Humanized CYP2C19 transgenic mouse as an animal model of cerebellar ataxia

Background: Animal models are essential for understanding etiology and pathophysiology of movement disorders. Previously, we have found that mice transgenic for the human CYP2C19 gene, expressed in the liver and developing brain, exhibit altered neurodevelopment associated with impairments of their motor function and emotionality. Objectives: To characterize motoric phenotype of the CYP2C19 transgenic mice and validate its usefulness as an animal model of ataxia. Methods: The rotarod and beam-walking tests were utilized to quantify the functional alterations induced by motoric phenotype. Dopaminergic system was assessed by tyrosine hydroxylase immunohistochemistry and by chromatographic quantification of the whole-brain dopamine levels. Beam-walking test was also repeated after the treatment with the dopamine receptor antagonists, ecopipam and raclopride. The volumes of 20 brain regions in the CYP2C19 transgenic mice and controls were quantified by 9.4T gadolinium-enhanced postmortem structural neuroimaging. Results: CYP2C19 transgenic mice were found to exhibit abnormal, unilateral ataxia-like gait, clasping reflex and 5.6-fold more paw-slips using the beam-walking test (p<0.0001, n=89); the phenotype was more pronounced in younger animals. Hyperdopaminergism was observed in the CYP2C19 mice; however, the motoric impairment was not ameliorated by dopamine receptor antagonists and there was also no midbrain dopamine neuron loss in CYP2C19 mice. However, in these mice, cerebellar volume was drastically decreased (-11.8% [95%CI: -14.7, -9.0], q<0.0001, n=59), whereas a moderate decrease in hippocampal volume was observed (-4.2% [95%CI: -6.4%, -1.9%], q=0.015, n=59). Conclusions: Humanized CYP2C19 transgenic mice exhibit altered motoric function and functional motoric impairments; this phenotype is likely caused by an aberrant cerebellar development.

Associations of rs4244285 in the CYP2C19 gene with multifactorial diseases

Xenobiotic metabolism system in the current populations is involved in the biotransformation of a wide range of endogenous substrates and various xenobiotics, which can contribute to developing the diseases of various organ systems, and, in some cases, comorbid conditions where increased biotransformation system activity is observed. In this regard, it is of great interest to study the involvement of polymorphism in xenobiotic metabolism genes in the development of both isolated pathology and various comorbid conditions.Aim. The goal of study was to investigate the involvement of rs4244285 in the CYP2C19 gene in the development of isolated pathology and comorbidities.Material and Methods. The frequencies of alleles and genotypes were studied in groups of patients with comorbid conditions including groups of coronary artery disease (CAD) with hypertension (HTN) (CAD_HTN, n = 133) and bronchial asthma (BA) with HTN (BA_HTN, n = 178), in group of isolated BA (n = 135), and in the population sample of the city of Tomsk (n = 377). Association analysis covered three initial groups of patients (CAD, BA, and BA_HTN) and subgroups assigned based on the presence of absence of HTN diagnosis taking into account comorbid conditions both in patient samples and in population control.Results and Discussion. The study demonstrated the predisposing eff ect of GA genotype on the development of comorbid BA and HTN (OR = 1.94, p = 0.038) and comorbid CAD and HTN (OR = 2.26, p = 0.009) compared to isolated BA. The AA genotype was observed 3.98 times less often in HTN patients than in normotensive individuals. However, the diff erences did not reach the level of statistical signifi cance due to the low occurrence of this genotype.Conclusion. The obtained results may be explained by the involvement of CYP2C19-metabolites of arachidonic acid in the regulation of vascular tone, which requires further study.

Analysis The Effect of Gene and Platelet Testing Guide Dual Anti-Upgrade Therapy After PCI in Patients With ACS

Objective To analyze whether CYP2C19 gene and platelet testing guide ACS patients PCI benefit from postoperative dual antiplatelet escalation therapy. Methods Selecting ACS patients with 209 routine PCI surgery from January 2018 to January 2019 in Department of Cardiology, Third Affiliated Hospital of Guangzhou Medical University. Preoperative administration of aspirin 300mg and clopidogrel 600mg, and continued administration of clopidogrel 75mg/d and aspirin 100mg/d after operation. Genotype and light transmittance aggregation (LTA) was detected by gene chip 24 h after operation. According to genotype the remaining patients were divided into non loss of function (Non-LOF) alleles group Extensive-metabolisms (EMs) type, loss of function (LOF) alleles group as Intermediate metabolic (IMs) type and Poor-metabolisms (PMs) type. Define the maximum platelet aggregation rate (MPA)≥46% as hyperplatelet reactivity (HPR). The LOF group consisted of 23 patients who had both HPR and proclopidogrel and were upgraded to tigrillo for further treatment.The remaining patients without HPR who continued to be treated with clopidogrel comprised 90 patients in the LOF group without upgrade and 95 patients in the non-LOF group who continued to be treated with clopidogrel.Major adverse cardiovascular events (MACE) were recorded in the follow-up period of 1 year, and the incidence of MACE in the three groups was compared to determine whether gene and platelet detection could guide the benefit of dual anti-platelet upgrade therapy in ACS patients after PCI. Results There were 26 cases occurred during follow-up MACE, among which the incidence of unstable angina recurrence and overall MACE in the LOF allele-not-up group was the highest and significantly different compared with the Non-LOF allele group (P<0.05), there was no significant difference compared with the LOF allele-up group (0.05). while there was no significant difference between the Non-LOF allele and the LOF allele upgrading group (P>0.05). Conclusions Gene is an important factor in the difference of platelet reactivity and is associated with MACE. Upgraded treatments for high-risk patients screened for gene and platelet testing did not benefit.

Experience of a Strategy Including CYP2C19 Preemptive Genotyping Followed by Therapeutic Drug Monitoring of Voriconazole in Patients Undergoing Allogenic Hematopoietic Stem Cell Transplantation

Many factors have been described to contribute to voriconazole (VCZ) interpatient variability in plasma concentrations, especially CYP2C19 genetic variability. In 2014, Hicks et al. presented data describing the correlation between VCZ plasma concentrations and CYP2C19 diplotypes in immunocompromised pediatric patients and utilized pharmacokinetic modeling to extrapolate a more suitable VCZ dose for each CYP2C19 diplotype. In 2017, in our hospital, a clinical protocol was developed for individualization of VCZ in immunocompromised patients based on preemptive genotyping of CYP2C19 and dosing proposed by Hicks et al., Clinical Pharmacogenetics Implementation Consortium (CPIC) clinical guidelines, and routine therapeutic drug monitoring (TDM). We made a retrospective review of a cohort of 28 immunocompromised pediatric patients receiving VCZ according to our protocol. CYP2C19 gene molecular analysis was preemptively performed using PharmArray®. Plasma trough concentrations were measured by immunoassay analysis until target concentrations (1–5.5 μg/ml) were reached. Sixteen patients (57.14%) achieved VCZ trough target concentrations in the first measure after the initial dose based on PGx. This figure is similar to estimations made by Hicks et al. in their simulation (60%). Subdividing by phenotype, our genotyping and TDM-combined strategy allow us to achieve target concentrations during treatment/prophylaxis in 90% of the CYP2C19 Normal Metabolizers (NM)/Intermediate Metabolizers (IM) and 100% of the Rapid Metabolizers (RM) and Ultrarapid Metabolizers (UM) of our cohort. We recommended modifications of the initial dose in 29% (n = 8) of the patients. In RM ≥12 years old, an increase of the initial dose resulted in 50% of these patients achieving target concentrations in the first measure after initial dose adjustment based only on PGx information. Our experience highlights the need to improve VCZ dose predictions in children and the potential of preemptive genotyping and TDM to this aim. We are conducting a multicenter, randomized clinical trial in patients with risk of aspergillosis in order to evaluate the effectiveness and efficiency of VCZ individualization: VORIGENIPHARM (EudraCT: 2019-000376-41).

Detection of CYP2C19*2_ allele among Helicobacter pylori -infected patients in two tertiary hospitals of Khartoum, Sudan, 2019

Background: CYP2C19*2 has been identified as the most common allelic variant of CYP2C19 affecting the response to Proton pump inhibitors (PPI). This study aims to detect CYP2C19*2 allele in H. pylori-infected Sudanese population, owing its probable effect on H. pylori eradication. Methods: Antral biopsies was collected from 30 patients attending endoscopy units. Extraction of DNA was performed through QIAamp® DNA Mini Kit. Samples were screened for Urease C (UreC) gene of H. pylori using conventional PCR. Detection of CYP2C19*2 was performed in positive H. pylori samples using Real time-PCR. Results: The mean age of patients was 40.7 (±20.2 SE). Positive samples for UreC were 24 (80%) samples. Among them, four samples (16.6%) were found positive for CYP2C19*2 allele presence. Gender was found to be statistically associated with the presence of the allele (p < 0.05). Conclusion: This study illustrates that CYP2C19*2 is of modest prevalence among H. pylori-infected Sudanese population. The determination of genotypic and allelic frequencies of CYP2C19 gene among different populations will provide data to be used to personalize treatment according to individual genetic profile, and minimize the possible adverse side effects of CYP2C19 substrates.

Associations of Gene Polymorphisms and Prognosis in Highly Adherent to Treatment Patients After Myocardial Infarction

Aim. To evaluate the influence of genetic factors on the risk of developing a combined endpoint, during a one-year supervision of patients, who had myocardial infarction and highly adherent to drug therapy.Material and methods. The research included 250 patients with high adherence to treatment with myocardial infarction, using the method of polymerase chain reaction we determined the polymorphisms Thr174Met and Met235Thr in the AGT gene, Arg389Gly and Ser49Gly in the ADRB1 gene, Ser447Ter in the LPL gene and Leu28Pro in the APOE gene, Trp212Ter and G681A in the CYP2C19 gene, and then we evaluated their influence on the prognosis.Results. A significant influence on the risk of developing combined endpoint was noticed for the polymorphism of CYP2C19 (G681A) gene. For the GA genotype of the CYP2C19 gene (G6881A), the OR of developing an unsuccessful outcome was 1.97 (95 % CI 1.05 — 3.69) (P = 0.03). For сarrier-state of A allele the OR was 1.46 (95 % CI 1.06 — 3.64) (P = 0.03). Conclusion. The results received indicate the need for individual approach for the choice of drugs from the group of inhibitors P2Y12-receptors for dual antiplatelet therapy, and if clopidogrel is chosen it is necessary to resolve the issue of pharmacogenetic testing for CYP2C19.

Characterization of CYP2C19*17 Polymorphism in a Portuguese Population Sample Relevant for Proton Pump Inhibitor Therapy—A Pilot Study

The interindividual variability of Proton Pump Inhibitor (PPI) therapy results from the phenotype variability associated with the cytochrome P450 2C19 (CYP2C19) gene, namely the CYP2C19*17 allele. Our aim was to characterize patients’ genetic variability undergoing PPI therapy. A sample of 33 oral mucosa cells from Portuguese pharmacy patients was collected, followed by genotyping. The allelic frequencies of CYP2C19*1 (-806C) and CYP2C19*17 (-806T) were 71.2% and 28.8%, respectively. The genotypic frequencies for CYP2C19*1/*1 and CYP2C19*1/*17 were 42.4% and 57.6%, respectively, and 19 of these patients may have a Rapid Metabolizer (RM) phenotype pharmaceutical opinion letter, based on genetic evidence.

The Frequencies of Allele Distribution of CYP2C9 and CYP2C19 Gene Polymorphisms in Healthy Papuan Population, Indonesia

This study's objective was to determine the distribution of allele frequencies of CYP2C9 and CYP2C19 gene polymorphisms among the Papuan population, known as the second-largest ethnic group in Indonesia. According to recent research, there is a decrease in CYP2C9 and CYP2C19 produced by humans globally, including in Indonesia. These gene polymorphisms aid in the transmission of various endogenous and exogenous drugs in the human body. Material and Methods: A sum of 99 subjects, comprising 73 male and 26 female subjects aged 20-30 years, were used for this research. PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) analysis using AvaII, NsiI, and SfaNI enzymes tested for the genotypes CYP2C9 and CYP2C19 administered. The distribution of genotypes was calculated in the population (P<0.05) using the Hardy-Weinberg equilibrium. The Faculty of Medicine Gadjah Mada University's Medical and Health Research Ethics Committee (MHREC) accepted this research with written consent. The results revealed that in Papua subjects, CYP2C9*2 (rs1799853) and CYP2C19*17 (rs12248560) alleles were absent while in 17 percent of the population CYP2C9*3 (rs1057910) allele frequency was. In conclusion, CYP2C9*3 has the highest polymorphism rate in Indonesia, with the absence of CYP2C9*2 and CYP2C19*17. Therefore, genetic drift can occur within this ethnic group. Keywords: Genotyping; Papuan ethnic; Pharmacogenetics; Polymorphisms

Effect of polymorphism of platelet receptors genes P2RY12, ITGB3 and CYP2C19 cytochrome metabolizer enzyme on the platelet activity and efficiency of clopidogrel in patients with stable stenocardia in the Grodno region

The aim of the study was to assess the distribution of polymorphic variants G681A of the CYP2C19 gene, H1/H2 of the P2RY12 gene, and T1565C of the ITGB3 gene and to study their effect on the platelet activity and clopidogrel efficacy in patients with stable stenocardia living in the Grodno region. The study included 92 patients with stable stenocardia, 89 of them underwent elective percutaneous coronary intervention (PCI), and 93 practically healthy people. The survey data (general clinical, aggregometry, general blood count and platelet indices, and polymerase chain reaction genotyping) were analyzed using the STATISTICA 10.0 software.A high prevalence of carriage of genotypes associated with possible variability in response to clopidogrel therapy was revealed both among patients with stable stenocardia and among practically healthy individuals in the Grodno region. The frequency of occurrence of studying genotypes among patients with stable stanocardia was 23.9 % for the CYP2C19 gene (polymorphic locus G681A), 40.2 % for the P2RY12 gene (polymorphic locus H1/H2), and 31.5 % for the gene ITGB3 (polymorphic locus T1565C). For the group of practically healthy individuals, the distribution of these genotypes was 18.3; 46.2; 37.6 %, respectively. Associations were revealed between the carriage of the 681A allele of the CYP2C19 gene and the H2 haplotype of the P2RY12 gene with high residual platelet reactivity during clopidogrel therapy in patients with stable stenocardia. An association was found between the carriage of the H2 haplotype of the H1/H2 polymorphism of the P2RY12 gene with high platelet MPV values and a higher frequency of large platelets (P-LCR) in patients with stable stenocardia.