CYP3A5基因多态性分析指导肾移植术后他克莫司的个体化用药

目的:研究肾移植术患者CYP3A5基因多态性与术后个体化给药剂量的关系。方法:采用等位基因特异扩增法对27例肾移植术后患者进行CYP3A5基因分型。采用酶联免疫法测定他克莫司的血药浓度。比较不同基因型之间的他克莫司的血药浓度与给药剂量(C/D)比值的差异。结果:肾移植患者CYP3A5(A6986G)基因多态性,CYP3A5*3的发生频率为50%,CYP3A5*1/*3基因型与*1/*1基因型患者C/D比值相比差异无显著性(P>0.05),但两者C/D比值均显著低于*3/*3基因型患者(P<0.05)。结论:肾移植患者的CYP3A5基因多态性与他克莫司血药浓度具有相关性,CYP3A5*1/*3基因型和*1/*1基因型患者拟取得相似的血药浓度要比*3/*3型患者需服用更高剂量的他克莫司。分析肾移植患者的CYP3A5基因多态性与血药浓度关系,可指导其术后他克莫司的个体化用药方案。     

CYP 3A5*3基因多态性对肾移植术后他克莫司药代动力学的影响

目的探讨CYP3A5*3基因多态性对肾移植术后他克莫司(免疫抑制药)剂量校正给药2h后浓度的影响。方法选取61例肾移植术后患者,用聚合酶链式反应-限制性片段长度多态性的方法,分析CYP 3A5*3基因型;用微粒酶联免疫吸附法,测定患者他克莫司浓度。并分析CYP 3A5*3基因多态性与他克莫司给药剂量、给药2h浓度(C2)及剂量校正给药2h后浓度(C2/D)的相关性。结果肾移植术后1周及1、3个月,CYP 3A5*1/*1 CYP 3A5*1/*3组和CYP3A5*3/*3组他克莫司剂量比较均无显著性差异。术后1周和1个月,2组间他克莫司C2比较无显著性差异;术后3个月,CYP 3A5*1/*1 CYP 3A5*1/*3组的C2显著低于CYP 3A5*3/*3组(P<0.05)。术后1周及1、3个月,CYP 3A5*1/*1 CYP 3A5*1/*3组的C2/D均明显低于CYP 3A5*3/*3组(P<0.05)。结论肾移植术后,他克莫司C2/D的个体化差异与患者CYP3A5*3基因型密切相关。     

CYP3A4*18B和CYP3A5*3基因多态性对肾移植患者他克莫司剂量及浓度的影响

研究CYP3A5*3和CYP3A4*18B基因突变对他克莫司血药浓度/剂量×体表面积(C/D′)、不良反应和急性排斥反应的影响。采用聚合酶链反应(PCR)和限制性内切片段长度多态性(RFLP)方法检测227例肾移植患者CYP3A5*3和CYP3A4*18B基因型,比较不同基因型患者之间他克莫司的C/D′值、不良反应和急性排斥反应发生率的差异。测得CYP3A4*18B和CYP3A5*3基因型在肾移植患者中的突变频率分别为30.8%和74.2%。消除CYP3A5*3等位基因影响后,CYP3A4*18B各基因型间他克莫司C/D′值无显著性差异(P>0.05);而消除CYP3A4*18B等位基因影响后,CYP3A5*1/*1和*1/*3基因型患者的他克莫司C/D′值显著低于*3/*3(P<0.01)。CYP3A4*18B和CYP3A5*3基因多态性与不良反应和排斥反应间差异无统计学意义(P>0.05)。     

CYP3A4* 1G基因多态性对肾移植受者他克莫司给药剂量及血药浓度影响的系统评价

目的系统评价CYP3A4*1G基因多态性对肾移植受者他克莫司日剂量、全血谷浓度及浓度剂量比的影响。方法计算机检索Em Base、Pub Med、Cochrane Library、CNKI、万方及Sino Med等数据库,收集CYP3A4*1G基因多态性对他克莫司给药剂量及血药浓度影响的研究,用Revman 5.2软件进行Meta分析。结果共纳入7项研究(中文5篇,英文2篇),包括750名成年肾移植受者。Meta分析结果表明,CYP3A4*1G组他克莫司日剂量显著高于CYP3A4*1/*1组患者(P<0.05)。亚组分析显示,肾移植术后14 d内,2组他克莫司日剂量比较差异无统计学意义(P>0.05);而术后1个月及2~3个月时,CYP3A4*1G组他克莫司日剂量均显著高于CYP3A4*1/*1组(均P<0.05),他克莫司全血谷浓度及浓度剂量比均显著低于CYP3A4*1/*1组(均P<0.05)。结论 CYP3A4*1G基因多态性显著影响肾移植受者他克莫司日剂量及其血药浓度。     

肾移植患者他克莫司的血药浓度与CYP3A5*3基因多态性的关系

目的研究CYP3A5*3基因突变对他克莫司全血谷浓度(经体表面积剂量校正)、不良反应和急性排斥反应的影响。方法采用聚合酶链反应(PCR)和限制性内切片段长度多态性(RFLP)方法检测227例肾移植患者CYP3A5*3基因型,比较不同基因型患者之间他克莫司的全血谷浓度、不良反应和急性排斥反应发生率的差异。结果 CYP3A5*3基因多态性中,*1/*1型18例(7.9%),*1/*3型81例(35.7%),*3/*3型128例(56.4%)。肾移植术后3个月内,*1/*1型、*1/*3型和*3/*3型患者的他克莫司全血谷浓度经体表面积剂量校正后分别为1.84±0.71、2.06±0.83和4.11±2.13,*1/*1型和*1/*3型之间差异未见统计学意义(P>0.05),但与*3/*3型之间差异均有高度统计学意义(P<0.01)。组间不良反应和急性排斥反应发生率之间差异无统计学意义(P>0.05)。结论肾移植患者的CYP3A5*3基因多态性与他克莫司的服用剂量密切相关,对含CYP3A5*3等位基因的患者在应用他克莫司时应较常规减少用药剂量并注意不良反应的发生,而对CYP3A5野生型的肾移植患者应适当增加服药次数以降低排异反应。     

CYP3A4*18B基因多态性与他克莫司血药浓度的相关性研究

目的:探讨中国汉族肾移植患者CYP3A 4* 18B基因型对术后1个月内他克莫司谷浓度的影响.方法:采用限制性片段长度多态性技术分析了30例汉族患者CYP3A4* 18B基因型,采用酶增强免疫测定技术测定患者他克莫司谷浓度.将血药浓度标准化后对不同基因型患者剂量调整谷浓度差异进行t检验.结果:测得CY P3A 4*18B等位基因频率为0.333,符合Hardy-Weinberg平衡.将患者分成*1/*1型慢代谢组和*1/*18B合并*18B/*18B型快代谢组,两组标准化谷浓度分别为(98.02±18.56) ng·kg·mL-1· mg-1和(62.91±18.15) ng· kg· mL-1· mg-1 (P＜0.01),慢代谢组的FK506剂量调整谷浓度显著高于快代谢组.结论:CYP3A 4* 18B基因多态性与他克莫司剂量调整谷浓度显著相关,该突变可能导致CYP3A4酶活性的提高.     

CYP3A5和MDR1基因型对尿毒症患者肾移植术后早期他克莫司血药浓度和肌酐水平的影响

目的 评价真实临床实践中CYP3A5(CYP3A5*3,6986A>G)及MDR1(C3435>T,G2677>T/A,C1236>T)基因多态性对尿毒症患者接受肾移植术后早期他克莫司血药浓度的影响及其最佳治疗浓度。方法 以入选2013～2017年单中心的131例首次肾移植术且术后以他克莫司为基础进行三联免疫治疗的患者为对象,开展回顾性研究,考察患者基因多态性对他克莫司的日剂量、血药浓度、血药浓度/剂量比值和肌酐水平的影响。结果 在维持他克莫司靶浓度（10～15 ng/ml）的前提下,肾移植术后4周内基因型为CYP3A5*3/*3(GG)肾移植受者的给药剂量低于基因型CYP3A5*1/*1(AA)和CYP3A5*1/*3(AG)。患者血药浓度在10～13 ng/ml内时,其血肌酐水平最接近正常值。结论 CYP3A5基因多态性影响肾移植受者他克莫司的血药浓度,未发现MDR1基因多态性对他克莫司血药浓度的影响。早期肾移植血药浓度控制在10～13 ng/ml时,患者移植肾功能最接近正常人肾功能水平。     

CYP3A基因多态性与他克莫司血药浓度的相关性研究

目的:探讨肾移植术后口服免疫抑制剂他克莫司的剂量及其全血谷浓度个体差异的原因。方法:用基质辅助激光解吸电离飞行时间质谱技术对60例肾移植稳定期患者的CYP3AP1、CYP3A5*3的基因型进行检测,并分析各项临床指标对他克莫司血药浓度的影响。结果:60例肾移植患者中,性别、年龄、体质量、身高、激素剂量、血清肌酐对他克莫司浓度/(剂量×体表面积)比值并没有显著影响(P>0.05),术后时间和CYP3AP1、CYP3A5*3是主要影响因素(P<0.05)。CYP3AP1他克莫司浓度/(剂量×体表面积)比值高低依次为GG组相似文献   

CYP3A5*3基因多态性与他克莫司血药浓度及临床疗效的相关性研究

目的 探讨CYP3A5*3在中国人群中的分布,明确其对他克莫司稳态谷浓度的影响及临床疗效的相关性。 方法 收集55例慢性肾小球肾炎患者的他克莫司稳态谷浓度,酶免疫放大分析法测定其浓度值,根据TL998A荧光检测仪及试剂盒要求进行样品处理及CYP3A5*3基因型测定。分析CYP3A5*3不同基因型对他克莫司血药浓度及临床疗效的影响。 结果 55例患者,共收集他克莫司稳态谷浓度268份, 5~<10 ng.mL_^-1 与10~20 ng.mL_^-1浓度范围他克莫司的临床有效率(82.0%,82.6%)显著高于5 ng.mL_^-1以下浓度范围(45.5%)(p<0.05),同时5~<10 ng.mL_^-1 与10~20μg.mL_^-1浓度范围他克莫司的临床有效率相近(p＞0.05)。CYP3A5*3三种基因型(GA、GG、AA)患者分布频率均符合Hardy－Weinberg平衡(p＞0.05)。三种基因型患者他克莫司血药谷浓度比较,差异无统计学意义(p＞ 0.05);他克莫司剂量和C/D值比较,差异均有统计学意义(p<0.05)。其中突变纯合子GG患者的他克莫司剂量显著低于突变杂合子GA和野生型AA患者,且突变杂合子GA患者显著低于野生型AA患者;突变纯合子GG患者的他克莫司C/D显著高于突变杂合子GA和野生型AA患者,且突变杂合子GA患者显著高于野生型AA患者。C3435T 基因型不同的患者临床有效率相近(p＞ 0.05)。 结论CYP3A5*3基因多态性对我国肾小球肾炎患者他克莫司血药浓度有显著影响,等位基因G携带者他克莫司C/D值更高,且每日所需剂量更低;但CYP3A5*3基因多态性可能与临床疗效无关。     

CYP3A5、UGT1A1、UGT2B7基因多态性与肾移植受者 他克莫司血药浓度的相关性研究

目的:探讨CYP3A5、UGT1A1、UGT2B7基因多态性与肾移植受者他克莫司血药浓度的相关性.方法:共纳入124例肾移植术后采用他克莫司十霉酚酸酯+泼尼松三联治疗方案的患者.采用酶放大免疫测定法(Emit)检测他克莫司血药浓度;采用实时荧光定量PCR方法和Taqman基因分型技术测定CYP3A5*3、UGT1A1*6、UGT2B7*3、UGT1A1*28、UGT2B7*2基因多态性;应用Kruskal-Wallis H检验法分析5个SNPs基因多态性与他克莫司血药浓度的相关性.结果:CYP3A5*3突变型的他克莫司血药浓度GG/AG(7.75±2.56)/(6.75±1.85) ng· mL-1显著高于野生型AA (5.00±1.81)ng·mL-1 (P＜0.01);UGT1A1*6基因型GG/AG的血药浓度分别为(7.15±2.72)/(6.74±1.81)ng·mL-1,显著高于基因型AA(4.45±0.49)ng·mL-1(P=0.022).UGT2B7*3基因型GG/GT的血药浓度分别为(7.00±1.95)、(7.48±2.22)ng·mL-1,显著高于基因型TT(6.78+3.00)ng·mL-1(P=0.014).UGT1A1*28与UGT2B7*2基因多态性与他克莫司血药浓度无显著相关性(P＞0.05).结论:他克莫司血药浓度与CYP3A5*3、UGT1A1*6、UGT2B7*3基因多态性相关.     

Effect of intestinal CYP3A5 on postoperative tacrolimus trough levels in living-donor liver transplant recipients

It has been reported that hepatic and intestinal cytochrome P450 (CYP) 3A4, CYP3A5 and P-glycoprotein affect the pharmacokinetics of tacrolimus, and that these proteins are associated with the large inter-individual variation in the pharmacokinetics of this drug. We previously showed that the concentration/dose ratio of tacrolimus tended to be lower in recipients of living-donor liver transplantation (LDLT) with a CYP3A5*1/*1-carrying graft. However, the effect of intestinal CYP3A5 remains to be elucidated. In the present study, we examined the CYP3A5 genotype in both recipients and donors, and the effect of the recipients' polymorphism on the concentration/dose ratio of tacrolimus in patients after LDLT. The CYP3A5*3 allele frequency was 80% in recipients and 77% in donors. The intestinal CYP3A5 mRNA expression level was significantly associated with genotype. The tacrolimus concentration/dose ratio was lower in recipients with the CYP3A5*1/*1 and *1/*3 genotype (CYP3A5 expressors) compared to the CYP3A5*3/*3 genotype (non-expressors). Amongst the combination of CYP3A5 genotypes between the graft liver and the native intestine, CYP3A5 expressors in both the graft liver and the native intestine had the lowest concentration/dose ratio of tacrolimus during 35 days after LDLT. Patients with the intestinal CYP3A5*1 genotype tended to require a higher dose of tacrolimus compared to the other group with the same hepatic CYP3A5 genotype. These results indicate that intestinal CYP3A5, as well as hepatic CYP3A5, plays an important role in the first-pass effect of orally administered tacrolimus.     

Impact of MDR1 and CYP3A5 on the oral clearance of tacrolimus and tacrolimus-related renal dysfunction in adult living-donor liver transplant patients

OBJECTIVE: The potential influence of the multidrug resistance 1 (MDR1) gene and the cytochrome P450 (CYP) genes, CYP3A4 and CYP3A5, on the oral clearance (CL/F) of tacrolimus in adult living-donor liver transplant patients was examined. Furthermore, the development of renal dysfunction was analyzed in relation to the CYP3A5 genotype. METHODS: Sixty de novo adult liver transplant patients receiving tacrolimus were enrolled in this study. The effects of various covariates (including intestinal and hepatic mRNA levels of MDR1 and CYP3A4, measured in each tissue taken at the time of transplantation, and the CYP3A5*3 polymorphism) on CL/F during the first 50 days after surgery were investigated with the nonlinear mixed-effects modeling program. RESULTS: CL/F increased linearly until postoperative day 14, and thereafter reached a steady state. The initial CL/F immediately after liver transplantation was significantly affected by the intestinal MDR1 mRNA level (P<0.005). Furthermore, patients carrying the CYP3A5*1 allele in the native intestine, but not in the graft liver, showed a 1.47 times higher (95% confidence interval, 1.17-1.77 times, P<0.005) recovery of CL/F with time than patients having the intestinal CYP3A5*3/*3 genotype. The cumulative incidence of renal dysfunction within 1 year after transplantation, evaluated by the Kaplan-Meier method, was significantly associated with the recipient's but not donor's CYP3A5 genotype (*1/*1 and *1/*3 vs. *3/*3: recipient, 17 vs. 46%, P<0.05; donor, 35 vs. 38%, P=0.81). CONCLUSION: These findings suggest that the CYP3A5*1 genotype as well as the MDR1 mRNA level in enterocytes contributes to interindividual variation in the CL/F of tacrolimus in adult recipients early after living-donor liver transplantation. Furthermore, CYP3A5 in the kidney may play a protective role in the development of tacrolimus-related nephrotoxicity.     

Tacrolimus Elimination in Four Patients With a CYP3A5*3/*3 CYP3A4*22/*22 Genotype Combination

Cytochrome P450 3A5 (CYP3A5) and cytochrome P450 3A4 (CYP3A4) are the predominate enzymes responsible for tacrolimus metabolism. The presence of CYP3A4 and CYP3A5 genetic variants significantly affects tacrolimus clearance and dose requirements. CYP3A5*3 is a loss‐of‐function variant resulting in no CYP3A5 enzyme production. CYP3A4*22 is a variant that reduces production of functional CYP3A4 protein. Caucasians commonly carry these variant alleles but are very rarely homozygous for both CYP3A5*3 and CYP3A4*22. This report describes four kidney transplant recipients who carry a rare genotype combination (CYP3A5*3/*3 and CYP3A4*22/*22). These patients were identified from a larger cohort of Caucasian kidney transplant recipients (n=1366). To understand the significance of this genotype combination on tacrolimus troughs and doses, we compared these patients to recipients without this combination. Patients homozygous for both variants are at risk for profound reductions in metabolism of CYP3A substrates. A 342% and a 90.6% increase in the median dose‐normalized trough was observed, when the CYP3A5*3/*3 and CYP3A4*22/*22 genotype combination was compared to the CYP3A5*1/*1 and CYP3A4*1/*1 genotype combination and the CYP3A5*3/*3 and CYP3A4*1/*1 genotype combination, respectively. These four individuals only required on average 2.5 mg/day of tacrolimus. Knowledge of these genotypes would be useful in selecting appropriate tacrolimus doses to avoid overexposure.     

CYP3A5*1-carrying graft liver reduces the concentration/oral dose ratio of tacrolimus in recipients of living-donor liver transplantation

OBJECTIVES: Tacrolimus is widely used for immunosuppressive therapy after organ transplantation, but its pharmacokinetics shows such great interindividual variation that control of its blood concentration is difficult. We have previously reported that an intestinal P-glycoprotein (MDR1) contributes to this variation as an absorptive barrier, but the role of hepatic metabolism is not clear. METHODS: In this study, we have evaluated the genotypes of MDR1 and cytochrome P450 (CYP) 3A in donor and recipient, and the influence of polymorphisms on mRNA expression and the tacrolimus concentration/dose (C/D) ratio in recipients of living-donor liver transplantation (LDLT). RESULTS: The expression level of MDR1 and tacrolimus C/D ratio were not affected by either MDR1 C3435T or G2677T/A. The CYP3A4*1B genotype was not detected, but the CYP3A5*3 genotype had an allelic frequency of 76.3%. The mRNA level of CYP3A5 was significantly reduced by the *3/*3 genotype, and the tacrolimus C/D ratio was decreased in recipients engrafted with partial liver carrying CYP3A5*1/*1 genotype. An analysis of the combination of intestinal MDR1 level and liver CYP3A5 genotype revealed that the tacrolimus C/D ratio was lower in the group with higher MDR1 levels regardless of CYP3A5 genotype during postoperative week 1. CONCLUSIONS: These results indicate that in recipients of LDLT, the pharmacokinetics of tacrolimus is influenced by flux via P-glycoprotein in the intestine during the first week; after that, it is mostly the hepatic metabolism that contributes to the excretion of tacrolimus, and carriers of the CYP3A5*1/*1 genotype require a high dose of tacrolimus to achieve the target concentration.     

The effect of CYP3A5 and MDR1 (ABCB1) polymorphisms on cyclosporine and tacrolimus dose requirements and trough blood levels in stable renal transplant patients

Cyclosporine and tacrolimus are immunosuppressive drugs largely used in renal transplantation. They are characterized by a wide inter-individual variability in their pharmacokinetics with a potential impact on their therapeutic efficacy or induced toxicity. CYP3A5 and P-glycoprotein appear as important determinants of the metabolism of these drugs. The objective of this study was to investigate the effect of CYP3A5 and MDR1 (ABCB1) polymorphisms on cyclosporine and tacrolimus dose requirements and trough blood concentrations in stable transplant patients. Stable renal transplant recipients receiving cyclosporine (n = 50) or tacrolimus (n = 50) were genotyped for CYP3A5*3 and *6, and MDR1 C1236T, G2677T/A and C3435T. Dose-adjusted trough blood levels (ng/ml per mg/kg body weight) as well as doses (mg/kg body weight) required to achieve target blood concentrations were compared among patients according to allelic status for CYP3A5 and MDR1. Dose-adjusted trough concentrations were three-fold and 1.6-fold higher in CYP3A5*3/*3 patients than in CYP3A5*1/*3 patients for tacrolimus and cyclosporine, respectively. In the case of tacrolimus, the difference was even more striking when considering CYP3A5*1/*1 patients showing dose-adjusted trough concentrations 5.8-fold lower than CYP3A5*3/*3 patients. For both drugs, no association was found between trough blood concentrations or dose requirement and MDR1 genotype. Multiple regression analyses showed that CYP3A5*1/*3 polymorphism explained up to 45% of the variability in dose requirement in relation to tacrolimus use. Given the importance of rapidly achieving target blood concentrations after transplantation, further prospective studies should consider the immediate post-graft period and assess the influence of this specific polymorphism. Beside non-genetic factors (e.g. steroids dosing, drugs interactions), CYP3A5 pharmacogenetic testing performed just before transplantation could contribute to a better individualization of immunosuppressive therapy.     

Effect of CYP3A5 polymorphism on tacrolimus metabolic clearance in vitro.

Previous investigations of solid organ transplant patients treated with tacrolimus showed that individuals carrying a CYP3A5*1 allele have lower dose-adjusted trough blood concentrations compared with homozygous CYP3A5*3 individuals. The objective of this investigation was to quantify the contribution of CYP3A5 to the hepatic and renal metabolic clearance of tacrolimus. Four primary tacrolimus metabolites, 13-O-desmethyl tacrolimus (13-DMT) (major), 15-O-desmethyl tacrolimus, 31-O-desmethyl tacrolimus (31-DMT), and 12-hydroxy tacrolimus (12-HT), were generated by human liver microsomes and heterologously expressed CYP3A4 and CYP3A5. The unbound tacrolimus concentration was low (4-15%) under all incubation conditions. For CYP3A4 and CYP3A5, V(max) was 8.0 and 17.0 nmol/min/nmol enzyme and K(m,u) was 0.21 and 0.21 muM, respectively. The intrinsic clearance of CYP3A5 was twice that of CYP3A4. The formation rates of 13-DMT, 31-DMT, and 12-HT were >or=1.7-fold higher, on average, in human liver microsomes with a CYP3A5*1/*3 genotype compared with those with a homozygous CYP3A5*3/*3 genotype. Tacrolimus disappearance clearances were 15.9 +/- 9.8 ml/min/mg protein and 6.1 +/- 3.6 ml/min/mg protein, respectively, for the two genotypes. In vitro to in vivo scaling using both liver microsomes and recombinant enzymes yielded higher predicted in vivo tacrolimus clearances for patients with a CYP3A5*1/*3 genotype compared with those with a CYP3A5*3/*3 genotype. In addition, formation of 13-DMT was 13.5-fold higher in human kidney microsomes with a CYP3A5*1/*3 genotype compared with those with a CYP3A5*3/*3 genotype. These data suggest that CYP3A5 contributes significantly to the metabolic clearance of tacrolimus in the liver and kidney.     

Effects of genetic polymorphisms of CYP3A4, CYP3A5 and MDR1 on cyclosporine pharmacokinetics after renal transplantation

1. The calcineurin inhibitor cyclosporine is widely used to prevent allograft rejection after solid organ transplantation. It has a narrow therapeutic index and shows considerable interindividual differences in its pharmacokinetics. Interindividual differences in the activity and expression of the metabolising enzymes cytochrome P450 (CYP) 3A4 and 3A5 and the multidrug efflux pump P-glycoprotein (P-gp) contribute considerably to cyclosporine pharmacokinetics. Variability in the activity of CYP3A4, CYP3A5 and P-gp could be considered to result from genetic polymorphisms encoding their genes. 2. The aim of the present study was to evaluate retrospectively the effects of genetic polymorphisms of CYP3A4, CYP3A5 and MDR1 on cyclosporine dose adjusted trough blood concentration during the early period after renal transplantation in Chinese patients. 3. One hundred and six renal transplant recipients in China were genotyped by polymerase chain reaction-restriction fragment length polymorphism for CYP3A4*18A, CYP3A5*3 and MDR1 C3435T. Cyclosporine whole blood levels were measured by fluorescence polarization immunoassay. Dose-adjusted trough blood concentrations (C(0)) were determined and compared among the different genotype groups. 4. The frequency of the CYP3A4*18A, CYP3A5*3 and MDR1 C3435T variant alleles were 0.005 (95% confidence interval (CI) 0.048, 0.0049), 0.783 (95% CI 0.781, 0.785) and 0.528 (95% CI 0.526, 0.531), respectively, and these alleles exhibited incomplete linkage disequilibrium. The median cyclosporine dose-adjusted C(0) in CYP3A5*1/*1 genotype subjects (n = 6) was 14.8 ng/mL per mg per kg (range 11.1-26.8 ng/mL per mg per kg), in CYP3A5*1/*3 patients (n = 34) it was 23.7 ng/mL per mg per kg (range 9.0-61.0 ng/mL per mg per kg) and for CYP3A5*3/*3 patients (n = 66) it was 26.4 ng/mL per mg per kg (range 9.8-85.8 ng/mL per mg per kg; P = 0.012, Kruskal-Wallis test). Accordingly, cyclosporine dose-adjusted C0 was larger in CYP3A5 non-expressors than expressors in the first week after renal transplantation. In addition, wild-type homozygotes (n = 21) for MDR1 C3435T had a slight but significantly lower dose-adjusted C0 compared with heterozygotes (n = 58): 17.7 (10.3-60.8) versus 26.4 (9.0-67.3) ng/mL per mg per kg, respectively (P = 0.014, Mann-Whitney U-test). 5. In conclusion, the present study shows that genetic polymorphisms in CYP3A5 may be responsible, in part, for the large interindividual variability of cyclosporine pharmacokinetics during the early phase after renal transplantation in Chinese patients. Patients with the CYP3A5*3 variant genotype require a low dose of cyclosporine to reach target levels compared with those with the CYP3A5*1 allele.     

Recipient ABCB1, donor and recipient CYP3A5 genotypes influence tacrolimus pharmacokinetics in liver transplant cases

BackgroundEffective immunosuppression through optimization of trough levels tacrolimus reduces post-transplant mortality rate in liver transplant cases.MethodsMeta-analysis was carried out to evaluate how donor/recipient CYP3A5 (n = 678) and recipient ABCB1 (n = 318) genotypes influence tacrolimus pharmacokinetics till one-month of transplantation.ResultsThe donor CYP3A5*3/*3 genotype exhibited higher concentration/dose (C/D) ratio of tacrolimus in week 1 (mean difference: 65.04, 95% CI: 15.30–114.79 ng/ml/mg/kg), week 2 (mean difference: 21.7, 95% CI: 12.6–30.9 ng/ml/mg/kg) and week 4 (mean difference: 43.28, 95% CI: 17.09 – 69.49 ng/ml/mg/kg) compared to *1/*1 and *1/*3 genotypes. The recipient CYP3A5 *3/*3 genotype did not showed significant difference in tacrolimus C/D ratio in week 1 compared to other two genotypes. However, week 2 (mean difference: 44.16, 95% CI: 3.68–84.65 ng/ml/mg/kg) and week 4 (mean difference: 43.74, 95% CI: 12.50–75.00 ng/ml/mg/kg) availability was higher in *3/*3 mutant recipients. However, the recipient ABCB1 3435 C > T polymorphism has no significant influence on tacrolimus pharmacokinetics till one month of transplant.ConclusionsThe donor and recipient CYP3A5*3 polymorphism influences tacrolimus pharmacokinetics in the first month post-transplantation, whereas the association with recipient ABCB1 3435 C > T is inconclusive.     

CYP3A5、ABCB1基因多态性对中国肾移植患者服用他克莫司剂量和血药浓度的影响

目的：研究肾移植患者CYP3A5、ABCB1基因多态性对肾移植术后患者他克莫司（TAC）血药浓度及给药剂量的影响。方法：采集83例中国肾移植患者术后3个月内TAC的常规监测的谷浓度（C0）。测定受试者CYP3A5*3（rs776746）、ABCB1 1236C＞ T（rs1128503）、2677G＞ T/A（rs2032582）、3435C＞ T（rs1045642）位点的基因型，分析基因多态性对TAC的C0、剂量的影响。结果：患者CYP3A5、ABCB1基因型频率均符合Hardy-Weinberg平衡（P ＞ 0.05）。在移植后3个月期间，CYP3A5*3/*3型患者相较于携带*1等位基因患者，具有更高的C0和更低的剂量（P ＜ 0.05）。ABCB1 2677GG基因型的C0显著低于GT、GA、AA、TT、AT型（P ＜ 0.05）；3435CT型的C0显著高于CC、TT型（P ＜ 0.05）。根据ABCB1的单倍型进行分组，并与CYP3A5进行了联合分析，结果发现，发现CYP3A5*1/*1与*1/*3组与*3/*3组中，不同ABCB1单倍型对TAC血药浓度影响的差异无统计学意义。术后随时间延长，CYP3A5*3/*3型患者的TAC剂量逐步降低，而携带*1基因患者的剂量则呈增加趋势。结论：CYP3A5比ABCB1基因多态性对肾移植受者TAC血药浓度的影响更显著，若达到相同的血药浓度，CYP3A5*3/*3型患者每日所服用的剂量更低。根据CYP3A5基因型制定给药方案，有助于尽早达到浓度标准，达到精准治疗的目标。