CYP2C19 Polymorphisms Research Articles

Functional evaluation of CYP2C19 and CYP3A4 gene polymorphism on ibuprofen metabolism

AimIbuprofen is the most commonly used analgesic. CYP polymorphisms are mainly responsible for the differences in drug metabolism among individuals. Variations in the ability of populations to metabolize ibuprofen can lead to drug exposure events. The aim of this study was to evaluate the effects of CYP2C19 and CYP3A4 polymorphisms on ibuprofen metabolism in a Chinese population. MethodsFirst, 31 CYP2C19 and 12 CYP3A4 microsomal enzymes were identified using an insect expression system. Then, variants were evaluated using a mature incubation system. Moreover, ibuprofen metabolite content was determined via ultra-performance liquid chromatography-tandem mass spectrometry analysis. Finally, kinetic parameters of CYP2C19 and CYP3A4 genotypes were determined via Michaelis-Menten curve fitting. ResultsMost variants exhibited significantly altered intrinsic clearance compared to the wild type. In the CYP2C19 metabolic pathway, seven variants exhibited no significant alterations in intrinsic clearance (CLint), six variants exhibited significantly high CLint (121–291%), and the remaining 15 variants exhibited substantially reduced CLint (1–71%). In the CYP3A4 metabolic pathway, CYP3A4*30 was not detected in the metabolite content due to the absence of activity, and 10 variants exhibited significantly reduced CLint. ConclusionTo the best of our knowledge, this is the first study to assess the kinetic characteristics of 31 CYP2C19 and 12 CYP3A4 genotypes on ibuprofen metabolism. However, further studies are needed on poor metabolizers as they are more susceptible to drug exposure. Our findings suggest that the kinetic characteristics in combination with artificial intelligence to predict the toxicity of ibuprofen and reduce any adverse drug reactions.

Ticagrelor plus aspirin in patients with minor ischemic stroke and transient ischemic attack: a network meta-analysis

BackgroundDual antiplatelet therapy (DAPT) with aspirin and clopidogrel was recommended as the secondary prevention of minor ischemic stroke or transient ischaemic attack (TIA). However, genetic polymorphisms of CYP2C19 had been identified as the major cause of poor responsiveness to clopidogrel. Ticagrelor, unlike clopidogrel, did not depend on metabolic activation, but it remained unclear whether ticagrelor was superior to clopidogrel in ischemic stroke. We performed a network meta-analysis to compare the efficacy and safety of ticagrelor, clopidogrel, and aspirin in the minor ischemic stroke and TIA populations.MethodsDatabases of Cochrane Library, ClinicalTrials.gov, and PubMed were searched up to June 19, 2023. Randomized controlled trials (RCTs) assessing antiplatelet drugs for minor stroke or TIA were included. Statistical processing was conducted by using multivariate meta-analysis routines of STATA.ResultsSeven RCTs were included involving 41,745 participants. There was no significant difference between the two DAPTs in preventing stroke recurrence (OR, 1.16; 95% CI, 0.93-1.44), ischemic stroke recurrence (OR, 1.16; 95% CI, 0.93-1.45), and major hemorrhage (OR, 1.22; 95% CI, 0.62,2.39). Compared with aspirin alone, the two DAPT regimen reduced the risk of stroke recurrence (clopidogrel: OR, 0.69; 95% CI, 0.60-0.80, ticagrelor: OR, 0.66; 95% CI, 0.49-0.87) and ischemic stroke recurrence, but increased the incidence of major hemorrhage (clopidogrel: OR, 2.05; 95% CI, 1.22- 3.77; ticagrelor: OR, 2.55; 95% CI, 1.25-4.99). Despite being associated with a higher risk of any bleeding, ticagrelor did not impact the composite of vascular events or mortality. While ticagrelor and aspirin reduced the risk of ischemic stroke recurrence (OR, 0.77; 95% CI, 0.63- 0.92) without increasing the risk of major bleeding (OR 0.94; 95% CI 0.45–1.95) in the Asian population mainly Chinese.ConclusionsDAPT was superior to aspirin in stroke prevention, but little difference existed between the two DAPT regimens. Asian population mainly Chinese may benefit from DAPT with aspirin and ticagrelor. But further head-to-head RCTs are needed to validate the study results.

Association between CYP4A11 and EPHX2 genetic polymorphisms and chronic kidney disease progression in hypertensive patients

BackgroundThere is evidence indicating that some metabolites of arachidonic acid produced by cytochromes P450 (CYP) and epoxide hydroxylase (EPHX2), such as hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs) or dihydroxyeicosatrienoic acids (DHETEs), play an important role in blood pressure regulation and they could contribute to the development of hypertension (HT) and kidney damage. Therefore, the main aim of the study was to evaluate whether the genetic polymorphisms of CYP2C8, CYP2C9, CYP2J2, CYP4F2, CYP4F11 and EPHX2, responsible for the formation of HETEs, EETs and DHETEs, are related to the progression of impaired renal function in a group of patients with hypertension. Methods151 HT patients from a hospital nephrology service were included in the study. Additionally, a group of 87 normotensive subjects were involved in the study as control group. For HT patients, a general biochemistry analysis, estimated glomerular filtration rate and genotyping for different CYPs and EPHX2 variant alleles were performed. ResultsCYP4A11 rs3890011, rs9332982 and EPHX2 rs41507953 polymorphisms, according to the dominant model, presented a high risk of impaired kidney function, with odds ratios (OR) of 2.07 (1.00–4.32; P=0.049), 3.02 (1.11–8.23; P=0.030) and 3.59 (1.37–9.41; P=0.009), respectively, and the EPHX2 rs1042032 polymorphism a greater risk according to the recessive model (OR=6.23; 95% CI=1.50–25.95; P=0.007). However, no significant differences in allele frequencies between HT patients and in normotensive subjects for any of the SNP analyzed. In addition, the patients with diagnosis of dyslipidemia (n=90) presented higher frequencies of EPHX2 K55R (rs41507953) and *35A>G (rs1042032) variants than patients without dyslipidemia, 4% vs. 14% (P=0.005) and 16 vs. 27% (P=0.02), respectively. ConclusionsIn this study has been found higher odds of impaired renal function progression associated with rs3890011 and rs9332982 (CYP4A11) and rs41507953 and rs1042032 (EPHX2) polymorphisms, which may serve as biomarkers for improve clinical interventions aimed at avoiding or delaying, in chronic kidney disease patients, progress to end-stage kidney disease needing dialysis or kidney transplant.

Influence of polymorphisms in CYP2C9, VKORC1, MDR1 and APOE genes on the warfarin maintenance dose in Brazilian patients.

Background: Polymorphisms in the CYP2C9, VKORC1, MDR1 and APOE genes may impact warfarin dose. Aim: To investigate the influence of sociodemographic and clinical factors and polymorphisms *1, *2 and *3 for CYP2C9, -1639G>A for VKORC1, 3435C>T for MDR1, and ϵ2, ϵ3 and ϵ4 for APOE genes on the mean weekly warfarin maintenance dose in adults. Methods: This cross-sectional study recruited a calculated sample of 315 patients in three anticoagulation clinics in Brazil. A model containing the variables significantly associated with warfarin dose was estimated. Results: The mean age of patients was 64.1±13.1 years, with 173 (54.9%) women. Age, use of amiodarone, genotype VKORC1 GA, genotype VKORC1 AA, genotypes CYP2C9*1/*2 or *1/*3 and genotypes CYP2C9*2/*2 or *2/*3 or *3/*3 were associated with a reduced warfarin dose. Conclusion: This study pointed out factors that could impact the management of oral anticoagulation.

Effects of CYP2D6 and CYP2C19 genetic polymorphisms and cigarette smoking on the pharmacokinetics of tolperisone.

Tolperisone, a muscle relaxant used for post-stroke spasticity, is metabolized to its main metabolite by CYP2D6 and to a lesser extent by CYP2C19 and CYP1A2. We investigated the effects of CYP2D6 and CYP2C19 genetic polymorphisms and cigarette smoking on tolperisone pharmacokinetics. A 150mg oral dose of tolperisone was given to 184 healthy Korean subjects and plasma concentrations of tolperisone were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A 3.14-fold significant increase in AUC0-∞ was observed in the CYP2D6*10/*10 group compared with the CYP2D6*wt/*wt group, whereas a 3.59-fold increasein AUC0-∞ was observed in CYP2C19PMs compared to CYP2C19EMs. Smokers had a 38.5% decrease in AUC0-∞ when compared to non-smokers. When these effects were combined, CYP2D6*10/*10-CYP2C19PM-Non-smokers had a 25.9-fold increase in AUC0-∞ compared to CYP2D6*wt/*wt-CYP2C19EM-Smokers. Genetic polymorphisms of CYP2D6 and CYP2C19 and cigarette smoking independently and significantly affected tolperisone pharmacokinetics and these effects combined resulted in a much greater impact on tolperisone pharmacokinetics.

Association of polymorphic variants of <i>CYP2C19</i>, <i>P2RY12</i>, <i>ITGB3</i>, <i>ITGA2</i> and <i>eNOS3</i> genes with high residual platelet reactivity while taking clopidogrel and acetylsalicylic acid at different terms of myocardial infarction

Aim. Study of the association of polymorphic variants of CYP2C19 (G681A), P2RY12 (H1/H2), ITGB3 (T1565C), ITGA2 (C807T), eNOS3 (T786C) genes with high residual platelet reactivity (HRPR) to clopidogrel and acetylsalicylic acid (ASA) at different terms of myocardial infarction (MI).Material and methods. The study included 400 patients with MI aged 31-74 years, 317 (79,3%) men and 83 (20,7%) women. Platelet aggregation performed on days 1-2, 12-14 and 28-30 of MI, and genotyping by the polymerase chain reaction were analyzed using the STATISTICA 10.0 program.Results. Differences were found in ADP-test 1-3 depending on the CYP2C19 (G681A) polymorphism, ADP-test 1 depending on the P2RY12 (H1/H2) polymorphism, ADP-test 2 depending on the ITGB3 (T1565C) polymorphism, ASPI-test 1 depending on the eNOS (T786C) polymorphism. The risk of HRPR to clopidogrel is higher in 681A CYP2C19 allele carriers compared to the G681 carriers throughout the entire observation period: initially odds ratio (OR) of 1,8 (1,14-2,88), p=0,012, on days 12-14 of MI, OR of 1,7 (1,08-2,68), p=0,023 and on days 28-30 of MI, OR of 2,3 (1,42-3,81), p=0,0008. The risk of HRPR to clopidogrel is higher in AA CYP2C19 genotype carriers compared to GG genotype carriers, on days 1-2 of MI (OR 6,5 (1,16-36,4), p=0,033), on days 28-30 of MI (OR 7,8 (1,26-48,0), p=0,027). The risk of HRPR to clopidogrel on days 1-2 of MI is higher in H2 P2RY12 locus carriers compared to H1 locus carriers (OR 1,5 (1,02-2,22), p=0,039). The risk of HRPR to ASA on days 1-2 of MI is higher in the 786C eNOS3 allele carriers compared to T786 allele carriers (OR 1,4 (1,02-1,96), p=0,036). Carriers of haplotypes of minor alleles of CYP2C19 + ITGA2 + P2RY12 + eNOS genes (OR 3,9 (1,13-13,65), p=0,032) and CYP2C19 + ITGA2 + eNOS genes (OR 5,1 (1,7214,96), p=0,0032) have higher risk of HRPR to dual antiplatelet therapy (DAPT) on days 28-30 of MI compared to the rest of patients.Conclusion. The association of HRPR to clopidogrel with the CYP2C19 (G681A) polymorphism was found during the entire observation period, with the P2RY12 (H1/H2) polymorphism on days 1-2 of MI, with the ITGB3 (T1565C) polymorphism on days 10-12 of MI. The association of HRPR to ASA with eNOS (T786C) polymorphism was found on days 1-2 of MI. Minor allele haplotypes of the CYP2C19 + ITGA2 + P2RY12 + eNOS genes and CYP2C19 + ITGA2 + eNOS genes were associated with a higher risk of developing HRPR to DAPT on days 28-30 of MI.

The Utility of CYP2D6 and CYP2C19 Variants to Guide Pharmacological Treatment in Complex Unipolar Major Depression: A Pilot Longitudinal Study

Major depression is a frequent condition which variably responds to treatment. In view of its high prevalence, the presence of treatment resistance in major depression significantly impacts on quality of life. Tailoring pharmacological treatment based on genetic polymorphisms is a current trend to personalizing pharmacological treatment in patients with major depressive disorders. Current guidelines for the use of genetic tests in major depression issued by the Clinical Pharmacogenomics Implementation Consortium (CPIC) are based on CYP2D6 and CYP2C19 polymorphisms which constitute the strongest evidence for pharmacogenomic guided treatment. There is evidence of increased clinical response to pharmacological treatment in major depression although largely in non-treatment resistant patients from Western countries. In this study, well characterised participants (N = 15) with complex, largely treatment resistant unipolar major depression were investigated, and clinical improvement was measured at baseline and at week-8 after the pharmacogenomics-guided treatment with the Montgomery Åsberg Depression Rating Scale (MÅDRS). Results suggested a statistically significant improvement (p = 0.01) of 16% at endpoint in the whole group and a larger effect in case of changes in medication regime (28%, p = 0.004). This small but appreciable effect can be understood in the context of the level of treatment resistance in the group. To our knowledge, this is the first study from the Middle East demonstrating the feasibility of this approach in the treatment of complex major depressive disorders.

Pharmacogenetics and Personalized Medicines

Personalized or precision medicine has been used to describe the right drug to the right person at the right dose at the right time. One important aspect of personalized medicines is the genetic makeup of the individual. Pharmacogenetics investigates the role of individual genes in drug disposition. The use of pharmacogenetics will increase drug efficacy with minimum side effects. Several tables have been published by the FDA that list the pharmacogenetic associations with certain drugs. These tables suggest that certain subgroups of patients with certain genetic variants are likely to have “altered drug metabolism, and in certain cases, differential therapeutic effects, including differences in risks of adverse events” (https://www.fda.gov/medical-devices/precision-medicine/table-pharmacogenetic-associations#about).These tables include: Section 1: Pharmacogenetic associations for which the data support therapeutic management recommendations such as celecoxib and CYP2C9 polymorphisms. Section 2: Pharmacogenetic associations for which the data indicate a potential impact on safety or response such as codeine in CYP2D6 poor metabolizers will result in a lower concentration of the active form morphine. Section 3: Pharmacogenetic associations for which the data demonstrate a potential impact on pharmacokinetic properties only. In this list, the implications of the genotypes have not been well established for example atorvastatin and SLCO1B1 phenotypes may result in a higher systemic concentration of the drug. In the US pharmacogenetic tests are available as direct-to-consumer (DTC) tests. With DTC tests, individuals can send in a saliva sample and get results directly at their homes (Drelles et al 2021). Although the evidence on the effects of such tests and pharmacogenetic counseling is available and mounting in many clinical practices all around the world but is still to be implemented in the clinical practice in Jordan.

Predictive modeling of adverse drug reactions to tamoxifen therapy for breast cancer on base of pharmacogenomic testing.

The present study investigated the analysis of adverse drug reactions (ADRs) to tamoxifen (TAM) in breast cancer patients in relation to the carriage of genetic polymorphisms of genes encoding enzymes of CYP system and transporters of P-glycoprotein (Pg) and predictive models based on it. A total of 120 women with breast cancer taking adjuvant TAM were examined for the gene polymorphisms such as CYP2D6*4, CYP3A5*3, CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2C19*3 and ABCB1 (C3435T). Allelic variants were determined using the real-time polymerase chain reaction method. The research material was double sampling of buccal epithelium. Medical history data and extracts from case histories were used as sources of medical information, on the basis of which questionnaires specially created by us were filled out. An associative analysis showed association with the development of ADRs to TAM indicating their clinical significance from different genetic polymorphisms of CYP2D6, CYP3A5, CYP2C9 and ABCB1. The complex associative analysis performed using mathematical modeling made it possible to build predictive risk models for the development of ADRs such as hot flashes, dyspepsia, bone pain, and asthenia. Models that include both genetic and non-genetic determinants of ADRs of TAM may further improve the prediction of individual response to TAM.

Therapeutic drug monitoring of voriconazole and CYP2C19 phenotype for dose optimization in paediatric patients.

The objective of this study was to evaluate factors influencing voriconazole (VRC) plasma trough concentrations and provide research data for optimizing VRC dosing in Chinese paediatric patients. Medical records of inpatients were reviewed retrospectively. Multivariate linear regression analysis was used to identify the factors contributing to the variability of VRC plasma trough concentrations. A total of 250 VRC plasma trough concentrations from 131 paediatric patients were included in the analysis. The median VRC plasma trough concentration was 1.28mg·L-1 (range, 0.02 to 9.69mg·L-1). The target range was achieved in 51.6% of patients, while subtherapeutic and supratherapeutic concentrations were obtained in 40.4% and 8.0% of paediatric patients, respectively. The most commonly identified cytochrome P450 2C19 (CYP2C19) phenotype was intermediate metabolizers (IMs) (48.9%), followed by normal metabolizers (NMs) (40.5%) and poor metabolizers (PMs) (10.7%), but no ultrarapid metabolizers (UMs) were observed in our study. VRC plasma trough concentrations adjusted for dose (Cmin/D) were significantly lower in both NMs and IMs compared to PMs (PN-P < 0.001 and PI-P = 0.010, respectively). The dosage of VRC required to achieve the therapeutic range was related to age, with children aged < 6years needing a significantly higher oral dose of VRC. The oral and intravenous maintenance doses needed to reach the therapeutic range were significantly lower than the recommended maintenance dose (P < 0.001, P < 0.001). Factors such as CYP2C19 polymorphisms, the combination of omeprazole, levels of albumin and alanine aminotransferase, were found to affect VRC exposure and explained some of the variability. The VRC plasma trough concentration is significantly influenced by the CYP2C19 phenotype. The recommended maintenance dose for pediatric patients may not be appropriate for Chinese patients. To increase the probability of achieving the therapeutic range for VRC plasma trough concentration, the administration of VRC should consider the age of paediatric patients and the presence of CYP2C19 polymorphisms.

The relationship between genetic polymorphism of CYP2C19 and the efficacy of Helicobacter pylori eradication therapy in children

Objective: To investigate the relationship between genetic polymorphisms of cytochrome P450 2C19 (CYP2C19) and the efficacy of Helicobacter pylori (Hp) eradication therapy in children. Methods: The retrospective cohort study was conducted on 125 children with gastroscopy and positive rapid urease test (RUT) from September 2016 to December 2018 who presented to the Children's Hospital of Zhejiang University School of Medicine due to gastrointestinal symptoms including nausea, vomiting, abdominal pain, bloating, acid reflux, heartburn, chest pain, vomiting blood and melena. Hp culture and drug susceptibility test were carried out with gastric antrum mucosa before treatment. All the patients completed 2 weeks of standardized Hp eradication therapy and had 13C urea breath test 1 month after that, which was used to evaluate the curative effect. The DNA of gastric mucosa after RUT was analyzed and CYP2C19 gene polymorphism was detected. Children were grouped according to metabolic type. Combined with the results of Hp culture and drug susceptibility, the relationship between CYP2C19 gene polymorphism and the efficacy of Hp eradicative treatment was analyzed in children. Chi square test was used for row and column variables, and Fisher exact test was used for comparison between groups. Results: One hundred and twenty five children were enrolled in the study, of whom 76 were males and 49 females. The genetic polymorphism of CYP2C19 in these children found poor metabolizer (PM) of 30.4% (38/125), intermediate metabolizer (IM) of 20.8% (26/125), normal metabolizer (NM) of 47.2% (59/125), rapid metabolizer (RM) of 1.6% (2/125), and ultrarapid metabolizer (UM) of 0. There were statistically significant in positive rate of Hp culture among these groups (χ2=124.00, P<0.001). In addition, the successful rates of Hp eradication in PM, IM, NM and RM genotypes were 84.2% (32/38), 53.8% (14/26), 67.8% (40/59), and 0, respectively, with significant differences (χ2=11.35, P=0.010); those in IM genotype was significantly lower than that in PM genotype (P=0.011). With the same standard triple Hp eradicative regimen, the successful rate of Hp eradication for IM type was 8/19, which was lower than that of PM (80.0%, 24/30) and NM type (77.3%, 34/44) (P=0.007 and 0.007, respectively). There was a significant difference in the efficacy of Hp eradication treatment among different genotypes (χ2=9.72, P=0.008). According to the clarithromycin susceptibility result, the successful rate of Hp eradication treatment for IM genotype was 4/15 in the sensitive group and 4/4 in the drug-resistant group (χ2=6.97, P=0.018). Conclusions: The genetic polymorphism of CYP2C19 in children is closely related to the efficacy of Hp eradication treatment. PM has a higher successful rate of eradication treatment than the other genotypes.

The Role of CYP3A4 and CYP2C8 Polymorphism on Amiodarone Responses: Review Article

The Role of CYP3A4 and CYP2C8 Polymorphism on Amiodarone Responses: Review Article

Efficacy of Warfarin Therapy Guided by Pharmacogenetics: A Real-world Investigation Among Han Taiwanese

The anticoagulation activity of warfarin in populations with CYP2C9, VKORC1, and CYP4F2 variants differs between individuals and is correlated with poor international normalized ratio (INR) control. Pharmacogenetics-guided warfarin dosing has been successfully developed for patients with genetic variations in recent years. However, few real-world data have been used to investigate the INR and warfarin dosage and the time to target INR. This study examined the largest collection of genetic and clinical real-world data related to warfarin to provide further evidence supporting the benefits of pharmacogenetics in clinical outcomes. We retrieved a total of 69,610 INR-warfarin records after the index date from 2,613 patients in the China Medical University Hospital database between January 2003 and December 2019. Each INR reading was obtained from the latest laboratory data after the hospital visit date. Patients with a history of malignant neoplasms or pregnancy before the index date were excluded, as were patients without data on INR measurements after the fifth day of prescription, genetic information, or gender variables. The primary outcomes were the INR and warfarin dosage during days 7, 14, 28, 56, and 84 after prescription. The secondary outcome was the time required to reach the INR ranges of 1.5 to 3.0 and >4.0. A total of 59,643 INR-warfarin records from 2188 patients were retrieved. The average INR was higher for homozygous carriers of the minor allele at CYP2C9 and VKORC1 during the first 7 days (1.83 [1.03] [CYP2C9*1] and 2.46 [1.44] [CYP2C9*3], P < 0.001; 1.39 [0.36] [rs9923231 G/G], 1.55 [0.79] [rs9923231 G/A], and 1.96 [1.13] [rs9923231 A/A], P < 0.001) than for the wild-type allele. These patients with variants required lower warfarin doses than those with the wild-type allele during the first 28 days. CYP4F2 variant patients seemed to require higher doses of warfarin than those in the wild-type group; however, no significant difference in the average INR was observed (1.95 [1.14] [homozygous V433 carriers], 1.78 [0.98] [heterozygous V433M carriers], and 1.66 [0.91] [homozygous M433 carriers], P=0.016). Our study indicates that genetic variants in the Han population may enhance warfarin responsiveness, which holds clinical relevance. An increased warfarin dosage was not linked to a shorter time to therapeutic INR between CYP4F2 variant patients and those with a wild-type allele. Assessing CYP2C9 and VKORC1 genetic polymorphisms before initiating warfarin treatment in real-world practice is essential for potentially vulnerable patients and is likely to optimize therapeutic dosing.

Computational Structural Validation of CYP2C9 Mutations and Evaluation of Machine Learning Algorithms in Predicting the Therapeutic Outcomes of Warfarin.

The study aimed to identify the key pharmacogenetic variable influencing the therapeutic outcomes of warfarin using machine learning algorithms and bioinformatics tools. Warfarin, a commonly used anticoagulant drug, is influenced by cytochrome P450 (CYP) enzymes, particularly CYP2C9. MLAs have been identified to have great potential in personalized therapy. The purpose of the study was to evaluate MLAs in predicting the critical outcomes of warfarin therapy and validate the key predictor genotyping variable using bioinformatics tools. An observational study was conducted on adults receiving warfarin. Allele discrimination method was used for estimating the single nucleotide polymorphisms (SNPs) in CYP2C9, VKORC1, and CYP4F2. MLAs were used for identifying the significant genetic and clinical variables in predicting the poor anticoagulation status (ACS) and stable warfarin dose. Advanced computational methods (SNPs' deleteriousness and impact on protein destabilization, molecular dockings, and 200ns molecular dynamics simulations) were employed for examining the influence of CYP2C9 SNPs on structure and function. Machine learning algorithms revealed CYP2C9 to be the most important predictor for both outcomes compared to the classical methods. Computational validation confirmed the altered structural activity, stability, and impaired functions of protein products of CYP2C9 SNPs. Molecular docking and dynamics simulations revealed significant conformational changes with mutations R144C and I359L in CYP2C9. We evaluated various MLAs in predicting the critical outcome measures associated with warfarin and observed CYP2C9 as the most critical predictor variable. The results of our study provide insight into the molecular basis of warfarin and the CYP2C9 gene. A prospective study validating the MLAs is urgently needed.

GENETIC VARIATION AND PREDICTED PHENOTYPES IN CYP2C9, CYP2C19, CYP3A4, CYP3A5 AND CYP2D6 GENES AMONG 552 PATIENTS WITH UNCONTROLLED TREATED HYPERTENSION

Objective: Altered drug metabolism may be a contributing factor to uncontrolled hypertension. Beta-blockers, alpha-blockers, calcium antagonists and angiotensin receptor blockers undergo hepatic metabolism by cytochrome P450 (CYP) enzymes. Genetic variation can contribute to interindividual variation, lack of treatment response or side effects with discontinuation of treatment. We aimed to determine common CYP gene variations in patients with treated but uncontrolled hypertension and to compare the distribution with the prevalence in the overall Caucasian population. Design and method: In this national multicenter study we mapped CYP2D6, CYP2C9, CYP2C19, CYP3A4 and CYP3A5 polymorphisms in 552 patients prescribed &gt; = 2 antihypertensive agents and with systolic daytime ambulatory blood pressure (ABPM) &gt; = 135 mmHg. On the (MALDI-TOF) MassARRAY analyzer, single nucleotide variants and small insertions/deletions (indels) were investigated with the VeriDose Core Panel and CYP2D6 copy-number variation with the VeriDose CYP2D6 CNV Panel (Agena Biosciences). Each allele is associated with either normal, decreased, absent, increased or unknown enzyme function based on activity scores defined by the The Clinical Pharmacogenetics Implementation Consortium (CPIC) and describe function and phenotypes for genes (IM = Intermediate metabolizer, PM = poor metabolizer, RM = rapid metabolizer and UM = ultra-rapid metabolizer). Results: 94% of patients were Caucasian. Mean daytime ABPM was 146/84 mmHg (135-190/55-106 mmHg), median age 63 (26-86) years and 35% were female. The distributions of the predicted phenotypes (illustrated in colors in Figure) for each enzyme did not differ from that reported in Caucasian population by The Pharmacogenomics Knowledgebase (PharmGK) (gray). 11% had normal phenotype in all five enzymes whereas 49% had &gt; = 2 enzymes affected by gene variants. Conclusions: The phenotype distribution of five relevant CYP genes in patients with uncontrolled hypertension did not differ from the general Caucasian population. Dosing guidelines based on CYP2D6 genotype currently exist for metoprolol, but for other antihypertensive drugs further investigation is needed. The low proportion of patients with five normal enzymes and the high proportion with &gt; = 2 enzymes affected suggest that pharmacogenetic CYP-testing may be useful for individualizing drug treatment in patients with uncontrolled hypertension.

Integrated analysis of clinical and genetic factors on the interindividual variation of warfarin anticoagulation efficacy in clinical practice

AimThe anticoagulation effect of warfarin is usually evaluated by percentage of time in therapeutic range (PTTR), which is negatively correlated with the risk of warfarin adverse reactions. This study aimed to explore the effects of genetic and nongenetic factors on anticoagulation efficacy of warfarin during different therapeutic range.MethodsWe conducted an observational retrospective study aiming at evaluating the impact of clinical and genetic factors on PTTR from initial to more than six months treatment. This analysis included patients with heart valve replace (HVR) surgery who underwent long-term or life-long time treatment with standard-dose warfarin for anticoagulation control in Second Xiangya Hospital. All patients were followed for at least 6 months. We genotyped single nucleotide polymorphisms in VKORC1 and CYP2C9 associated with altered warfarin dose requirements and tested their associations with PTTR.ResultsA total of 629 patients with intact clinical data and available genotype data were enrolled in this study, and only 38.63% patients achieved good anticoagulation control (PTTR > 0.6). Clinical factors, including male gender, older age, overweight, AVR surgery and stroke history, were associated with higher PTTR. Patients with VKORC1 -1639AA genotype had significantly higher PTTR level compared with GA/GG genotype carriers only in the first month of treatment. Patients with CYP2C9*3 allele had higher PTTR compared with CYP2C9*1*1 carriers. Moreover, compared with VKORC1 -1639 AG/GG carriers, INR > 4 was more likely to be present in patients with AA genotype. The frequency of CYP2C9*1*3 in patients with INR > 4 was significantly higher than these without INR > 4.ConclusionWe confirmed the relevant factors of warfarin anticoagulation control, including genetic factors (VKORC1 -1639G > A and CYP2C9*3 polymorphisms) and clinical factors (male gender, older age, overweight, AVR surgery and stroke history), which could be helpful to individualize warfarin dosage and improve warfarin anticoagulation control during different treatment period.

Prediction of Omeprazole Pharmacokinetics and its Inhibition on Gastric Acid Secretion in Humans Using Physiologically Based Pharmacokinetic-Pharmacodynamic Model Characterizing CYP2C19 Polymorphisms.

To develop a whole physiologically based pharmacokinetic-pharmacodynamic (PBPK-PD) model to describe the pharmacokinetics and anti-gastric acid secretion of omeprazole in CYP2C19 extensive metabolizers (EMs), intermediate metabolizers (IMs), poor metabolizers (PMs) and ultrarapid metabolizers (UMs) following oral or intravenous administration. A PBPK/PD model was built using Phoenix WinNolin software. Omeprazole was mainly metabolized by CYP2C19 and CYP3A4 and the CYP2C19 polymorphism was incorporated using in vitro data. We described the PD by using a turn-over model with parameter estimates from dogs and the effect of a meal on the acid secretion was also implemented. The model predictions were compared to 53 sets of clinical data. Predictions of omeprazole plasma concentration (72.2%) and 24h stomach pH after administration (85%) were within 0.5-2.0-fold of the observed values, indicating that the PBPK-PD model was successfully developed. Sensitivity analysis demonstrated that the contributions of the tested factors to the plasma concentration of omeprazole were Vmax,2C19 ≈ Papp > Vmax,3A4 > Kti, and contributions to its pharmacodynamic were Vmax,2C19 > kome > kms > Papp > Vmax,3A4. The simulations showed that while the initial omeprazole dose in UMs, EMs, and IMs increased 7.5-, 3- and 1.25-fold compared to those of PMs, the therapeutic effect was similar. The successful establishment of this PBPK-PD model highlights that pharmacokinetic and pharmacodynamic profiles of drugs can be predicted using preclinical data. The PBPK-PD model also provided a feasible alternative to empirical guidance for the recommended doses of omeprazole.

Role of Cytochrome p450 in Clopidogrel Resistance in Indonesian Stroke Patients

BACKGROUND: Stroke is the second leading cause of death in the world. Clopidogrel is one of the recommended therapies for it. Disturbances in the metabolic stages of clopidogrel, such as dysregulation of cytochrome p450 (CYP450) and cytochrome P450 2C19 (CYP2C19), can cause unresponsiveness or resistance. However, studies on clopidogrel resistance related to CYP450 and CYP2C19 in Indonesia are limited. METHODS: This cross-sectional study was conducted in two hospitals over a 1-year period. All patients had a minimum of one episode of ischemic stroke. Data on demographics, clopidogrel resistance, CYP450 concentration, and CYP2C19 polymorphism were collected. In total, 112 participants were enrolled in this study. RESULTS: We found that the incidence of clopidogrel resistance was 14.3% and the bleeding risk was high (40.3 %). The number of mutations in the CYP2C19 allele *17 was 96.0%. We also found that sex, hemoglobin, and CYP450 were significantly correlated with clopidogrel resistance, and with hemoglobin and CYP450 as independent factors. Fasting blood glucose and CYP2C19 allele *3 were independent factors for CYP450. CONCLUSION: The incidence of clopidogrel resistance in the Indonesian population is low; therefore, it is not an urgent issue. An important issue in this population is the high risk for bleeding. Patient treatment should be adjusted by considering this risk.

Association Between CYP2C19 Genotypes With Clinical Phenotypes and Adipokine Levels Among Ischemic Stroke Patients: A Prospective Observational Study.

Background Cytochrome P450 system is implicated in vascular pathologies, including stroke. Besides its role as a drug metabolizer, it also plays an important role in the metabolism of several endogenous substances like fatty acids, arachidonic acid, etc., which have pro-inflammatory effects. On the other hand, leptin and adiponectin are two of the most common adipose tissue-derived cytokines (adipokines), which are pro-inflammatory andanti-inflammatory in nature,respectively. Both of them are implicated in the pathogenesis of stroke. Methods We prospectively recruited ischemic stroke patients (within three months of occurrence of an attack of stroke). The occurrence of composite outcome (recurrence of transient ischemic attack/ischemic stroke or death)was evaluated for association with genetic variants of CYP2C19 (allele *2, *17, *3, and *4, i.e., single nucleotide polymorphism (SNP) 1/2/3/4, identified using TaqMan assays and DNA sequencing). Adiponectin and leptin levels weredetermined usingan enzyme-linked immunosorbent assay. Comparisons were made betweenstroke vs. control patients and between CYP2C19 intermediate metabolizer (IM)/poor metabolizer (PM) vs. extensive metabolizer (EM)/ultra metabolizer (UM) (PM: *2/*2; IM: *1/*2vs. EM: *1/*1; UM: *1/*17). P < 0.05 was taken as the threshold for statistical significance. Results A total of 204 patients and 101 controls were recruited. With regardto the occurrence of stroke, SNP2 showed a significant positive association. Haplotypes (SNP1/SNP2) AC (OR = 1.75 (1.08-2.83), p= 0.024) and GT (OR = 3.33 (1.53-7.22), p = 0.0026) were strongly associated with the occurrence of ischemic stroke even after adjustment for age and sex (global haplotype association p-value: 0.0062). Haplotype phenotype gender interaction was evident. Among stroke patients, with regardto composite outcome, only SNP1 showed a positive association. The AC haplotype was significantly associated with the occurrence of composite outcome (OR = 2.27 (1.17-4.41), p = 0.016). Among stroke patients, a significant positive association was seen between death and SNP1 (OR = 2.35 (1.13-4.90), p = 0.021) and AC haplotype (OR = 2.73 (1.20-6.22), p = 0.018). However, none of the SNPs or haplotypes showed any association with recurrence. Significant higher leptin and lower adiponectin levels were observed among stroke patients compared to controls.Leptin levels were higher in IM/PM group. IM/PM phenotypes showed a higher incidence of occurrence of composite outcome (hazard ratio = 2.07 (0.96-4.47), p = 0.056). Conclusion CYP2C19 polymorphisms may play a significant role in the pathogenesis of stroke. Leptin could serve as a prominent biomarker of atherosclerosis and inflammation in the early post-stroke period; however, further study is warranted with a larger sample size.

The Role of Endoplasmic Reticulum Stress in Gastroesophageal Reflux Disease Symptoms and Treatment.

Gastroesophageal reflux disease is a common condition worldwide. There is no curative treatment for gastroesophageal reflux disease. Endoplasmic reticulum stress leads to the activation of the unfolded protein response and has an important role in inflammation. The aim is to determine the role of endoplasmic reticulum stress in the follow-up of individuals with gastroesophageal reflux disease and the temporal changes of endoplasmic reticulum stress markers with treatment. Twenty-four subjects in total were recruited prospectively, of whom 15 had nonerosive reflux disease. Two biopsies from 2 cm above the esophagogastric junction, 2 biopsies from gastric antrum mucosa, and 2 biopsies from gastric corpus mucosa were taken. Simultaneously, 2 tubes of venous blood samples were drawn from each individual (1 tube for studying the genetic markers and 1 tube for analyzing the CYP2C19 polymorphism). The mean age was 42.3 ± 17.6 for women and 34.66 ± 11.2 for men. Pantoprazole, esomeprazole, rabeprazole, and lansoprazole preparations were used for treatment. There was no significant difference between tissue and blood samples for panel genes ATF-6, XBP-1, DDIT-3, DNAJC-10, and EIF-2-AK before treatment. There was a significant decrease in the level of ATF-6, XBP-1, DNAJC-9, EIF2-AK, and NF-2L-2 genes in blood after treatment. In the comparison of proton pump inhibitors, significant decreases in the expression of the ATF-6, XBP-1, and DNAJC-9 mRNAs were detected in blood from individuals after treatment. Endoplasmic reticulum stress can be for evaluating the clinical improvement and the effectiveness of treatment in gastroesophageal reflux disease.