Verification of accuracy of warfarin stable dose prediction models in Shandong population / 中华医学遗传学杂志

OBJECTIVE@#To compare the accuracy of five warfarin-dosing algorithms and warfarin stable dose model (2.5 mg/day) for Shandong population.@*METHODS@#One hundred and twenty five patients who achieved stable warfarin dose were enrolled. Clinical and genetic data were used to evaluate the value of each algorithm by calculating the percentage of patients whose predicted warfarin dose was within 20% of the actual stable therapeutic dose and mean absolute error (MAE).@*RESULTS@#The frequency of patients with CYP2C9*1/*1, CYP2C9*1/*3 and CYP2C9*1/*2 genotype was 92.00%, 7.20%, 0.80%, respectively. That of VKORC1-1639 AA, AG and GG genotype was 82.40%, 15.20%, 2.40%, respectively. CYP4F2*1/*1, *1/*3, *3/*3 genotype was 50.40%, 39.20%, 10.40%, respectively. With the same genotypes for other loci, patients who carried at least one VKORC1-16398G mutant allele had increased warfarin stable daily dose compared with VKORC1-1639AA. Compared with CYP4F2*1/*1, those carrying at least one CYP4F2*3 mutant allele had warfarin stable daily dose increased by 5.9%-13.00%. The percentage of ideal prediction calculated from IWPC model (59.20%), Huang model (57.60%) and Ohno model (52.80%) were higher than others. The MAE were 0.35 (95%CI: 0.11-0.49), 0.15 (95%CI: 0.10-0.32), 0.39 (95%CI: 0.12-0.51), respectively.@*CONCLUSION@#The polymorphisms of CYP2C9, VKORC1 and CYP4F2 genes can influence the stable dose of warfarin in Shandong population. IWPC algorithm is suitable for guiding the use of warfarin in this population.

Maternal protein restriction during lactation modulated the expression and activity of rat offspring hepatic CYP1A1, CYP1A2, CYP2B1, CYP2B2, and CYP2E1 during development

Early nutrition plays a long-term role in the predisposition to chronic diseases and influences the metabolism of several drugs. This may happen through cytochromes P450 (CYPs) regulation, which are the main enzymes responsible for the metabolism of xenobiotics. Here, we analyzed the effects of maternal protein restriction (MPR) on the expression and activity of hepatic offspring’s CYPs during 90 days after birth, using Wistar rats as a mammal model. Hepatic CYP1A1, CYP1A2, CYP2B1, CYP2B2 and CYP2E1 mRNA and protein expression, and associated catalytic activities (ECOD, EROD, MROD, BROD, PROD and PNPH) were evaluated in 15-, 30-, 60-, and 90-day-old offspring from dams fed with either a 0% protein (MPR groups) or a standard diet (C groups) during the 10 first days of lactation. Results showed that most CYP genes were induced in 60- and 90-day-old MPR offspring. The inductions detected in MPR60 and MPR90 were of 5.0- and 2.0-fold (CYP1A2), 3.7- and 2.0-fold (CYP2B2) and 9.8- and 5.8– fold (CYP2E1), respectively, and a 3.8-fold increase of CYP2B1 in MPR90. No major alterations were detected in CYP protein expression. The most relevant CYP catalytic activities’ alterations were observed in EROD, BROD and PNPH. Nevertheless, they did not follow the same pattern observed for mRNA expression, except for an induction of EROD in MPR90 (3.5-fold) and of PNPH in MPR60 (2.2-fold). Together, these results suggest that MPR during lactation was capable of altering the expression and activity of the hepatic CYP enzymes evaluated in the offspring along development.

Association of cytochrome P450 2A6 gene polymorphisms with smoking behaviors:a Meta-analysis / 中华预防医学杂志

<p><b>OBJECTIVE</b>A Meta-analysis was performed to assess the association of defective hepatic cytochrome P450 2A6 (CYP2A6) gene with smoking behaviors.</p><p><b>METHODS</b>All eligible studies published up to 2014 were searched out from PubMed, China National Knowledge Internet (CNKI), ISI Web of knowledge (ISI), vip citation databases (VIP), Chinese BioMedical Literature (CBM) and Elsevier Science Direct, searching words were "smok*","nicotine dependence","CYP2A6","cytochrome P450 2A6","polymorphism","mut*"and"varia*", while 436 articles were concluded. Meta-analysis was performed using Statal 3.1.</p><p><b>RESULTS</b>A total of ten studies were finally included. We didn't find a significant effect of defective CYP2A6 gene on smoking initiation (fixed effect model (FEM): OR = 0.90, 95%CI: 0.78-1.03, I(2) = 25.8%), smoking persistence (random effect model (REM): OR = 0.85, 95%CI: 0.59-1.23, I(2) = 66.3%) and smoking cessation (REM: OR = 0.89, 95%CI: 0.57-1.40, I(2) = 67.1%). But it showed a significant protective effect of CYP2A6*4 on smoking initiation (FEM: OR = 0.78, 95%CI: 0.61-0.99, I(2) = 28.2%), smoking persistence (FEM: OR = 0.53, 95%CI: 0.36-0.77, I(2) = 41.0%) and smoking cessation (REM: OR = 0.49, 95%CI: 0.31-0.80, I(2) = 0.0%).</p><p><b>CONCLUSIONS</b>This Meta-analysis suggested that there was not a protective effect of defective CYP2A6 gene against smoking behaviors. But smokers with whole CYP2A6 gene deletion would be less likely to start smoking, less smoking persistence and more likely to quit smoking successful than smokers with wild CYP2A6 gene.</p>

Association of single nucleotide polymorphisms of cytochrome P450 gene with susceptibility to gout in ethnic Han males from coastal regions of Shandong province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of cytochrome P450 gene single nucleotide polymorphisms (SNPs) with susceptibility to gout in ethnic Han males from coastal regions of Shandong province.</p><p><b>METHODS</b>Four hundred and eighty male patients with gout and 480 healthy male controls were included. Genotyping was carried out with a custom Illumina GoldenGate Genotyping assay to detect SNP rs2275620 of CYP2C8 gene, SNP rs2070676 of CYP2E1 gene, SNP rs837395 of CYP4B1 gene, and SNP rs194150 of TBXAS1 gene. The association was assessed with chi-square test.</p><p><b>RESULTS</b>No significant difference has been found between the two groups in regard to the genotypic and allelic frequencies of the TT, AT, AA genotypes and A, T alleles of the SNP rs2275620 of the CYP2C8 gene (P=0.88; P=0.97), the CC, CG, GG genotypes and C,G alleles of SNP rs2070676 of the CYP2E1 gene (P=0.24; P=0.09), the TT, AT, AA genotypes and A, T alleles of SNP rs837395 of the CYP4B1 (P=0.88; P=0.97), and TT, AT, AA genotypes and the A,T alleles of SNP rs194150 of TBXAS1 gene (P=0.15; P=0.06).</p><p><b>CONCLUSION</b>This study has identified no association of SNP loci rs2275620(A/T) of CYP2C8, rs2070676(C/G) of CYP2E1, rs837395(A/T) of CYP4B1 and rs194150(A/T) of TBXAS1 with gout in ethnic Han males from coastal regions in Shandong province. However, our result needs to be replicated in larger sets of patients collected from other regions and populations.</p>

Borneol is an inducer of rat hepatic CYP2D activity in vivo / 药学学报

Borneol is a traditional Chinese medicine. In the past few years, many studies showed that borneol can improve the bioavailability of other drugs, promoting drugs to cross the blood-brain barrier, so the potential drug interactions between borneol and other medicines have attracted great attention, but the influence of borneol to CYP450 and its isoforms are rarely reported. In this research, male Wistar rats were orally administered by borneol for 7 days, then the mRNA and protein expression and the activities of CYP2D were detected, we also compared the pharmacokinetic parameters of CYP2D's specific substrate between control group and borneol group. The results show that borneol (33, 100 and 300 mg x kg(-1) x d(-1)) have no significant effect on CYP2D, while the activites of CYP2D increased 1.71, 1.97 and 2.89 times comparing to the control group. At the same time, borneol (300 mg x kg(-1) x d(-1)) caused the C(max) decreased 10.6% (P > 0.05), AUC(0-∞) decreased 27.5% (P < 0.01), CL/F increased 41.1% (P < 0.01), V(z)/F increased 23.1% (P > 0.05) of dextromethorphan. Our data provided that borneol speed up dextromethorphan's elimination in vivo. Since the activity of CYP2D can be induced by borneol, the metabolic interactions might happen when borneol and the substrate drug CYP2D are used together.

CYP2C8-derived epoxyeicosatrienoic acids decrease oxidative stress-induced endothelial apoptosis in development of atherosclerosis: Role of Nrf2 activation / 华中科技大学学报（医学）（英德文版）

The aim of the present study is to investigate how cytochrome P450 enzymes (CYP) 2C8-derived epoxyeicosatrienoic acids (EETs) regulate the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and protect against oxidative stress-induced endothelial injuries in the development and progression of atherosclerosis. In this study, cultured human umbilical vein endothelial cells (HUVECs) were transfected with CYP2C8 or pretreated with exogenous EETs (1 μmol/L) before TNF-α (20 ng/mL) stimulation. Apoptosis and intracellular ROS production were determined by flow cytometry. The expression levels of ROS-associated NAD(P)H subunits gp91 and p47, the anti-oxidative enzyme catalase (CAT), Nrf2, heme oxygenase-1 (HO-1) and endothelial nitric oxide synthase (eNOS) were detected by Western blotting. The results showed that CYP2C8-derived EETs decreased apoptosis of HUVECs treated with TNF-α. Pretreatment with 11, 12-EET also significantly blocked TNF-α-induced ROS production. In addition, 11, 12-EET decreased oxidative stress-induced apoptosis. Furthermore, the ability of 11, 12-EET to protect cells against TNF-α-induced apoptosis via oxidative stress was abrogated by transient transfection with Nrf2-specific small interfering RNA (siRNA). In conclusion, CYP2C8-derived EETs prevented TNF-α-induced HUVECs apoptosis via inhibition of oxidative stress associated with the Nrf2 signaling.

SNP genetic polymorphisms of MDR-1, CYP1A2 and CYPB11 genes in four canine breeds upon toxicological evaluation

The fields of pharmacogenetics and pharmacogenomics have become increasingly promising regarding the clinical application of genetic data to aid in prevention of adverse reactions. Specific screening tests can predict which animals express modified proteins or genetic sequences responsible for adverse effects associated with a drug. Among the genetic variations that have been investigated in dogs, the multidrug resistance gene (MDR) is the best studied. However, other genes such as CYP1A2 and CYP2B11 control the protein syntheses involved in the metabolism of many drugs. In the present study, the MDR-1, CYP1A2 and CYP2B11 genes were examined to identify SNP polymorphisms associated with these genes in the following four canine breeds: Uruguayan Cimarron, Border Collie, Labrador Retriever and German Shepherd. The results revealed that several SNPs of the CYP1A2 and CYP2B11 genes are potential targets for drug sensitivity investigations.

Impact of six genetic polymorphisms on Warfarin maintenance dose variation in Chinese Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of VKORC1, CYP2C9, GGCX, PROC, EPHX1 and CYP4F2 gene polymorphisms on Warfarin maintenance dose variation in Chinese Han Population.</p><p><b>METHODS</b>Four hundred eighty-eight patients with prosthetic heart valves, atrial fibrillation or pulmonary thromboembolism and achieved stable Warfarin dose were enrolled. TaqMan probe or direct sequencing were used to genotype Y9VKORC1, CYP2C9, GGCX, EPHX1 and CYP4F2 gene polymorphisms. Demographic characteristics, stable therapeutic dose of Warfarin and concomitant medications were collected for all patients. The effect of VKORC1, CYP2C9, GGCX, PROC, EPHX1 and CYP4F2 gene polymorphisms, demographic characteristics and concomitant medications on Warfarin daily maintenance dose were analyzed with statistical method.</p><p><b>RESULTS</b>VKORC1 and CYP2C9 gene polymorphisms could explain more than 50% Warfarin maintenance dose variation in recruited patients, while CYP4F2 gene polymorphisms could only explain 1%. GGCX, PROC and EPHX1 gene polymorphisms had no impact no Warfarin maintenance dose. VKORC1 and CYP2C9 gene polymorphisms have a greater impact on Warfarin maintenance dose compared with demographic characteristics and concomitant medications.</p><p><b>CONCLUSION</b>VKORC1 and CYP2C9 gene polymorphisms have a significant impact on Warfarin maintenance dose in Chinese Han population.</p>

Future Trends of Helicobacter pylori Eradication Therapy in Korea / 대한소화기학회지

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis' as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.

Effects of coexisting polymorphisms of CYP2C19 and P2Y12 on clopidogrel responsiveness and clinical outcome in patients with acute coronary syndromes undergoing stent-based coronary intervention / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The CYP2C19 G681A single polymorphism has been proven to affect clopidogrel responsiveness. However, the effect of coexisting polymorphisms of other genes has not yet been reported in the Chinese population. This study investigated the effect of coexisting polymorphisms of CYP2C19 and P2Y12 on clopidogrel responsiveness and adverse clinical events in Chinese patients.</p><p><b>METHODS</b>In 577 Han Chinese patients undergoing stent placement because of acute coronary syndrome had platelet reactivity assessed by thromboelastography, and the CYP2C19 G681A and P2Y12 C34T polymorphisms were detected by the ligase detection reaction. Primary clinical endpoints included cardiovascular death, nonfatal myocardial infarction, target vessel revascularization, and stent thrombosis. The secondary clinical endpoints were thrombolysis in myocardial infarction bleeding. The follow-up period was 12 months.</p><p><b>RESULTS</b>Genotyping revealed 194 carriers of the wild type GG genotype of CYP2C19 and the wild type CC genotype of P2Y12 (group 1), 102 carriers of the wild type GG genotype of CYP2C19 and the mutational T allele of P2Y12 (group 2), 163 carriers of the mutational A allele of CYP2C19 and the wild type CC genotype of P2Y12 (group 3), and 118 carriers of the mutational A allele of CYP2C19 and the mutational T allele of P2Y12 (group 4). Group 4 had the lowest ADP-inhibition (49.74 ± 32.61) and the highest prevalence of clopidogrel low response (29.7%) of the four groups. The rate of the composite of primary clinical endpoints increased more in group 4 (8.5%) than in the other three groups; the rate of composite primary endpoints in group 2 (2.9%) and group 3 (3.7%) were not significantly different than that of group 1 (1.5%).</p><p><b>CONCLUSION</b>Coexisting polymorphisms of different genes affected clopidogrel responsiveness and clinical outcome more than single polymorphism in Chinese patients with acute coronary syndrome undergoing percutaneous coronary intervention.</p>

Chemopreventive effect of Ardisia crispa hexane fraction on the peri-initiation phase of mouse skin tumorigenesis

To investigate the chemopreventive effect of the hexane extract of Ardisia crispa during the peri-initiation phase of mouse skin tumorigenesis. This study was conducted for 12 weeks on two-stage 7,12-dimethylbenz[alpha]-anthracene [DMBA]-induced tumor initiation followed by croton-oil-induced tumor promotion in mice. A. crispa root hexane extract [ACRH] was applied at various doses [30, 100, 300 mg/kg] 7 days prior to and after DMBA treatment. Throughout the study, morphological observations, i.e., tumor incidence, tumor volume and tumor burden were measured for each of the treated groups. At the end of the experiment, the mice were sacrificed and their skin tissues were examined histopathologically. The highest dose of ACRH [300 mg/kg] significantly delayed tumor formation [week 9, p < 0.05] and exhibited the lowest tumor volume [0.71 +/- 0.00 mm[3], p < 0.05], tumor burden [2.00 +/- 0.00, p < 0.05], and tumor incidence [16.67%, p < 0.05] compared to other doses of ACRH. A 100-mg/kg dose produced tumor latency at week 7, tumor volume of 2.44 +/- 0.88 mm[3] [p < 0.05], tumor burden of 1.60 +/- 0.60 [p < 0.05], and tumor incidence of 50%; 30 mg/kg produced tumor latency at week 8, tumor volume of 2.04 +/- 0.45 mm[3] [p < 0.05], tumor burden of 2.17 +/- 0.54, tumor incidence of 60% and carcinogen control [tumor latency at week 7; tumor volume, 3.56 mm3; tumor incidence of 66.67%].The highest dose of A. crispa hexane extract delayed tumor development, thus showing a chemopreventive effect on mouse skin tumorigenesis

In vivo effect of triptolide combined with glycyrrhetinic acid on rat cytochrome P450 enzymes / 药学学报

Triptolide (TP) is a major active component in Tripterygium root, but its therapeutic window was very narrow due to its severe multi-organ toxicity. In this work, the effect of TP combined with glycyrrhetic acid (GA) on mRNA expression and activity of four cytochrome P450 (CYP) enzymes in rat liver was studied after intragastric administration of TP (0.05, 0.3 and 0.6 mg x kg(-1) x day(-1)) and TP (0.6 mg x kg(-1) x day(-1)) combined with GA (30 mg x kg(-1) x day(-1)) for 7 consecutive days. Compared with the control, the high dose of TP significantly up-regulated the mRNA expression levels of CYP2E1, 1A2, 3A1 and 2C11, the co-administration of TP and GA further up-regulated the mRNA expression levels of CYP3A1, 2C11 and 2E1 as compared with the high dose of TP. Meanwhile, TP at high dose and combined with GA significantly increased CYP3A-associated testosterone 6beta-hydroxylation activity (2.2-fold and 4.1-fold, respectively) as compared with the control. Because TP is mainly metabolized by CYP3A2 in male rats, the present work indicated that TP-induced increase of CYP3A activity might be an important reason for the rapidly metabolic clearance of TP in rat liver, and GA can reduce the hepatotoxicity of TP by promoting its hepatic metabolic clearance. Furthermore, the results also suggest that the drug interactions might be occurred when TP and GA were co-administered with other CYP3A substrate drug.

Establishment of in vitro evaluation model for CYP2B6 induction and its application to screen inducers among TCMs / 药学学报

This paper is to report the development of a high-throughput in vitro system to screen hPXR/CAR mediated CYP2B6 drug inducers, and the application of it into the quick determination of induction activity toward CYP2B6 by various commonly used traditional Chinese medicines (TCMs) extract. Dual reporter gene assays were performed. The hPXR/CAR expression vectors and the reporter vector pGL3-CYP2B6-Luc involved in the distal and proximal promoters of CYP2B6 were co-transfected into HepG2 cells. Relative luciferase activities in cell lysate were analyzed after 48 h treatment of blank vehicle or drugs to determine the induction activity toward CYP2B6 by various commonly used TCMs extract. The positive hPXR/hCAR activators rifampicin and CITCO were applied to make sure that the reporter gene model was successfully established. Then 5 kinds of commonly used TCM extracts and 1 herbal compound were successfully investigated, some were found to activate hPXR or hCAR and therefore have the potential to induce CYP2B6 enzyme. This is the first domestic article to report the hCAR3-mediated CYP2B6 induction model and the establishment of a reporter gene system for hPXR/CAR-mediated CYP2B6 induction can be an effective and systemic in vitro method to investigate the drug inducers of CYP2B6 and to explain the mechanism involved.

Effect of shenfu injection on CYP450s of rat liver / 药学学报

The paper is to report the study of the effect of Shenfu injection on the enzyme activity of liver CYP450 and its mRNA level of rat liver. Microsome of rat liver was prepared after intravenous administration of Shenfu injection for 7 days. The enzyme activity was quantified by Cocktail method. Meanwhile, the mRNA expression of CYP1A2, CYP2B1/2, CYP2C11 and CYP3A1 in the liver was detected by RT-PCR. Shenfu injection obviously induced the enzyme activities of CYP2B and CYP2C. Meantime Shenfu injection decreased the enzyme activities of CYP1A2 and CYP3A. The mRNA levels of CYP2B and CYP2C were also induced in rats treated with Shenfu injection. But it obviously inhibited the mRNA level of CYP1A2 and CYP3A. Since the enzyme activity and mRNA level were obviously changed after administration, the potential effect of drug-drug interaction should be concerned.

Functional polymorphisms in CYP2C19 & CYP3A5 genes associated with decreased susceptibility for paediatric tuberculosis.

Background & objectives: Tuberculosis (TB) bacilli ingested by macrophages evade host immune responses by multiple mechanisms including the inhibition of apoptosis. As the cytochrome-P-450 system (CYP) contributes to apoptosis it has been suggested that genetic variation in CYP may be associated with susceptibility to TB infection. This study was carried out to evaluate cytochrome P-450 polymorphisms in Chinese Han children and to investigate the effect of these polymorphisms in paediatric TB. Methods: Frequencies for the CYP2C19, CYP3A4, CYP3A5 and CYP2E1 mutated alleles and genotypes were compared between 142 Chinese paediatric TB patients and 150 non-infected controls by real time PCR genotyping on peripheral leukocyte DNA. Results: CYP2C19 (636 G>A, rs4986893) A allele and AG genotype were associated with decreased susceptibility to TB (P = 0.006, OR= 0.33, 95% CI: 0.15-0.76; and P = 0.005, OR =0.31, 95% CI: 0.14-0.72 respectively), as were the CYP3A5 (6986A>G, rs776746) G allele and particularly homozygous GG (recessive mode) genotype (P = 0.004, OR=0.61, 95% CI: 0.43-0.85; and P=0.002, OR=0.47, 95% CI: 0.29-0.76). Interpretation & conclusions: The data suggested that CYP2C19 and CYP3A5 polymorphisms affect susceptibility to paediatric TB. Further studies are indicated to confirm and elucidate these observations.

Variantes genéticas de CYP2A6 y su relación con la dependencia tabáquica y el hábito de fumar en una muestra individuos chilenos: Un estudio piloto / Relation of genetic variants of CYP2A6 with tobacco dependence and smoking habit in Chilean subjects: A pilot study

Background: Genetic and metabolic factors associated with nicotine metabolism may be related to smoking behavior. Aim: To assess the prevalence of allelic and genotype variants of CYP2A6 in a sample of Chilean subjects and to evaluate their relationship with smoking and tobacco dependence. Material and Methods: The genotype frequencies for *2, *3 and *4 of CYP2A6*1 (wild type) gene were determined by polymerase chain reaction (PCR) in 54 volunteers. Addiction to tobacco was evaluated using the Fagerstrom Test. The association between the presence of allelic variants of CYP2A6 and smoking and tobacco dependence was evaluated with chi square test. Results: The prevalence of *1, *2 (wt/*2), *3 (wt/*3 or *31*3) and *4 (del/del) were 92.6%, 3.7%, 0% y 3.7%, respectively. No significant association was observed between being a carrier of a variant genotype of CYP2A6 and smoking or tobacco dependence. Conclusions: In this sample of Chilean individuals we did not find a relation between any CYP2A6 genotype with smoking or tobacco dependence.

Development of the high resolution melting method for genotyping CYP2C9*3 (1075A/C, rs1057910) and VKORC1 (-1639A/G, rs9923231) / 中华心血管病杂志

<p><b>OBJECTIVE</b>To establish the high-resolution melting curve (HRM) approach for genotyping CYP2C9*3 (1075A/C, rs1057910) and VKORC1 (-1639A/G, rs9923231) and explore its value on estimation of the Warfarin initial dose in comparison with various traditional genotyping methods.</p><p><b>METHODS</b>CYP2C9*3 (1075A/C, rs1057910) and VKORC1 (-1639A/G, rs9923231) genotyping was detected in 100 patients receiving Warfarin therapy by the newly developed HRM method and traditional genotyping methods including PCR-restriction fragment length polymorphism (PCR-RFLP), TaqMan probe and DNA sequencing.</p><p><b>RESULTS</b>The results of the genotypes obtained from above mentioned methods to detect CYP2C9*3 (1075A/C, rs1057910) and VKORC1 (-1639A/G, rs9923231) were similar and consistent. The HRM method is simpler, more economical, and faster compared to the traditional methods. The frequencies of the VKORC1-1639 AA, AG, GG genotypes from these 100 clinical samples were 73 (73%), 23 (23%), 4 (4%), respectively; Frequencies of the CYP2C9 1075 AA, AC, CC genotypes were 94(94%), 6 cases (6%), 0, respectively.</p><p><b>CONCLUSIONS</b>HRM approach can effectively detect CYP2C9*3 (1075A/C, rs1057910) and VKORC1 (-1639A/G, rs9923231) polymorphisms and this method is simpler, more economical, and faster compared to the traditional methods for detecting CYP2C9*3 (1075A/C, rs1057910) and VKORC1 (-1639A/G, rs9923231) polymorphisms.</p>

Validation and comparison of pharmacogenetics-based warfarin dosing algorithms in Han Chinese patients / 中华心血管病杂志

<p><b>OBJECTIVE</b>To assess whether the existing three types of pharmacogenetics-based Warfarin dosing algorithms appropriately predict the actual maintenance dose in Han Chinese mechanical heart valve replacement patients (n = 130).</p><p><b>METHODS</b>The patients' CYP2C9 and VKORC1 genetic polymorphisms were detected by PCR-RFLP. The genotype of CYP2C9, VKORC1 and other information were used to calculate predicted doses. Accuracy of the models was assessed using the absolute value of the difference between predicted dose and actual dose, calculated on both an absolute and percentage basis. Actual weekly dose was also regressed on predicted weekly dose, from which we obtained R(2) values. Clinical accuracy of the predictions was assessed by computing the proportion in which the predicted dose was 20% or more below the actual dose (under dosed), within 20% of the actual dose (ideally dosed), or 20% or greater above the actual dose (over dosed).</p><p><b>RESULTS</b>The average absolute error is the smallest for the predictions made by the Wen model (3.74 mg/wk), followed by the Ohno model (4.07 mg/wk) and IWPC model (5.05 mg/wk). R(2) was 40.2% in the Wen model, 38.2% in the Ohno model and 26.7% in the IWPC model. When comparing the percentage of patients for whom the predicted doses were ideal, the Wen model works the best (50.0%) in low-dose group (≤ 21 mg/wk), but the Ohno model works the best (85.29%) in middle-dose group (21 - 49 mg/wk), followed by the Wen model.</p><p><b>CONCLUSION</b>The best accuracy is achieved by the Wen model and the best clinical accuracy is obtained by the Ohno model for predicting the actual maintenance dose in Han Chinese mechanical heart valve replacement patients.</p>

Clopidogrel metabolism related gene polymorphisms in Chinese patients with acute coronary syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To detect the single nucleotide polymorphisms of clopidogrel metabolism related genes (CYP2C19, ABCB1 and PON1) in Chinese patients with acute coronary syndrome (ACS) by genotype analysis.</p><p><b>METHODS</b>Genetic analysis was performed in patients admitted to Fuwai Hospital from 2005 to 2008 with ACS within 4 weeks. The detection of polymorphisms was performed by TaqMan real-time PCR method. The alleles genotyped were CYP2C19 *2-*8, *17, ABCB1 C3435T, PON1 Q192R and PON1 L55M. Minor allele frequency (MAF) was calculated. Patients were classified as one of the 5 categories by clopidogrel metabolizer phenotypes as extensive [without any "loss-of-function" (LOF) allele *2-*8 or "gain-of-function" (GOF) allele *17], intermediate (with only one LOF allele), Poor (with two or more LOF alleles), ultra (with one or two GOF alleles) or unknown (with one LOF allele and one GOF allele).</p><p><b>RESULTS</b>A total of 2800 ACS patients were enrolled [mean age (59.0 ± 12.3) years and 2236 males (79.9%)]. There were 74% patients with ST-segment elevation myocardial infarction (STEMI, n = 2072), 22.0% patients with non-ST-segment elevation myocardial infarction (NSTEMI, n = 617) and 4.0% patients with unstable angina (UA, n = 111). The minor allele frequency (MAF) for each genotype of CYP2C19 *2, *3, *4, *17 was 28.7%, 4.6%, 0.1% and 1.2%, respectively. There was no LOF allele *5-*8 in the study population. The MAF for ABCB1 C3435T, PON1 Q192R and PON1 L55M was 39.4%, 37.8% and 4.4%, respectively. Clopidogrel metabolizer groups were defined as extensive in 41.7%, intermediate in 45.6%, poor in 10.3%, ultra in 1.9% and unknown in 0.6% patients, respectively. There were no significant differences for all genotypes between males and females. Total LOF carriers of CYP2C19 were 56.4% and GOF carriers were 2.5%.</p><p><b>CONCLUSIONS</b>Our study demonstrated a high distribution of the LOF allele of CYP2C19 in China ACS population.</p>