Study On The Relationship Between Clopidogrel Metabolic Key Enzyme Gene Polymorphism And Clopidogrel Resistance

Part1. The polymorphic distribution of Clopidogrel metabolism key enzyme gene and the clinical phenotypic characteristicsObjective: To detect polymorphic distribution of Clopidogrel metabolism enzyme gene of ACS patients in Northeast Sichuan.Methods: 125 ACS patients, who visited the Department of Cardiology of Nanchong Central Hospital from February 2014 to January 2015, were recruited. The general clinical information, laboratory parameters, and medications of all the patients were collected. 2 m L blood sample was taken and then stored in freezer of-80 oC for each patient after they signed the informed consent form. The CYP2C19(681G>A, rs4244285, 636G>A, rs4986893), ABCB1(C3435T, rs1045642), and PON1(192Q>R, rs662) of all patients were detected with PCR-RFLP to count minor allele frequency of all the sits. According to the number of non-functional genes on CYP2C19, the patients can be divided into Normal metabolizers(CYP2C19*1/*1), intermediate metabolizers(CYP2C19*1/*2, CYP2C19*1/*3), and weak metabolizer(CYP2C19*2/*2, CYP2C19*2/*3, CYP2C19*3 /*3); According to the CC, CT, TT genes carried on ABCB1(C3435T) the patients can be divided into high expression type, intermediate expression type, and low expression type; According to CC, CT, TT genes carried on PON1(Q192R), the patients can be divided into high expression type, intermediate expression type, and low expression type. The proportions of each phenotype were calculated.Results: The clinical data, laboratory parameters, and other drugs applicationof the 125 patients while in hospital: The 125 patients were between 26 and 75 years old, with a mean age 62.2±9.18 years; 86 of the 125 patients were male(68.8%), and 39 female(31.2%); the patient height was between 151 and 192 cm, with an average height 165.7±10.16 cm; and the patient weight was between 41.4 and 92.6 kg, with an average weight 67.7±13.4 kg. 84 patients had hypertension(60.7%), and 37 patients had diabetes(24.7%). 58 patients were smoker(48%). The average cholesterol in all patients was 4.68±1.29 mmol/L. The average triglycerides was 1.80 ±1.21 mmol/L. The average low-density lipoprotein was 2.6±21.31 mmol/L. The average high-density lipoprotein was 1.33±0.99 mmol/L. The mean body mass index was 25.85 ± 4.63 kg / m2. And the mean platelet desity was 192.4±51.5x109 L-1. In the 125 patients, 81 had STEMI(64.7%), 28 had NSTEMI(22.6%), and 16 had UA(12.7%). 115 of the 125 patients used statins(92.7%), 110 usedβ-blockers(87.3 %), 112 used ACEI / ARB(90%), and 67 used PPI(53.3%).Genetic polymorphic distribution of CYP2C19, ABCB1, PON1: The GG, GA, AA genotypes on CYP2C19*2 were: 50 cases(40.0%), 61 cases(48.8%), and 14 cases(11.2%), respectively. The frequency of allele G and A on CYP2C19*2 was: 0.644 and 0.356, respectively. MAF was 0.356. The GG, GA, AA genotypes on CYP2C19*3 were: 79 cases(63.2%), 39 cases(31.2%), and 7 cases(5.6%). Frequency of allele G and A on CYP2C19*3 was: 0.788 and 0.212, respectively. MAF was 0.212. The CC, CT, TT genotypes on ABCB1(C3435T) were: 45 cases(36.0%), 60 patients(48.0%), and 29(16.0%). The frequency of C and T on ABCB1(C3435T) was: 0.600, and 0.400, respectively.MAF was 0.400 The CC, CT, TT genotypes on PON1(Q192R) were: 51 cases(40.8%), 52 cases(41.6%), and 22 cases of type(17.6%), respectively. The frequency of T and C on PON1(Q192R) was: 0.384 and 0.616, respectively. MAPFwas 0.384The clinical phenotypical distribution of CYP2C19, ABCB1, PON1 genes: CYP2C19: the number of wild type cases(CYP2C19*1/*1), intermediate metabolizers cases(CYP2C19*1/*2, CYP2C19*1/*3), weak metabolizer cases(CYP2C19*2/*2, CYP2C19*2/*3, CYP2C19*3/*3) was: 29, 60, and 39, respectively. The proportion of each was: 20.8%, 40.8%, and 31.2% respectively. During the intermediate metabolizers, the number of cases with CYP2C19*1/*2, CYP2C19*1/*3 was 43 and 17 respectively. The proportion was 34.4%, and 13.6%, respectively. During the weak metabolizer, the number of cases with CYP2C19*2/*2, CYP2C19*2/*3, CYP2C19*3/*3 was 14, 18, and 7, respectively. The proportion was 11.2%, 14.4%, and 5.5%, respectively.Conclusion: The CYP2C19(681G> A, 626G> A), PON1(Q192R), ABCB1(C3435T) genotypic distribution of ACS patients in this research consist with the previous report. Compared with western people, the frequency of LOF on CYP2C19 is higher, the allele genes related with poor metabolism of clopidogrel PON1(Q192R), ABCB1(C3435T) have low frequency.Part 2. The Association study of genetic polymorphism on CYP2C19 * 2, * 3, ABCB1(C3435T), PON1(Q192R) and clopidogrel resistanceObjective: To detect the relationship between the genetic polymorphism on ABCB1, CYP2C19, PON1 and clopidogrel resistance.Methods : 125 ACS patients, who visited the Department of Cardiology of Nanchong Central Hospital from February 2014 to January 2015, were recruited. Venous blood samples were collected before and after clopidogrel were taken. The venous blood samples were stored in the sodium citrate anticoagulation tube edge. LTA was used to detect platelet aggregation capability in each sample. The samples were divided into CR group and NCR group according to the aggregation force of residual platelet. The allele genes on CYP2C19, ABCB1, PON1 were counted to investigate the possibility of statistical significance.Results: The foundation platelet aggregation force before taking clopidogrel was 48.72 ± 14.32%, and after taking clopidogrel the residual platelet aggregation force was 26.34 ± 15.37%. According to the definition of clopidogrel resistance, 27 cases were defined as CR and 98 cases NCR. The proportion was 21.6% and 78.4% respectively. The clinical data, laboratory tests, and medications of CR and NCR groups did not have any statistical significance. The GG, GA, AA genotypes on CYP2C19 * 2 in CR group were: 8 cases, 12 cases, and 7 cases, respectively. The allele frequency of A was 0.481. The GG, GA, AA genotypes on CYP2C19 * 2 in NCR group were: 42, 49, and 7 cases, respectively. The allele frequency of A was 0.321. The difference of allele frequency of A on CYP2C19 * 2 between CR and NCR group hasstatistical significance(P =0.03). The GG, GA, AA genotypes on CYP2C19 * 3 in CR were: 12 cases, 11 cases, and 4 cases. The allele frequency of A was 0.352. The GG, GA, AA genotypes on CYP2C19 * 3 in NCR group were: 67, 28, and 3 cases. The allele frequency of A was 0.033. The difference of allele frequency of A on CYP2C19 * 3 between CR and NCR group has statistical significance(P =0.005). The CC, CT, TT genotypes on ABCB1(C3435T) in CR group were: 9 cases, 13 cases, and 5 cases, respectively. The frequency of allele T was 0.426. The CC, CT, TT genotypes on ABCB1(C3435T) in NCR group were: 36, 47, and 15. The frequency of allele T was 0.369. Frequency differences of allele T on ABCB1(C3425T) between CR group and NCR group did not have statistical significance(P=0.661).The CC, CT, TT genotypes on PON1(Q192R) in CR group were: 10 cases, 12 cases, and 5 cases. The frequency of allele Q was 0.497. The CC, CT, TT genotypes PON1(Q192R) in NCR group were: 41, 40, and 17. The frequency of allele Q was 0.378. The frequency difference of allele T on PON1(Q192R) between CR group and the NCR group did not have statistical significance(P=0.690).Conclusion: Clopidogrel resistance correlates with the CYP2C19*2 、 CYP2C19*3 genotypes, Patients who are carrying loss of function of CYP2C19 gene more likely occur CR; and clopidogrel resistance does not correlate with gene polymorphism of ABCB1(C3435T), PON1(Q192R).