肾移植中环孢素的血药浓度与多药耐药基因多态性的关系

目的 探讨肾移植术后患者的MDR1C3435T、G2677T/A和C1236T位点的基因多态性对环孢素(CsA)血药浓度的影响.方法 使用荧光偏振免疫分析法(AxsYM)测定65例肾移植患者在术后1 wk和1 mo时的CsA血药浓度(包括峰浓度ρ2和谷浓度ρ0),使用等位基因特异扩增法(ASA-PCR)对患者进行MDR1基因分型,比较不同基因型之间CsA浓度剂量比的差异.结果 在65例患者中,C3435T,CC型25例(38.5%),CT型35例(53.8%),TT型5例(7.7%);G2677T/A,GG型15例(23.1%),GT型21例(32.3%),TT型10例(15.4%),GA型12例(18.5%),AT型6例(9.2%),AA型1例(1.5%);C1236T,CC型10例(15.4%),CT型32例(49.2%),TT型23例(35.4%).C3435T的CT型患者的CsA浓度剂量比略大于CC型和TT型;G2677T/A的从型患者的CsA浓度剂量比略大于其他基因型;C1236T的TT型患者的谷浓度剂量比略大于CC型和CT型,CC型患者的峰浓度剂量比略大于CT型和TT型,但差异均无统计学意义(P＞0.05).结论 在肾移植患者中,MDR1多态性与CsA血药浓度无明显相关性,有待进一步确认.     

ABCB1基因多态性对肾移植受者环孢素血浓度的影响

目的:研究肾移植术后患者ABCB1基因多态性对环孢素（CsA）血浓度的影响。方法:采用PCR-RFLP（聚合酶链反应-限制性片段长度多态性）方法对339名服用CsA的肾移植患者进行ABCB1基因1236C>T、2677G>T/A和3435C>T多态性检测,荧光偏振免疫法检测肾移植患者CsA血浓度。结果:在339名肾移植患者中,ABCB1基因1236C>T、2677G>T/A和3435C>T突变等位基因频率分别为64.25%、51.54%和35.75%。ABCB1 1236C>T基因多态性检测显示,在移植术后1年,CC基因型个体的CsA血谷浓度明显高于CT和TT基因型个体（P<0.05）。2677G>T/A基因多态性检测提示,在移植术后7d,杂合子GA+GT基因型携带者的C₀高于GG和AA+TT+AT基因型携带者（P<0.05）。3435C>T基因多态性检测表明:在移植术后3个月,突变纯合子TT基因型携带者的C₀低于CC和CT基因型携带者（P<0.05）。其余各时间点,上述3种基因多态性对CsA血谷浓度无明显影响（P>0.05）。结论:ABCB1基因1236C>T、2677G>T/A和3435C>T多态性对极少数时间点的CsA浓度有影响,但对绝大多数时间点的环孢素浓度无影响。     

多药耐药基因多态性和单倍体对肾移植患者他克莫司血药浓度的影响

目的 研究多药耐药基因(MDR1)单核苷酸多态性及单倍体对中国汉族肾脏移植人群术后稳定期与他克莫司(免疫抑制剂)血药浓度的关系.方法 用基质辅助激光吸收电离子化-飞行时间质谱技术,分析63例肾移植患者的MDR1 exon12 C1236T、exon 21 G2677T/A、exon 26 C3435T的基因型,结合其口服他克莫司12 h后血药浓度,判断两者是否存在关联.结果 MDR1 C3435T基因多态性与他克莫司血药浓度/(剂量×体表面积)具有相关性,比值由小到大顺序:野生型纯合子＜杂合子＜突变型纯合子,差异具有统计学意义(P＜0.05).MDR1 C1236T、G2677T/A及单倍体型各组之间比较均无明显差异.结论 中国汉族肾移植患者稳定期,MDR1 C3435T与他克莫司血药浓度的个体差异具有相关性.     

中国朝鲜族人群MDR1基因多态性与环孢素A谷浓度的相关性研究

目的:研究中国朝鲜族肾移植术后患者服用环孢素A(CsA)的谷浓度与多药耐药基因(MDR1)C3435T多态性的相关性。方法:选择中国朝鲜族同种异体肾移植术后患者75例,采用聚合酶链反应(PCR)扩增MDR1C3435T基因,利用DNA限制性片段长度多态性(RFLP)方法对MDR1C3435T基因进行分型,结合口服CsA的谷浓度,判断二者是否存在关联。结果:75例患者中,C/C型31例(41.3%),C/T型37例(49.3%)和T/T型7例(9.3%)。C3435T基因多态性与CsA谷浓度差异无统计学意义(P>0.05)。结论:C3435T基因多态性可能不是影响中国朝鲜族肾移植术后患者CsA谷浓度的主要因素。     

MDR1基因多态性和单倍体对肾移植术后稳定期患者他克莫司浓度/剂量比值的影响

目的 探讨MDR1 C1236T、G2677T/A和C3435T 基因多态性和单倍体对中国汉族肾移植术后稳定期患者他克莫司浓度/剂量比值的影响,为他克莫司个体化用药提供依据。方法 采用PCR-基因测序法检测104例肾移植术后稳定期患者MDR1 C1236T、G2677T/A和C3435T 的基因多态性,采用均相酶免疫测定方法(EMIT法)测定他克莫司的谷浓度,比较不同基因型患者之间他克莫司血药浓度/(剂量×体质量)(C/D)比值。结果 104例患者中,MDR1 C1236T、G2677T/A和C3435T突变频率分别为56.73%、55.77%和33.17%。MDR1 C3435T、MDR1 TTT单倍体与他克莫司C/D比值具有相关性(P<0.05)。CYP3A5*3*3患者中,MDR1 TTT单倍体与他克莫司C/D比值仍存在显著相关(P<0.05)。MDR1 C1236T、G2677T/A、CGC单倍体与他克莫司C/D比值无显著性差异(P>0.05)。结论 MDR1 C3435T、MDR1 TTT单倍体与中国汉族肾移植术后稳定期患者他克莫司C/D比值具有显著相关性,是影响肾移植患者他克莫司浓度个体化差异的重要因素。     

中国汉族肾移植术后稳定期患者MDR1基因多态性与口服环孢素A谷质量浓度的相关性探讨

目的研究中国汉族肾移植术后稳定期(>1 a)患者服用环孢素A(cyclosporine A,CsA)的谷质量浓度与多耐药基因(multidrug resistance gene,MDR1)C3435T多态性的相关性。方法采用聚合酶链反应结合限制性片段长度多态性(PCR-RFLP)分析法检测87例肾移植术后患者MDR1C3435T基因多态性,结合口服环孢素A的谷质量浓度,判断二者是否存在关联。所有血样均为肾移植术后稳定期患者的血样。结果 87例患者中,C/C型36例(41.4%),C/T型42例(48.3%)和T/T型9例(10.3%)。87例患者CsA谷质量浓度的均值为(169.5±71.8)μg.L-1(中位数为157.4μg.L-1;范围为76.6~410.9μg.L-1)。C3435T基因多态性与CsA谷质量浓度无显著性差异(P>0.05)。结论 C3435T基因多态性不是影响中国肾移植稳定期患者口服CsA谷质量浓度的主要因素。     

MDR1C1236T基因多态性对环孢素药代动力学影响的系统评价

目的 系统评价MDR1C1236T基因多态性与环孢素(免疫抑制剂)药代动力学的相关性.方法 计算机检索相关数据库,收集MDR1C1236T基因多态性与环孢素药代动力学的相关性研究.用Revman 5.0软件对符合纳入标准的研究进行荟萃分析.结果 共纳入7篇回顾性研究(n=605).分析显示,CC基因型患者给药后2 h,剂量调整浓度明显低于其他基因型;但仅与TT基因型组有统计学差异(P＜0.05),剂量调整谷浓度及平均日剂量与其他基因型问均无统计学差异.结论 MDRI C1236T基因多态性对环孢素给药后2 h剂量调整浓度有一定影响.     

江苏地区汉族儿童多药耐药基因3个单核苷酸多态性位点的单倍型研究

目的 分析江苏汉族人群多药耐药基因-1(MDR1)的单核甘酸多态(12外显子1236 C→T突变、21外显子2677G→T/A突变、26外显子3435C→T突变)及其构成的单倍型分布.方法 通过多重单碱基延伸反应(SNaPshot SNP分型技术)对江苏地区170名健康儿童的MDR1 C1236T、G2677T/A、C3435T的SNP位点进行基因分型,统计各基因型频率.UNPHASED软件对MDR1的SNPs(C1236T-G2677T/A-C3435T)进行单倍型分析.结果 在170例儿童中,等位基因1236T、2677T、2677A、3435T频率分别为63.5%、37.4%、17.0%和35.0%.基因型频率分布符合Hardy-Weinberg平衡(HWE),差异无统计学意义(P>0.05).MDR1的1236、2677、3435三个位点间(C1236T-G2677T/A-C3435T)存在连锁不平衡性,以TTT(31.8%)、TGC(25.3%)、CGC(17.7%)和CAC(16.2%)四种单倍型为主.结论 江苏地区汉族人群MDR1的单核甘酸多态及单倍型分布具有自己的特点.在临床应用相关药物时,进行基因型及单倍型检测,将有助于指导临床个体化用药.     

药物代谢酶CYP3A和多药耐药基因在中国肾移植人群的遗传多态性

目的 建立基质辅助激光解吸电离飞行时间质谱技术(MASS ARRAY)测定中国肾移植人群的CYP3A5*3、CYP3AP1和多药耐药基因(MDR1)的多态性.方法 用MASS ARRAY技术对60例中国肾移植人群的CYP3AS*3、CY3AP1和MDR1位点进行基因分型.结果 CYP3A5*I等位基因占25.9%,*3等位基因占74.1%,CYP3AP1 A等位基因占26.7%,G等位基因占73.3%,MDR1 C1236T、G2677T/A、C3435T个体突变频率分别为65.6%、38.3%、36.6%.结论 中国肾移植人群中CYP3A5*3、CYP3AP1和MDR1位点存在遗传多态性,影响不同个体药物代谢酶活性和药物代谢.     

CYP3A5和MDR1基因多态性对中国肝移植患者他克莫司药动学的影响

目的探讨细胞色素P450酶3A5（CYP3A5）基因和多药耐药基因（MDR1）C1236T、G2677T／A、C3435T多态性对肝移植患者口服他克莫司（TAC）后体内药动学参数的影响。方法采集28例肝移植患者手术后第1周和第3周血标本,采用LC—MS／MS法检测TAC血药浓度,计算主要药动学参数。采用聚合酶链反应结合基因测序分析28例肝移植患者CYP3A5＊3和MDR1主要基因型。结果携带MDR1 3435T基因型的肝移植患者口服TAC后,药动学参数AUC0→1和ρmax明显高于3435CC型患者,而CYP3A5＊3、MDR1 C1236T和G2677T／A基因多态性对TAC的药动学参数无明显影响。结论携带MDR1 3435T基因型肝移植患者比3435CC型患者需要较高剂量才能达到目标浓度。     

The effect of CYP3A5 and MDR1 polymorphic expression on cyclosporine oral disposition in renal transplant patients

Variability in CYP3A (CYP3A4/5) and P-glycoprotein (human MDR1 gene product) activity underlies interindividual differences in oral cyclosporine (CsA) bioavailability. Racial differences in polymorphic expression of CYP3A5 and MDR1 may explain observed interracial variability in oral bioavailability. Our objective was to evaluate the effect of CYP3A5 and MDR1 polymorphic expression on CsA oral disposition. Steady-state plasma concentration profiles (n = 19) were sampled in renal transplant recipients receiving concentration-adjusted CsA maintenance therapy. CsA plasma concentrations were measured by fluorescence polarization immunoassay. CYP3A5 and MDR1 genotypes were determined by real-time polymerase chain reaction. Noncompartmental pharmacokinetic analysis and nonlinear mixed-effects modeling (NONMEM) were performed to assess the effect of genotype on CsA pharmacokinetics. MDR1 C3435T genotype was identified as the best predictor of CsA systemic exposure. CsA oral clearance was significantly higher in subjects who carried at least one 3435T allele compared to homozygous wild-type individuals (40.0 +/- 2.2 vs. 26.4 +/- 3.1 L/h, p = 0.007). MDR1 C3435T genotype accounted for 43% of the interindividual variability of CsA oral clearance in the study population after accounting for interoccasion variability. The authors were unable to independently assess whether CYP3A5 correlated with any CsA pharmacokinetic parameter since all CYP3A5 nonexpressors were also 3435T allele carriers. MDR1 3435T allele carriers have enhanced oral clearance compared to individuals with the CC genotype. The frequency of the 3435T allele is lower in African Americans compared to Caucasians. Thus, the MDR1 C3435T genotype offers a potential mechanistic basis to explain interracial differences in CsA oral bioavailability. Further studies are needed to explore the relationship between CYP3A5 and MDR1 genotype and phenotype.     

MDR1 haplotypes derived from exons 21 and 26 do not affect the steady-state pharmacokinetics of tacrolimus in renal transplant patients

AIM: This retrospective study investigated the influence of MDR1 haplotypes derived from the polymorphisms 2677G > T (exon 21) and 3435C > T (exon 26) on the pharmacokinetics of the immunosuppressant drug tacrolimus in 73 renal transplant patients. METHODS: Based on both variants of SNPs 2677 and 3435, four different haplotypes and eight different genotypes were identified in the study sample. Tacrolimus trough concentrations (C(0)) were compared between different SNP variants and genotypes, as well as between carriers and noncarriers of each haplotype. Additionally, CYP3A5 genotype (6956G > A) was determined. RESULTS: No significant differences were observed between groups. Differences in mean tacrolimus C(0) values between carriers and noncarriers of each haplotype ranged from -0.04 microg/litre (95% confidence interval: -0.53 to 0.60) to -23 microg/litre (-1.07 to 1.53). No association was found between CYP3A5*1/*3 genotype and tacrolimus Co concentractions. CONCLUSION: MDR1 haplotypes derived from the SNPs 2677G > T (exon 21) and 3435C > T (exon 26) do not influence the pharmacokinetics of tacrolimus in renal transplant patients.     

MDR1基因多态性对口服环孢素A药代动力学的影响

目的非线性混合效应模型(NONMEM)考察中国健康人多药耐药基因(MDR1)中26外显子的C3435T多态性与环孢素A (CsA)药代动力学特性间的关系。方法HPLC法测定20名健康男性单次口服CsA微乳溶液制剂500 mg后24 h内不同时间点的药物浓度。MDR1的基因多态性测定采用DNA限制性片段长度多态性法，并用基因测序法验证。数据处理与模型拟合采用NONMEM法。结果中国健康人中含MDR1 C3435T CC或CT型的相对生物利用度较TT型高40%。结论MDR1中C3435T多态性是个体间CsA相对生物利用度差异的影响因素。     

Effect of genetic polymorphisms of CYP3A5 and MDR1 on cyclosporine concentration during the early stage after renal transplantation in Chinese patients co-treated with diltiazem

Objective  The aim of this study was to assess the influence of the cytochrome (CYP450)3A5 and multidrug resistance (MDR1) gene polymorphisms on cyclosporine A (CsA) trough concentration during the early stage after renal transplantation in Chinese patients co-treated with diltiazem. Methods   CYP3A5*3 (A6986G) and MDR1 C1236T, G2677T/A and C3435T polymorphisms were determined by PCR followed by restriction fragment length polymorphism (RFLP) analysis. A total of 112 Chinese renal transplant patients were enrolled in the study. The whole blood trough concentration was measured at 7 days after transplantation, and the dose-adjusted trough levels were compared among the different genotypes. Results  The dose-adjusted trough levels of CsA were significantly higher in MDR1 2677TT carriers than in GG plus GT carriers (59.5 ± 15.9 vs. 34.5 ± 9.4 vs. 43.2 ± 13.6 ng/mL per mg per kg; P < 0.0001). In patients who were co-treated with diltiazem, compared with carriers of haplotype T-T-C, the carriers of haplotype C-G-C and haplotype T-G-T had significantly lower dose-adjusted trough blood concentrations of CsA than the non-carrier group (P = 0.002, P = 0.000 and P = 0.000, respectively). However, no evidence was found that there was a relationship between the CYP3A5*3, MDR1 C1236T and MDR1 C3435T polymorphisms and CsA dose-adjusted trough concentrations. Conclusion  This study demonstrated that the G2677T/A single nucleotide polymorphisms in MDR1 and MDR1 haplotypes C-G-C, T-G-T and T-T-C are associated with the CsA concentration during the very early post-transplant period in Chinese renal transplant patients co-treated with diltiazem. These polymorphisms may be useful for determining the appropriate initial dose of CsA after renal transplantation.     

MDR1 haplotypes do not affect the steady-state pharmacokinetics of cyclosporine in renal transplant patients

This retrospective study investigated the impact of MDR1 haplotypes derived from the single-nucleotide polymorphisms (SNPs) 2677G>T (exon 21) and 3435C>T (exon 26) on the pharmacokinetics of cyclosporine in 98 renal transplant patients. Based on SNPs 2677 and 3435, four different haplotypes and nine different genotypes were identified in the study sample. Frequencies of SNPs, genotypes, and haplotypes were in agreement with previously reported values. Cyclosporine pharmacokinetics were characterized using a 2-hour AUC (AUC0-12), trough concentrations (C0), and blood concentrations 2 hours after cyclosporine administration (C2). No significant differences in dose-corrected AUC0-12, C0, or C2 values were observed between carriers of different SNP variants and genotypes (Kruskal-Wallis test), as well as between carriers and noncarriers of each haplotype (Mann-Whitney U test). Carriers of haplotype 12 (2677G and 3435T), which has previously been associated with increased digoxin AUC values, had a median AUC0-12 of 18.9 micro g*h*L-1 (range: 9.0-35.2) compared to 17.5 micro g*h*L-1 (range: 7.5-37.1) in the noncarrier group. It was concluded that MDR1 haplotypes derived from the SNPs 2677G>T (exon 21) and 3435C>T (exon 26) are not associated with cyclosporine pharmacokinetics in renal transplant patients.     

Diltiazem augments the influence of MDR1 genotype status on cyclosporine concentration in Chinese patients with renal transplantation

Aim:

Co-administration of diltiazem can reduce the dosage of cyclosporine (CsA) in patients with renal transplantation. In this study, we investigated how diltiazem altered the relationship between MDR1 genetic polymorphisms and CsA concentration in Chinese patients with renal transplantation.

Methods:

A total of 126 renal transplant patients were enrolled. All the patients received CsA (2–4 mg·kg⁻¹·d⁻¹), and diltiazem (90 mg/d) was co-administered to 76 patients. MDR1-C1236T, G2677T/A, and C3435T polymorphisms were genotyped. The whole blood concentration was measured using the FPIA method, and the adjusted trough concentrations were compared among the groups with different genotypes.

Results:

In all patients, MDR1-C1236T did not influence the adjusted CsA trough concentration. With regard to MDR1-3435, the adjusted CsA trough concentration was significantly higher in TT carriers than in CC and CT carriers when diltiazam was co-administered (58.83±13.95 versus 46.14±7.55 and 45.18±12.35 ng/mL per mg/kg, P=0.011), and the differences were not observed in patients without diltiazam co-administered. With regard to MDR1-2677, the adjusted CsA trough concentration was significantly higher in TT carriers than in GG and GT carriers when diltiazam was co-administered (61.31±12.93 versus 52.25±7.83 and 39.70±7.26 ng/mL per mg/kg, P=0.0001). The differences were also observed in patients without diltiazam co-administered (43.27±5.95 versus 35.22±7.55 and 29.54±5.35 ng/mL per mg/kg, P=0.001). The adjusted CsA trough blood concentration was significantly higher in haplotype T-T-T and haplotype T-T-C carriers than in non-carriers, regardless of diltiazem co-administered.

Conclusion:

MDR1 variants influence the adjusted CsA trough concentration in Chinese patients with renal transplant, and the influence more prominent when diltiazem is co-administered.     

Association of MDR1, CYP3A4*18B, and CYP3A5*3 polymorphisms with cyclosporine pharmacokinetics in Chinese renal transplant recipients

Objective  The objective of this study was to retrospectively evaluate the effects of MDR1, CYP3A4*18B, and CYP3A5*3 genetic polymorphisms on cyclosporine A (CsA) pharmacokinetics in Chinese renal transplant patients during the first month after transplantation. Methods  A total of 103 renal transplant recipients receiving CsA were genotyped for MDR1 (C1236T, G2677T/A, and C3435T), CYP3A4*18B, and CYP3A5*3. The predose and 2-h postdose concentrations of CsA (C₀ and C₂, respectively) were determined by fluorescence polarization immunoassay, and their relationships with corresponding genotypes and haplotypes were investigated. Results  Patients with a CYP3A4*1/*1 genotype were found to have a higher dose-adjusted concentration compared with those with CYP3A4*18B/*18B, as follows: for C₂, 19.3% (P = 0.008) during days 8-15, 35.2% (P = 0.008) during days 16–30, and for C₀, 39.7% (P = 0.012) during days 16–30. The dose-adjusted C₀ was higher in patients with MDR1 1236CC compared with those with 1236TT in the first month postoperation. The dose-adjusted C₀ in patients with the CYP3A5*3/*3 genotype was 25.5% and 30.7% higher than those with the wild-type genotype during days 8–15 (P = 0.011) and days 16–30 (P = 0.015), respectively. Haplotype analysis revealed that the dose-adjusted C₀ was higher in the first month following surgery in carriers of haplotype MDR1 CAC than in noncarriers. Polymorphisms of MDR1 and CYP3A5*3 did not affect dose-adjusted C_2. Conclusion  The data suggests that the CYP3A4*18B genotype affects CsA pharmacokinetics during the first month following surgery in Chinese renal transplant recipients. Patients with CYP3A4*18B alleles may require higher doses of CsA to reach the target levels. Large prospective studies may be needed to further explore the impact of MDR1 and CYP3A5*3 polymorphisms on CsA pharmacokinetics in renal transplant recipients.     

环孢霉素A在服药患者血浆中的分布

目的了解环孢霉素A在服药患者血浆中的分布。方法检测26例肾移植患者CsA全血及血浆谷值浓度和24例。肾移植患者CsA全血及血浆峰值浓度。结果26例。肾移植患者CsA全血及血浆谷值浓度分别为（84．89±43．04）μg·L-1、（15．46±7．34）μg·L-1,24例肾移植患者CsA全血及血浆峰值浓度分别为（606．63±167．10）μg·L-1、（188．39±105．86）μg·L-1。结论血液中的CsA主要同血细胞结合,随着血药浓度的降低,血浆中药物分布的比例也随着减少。