequencies and genotype frequencies between the 2 ethnic groups in terms of CYP2C19*2, *3, *17, ABCB1 and PON1, (P < .05). For CYP2C19*17, the frequency of TT genotype was 2.5% in Uygur patients, but it was undetectable in Han patients. In both the intermediate and poor metabolizer groups, the genotypes polymorphisms CYP2C19*2, *3, *17 were significantly less common in Uygur patients than in Han patients (P < .001). By contrast, the proportion of ultra-metabolizers as defined by CYP2C19*2, *3, *17 polymorphisms significantly higher in Uygur patients (18.6%) than in Han patients (1.7%, P < .001). The CYP2C19*2 frequency was significantly different between Han patients and Han healthy groups (P < .001), while the CYP2C19*3 frequency was significantly different between Uygur patients and Uygur healthy groups (P < .001).Our study supports the notion of interethnic differences in terms of CYP2C19, PON1, and ABCB1 polymorphisms and CYP2C19 genotype-defined clopidogrel metabolic groups. These finding could provide valuable data and insights into personalized CAD treatment for the Uygur and Han populations in Xinjiang.

The impact of cytochrome 450 and Paraoxonase polymorphisms on clopidogrel resistance and major adverse cardiac events in coronary heart disease patients after percutaneous coronary intervention

Background

Clopidogrel is an inactive prodrug, it catalyzed into its active form by Cytochrome 450 and Paraoxonase-1(PON-1). polymorphisms of genes encoding these enzymes will affect the efficacy of Clopidogrel. The main objective of our study was to investigate the association of CYP2C19*2, CYP2C19*3 and PON-1Q192R polymorphisms with Clopidogrel resistance and major adverse cardiac events in Jin Hua district in the middle of Zhe Jiang Province in China.

Methods

One hundred sixty coronary heart disease patients with percutaneous coronary intervention, who were followed-up for 1 year, were enrolled in our study. These patients were co-administered aspirin 100 mg/d and clopidogrel 75 mg/d following a loading dose of 300 mg. The ADP-induced platelet aggregation rate was measured by Platelet aggregator. Genotypes of CYP2C19*2, CYP2C19*3, PON-1Q192R were determined using Sanger sequencing in all patients. Various clinical data were collected.

Results

The frequencies of CYP2C19*2, CYP2C19*3 and PON-1Q192R homozygous mutant genotypes were significantly lower in non-responders than those in responders. After for all variables, CYP2C19*2, CYP2C19*3 and PON-1Q192R independently increased the risk of clopidogrel resistance with adjusted ORs 46.65(95% CI,1.77–25.04; p = 0.005); 22.74(95% CI, 3.11–166.27; p = 0.002); 5.69 (95% CI,1.06–30.47; p = 0.042). Over a follow-up of 12 months, the incidence of major adverse cardiac events (MACE) in CYP2C19*1/*2, *1/*3, *2/*2, *2/*3 was significantly higher than no mutant genotype (18/40vs.2/63,3/9vs.2/63, 11/6vs.2/63, 7/1vs2/63, respectively). There was no significant correlation between PON-1Q192R mutant allele and MACE.

Conclusion

Our study was first time to report on CYP2C19 and PON-1 polymorphisms in Jin Hua population in the middle of Zhe Jiang province in China. The carriage of CYP2C19*2 or *3 mutant allele significantly reduced the platelet response to clopidogrel and increase the MACE. The carriage of PON-1 mutant allele also significantly reduced the platelet response to clopidogrel, but would not increase the major adverse cardiac events after 1 year follow-up.

Trial registration

ChiCTR, ChiCTR1800018316. Registered 11 September 2018 – prospective registered, http://www.chictr.org.cn/edit.aspx?pid=30927&htm=4.

Both CYP2C19 and PON1 Q192R Genotypes Influence Platelet Response to Clopidogrel by Thrombelastography in Patients with Acute Coronary Syndrome

Objective

The objective of this study is to explore the relationships of the effects of CYP2C19 and PON1 Q192R polymorphism on the activity of clopidogrel and the risk of high platelet responsiveness (HPR) by thrombelastography in patients with acute coronary syndrome (ACS).

Methods

459 ACS patients with aspirin and clopidogrel were enrolled in this observational case control study from July 13, 2015, to November 11, 2017. The patients with <30% platelet inhibition were defined as HPR group, while the others were defined as normal platelet responsiveness (NPR) group. The genotypes distribution between the groups was assessed, and the clinical impact of genetic variants was investigated by comparing the relationship between the risk of HPR and genotypes including CYP2C19⁎2, CYP2C19⁎3, CYP2C19⁎17, ABCB1, and PON1.

Results

Compared with CYP2C19⁎1/⁎1 wild type carriers, CYP2C19⁎2 and ⁎3 carriers showed a significant association with the lower platelet inhibition (P=0.048). The platelet inhibition in carriers of at least one CYP2C19 loss-of-function (LOF) alleles was obviously higher than noncarriers (P=0.031). The platelet inhibition of PON1 192R carriers was lower than PON1 192Q carriers (P=0.044). Patients with the CYP2C19⁎2 and ⁎3 alleles had a greater risk of HPR than CYP2C19 wild type carriers (adjusted P=0.018 and adjusted P=0.005). At least one PON1 192R carrier predicted a significantly higher risk of HPR than PON1 192Q carriers (adjusted P=0.021). Individual CYP2C19⁎17 and ABCB1 variants did not differ significantly between the two groups.

Conclusions

CYP2C19 and PON1 Q192R variants influence ADP-induced platelet inhibition by thrombelastography (TEG) in ACS patients with clopidogrel. In addition, both LOF CYP2C19 and PON1 192R variants are independent risk factors of HPR, which is measured by the relative platelet inhibition.

Investigating the Effect of Demographics, Clinical Characteristics, and Polymorphism of MDR-1, CYP1A2, CYP3A4, and CYP3A5 on Clopidogrel Resistance

Clopidogrel is an antiplatelet agent that is indicated for cardiovascular emergencies and procedures. The drug, however, is subject to response variability leading to therapy resistance. In this research, we explored the demographic, clinical, and genetic factors associated with clopidogrel resistance. Data analysis among our 280 subjects receiving clopidogrel showed some risk factors that are significantly associated with clopidogrel resistance compared with responders. Those were: female sex (P = 0.021), advanced age (P = 0.011), obesity (P = 0.002), and higher body mass index (P = 0.008) and higher platelets count (P = 0.002). However, known polymorphisms of MDR-1, CYP1A2, CYP3A4, and CYP3A5 were not associated with treatment resistance when compared to responders to clopidogrel therapy. Knowledge about such risk factors might provide recommendation in the future about starting doses or monitoring recommendations.

Association of PON1 gene promoter DNA methylation with the risk of Clopidogrel resistance in patients with coronary artery disease

BACKGROUND AND AIMS

The failure of therapeutic response to clopidogrel in platelet inhibition, which is called clopidogrel resistance (CR), is more likely to cause cardiovascular events. We aimed to study the contribution of promoter DNA methylation of paraoxonase 1 (PON1) to the risk of clopidogrel poor response.

METHODS

Through VerifyNow P2Y12 assay, patient' platelet functions were measured. Among 57 non-CR and 49 CR patients, the levels of DNA methylation in four CpG dinucleotides on the PON1 promoter were tested using bisulfite pyrosequencing technology. Besides, the relative expression of PON1 mRNA was analyzed by quantitative real-time PCR. Logistic regression was applied to investigate the interaction of PON1 methylation and clinical factors in CR.

RESULTS

In the subgroup with dyslipidemia, we discovered that higher CpG4 levels of the PON1 promoter indicated a poorer clopidogrel response (cases versus controls (%): 51.500 ± 14.742 vs 43.308 ± 10.891, P = 0.036), and the PON1 mRNA expression was reduced in CR patients. Additionally, the logistic regression indicated that higher level of albumin and the index of ALT were related to a lower risk of CR, and the index of AST as well as the quantity of stent may be positively associated with CR.

CONCLUSIONS

The DNA methylation of CpG4 in the PON1 promoter would lead to a low expression of PON1 mRNA, which might induce clopidogrel resistance in the patients with dyslipidemia, and the number of stents might be a risk for CR.

Pharmacogenomics research and clinical implementation in Brazil

We searched PubMed entries and the Lattes database of Brazilian Pharmacogenetics Network investigators, for pharmacogenetic/genomic (PGx) studies in the Brazilian population, focusing on the drugs and genes included in the Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines. Warfarin was the most extensively studied drug in a PGx context: a genomewide association study targeting warfarin stable dose identified significant signals in VKORC1 and CYP2C9, several PGx dosing algorithms were developed based on these and other genes, and the implications of population admixture on extrapolation of dosing recommendations in the CPIC guidelines were examined. A study in renal transplanted patients disclosed association of CYP3A5*6 and CYP3A5*7 with tacrolimus dosing, which led to addition of these variants to CYP3A5*3 in the CPIC tacrolimus guideline. Studies verified predisposition of HIV-positive carriers of UGT1A1*28 to severe atazanavir-induced hyperbilirubinaemia, intolerance to 5-fluorouracyl in gastrointestinal cancer patients with deleterious DPYD variants, failure of HCV-infected carriers of IFNL3 rs12979860 to obtain a sustained viral response to PEG-IFN-α, and hypersensitivity reactions to abacavir in HIV-positive carriers of HLA-B*57:01. No prospective analyses of drug therapy outcomes or cost-effectiveness assessments of PGx-guided therapy were found. In conclusion, the limited adoption of PGx-informed drug prescription in Brazil reflects combination of recognized barriers to PGx implementation worldwide plus factors specific to the Brazilian population. The latter include rarity/absence of genetic variants on which international PGx guidelines are based (eg HLA-B*15.02 for phenytoin and carbamazepine) and the caveat of extrapolating to the admixed Brazilian population, guidelines based on categorical variables, such as continental ancestry (eg warfarin guidelines), "race" or ethnicity.

Clopidogrel as a donor probe and thioenol derivatives as flexible promoieties for enabling H2S biomedicine

Hydrogen sulfide has emerged as a critical endogenous signaling transmitter and a potentially versatile therapeutic agent. The key challenges in this field include the lack of approved hydrogen sulfide-releasing probes for in human exploration and the lack of controllable hydrogen sulfide promoieties that can be flexibly installed for therapeutics development. Here we report the identification of the widely used antithrombotic drug clopidogrel as a clinical hydrogen sulfide donor. Clopidogrel is metabolized in patients to form a circulating metabolite that contains a thioenol substructure, which is found to undergo spontaneous degradation to release hydrogen sulfide. Model studies demonstrate that thioenol derivatives are a class of controllable promoieties that can be conveniently installed on a minimal structure of ketone with an α-hydrogen. These results can provide chemical tools for advancing hydrogen sulfide biomedical research as well as developing hydrogen sulfide-releasing drugs.

Hydrogen sulphide (H₂S) is a gaseous signalling molecule, which has shown therapeutic value. Here, the authors show that a thioenol metabolite of the antithrombotic drug clopidogrel is an efficient H₂S donor and masked thioenols can be linked to existing compounds to develop H₂S-releasing agents.