Influence of high-density lipoprotein and paraoxonase-1 on platelet reactivity in patients with acute coronary syndromes receiving clopidogrel therapy

CYP2C19 polymorphisms and lipoproteins associated with clopidogrel resistance in children with Kawasaki disease in China: A prospective study

Background

CYP2C19 genetic variation and clinical factors have been proved to be related with clopidogrel resistance (CR) in adults, while the presence of CR in children with Kawasaki disease (KD) was seldom reported. Our objective was to evaluate KD patients’ response to clopidogrel treatment and determine whether CYP2C19 gene polymorphisms and laboratory indicators are associated with CR in this population.

Methods

This was a prospective and single-center study. We recruited children with KD hospitalized in the cardiology department at the Children’s Hospital Capital Institute of Pediatrics between January 2019 and October 2021, and the distribution of the CYP2C19 gene polymorphisms was assessed. According to the light transmission aggregometry (LTA) test results, KD patients who were treated with clopidogrel were divided into CR group and non-CR (NCR) group. We also analyzed the influence of CYP2C19 gene polymorphisms and laboratory indicators on CR in children with KD.

Results

(1) A total of 346 children with KD were evaluated for the genotypic and phenotypic distributions of CYP2C19. Loss-of-function (LOF) mutated allele was included in 56.9% of CYP2C19 genotypes, and their corresponding phenotypes were intermediate metabolizers (46.2%) and poor metabolizers (10.7%). (2) The incidence of CR in this study population was 31.4%. The multivariate logistic regression showed that carrying CYP2C19 LOF allele (OR, 3.922; 95%CI, 1.504–10.282; P = 0.005) and high levels of low-density lipoprotein (OR, 1.675; 95%CI, 1.069–2.623; P = 0.024) were independent risk factor for CR, while low levels of high-density lipoprotein (OR, 0.120; 95%CI, 0.020, 0.734; P = 0.022) was an independent protective factor for CR. The area under the receiver operator characteristic curve of the multivariate logistic regression model (including high-density lipoprotein, low-density lipoprotein, and CYP2C19 LOF allele carriers) for predicting CR was 0.769 (95% CI, 0.674–0.863; P < 0.001). The sensitivity and specificity were 70.3 and 74.0%, respectively.

Conclusion

Carrying CYP2C19 LOF allele, low levels of high-density lipoprotein, and high levels of low-density lipoprotein were independent risk factors for CR in children with KD in China. This may benefit pediatricians in choosing appropriate individualized antiplatelet therapy.

The impact of catha edulis (vahl) forssk. ex endl. (celestraceae) (khat) on pharmacokinetics of clinically used drugs

INTRODUCTION

Catha edulis (Vahl) Forssk. ex Endl. (Celestraceae) is used as a recreational drug on daily basis for its euphoric and psychostimulant effects. It is also chewed by individuals who are on medications, raising the possibility of drug-khat interaction. However, limited data are available in the literature, although clinically significant interactions are expected, as khat contains a complex mixture of pharmacologically active constituents.

AREAS COVERED

It provides an overview of the phytochemistry, pharmacokinetics, pharmacodynamics, and pharmacogenetics of khat based on the literature mined from PubMed, Google Scholar, and Cochrane databases. It also presents a detailed account of drug-khat interactions with specific examples and their clinical significance. The interactions mainly occur at the pharmacokinetics level and particular attention is paid for the phases of absorption and cytochrome P450 enzyme-mediated metabolism.

EXPERT OPINION

Despite the increasing trend of khat chewing with medications among the populace and the potential risk for the occurrence of clinically significant interactions, there is paucity of data in the literature demonstrating the magnitude of the risk. The available data, however, clearly demonstrate that the consequence of drug-khat interaction is dependent on genotype. Genotyping, where feasible, could be used to improve clinical outcome and minimize adverse reactions.

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.

Cytochrome 2C19 and paraoxonase-1 polymorphisms and clopidogrel resistance in ischemic heart disease patients

Aim: Polymorphisms in cytochrome P450 (CYP) 2C19 and paraoxonase-1 (PON-1) genes are thought to be involved in clopidogrel high on treatment reactivity in ischemic heart disease (IHD) patients. Methods: A total of 240 patients with IHD were screened for CYP2C19 loss-of-function alleles (LOF; *2, *3) and PON-1 Q192R. Patients were classified as responders and nonresponders to clopidogrel based upon platelet aggregation studies. Genotyping of the CYP2C19 and PON-1 allele was carried out by PCR-RFLP. Results: Results showed that 14.3% of the patients were nonresponders, whereas 85.7% were responders to the clopidogrel therapy. CYP2C19*3 allele showed significant association with clopidogrel high on treatment reactivity in IHD patients. Conclusion: Result of our study demonstrate that IHD patients with CYP2C19*3 allele can face the problem of clopidogrel high on treatment reactivity in Punjabi Pakistani population.

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.

Clinical Relevant Polymorphisms Affecting Clopidogrel Pharmacokinetics and Pharmacodynamics: Insights from the Puerto Rico Newborn Screening Program

Background: Variations in several clopidogrel-pharmacogenes have been linked to clopidogrel response variability and clinical outcomes. We aimed to determine the frequency distribution of major polymorphisms on CYP2C19, PON1, ABCB1 and P2RY12 pharmacogenes in Puerto Ricans. Methods: This was a cross-sectional, population-based study of 200 unrelated "Guthrie" cards specimens from newborns registered in the Puerto Rican newborn screening program (PRNSP) between 2004 and 2014. Taqman® SNP assay techniques were used for genotyping. Results: Minor allele frequencies (MAF) were 46% for PON1 (rs662), 41% for ABCB1 (rs1045642), 14% for CYP2C19*17, 13% for CYP2C19*2, 12% for P2RY12-H2 and 0.3% for CYP2C19*4. No carriers of the CYP2C19*3 variants were detected. All alleles and genotype proportions were found to be in Hardy⁻Weinberg equilibrium (HWE). Overall, there were no significant differences between MAFs of these variants in Puerto Ricans and the general population (n = 453) of the 1000 Genome project, except when comparisons to each individual parental group were performed (i.e., Africans, Europeans and East-Asians; p < 0.05). As expected, the prevalence of these markers in Puerto Ricans most resembled those in the 181 subjects from reference populations of the Americas. Conclusions: These prevalence data provide a necessary groundwork for future clinical studies of clopidogrel pharmacogenetics in Caribbean Hispanics.

Low Levels of High-Density Lipoprotein Cholesterol Are Linked to Impaired Clopidogrel-Mediated Platelet Inhibition

Low high-density lipoprotein cholesterol (HDL-C) levels are an independent predictor of ischemic events in patients with atherosclerotic cardiovascular disease. This may in part be due to decreased clopidogrel-mediated platelet inhibition in patients with low HDL-C. We investigated the association of HDL-C with on-treatment platelet reactivity to adenosine diphosphate (ADP) in 314 patients on dual antiplatelet therapy with clopidogrel and aspirin undergoing angioplasty and stenting. Platelet P-selectin expression was assessed by flow cytometry, and platelet aggregation was determined by the VerifyNow P2Y₁₂ assay and the Impact-R. High-density lipoprotein cholesterol levels were inversely associated with P-selectin expression and the VerifyNow P2Y₁₂ assay (both P ≤ .01). Moreover, we found a positive correlation of HDL-C with surface coverage by the Impact-R ( P = .003). Patients with low HDL-C (≤35 mg/dL) exhibited a significantly higher P-selectin expression in response to ADP and higher platelet aggregation by the VerifyNow P2Y₁₂ assay and the Impact-R than patients with normal HDL-C (>35 mg/dL; all P < .05). High on-treatment residual platelet reactivity by the VerifyNow P2Y₁₂ assay occurred significantly more frequently in patients with low HDL-C levels than in those with normal HDL-C (47.4% vs 30.1%, P = .01). In conclusion, low HDL-C is linked to impaired clopidogrel-mediated platelet inhibition after angioplasty and stenting.

Protective effects of ginseng extracts and common anti-aggregant drugs on ischaemia-reperfusion injury

OBJECTIVE

Ginseng is a traditional herbal medicinal product widely used for various types of diseases because of its cellular protective effects. Possible protective effects of ginseng were investigated in blood, cardiac and renal tissue samples and compared with common anti-aggregant agents in an animal ischaemia-reperfusion (I/R) model.

METHODS

Twenty rats were equally divided into four different groups as follows: control group (I/R-induced group without drug use), group I (acetylsalicylic acid-administered group), group II (clopidogrel bisulfate-administered group), group III (ginsenoside Rb1-administered group). For the groups assigned to a medication, peripheral I/R was induced by clamping the femoral artery one week after initiation of the specified medication. After reperfusion was initiated, cardiac and renal tissues and blood samples were obtained from each rat with subsequent analysis of nitrogen oxide (NOx), malondialdehyde (MDA), paraoxonase 1 (PON1) and prolidase.

RESULTS

NOx levels were similar in each group. Significant decrements were observed in serum PON1 levels in each group when compared with the control (p < 0.05). Serum MDA levels were significantly lower in groups II and III (p < 0.05). Ameliorated renal prolidase levels were detected in study groups (p < 0.05) and recovered cardiac prolidase levels were obtained in groups II and III (p < 0.05).

CONCLUSION

These findings indicate that ginseng extracts may have a potential beneficial effect in I/R injury. However, more comprehensive studies are required to clarify the hypothetical cardiac, renal and systemic protective effects in reperfusion-induced oxidative damage.

Pharmacogenomics of oral antiplatelet drugs

Pharmacogenomics has been implicated in the response variability of antiplatelet drugs in coronary artery disease (CAD), particularly for aspirin and clopidogrel. A large number of studies and several meta-analyses have been published on this topic, but until recently, there have been no clear conclusions and no definite guidelines on the clinical use of pharmacogenetic testing before prescribing antiplatelet drugs for CAD. In this review, the available evidence is summarized. The most consistent results are on clopidogrel, where CYP2C19 loss-of-function alleles are associated with stent thrombosis events. We recommend to genotype for CYP2C19 loss-of-function alleles in patients with CAD who are to undergo percutaneous coronary intervention and stenting, and to adjust the antiplatelet treatment based on the genotyping results.

Impact of proton pump inhibitors on clinical outcomes in patients receiving clopidogrel and possible mechanisms

Clopidogrel, a second generation thienopyridine antiplatelet agent, is increasingly prescribed for patients with recent stroke, myocardial infarction, acute coronary syndrome, or those undergoing percutaneous coronary intervention. Current consensus recommends co-administration of proton pump inhibitors (PPIs) during clopidogrel therapy to reduce the risk of gastrointestinal complications. However, studies have demonstrated a significant reduction in platelet inhibition when PPIs therapy is administered to subjects on clopidogrel, which thus increases the risk of adverse cardiovascular events. There have been recent concerns about the safety of PPIs though the postulated link between PPI use and adverse cardiovascular events has not been well established since evidence from randomized controlled trials does not support such an association. Here, we review the impact of PPIs on clinical outcomes in patients on clopidogrel and the possible mechanisms.

Investigation of possible prophylactic, renoprotective, and cardioprotective effects of thromboprophylactic drugs against ischemia-reperfusion injury

The aim of this study was to investigate whether anticoagulant and antiaggregant agents have protective effects against oxidative damage induced by peripheral ischemia-reperfusion (I/R). Groups were created as follows: control group, I/R group (sham group), I/R plus acetylsalicylic acid (Group I), I/R+clopidogrel (Group II), I/R+rivaroxaban (Group III), I/R+bemiparin sodium (Group IV), and I/R+enoxaparin sodium (Group V). In Groups I, II, III, IV, and V, drugs were administered daily for 1 week before I/R creation. Peripheral I/R was induced in the I/R groups by clamping the right femoral artery. The rats were sacrificed 1 hour after reperfusion. Nitrogen oxide levels, malondialdehyde (MDA) levels, paraoxonase-1 (PON1) activity, and prolidase activity were evaluated in both cardiac and renal tissues. There was no significant difference in nitrogen oxide levels between the groups. However, cardiac and renal MDA were significantly higher and PON1 activity was markedly lower in the I/R groups compared with the control group (p<0.05). Although elevated prolidase activity was detected in both the cardiac and renal tissue of the I/R groups, only the sham group and Group V had significantly higher renal prolidase activity (p<0.05). Group V had significantly higher cardiac MDA, PON1, prolidase levels, and renal prolidase activity compared with the sham group (p<0.05). Significant improvement in renal MDA levels was only observed in Group III, and marked improvement was observed in the cardiac MDA levels of Group II when compared with the sham group (p<0.05). Thromboprophylactic agents appear to provide partial or prominent protection against I/R injury.

PON1 Q192R genotype influences clopidogrel responsiveness by relative platelet inhibition instead of on-treatment platelet reactivity

BACKGROUND

paraoxonase-1 (PON1) was recently identified as the crucial enzyme for clopidogrel bioactivation, with PON1 Q192R (rs662) polymorphism determining the clopidogel antiplatelet efficacy. However, subsequent studies showed controversies over the findings. This study aimed to evaluate the impact of PON1 Q192R in parallel to that of CYP2C19*2 (rs4244285) on clopidogrel responsiveness in a cohort of Chinese patients with unstable angina pectoris.

MATERIAL AND METHODS

One hundred and eighty Chinese-Han patients diagnosed with unstable angina pectoris and treated with clopidogrel were consecutively recruited. Clopidogrel responsiveness, measured by relative platelet inhibition {RI=[(pretreatment aggregation-posttreatment aggregation at 5days)/(pretreatment aggregation)] x100%}, was assessed in relation to PON1 Q192R and CYP2C19*2 genotypes. RI values were stratified into four quartiles, with patients in quartile 1 defined as individuals of clopidogrel non-responsiveness. The contributions of PON1 Q192R and CYP2C19*2 to on-treatment platelet reactivity (OTPR) at 5days maintenance dose of clopidogrel were also evaluated.

RESULTS

For PON1 Q192R genotypes, RI values were significantly lower in patients with QR and RR alleles than in patients with QQ alleles (p=0.01). OTPR values at 5days maintenance dose of clopidogrel were similar across all the PON1 Q192R genotypes (p=0.41). PON1 192 QR and RR conferred increased risks for clopidogrel non-responsiveness [OR 3.64; 95% CI (1.21-10.92), p=0.02]. For CYP2C19*2 genotypes, compared to CYP2C19*1/*1 wild type carriers, CYP2C19*2 carriers showed a significantly higher OTPR (p=0.009), and a trend for lower RI values (p=0.06). An increased risk for clopidogrel non-responsiveness was found in patients with CYP2C19*2 genotype [OR 2.02; 95% CI (1.03-3.96), p=0.04].

CONCLUSIONS

Both PON1 Q192R and CYP2C19*2 genotypes influence clopidogrel responsiveness, with the impact of PON1 Q192R mainly on relative platelet inhibition instead of OTPR of clopidogrel.

Association of PON1 genotype and haplotype with susceptibility to coronary artery disease and clinical outcomes in dual antiplatelet-treated Han Chinese patients

PURPOSE

The aim of this study was to evaluate the association of PON1 genetic variants with the susceptibility to coronary artery disease (CAD) and with the clinical endpoints in aspirin and clopidogrel (dual antiplatelet therapy)-treated Han Chinese patients with CAD after percutaneous coronary intervention (PCI).

METHODS

A total of 538 Han Chinese patients undergoing PCI and receiving dual-antiplatelet therapy were sequentially recruited to the study and followed for up to 1 year. Healthy controls (n = 539) were enrolled during the same period. All study participants were genotyped for five genetic variants in PON1 and the cytochrome P450 2C19*2 mutation (CYP2C19*2). The effect of genetic variants on disease risk and clinical outcome of major adverse cardiac events (MACE) within 1 year or bleeding within 6 months was assessed.

RESULTS

CYP2C19*2 was associated with a higher risk of MACE (adjusted P = 0.0098), but a lower risk of bleeding events (adjusted P = 0.0016). The PON1 Q192R polymorphism was significantly associated with a lower risk of bleeding events [odds ratio (OR) 0.61, 95% confidence interval (CI) 0.43-0.87, adjusted P = 0.0066). The haplotype bearing the PON1 -126C allele was associated with a higher risk to CAD (OR 1.48, 95% CI 1.04-2.09, P = 0.029) and a higher risk of bleeding events (OR 1.68, 95% CI 1.10-2.56, P = 0.017) compared to the most frequent haplotype. The transcription activity of haplotype p-162A-126C-108C in the PON1 promoter was 2.6-fold higher than that of the most frequent haplotype (p-162G-126G-108T).

CONCLUSIONS

Based on these results, we suggest that the haplotype-bearing PON1 -126C allele contributes to the disease risk and the risk of bleeding events in dual antiplatelet-treated CAD patients after PCI.

Influence of the paraoxonase-1 Q192R genetic variant on clopidogrel responsiveness and recurrent cardiovascular events: a systematic review and meta-analysis

BACKGROUND

A poor biological response to clopidogrel is associated with an increased risk of major cardiovascular ischemic events (MACE). Paraoxonase 1 (PON1) enzyme activity is modulated by the PON1-Q192R variant (rs662) and was recently suggested to be strongly involved in clopidogrel bioactivation, but the influence of the PON1-Q192R variant on the risk of MACE in clopidogrel-treated patients is controversial.

OBJECTIVES

To determine whether the PON1-Q192R variant influences clopidogrel biological responsiveness and the risk of MACE in patients treated with clopidogrel.

METHODS

Systematic review and meta-analysis of studies of the association between the PON1-Q192R polymorphism and the biological response to clopidogrel and/or the risk of MACE during clopidogrel administration.

RESULTS

Seventeen studies were included. In the 12 studies of the biological response to clopidogrel (n = 5302 patients), there was no significant difference between 192QQ and 192QR + 192RR subjects, whatever the laboratory method used (global mean standardized difference = 0.10 [-0.06; 0.25], P = 0.22). Eleven studies assessed the risk of MACE, four using a case-control design (n = 2739 patients) and seven a prospective design (n = 5353 patients). Overall, MACE occurred in 19% of patients in case-control studies and in 6% of patients in prospective cohort studies, with no significant difference between 192QQ and 192QR + 192RR patients (OR = 1.28 [0.97; 1.68], P = 0.08). Similar results were obtained when study design was taken into account. Heterogeneity was mainly driven by one publication.

CONCLUSIONS

This meta-analysis suggests that the PON1-Q192R polymorphism has no major impact on the risk of MACE and does not alter the biological response to clopidogrel in clopidogrel-treated patients.

Type 2 diabetes is associated with reduced ATP-binding cassette transporter A1 gene expression, protein and function

OBJECTIVE

Increasing plasma glucose levels are associated with increasing risk of vascular disease. We tested the hypothesis that there is a glycaemia-mediated impairment of reverse cholesterol transport (RCT). We studied the influence of plasma glucose on expression and function of a key mediator in RCT, the ATP binding cassette transporter-A1 (ABCA1) and expression of its regulators, liver X receptor-α (LXRα) and peroxisome proliferator-activated receptor-γ (PPARγ).

METHODS AND RESULTS

Leukocyte ABCA1, LXRα and PPARγ expression was measured by polymerase chain reaction in 63 men with varying degrees of glucose homeostasis. ABCA1 protein concentrations were measured in leukocytes. In a sub-group of 25 men, ABCA1 function was quantified as apolipoprotein-A1-mediated cholesterol efflux from 2-3 week cultured skin fibroblasts. Leukocyte ABCA1 expression correlated negatively with circulating HbA1c and glucose (rho = -0.41, p<0.001; rho = -0.34, p = 0.006 respectively) and was reduced in Type 2 diabetes (T2DM) (p = 0.03). Leukocyte ABCA1 protein was lower in T2DM (p = 0.03) and positively associated with plasma HDL cholesterol (HDL-C) (rho = 0.34, p = 0.02). Apolipoprotein-A1-mediated cholesterol efflux correlated negatively with fasting glucose (rho = -0.50, p = 0.01) and positively with HDL-C (rho = 0.41, p = 0.02). It was reduced in T2DM compared with controls (p = 0.04). These relationships were independent of LXRα and PPARγ expression.

CONCLUSIONS

ABCA1 expression and protein concentrations in leukocytes, as well as function in cultured skin fibroblasts, are reduced in T2DM. ABCA1 protein concentration and function are associated with HDL-C levels. These findings indicate a glycaemia-related, persistent disruption of a key component of RCT.