Distribution of CYP2C19 polymorphisms in Mongolian and Han nationals and the choice of specific antiplatelet drugs

Evaluation of CYP2C19 Genetic Variant and Its Lack of Association with Valproic Acid Plasma Concentrations Among Zhuang and Han Schizophrenia Patients in Guangxi

Purpose

To investigate the CYP2C19 genotype distribution and allelic frequency among the Zhuang and Han schizophrenic populations in Guangxi, examine the correlation between CYP2C19 genetic variants and standardized blood levels of Valproic Acid (VPA) in schizophrenic patients, and evaluate the effects of age, gender, and Body Mass Index (BMI) on standardized VPA blood concentrations.

Patients and Methods

Between February and December 2022, 192 Zhuang and Han schizophrenia patients treated with VPA were studied. Steady-state VPA concentrations were determined using homogeneous enzyme immunoassays, and CYP2C19 *1, *2, and *3 loci via q-PCR. CYP2C19 genotype distributions between Zhuang and Han groups in Nanning were compared using chi-square tests and contrasted with other ethnicities. Non-parametric tests analyzed VPA variations, identifying critical factors through multivariate stepwise regression.

Results

The study identified five CYP2C19 genotypes at the *2 and *3 loci, with the *3/*3 genotype absent in both cohorts. The CYP2C19 distribution in Guangxi Zhuang and Han mirrors, yet diverges significantly from Hui and Kazakh groups. Among 192 subjects, VPA blood levels remained consistent across metabolic types and ages 18-60 but varied significantly by gender. Multivariate analysis revealed gender and BMI as significant factors, overshadowing CYP2C19 genotype and age.

Conclusion

In Guangxi, CYP2C19 genetic variants in Zhuang and Han schizophrenia patients demonstrate statistically indistinguishable allelic and metabolic distributions. Gender and BMI can influence standardized VPA blood concentrations in schizophrenia patients. However, in our study cohort, the CYP2C19 genotype and age are not the primary determinants of standardized VPA blood levels.

Initial experience with the novel p64MW HPC flow diverter from a cohort study in unruptured anterior circulation aneurysms under dual antiplatelet medication

OBJECTIVE

p64MW HPC is a new low-profile flow diverter with reduced thrombogenicity due to hydrophilic coating. The purpose of this study was to evaluate its safety and efficacy in Mongolian patients under dual antiplatelet therapy.

METHODS

Consecutive patients with unruptured anterior circulation aneurysms were prospectively enrolled. All patients received aspirin and clopidogrel before and six months after the procedure, followed by lifelong aspirin medication. High platelet reactivity (VerifyNow) did not trigger further action. The safety and efficacy endpoints were clinical outcome and aneurysm occlusion.

RESULTS

In 29 patients (26 female, median age 57 years), 46 aneurysms (neck width 3.3 mm, fundus diameter 3.7 mm, median) were treated. Dual platelet function inhibition was confirmed in eight patients (28%). The response to Clopidogrel was between 100 and 239 P2Y12 reaction units (VerifyNow) in 13 patients (45%). Non-response to at least one drug was found in 8 of 29 patients (28%). One collapsed p64MW HPC required balloon angioplasty. No other periprocedural thrombus formation occurred. Postprocedural MRI revealed lesions with diffusion restriction in 3 of 29 patients. Digital subtraction angiography after three months for 42 of 46 (91%) aneurysms showed an adequate aneurysm occlusion in 25 (60%). Distal p64MW HPC migration of 3 implants was retreated with another p64MW HPC. Follow-up digital subtraction angiography of 26 of 46 (57%) aneurysms after six months showed adequate aneurysm occlusion in 22 (85%). Significant in-stent stenosis or thrombosis, morbidity or mortality was not encountered.

CONCLUSION

p64MW HPC implantation in patients under dual antiplatelet therapy with or without dual platelet function inhibition has a low procedural complication rate. The early aneurysm occlusion rate is high.

Inconsistency in race and ethnic classification in pharmacogenetics studies and its potential clinical implications

Introduction

Racial and ethnic categories are frequently used in pharmacogenetics literature to stratify patients; however, these categories can be inconsistent across different studies. To address the ongoing debate on the applicability of traditional concepts of race and ethnicity in the context of precision medicine, we aimed to review the application of current racial and ethnic categories in pharmacogenetics and its potential impact on clinical care.

Methods

One hundred and three total pharmacogenetics papers involving the CYP2C9, CYP2C19, and CYP2D6 genes were analyzed for their country of origin, racial, and ethnic categories used, and allele frequency data. Correspondence between the major continental racial categories promulgated by National Institutes of Health (NIH) and those reported by the pharmacogenetics papers was evaluated.

Results

The racial and ethnic categories used in the papers we analyzed were highly heterogeneous. In total, we found 66 different racial and ethnic categories used which fall under the NIH race category “White”, 47 different racial and ethnic categories for “Asian”, and 62 different categories for “Black”. The number of categories used varied widely based on country of origin: Japan used the highest number of different categories for “White” with 17, Malaysia used the highest number for “Asian” with 24, and the US used the highest number for “Black” with 28. Significant variation in allele frequency between different ethnic subgroups was identified within 3 major continental racial categories.

Conclusion

Our analysis showed that racial and ethnic classification is highly inconsistent across different papers as well as between different countries. Evidence-based consensus is necessary for optimal use of self-identified race as well as geographical ancestry in pharmacogenetics. Common taxonomy of geographical ancestry which reflects specifics of particular countries and is accepted by the entire scientific community can facilitate reproducible pharmacogenetic research and clinical implementation of its results.

Effects of different CYP2C19 genotypes on prognosis of patients complicated with atrial fibrillation taking clopidogrel after PCI

The effects of different cytochrome P450 2C19 (CYP2C19) genotypes on the prognosis of clopidogrel resistance in patients complicated with atrial fibrillation taking clopidogrel after percutaneous coronary intervention (PCI) were investigated. Eighty patients who were complicated with atrial fibrillation and treated with clopidogrel antiplatelet therapy after PCI in Meizhou Hospital Affiliated to Zhongshan University from September 2015 to January 2017 were selected, and divided into two groups according to the CYP2C19 genotype: extensive metabolism (EM) group and poor metabolism (PM) group. The related risk factors of clopidogrel resistance were determined, and the platelet aggregation rate and clopidogrel resistance rate were compared between the two groups during treatment. Non-fatal myocardial infarction and serious life-threatening complications in the two groups were observed. The increased total cholesterol level and the history of smoking and drinking were the independent risk factors of atrial fibrillation after PCI. The platelet aggregation rates in the EM group at 1, 3 and 12 months after medication were significantly lower than those in the PM group in the same period (P<0.05). The clopidogrel resistance rates in EM group before medication and at 1, 3 and 12 months after medication were higher than those in PM group in the same period (P<0.05). The onset time of non-fatal myocardial infarction in EM group was earlier than that in PM group (P<0.05), the infarct area was larger than that in PM group (P<0.05), and the left ventricular ejection fraction (EF) after onset was lower than that in PM group (P<0.05). In conclusion, the increased total cholesterol level and the history of smoking and drinking are the independent risk factors of clopidogrel resistance in patients complicated with atrial fibrillation after PCI. The incidence rates of cardiac complications are increased significantly in patients with PM CYP2C19 genotype.

Two common mutations within CYP2C19 affected platelet aggregation in Chinese patients undergoing PCI: a one-year follow-up study

The effect of dual antiplatelet therapy, clopidogrel combined with aspirin, was influenced by CYP2C19 gene mutation and heterogeneity of population. Related studies remained controversial and limited, especially in Chinese. Total 3295 unrelated ACS Chinese patients undergoing percutaneous coronary intervention (PCI) were recruited and followed up to 1 year. Meanwhile, baseline and clinical data were retrieved. CYP2C19*2 and *3 were genotyped by sequencing. Associations of variants and metabolic types with platelet reactivity (PR) were analyzed by a logistic regression model. And, a Cox proportional hazards model was utilized to analyze survival data. Confounders included gender, age, smoking status, dosage of aspirin and clopidogrel, and BMI. It was found that patients with allele A in CYP2C19*2 and *3 were susceptibility to high PR (OR, 95%CI and P values were 1.34, 1.20-1.50, <0.0001 and 1.42, 1.13-1.79, 0.0029, respectively) after taking clopidogrel. The PR increased along with the number of loss of function (LOF) allele increased and did in order of haplotype*1, *2, and *3. This research suggested that LOF alleles and risk haplotypes in CYP2C19 could significantly attenuate the response to clopidogrel, which resulted in platelet aggregation.