Pharmacogenetic testing for clinical applications is steadily increasing. Correct and adequate use of pharmacogenetic tests is important to reduce unnecessary medical costs and adverse patient outcomes. This document contains recommended pharmacogenetic testing guidelines for clinical application, interpretation, and result reporting through a literature review and evidence-based expert opinions for the clinical pharmacogenetic testing covered by public medical insurance in Korea. This document aims to improve the utility of pharmacogenetic testing in routine clinical settings.
Anticoagulants/therapeutic use ; Antidepressive Agents/therapeutic use ; Antimetabolites, Antineoplastic/therapeutic use ; Antitubercular Agents/therapeutic use ; Arylamine N-Acetyltransferase/genetics ; Coronary Artery Disease/drug therapy/genetics ; Cytochrome P-450 CYP2C19/genetics ; Cytochrome P-450 CYP2C9/genetics ; Cytochrome P-450 CYP2D6/genetics ; Depressive Disorder/drug therapy/genetics ; Genotype ; Isoniazid/therapeutic use ; Laboratories, Hospital/standards ; Methyltransferases/genetics ; Pharmacogenomic Testing/*methods/standards ; Platelet Aggregation Inhibitors/therapeutic use ; Pulmonary Embolism/drug therapy/genetics ; Ticlopidine/analogs & derivatives/therapeutic use ; Tuberculosis/drug therapy/genetics ; Vitamin K Epoxide Reductases/genetics ; Warfarin/therapeutic use

OBJECTIVETo assess the association of CYP2C19 gene polymorphisms with the incidence of ischemic stroke among patients receiving clopidogrel therapy following coronary stenting for coronary artery disease.

METHODSClinical data of patients receiving clopidogrel therapy after coronary stenting were retrospectively studied. For a case-control study, 137 patients with acute cerebral infarction and 122 non-stroke patients were selected. Based on the variants of the CYP2C19 gene detected by a DNA microarray assay, the patients were further divided into the wild-type group(CYP2C19*1/*1) and mutant group(defined by the presence of at least one loss-of-function allele, including CYP2C19*1/*2, CYP2C19*1/*3, CYP2C19*2/*2, CYP2C19*2/*3 and CYP2C19*3/*3). The incidences of ischemic stroke in the two groups were compared through a chi-square analysis. The influence of CYP2C19 gene polymorphisms and clopidogrel therapy on the incidence of ischemic stroke was analyzed through multivariable logistic regression.

RESULTSA total of 259 patients were enrolled. The case and control groups showed no difference in terms of gender and age. There were 123 cases (47.5%) in the CYP2C19 wild-type group and 136 cases (52.5%) in the mutant group. The incidence of ischemic stroke of mutant group was significantly higher than that of wild-type group (59.9% vs. 44.3%, X2=6.398, P=0.042). Multivariate analysis revealed that loss-of-function polymorphisms of the CYP2C19 gene carried a 1.13 times greater risk for ischemic stroke compared to wild-type genotype (OR=2.13, 95%CI: 1.23-3.71).

CONCLUSIONThe efficacy of clopidogrel for the prevention of ischemic stroke in post-coronary stent patients may be reduced by the insufficiency of the CYP2C19 gene. The dosage of clopidogrel therapy should be adjusted based on its polymorphisms.

Brain Ischemia ; prevention & control ; Cytochrome P-450 CYP2C19 ; genetics ; Genotype ; Humans ; Percutaneous Coronary Intervention ; adverse effects ; Platelet Aggregation Inhibitors ; therapeutic use ; Polymorphism, Genetic ; Stents ; adverse effects ; Stroke ; prevention & control ; Ticlopidine ; analogs & derivatives ; therapeutic use

BACKGROUND: An association has been reported between CYP2C19 polymorphism and the altered antiplatelet activity of clopidogrel. We investigated this association using the newly introduced platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test. METHODS: Polymorphisms of CYP2C19*2, *3, *17 and the degree of inhibition of platelet function were determined in 83 patients. Three different platelet function tests were used to evaluate the degree of platelet inhibition and to check the association with genotype. RESULTS: The post-procedure PFA-200 values of extensive metabolizers (EM) patients (285.3+/-38.8) were higher than those of intermediate metabolizers (IM) and poor metabolizers (PM) patients (227.7+/-98.3 and 133.7+/-99.2, respectively; P=0.024). Light transmittance aggregometry (LTA) and the VerifyNow system showed that the post-procedure values for EM patients were lower than those of IM and PM patients (LTA: 24.4+/-15.7, 34.1+/-17.6, and 42.2+/-16.9, respectively, P<0.001; VerifyNow: 133.2+/-60.5, 171.5+/-42.6, and 218.7+/-59.3, respectively, P<0.001). The high residual platelet reactivity (HPR) rates were significantly different among the EM, IM, and PM groups using PFA-200 (PM:IM:EM=82.4:40.6:11.8, P<0.001). CONCLUSIONS: Approximately, 59.0% of Korean patients with cardiovascular disease receiving clopidogrel had CYP2C19 loss-of-function genotypes classified as IM or PM, and the frequency was similar to the data from Asian people. The PFA-200, LTA, and VerifyNow platelet function tests revealed evidence of a significant association between the efficacy of clopidogrel and CYP2C19 genotypes.
Aged ; Cardiovascular Diseases/blood/*drug therapy ; Cytochrome P-450 CYP2C19/*genetics/metabolism ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Phenotype ; Platelet Aggregation Inhibitors/*therapeutic use ; Platelet Function Tests/instrumentation ; Polymorphism, Genetic ; Ticlopidine/*analogs & derivatives/therapeutic use

BACKGROUNDPlatelet function tests are widely used in clinical practice to guide personalized antiplatelet therapy. In China, the thromboelastography (TEG) test has been well accepted in clinics, whereas VerifyNow, mainly used for scientific research, has not been used in routine clinical practice. The aim of the current study was to compare these two point-of-care platelet function tests and to analyze the consistency between the two tests for evaluating on-clopidogrel platelet reactivity in Chinese acute myocardial infarction patients undergoing percutaneous coronary intervention (PCI).

METHODSA total of 184 patients admitted to Fuwai Hospital between August 2014 and May 2015 were enrolled in the study. On-clopidogrel platelet reactivity was assessed 3 days after PCI by TEG and VerifyNow using adenosine diphosphate as an agonist. Based on the previous reports, an inhibition of platelet aggregation (IPA) <30% for TEG or a P2Y12 reaction unit (PRU) >230 for VerifyNow was defined as high on-clopidogrel platelet reactivity (HPR). An IPA >70% or a PRU <178 was defined as low on-clopidogrel platelet reactivity (LPR). Correlation and agreement between the two methods were analyzed using the Spearman correlation coefficient (r) and kappa value (κ), respectively.

RESULTSOur results showed that VerifyNow and TEG had a moderate but significant correlation in evaluating platelet reactivity (r = -0.511). A significant although poor agreement (κ = 0.225) in identifying HPR and a significantly moderate agreement in identifying LPR (κ = 0.412) were observed between TEG and VerifyNow. By using TEG as the reference for comparison, the cutoff values of VerifyNow for the Chinese patients in this study were identified as PRU >205 for HPR and PRU <169 for LPR.

CONCLUSIONSBy comparing VerifyNow to TEG which has been widely used in clinics, VerifyNow could be an attractive alternative to TEG for monitoring on-clopidogrel platelet reactivity in Chinese patients.

Adenosine Diphosphate ; therapeutic use ; Aged ; Aspirin ; therapeutic use ; Blood Platelets ; drug effects ; China ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; drug therapy ; surgery ; Percutaneous Coronary Intervention ; methods ; Platelet Aggregation ; drug effects ; Platelet Aggregation Inhibitors ; therapeutic use ; Point-of-Care Systems ; Receptors, Purinergic P2Y12 ; metabolism ; Thrombelastography ; Ticlopidine ; analogs & derivatives ; therapeutic use

BACKGROUNDClopidogrel low response (CLR) is an independent risk factor of adverse outcomes in patients undergoing percutaneous coronary intervention (PCI), and intensified antiplatelet treatments (IAT) guided by platelet function assays might overcome laboratory CLR. However, whether IAT improves clinical outcomes is controversial.

METHODSRelevant trials were identified in PubMed, the Cochrane Library, and the Chinese Medical Journal Network databases from their establishment to September 9, 2014. Trials were screened using predefined inclusion criteria. Conventional meta-analysis and cumulative meta-analysis were performed using the Review Manager 5.0 and STATA 12.0 software programs.

RESULTSThirteen randomized controlled trials involving 5111 patients with CLR were recruited. During a follow-up period of 1-12 months, the incidences of cardiovascular (CV) death, nonfatal myocardial infarction (MI), and stent thrombosis were significantly lower in the IAT arm than in the conventional antiplatelet treatment arm (relative risk [RR] = 0.45, 95% confidence interval [CI]: 0.36-0.57, P < 0.000,01), whereas bleeding was similar between the two arms (RR = 1.05, 95% CI: 0.86-1.27, P = 0.65).

CONCLUSIONSIAT guided by platelet function assays reduces the risk of CV death, nonfatal MI, and stent thrombosis (ST) without an increased risk of bleeding in patients undergoing PCI and with CLR.

Cardiovascular Diseases ; mortality ; Humans ; Myocardial Infarction ; prevention & control ; Percutaneous Coronary Intervention ; adverse effects ; Platelet Aggregation Inhibitors ; therapeutic use ; Randomized Controlled Trials as Topic ; Stents ; adverse effects ; Ticlopidine ; analogs & derivatives ; therapeutic use

BACKGROUNDThe efficacy and safety of telmisartan combined with clopidogrel, leflunomide, or both drugs for immunoglobulin A nephropathy (IgAN) are unclear. This study was designed to evaluate the efficacy and safety of telmisartan combined with clopidogrel, leflunomide, or both drugs for IgAN.

METHODSIt is a multicenter, prospective, double-dummy randomized controlled trial. Primary IgAN patients were recruited in 13 renal units across Beijing, China, from July 2010 to June 2012. After a 4-week telmisartan (80 mg/d) wash-in, 400 patients continuing on 80 mg/d telmisartan were randomly assigned to additionally receive placebo (Group A), 50 mg/d clopidogrel (Group B), 20 mg/d leflunomide (Group C), or 50 mg/d clopidogrel and 20 mg/d leflunomide (Group D). The 24-week intervention was completed by 360 patients. The primary endpoint was change in 24-h proteinuria at 24 weeks. A linear mixed-effect model was used to analyze the changes at 4, 12, and 24 weeks. Generalized estimating equations were used to evaluate changes in hematuria grade. This trial was registered at the Chinese Clinical Trial Registry.

RESULTSThe effects of telmisartan combined with leflunomide on changes in proteinuria (0.36 [95% confidence interval (CI) 0.18-0.55] g/d, P < 0.001), in serum uric acid (76.96 [95% CI 57.44-96.49] μmol/L, P < 0.001), in serum creatinine (9.49 [95% CI 6.54-12.44] μmol/L, P < 0.001), and in estimated glomerular filtration rate (-6.72 [95% CI-9.46 to -3.98] ml·min-1·1.73 m-2, P < 0.001) were statistically significant, whereas they were not statistically significant on changes in systolic and diastolic blood pressure and weight (P > 0.05). Telmisartan combined with clopidogrel had no statistical effect on any outcome, and there was no interaction between the interventions. No obvious adverse reactions were observed.

CONCLUSIONSTelmisartan combined with leflunomide, not clopidogrel, is safe and effective for decreasing proteinuria in certain IgAN patients.

TRIAL REGISTRATIONchictr.org.cn, ChiCTR-TRC-10000776; http://www.chictr.org.cn/showproj.aspx?proj=8760.

Adolescent ; Adult ; Benzimidazoles ; adverse effects ; therapeutic use ; Benzoates ; adverse effects ; therapeutic use ; Blood Pressure ; drug effects ; China ; Creatinine ; blood ; Female ; Glomerular Filtration Rate ; drug effects ; Glomerulonephritis, IGA ; blood ; drug therapy ; Humans ; Isoxazoles ; adverse effects ; therapeutic use ; Kidney Function Tests ; Male ; Middle Aged ; Prospective Studies ; Ticlopidine ; adverse effects ; analogs & derivatives ; therapeutic use ; Treatment Outcome ; Uric Acid ; blood ; Young Adult

OBJECTIVETo investigate the impact of novel P2Y(12) receptor inhibitors including prasugrel or ticagrelor on platelet reactivity in patients with acute coronary syndrome (ACS) receiving percutaneous coronary intervention (PCI), and provide clinical data for novel oral P2Y(12) receptor inhibitors use among Chinese patients.

METHODSBetween October 2011 to February 2014, 174 consecutive patients (135 males; (67.8±11.8) years old) with ACS undergoing PCI in Kiang Wu Hospital, Macau were prospectively enrolled in this study. Oral aspirin and one P2Y(12) receptor inhibitor were administered for 5 days or above after PCI, patients were divided into clopidogrel, prasugrel and ticagrelor groups in accordance with the agent administered. Platelet reactivity of the patients was detected by VerifyNow P2Y(12) reaction unit (PRU); and the high on-treatment platelet reactivity (HPR) and non-HPR were defined as PRU≥208 and PRU<208 respectively. Patients with HPR during clopidogrel therapy were switched either to prasugrel or ticagrelor, or continued the same treatment; and then the platelet reactivity was monitored again.

RESULTSThere were 113 clopidogrel cases (64.9%), 20 prasugrel cases (11.5%) and 41 ticagrelor cases (23.6%). Fifty-seven cases (32.8%) were defined as HPR post P2Y(12) receptor inhibitor use, in which 55 cases (55/113, 48.7%) were treated with clopidogrel. The degree of inhibition of platelet reactivity was significantly different in patients on clopidogrel, prasugrel and ticagrelor therapy, percent inhibition assayed by the VerifyNow P2Y(12) system was 28.2%±23.5%, 61.4%±26.7% and 81.3%±19.8% respectively (P<0.05). Different degree of platelet reactivity was achieved by the 3 P2Y(12) receptor inhibitors at multiple time points. The among-group differences in platelet reactivity became apparent at the early treatment stage (P<0.05). Platelet aggregation decreased significantly in patients switched from clopidogrel to prasugrel or ticagrelor (P<0.05).

CONCLUSIONNovel oral P2Y(12) receptor inhibitors are more effective in inhibiting platelet reactivity in ACS patients, and our results show that novel oral P2Y(12) receptor inhibitors provide a new option for ACS patients with HPR post clopidogrel or high-risk features of ischemic complications, including stent thrombosis and post-PCI ischemic events.

Acute Coronary Syndrome ; Adenosine ; analogs & derivatives ; Aged ; Aspirin ; Blood Platelets ; Female ; Humans ; Male ; Percutaneous Coronary Intervention ; Platelet Aggregation ; Platelet Aggregation Inhibitors ; Platelet Function Tests ; Prasugrel Hydrochloride ; Prospective Studies ; Ticlopidine ; analogs & derivatives

OBJECTIVETo evaluate the value of a new platelet function test PFA P2Y (PFA-200) in monitoring clopidogrel treatment for cardiovascular disease in elderly patients.

METHODSFifty-six elderly patients receiving clopidogrel therapy in the Department of Cardiology of General Hospital of PLA from March to August in 2016 and 85 healthy volunteers were recruited for analysis. All the subjects underwent PFA P2Y, LTA (light transmittance aggregometry) and TEG (Thromboelastograph) tests, and Spearman correlation coefficients were used to test the associations between test results. The agreement among the 3 platelet function test methods was assessed using Cohen's kappa coefficient.

RESULTSCorrelation coefficient (r) was -0.701 (P<0.001) between PFA P2Y and LTA, and 0.475 (P<0.001) between PFA P2Y and TEG. The agreement was 75% between PFA P2Y and LTA and 67.9% between PFA P2Y and TEG. The κ value was 0.434 (P=0.001) between PFA P2Y and LTA and 0.242 (P=0.046) between PFA P2Y and TEG. With ADP-induced maximum platelet aggregation rate of LTA >50% as the laboratory clopidogrel resistance, the cut-off value of PFA P2Y was 119 s (AUC=0.733) with a sensitivity of 75.6% and a specificity of 73.3%.

CONCLUSIONPFA P2Y has a moderate correlation and agreement with LTA, but has a poor correlation and agreement with TEG. PFA P2Y can be useful for assessing the effects of clopidogrel therapy and the association of the cut-off value (119 s) with the long-term clinical ischemic events needs be confirmed in further study.

Biological Assay ; Blood Coagulation Tests ; Blood Platelets ; Cardiovascular Diseases ; drug therapy ; Humans ; Platelet Aggregation ; Platelet Aggregation Inhibitors ; therapeutic use ; Platelet Function Tests ; Sensitivity and Specificity ; Ticlopidine ; analogs & derivatives ; therapeutic use

OBJECTIVETo investigate the relationship between plasma cytochrome P450 3A4 (CYP3A4) 894C>T gene polymorphism and the risk of recurrence of adverse cardiac events after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS).

METHODSA total of 275 patients with ACS received standard dual antiplatelet therapy and PCI. Platelet aggregation rate (PAR) was detected in each patient before and 7 days after administration of the anti-platelet drugs. Single nucleotide polymorphism of CYP3A4 gene 894C>T was detected with PCR and microarray technique. The number of coronary artery lesions was determined by PCI and the Gensini score was calculated. The patients were followed up for 3-12 months after discharge.

RESULTSNo significant difference was found in CYP3A4 gene polymorphism between patients with clopidogrel resistance (CR group) and those without CR (NCR group) (P>0.05). Multivariate logistic regression analysis showed that CYP3A4 gene 894C>T polymorphism was not correlated with CR in patients with ACS (OR 1.359, P>0.05). During the follow-up, the incidence of cardiovascular events was significantly higher in CR group than in NCR group (P<0.05), but this difference was not related to the mutation type of 894C>T locus of CYP3A4 gene.

CONCLUSIONThe CYP3A4 gene 894C>T polymorphism is not associated with the effect of anti-platelet therapy and the risk of cardiovascular event in patients with ACS following PCI.

Acute Coronary Syndrome ; therapy ; Alleles ; Blood Platelets ; Cytochrome P-450 CYP3A ; genetics ; Humans ; Percutaneous Coronary Intervention ; Platelet Aggregation ; Platelet Aggregation Inhibitors ; therapeutic use ; Platelet Function Tests ; Polymorphism, Single Nucleotide ; Ticlopidine ; analogs & derivatives ; therapeutic use

OBJECTIVETo assess the association of genetic polymorphisms of CYP2C19*2,*3,*17 with the recurrence risk of ischemic stroke during clopidogrel prevention in ethnic Han Chinese from Fujian Province.

METHODSClinical data of 985 patients with acute ischemic stroke was collected. After 1 year postdischarge follow-up evaluations, only 114 patients with persistence of clopidogrel were enrolled. CYP2C19 genetic polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)and direct sequencing ,then we analysis the correlation between polymorphisms and the recurrence of stroke.

RESULTSAmong the 114 patients, 23 had a second onset whilst receiving clopidogrel treatment. During the antiplatelet therapy with clopidogrel, carriers of CYP2C19 poor metabolizer (CYP2C19*2/*2 or *2/*3) had a higher rate of recurrent stroke compared with extensive metabolizers (CYP2C19*1/*1) (OR=4.71, 95%CI: 1.18-18.80, P<0.05). Carriers of CYP2C19 *2 mutant allele had increased recurrence compared with those carrying none loss-of-function allele (OR=2.31, 95%CI: 1.20-4.46, P<0.05). The rate of recurrent stroke in those carrying homozygous mutant *2 allele (CYP2C19*2/*2) was 6.14 times greater than the rate of wild-type homozygotes (CYP2C19*1/*1) (95%CI: 1.54-24.54, P<0.05). Patients with previous stroke history had increased risk of recurrence (OR= 4.146, 95%CI: 1.259-13.655, P<0.05). However, CYP2C19*17 was not detected in the group.

CONCLUSIONFor ethnic Han Chinese patients receiving clopidogrel treatment, carriers of poor metabolizer or homozygous mutant *2 allele (CYP2C19*2/*2) have a higher risk of recurrent stroke. The CYP2C19 *2 allele is an independent risk factor for recurrent stroke. Those with previous history of stroke are more prone to the recurrence.

Aged ; Alleles ; Asian Continental Ancestry Group ; genetics ; Brain Ischemia ; complications ; ethnology ; China ; Cytochrome P-450 CYP2C19 ; genetics ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; ethnology ; genetics ; Genotype ; Humans ; Linkage Disequilibrium ; Logistic Models ; Male ; Middle Aged ; Platelet Aggregation Inhibitors ; therapeutic use ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Recurrence ; Risk Factors ; Sequence Analysis, DNA ; Stroke ; ethnology ; etiology ; genetics ; prevention & control ; Ticlopidine ; analogs & derivatives ; therapeutic use ; Time Factors