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)。     

肺移植患者术后使用他克莫司1年CYP3A5、CYP3A4、ABCB1、POR~*28基因多态性与他克莫司个体化用药的关系研究

目的:研究肺移植患者术后使用他克莫司1年CYP3A5、CYP3A4、ABCB1、POR*28基因多态性与他克莫司给药剂量(D)和稳态血药浓度/给药剂量比值(c0/D)的关系。方法:采用回顾性分析方法,选取2017年5月-2018年5月期间在中日友好医院接受肺移植术的46例受试者为研究对象,统计受试者术后使用他克莫司1年后他克莫司的c0和D,并计算c0/D。收集受试者CYP3A5(rs776746)、CYP3A4(rs2242480、rs28371759)、ABCB1(rs1045642、rs2032582、rs1128503)和POR*28(rs1057868)位点的基因型,对基因多态性与D、c0/D的关系进行统计学分析。结果:本研究中涉及位点的基因型频率均符合Hardy-Weinberg平衡(P>0.05)。维持他克莫司c0在治疗窗范围内的条件下,受试者的CYP3A5(rs776746)和CYP3A4(rs2242480)基因型多态性对他克莫司的D、c0/D有显著影响(P<0.05);其他位点各基因型之间的D、c0/D差异均无统计学意义(P>0.05)。联合CYP3A5(rs776746)和CYP3A4(rs2242480)两个位点分析受试者CYP3A代谢型发现,同时携带CYP3A5(rs776746)*1和CYP3A4(rs2242480)*1G等位基因的快代谢型受试者与只携带CYP3A5(rs776746)*1或CYP3A4(rs2242480)*1G等位基因的正常代谢型受试者和不携带CYP3A5(rs776746)*1和CYP3A4(rs2242480)*1G等位基因的慢代谢受试者比较,D、c0/D差异具有统计学意义(P<0.05),其中快代谢型受试者的他克莫司D最高,慢代谢型受试者的他克莫司D最低。结论:检测CYP3A5(rs776746)和CYP3A4(rs2242480)基因多态性对肺移植患者术后使用他克莫司1年后他克莫司的个体化给药具有指导意义。     

珠三角地区人群CYP3A5*3基因多态性及其临床意义

目的 研究CYP3A5*3(rs776746)在珠三角地区人群的基因频率分布及探讨它对临床个体化药物治疗的意义.方法 收集中山大学附属第五医院2018年1月～2021年7月间拟使用环孢素和他克莫司的住院患者310例,采用荧光原位杂交技术检测患者CYP3A5*3基因型,并总结近期该基因在中国人群中的研究.结果 (1)CYP3A5*3在珠三角地区的GG、GA和AA的频率分别为:0.480、0.410和0.110,G和A等位基因频率分别是0.685和0.315;(2)本研究的CYP3A5*3基因型和数据库中已有的中国人群有统计学差异(P=0.007);(3) CYP3A5 * 3的GG型与他克莫司、卡马西平和氯吡格雷药效增强相关.结论 CYP3A5*3多态性检测在中国人群他克莫司、卡马西平和氯吡格雷的个体化治疗中有潜在的指导意义.     

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和CYP3A5基因多态性对汉族肾移植患者他克莫司血药浓度的影响

目的:研究CYP3A4* 18B (rs2242480)、CYP3 A5 6989 A/G(rs776746)两个位点的基因多态性对肾移植术后他克莫司血药浓度/校正剂量比值(C/D)的影响,对肾移植患者基因导向的他克莫司个体化给药提供有意义的信息和数据.方法:101名健康志愿者和56例亲体肾移植且随访超过6个月的患者参加本研究,应用基因芯片法检测2个位点的基因型.用均相酶扩大免疫分析法(EMIT)测定术后7d、14 d、1个月、3个月和6个月时血药浓度.比较不同基因型间他克莫司C/D值之间的差异.结果:在101例汉族人群中,CYP3A4、CYP3A5的等位基因频率分别为:23.75％、73.80％.移植术后6个月内,CYP3A5 GG型(*3/*3)的C/D值显著高于AA型(*1/*1)和AG型(*1/*3)(P＜0.05).CYP3A5 AA型与AG型相比较,差异无统计学意义(P＞0.05).CYP3A4 CC型(*1/*1)的C/D值显著高于CT型(*1/*18B)和TT型(*18B/* 18B)(P＜0.05),其中CT型与TT型比较,C/D值差异无统计学意义(P＞0.05) 结论:肾移植患者术后服用他克莫司C/D值与CYP3A4、CYP3A5基因多态性具有显著相关性.     

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。     

CYP3A5基因多态性的他克莫司个体化用药临床研究分析

CYP3A5家族基因在肝含量占CYP3A总量一半以上,是许多药物代谢的酶。常见的免疫抑制药他克莫司是一种选择性抑制钙调磷酸酶,主要用于器官移植患者的抗排异治疗,经CYP3A5同工酶进行代谢。CYP3A5基因突变使酶失活,导致他克莫司不能正常代谢而在体内积聚,产生相关药物不良反应。由于产生充分免疫抑制效果的水平和产生毒性的水平差距很小,他克莫司使用时需要进行治疗药物监测,但是他克莫司的目标浓度因治疗的疾病而异,且操作复杂,初始用药剂量难以准确判定,给临床合理用药带来了困扰。基因型检测可以辅助指导他克莫司个体化治疗,在最大程度保证药物疗效的同时避免药物不良反应的发生。本研究综述了基于CYP3A5基因多态性的他克莫司个体化药物治疗现状,为抗排异治疗策略的优化提供参考。     

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。     

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。     

CYP3A4,CYP3A5和MDR1基因多态性对环孢素处置的影响

环孢素是一个广泛用于器官移植患者的免疫抑制剂,具有治疗指数窄,不同个体间药代动力学差异较大的特点。它主要通过肝脏和小肠的CYP3A4和CYP3A5代谢;同时它又是药物转运体的底物。不同个体间药物代谢酶和转运体活性的差异可能是造成不同器官移植患者环孢素药代动力学差异的主要原因。而遗传因素即编码药物代谢酶和转运体基因序列的差异可能是其产生活性差异的分子机制。因此,从编码药物代谢酶和转运体的基因入手,可能会为器官移植患者提供最优的治疗方案。     

CYP3A4, CYP3A5, and MDR1 in human small and large intestinal cell lines suitable for drug transport studies.

The aim of this study was to find a cell culture model of the intestinal epithelium for use in studies of CYP3A4-mediated first-pass metabolism of drugs and also for studies of the interplay between CYP3A4 metabolism and P-glycoprotein efflux. For this purpose, the expression of CYP3A4, CYP3A5, and MDR1 mRNA was studied in three cell lines of the normal human intestinal epithelium and three transformed cell lines of colonic (Caco-2) origin. Surprisingly, only transformed cell lines were induced by 1alpha,25-dihydroxy vitamin D3 (D3) to express high amounts of CYP3A4. In contrast to the original findings for this model, the monolayer integrity was maintained during D3 treatment. Levels of CYP3A mRNA expression in Caco-2 and TC7 cells differed dramatically. The highest levels of CYP3A4 and lowest levels of CYP3A5 mRNA expression were observed in D3 treated Caco-2 cells of high passage numbers, resulting in a CYP3A4/3A5 expression ratio greater than fourfold higher than that seen in TC7 cells. Functional studies, using the CYP3A probe testosterone, showed that CYP3A activity was completely absent only in uninduced Caco-2 cells. After D3 induction, high levels of the metabolite were produced in both cell lines (149.4 +/- 12.3 and 86.5 +/- 3.8 pmol 6beta-OH testosterone/min/mg cellular protein from 75 microM testosterone in Caco-2 and TC7 cells, respectively). The maximum velocity (Vmax) and the apparent Michaelis constant (Km) for the 6beta-hydroxylation of testosterone by CYP3A4 in intact Caco-2 monolayers were similar to those obtained from human intestinal microsomes. Only minor changes in P-glycoprotein activity were observed when the metabolically stable P-glycoprotein substrate celiprolol was used. In conclusion, these results show that the features of the generally available Caco-2 cell line from American Type Culture Collection make it suitable for studies of CYP3A4-mediated first-pass metabolism and also for studies of the interplay between CYP3A4 and drug efflux mechanisms.     

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.     

Clinical implications of CYP3A polymorphisms

Due to their enormous substrate spectrum CYP3A4, -3A5 and -3A7 constitute the most important drug-metabolising enzyme subfamily in humans. CYP3As are expressed predominantly, but not exclusively, in the liver and intestine, where they participate in the metabolism of 45 - 60% of currently used drugs and many other compounds such as steroids and carcinogens. CYP3A expression and activity vary interindividually due to a combination of genetic and nongenetic factors such as hormone and health status, and the impact of environmental stimuli. Over the past several years, genetic determinants have been identified for much of the variable expression of CYP3A5 and -3A7, but not for CYP3A4. Using these markers, an effect of CYP3A5 expression status has been demonstrated beyond doubt for therapies with the immunosuppressive drug tacrolimus. Further associations are likely to emerge for drugs metabolised predominantly by CYP3A5 or -3A7, especially for individuals or tissues with concomitant low expression of CYP3A4. However, as exemplified by the controversial association between CYP3A4*1B and prostate cancer, the detection of clinical effects of CYP3A gene variants will be difficult. The most important underlying problems are the continuing absence of activity markers specific for CYP3A4 and the strong contribution of nongenetic factors to CYP3A variability.     

Drugs as CYP3A Probes,Inducers, and Inhibitors

Human cytochrome P450 (CYP) 3A subfamily members (mainly CYP3A4 and CYP3A5) mediate the metabolism of approximately half all marketed drugs and thus play a critical role in the drug metabolism. A huge number of studies on CYP3A-mediated drug metabolism in humans have demonstrated that CYP3A activity exhibits marked ethnic and individual variability, in part because of altered levels of CYP3A4 expression by various environmental factors and functionally important polymorphisms present in CYP3A5 gene. Accumulating evidence has revealed that CYP3A4 and CYP3A5 have a significant overlapping in their substrate specificity, inducers and inhibitors. Therefore, it is difficult to define their respective contribution to drug metabolism and drug-drug interactions. Furthermore, P-glycoprotein and CYP3A are frequently co-expressed in the same cells and share a large number of substrates and modulators. The disposition of such drugs is thus affected by both metabolism and transport. In this review, we systematically summarized the frequently used CYP3A probe drugs, inducers and inhibitors, and evaluated their current status in drug development and research.     

Drugs as CYP3A probes, inducers, and inhibitors

Human cytochrome P450 (CYP) 3A subfamily members (mainly CYP3A4 and CYP3A5) mediate the metabolism of approximately half all marketed drugs and thus play a critical role in the drug metabolism. A huge number of studies on CYP3A-mediated drug metabolism in humans have demonstrated that CYP3A activity exhibits marked ethnic and individual variability, in part because of altered levels of CYP3A4 expression by various environmental factors and functionally important polymorphisms present in CYP3A5 gene. Accumulating evidence has revealed that CYP3A4 and CYP3A5 have a significant overlapping in their substrate specificity, inducers and inhibitors. Therefore, it is difficult to define their respective contribution to drug metabolism and drug-drug interactions. Furthermore, P-glycoprotein and CYP3A are frequently co-expressed in the same cells and share a large number of substrates and modulators. The disposition of such drugs is thus affected by both metabolism and transport. In this review, we systematically summarized the frequently used CYP3A probe drugs, inducers and inhibitors, and evaluated their current status in drug development and research.     

Functional Characterization of 22 CYP3A4 Protein Variants to Metabolize Ibrutinib In Vitro

Cytochrome P450 3A4 (CYP3A4) is quantitatively the most important P450 enzyme in adults. It is suggested that CYP3A4 genetic polymorphisms may influence the rate of the metabolism and elimination of CYP3A4 substrates in human beings. Ibrutinib is an anticancer drug and primarily metabolized by CYP3A4. The aim of this study was to systematically investigate the effects of 22 CYP3A4 protein variants on the metabolism of ibrutinib in vitro. When compared with wild‐type CYP3A4.1, two variants (CYP3A4.17 and CYP3A4.24) had no detectable enzyme activity; five variants (CYP3A4.10, .11, .18, .23 and .33) exhibited no significant differences; another five variants (CYP3A4.3, .4, .9, .19 and .34) showed increased intrinsic clearance values, while the remaining nine variants (CYP3A4.2, .5, .14, .15, .16, .28, .29, .31 and .32) displayed decreased enzymatic activities in different degrees. As the first study of 22 CYP3A4 protein variants in ibrutinib metabolism, these comprehensive data may help in the clinical assessment of the metabolism and elimination of ibrutinib and also offer a reference to the personalized treatment of ibrutinib in clinic.     

Genetic variability in CYP3A5 and its possible consequences

The cytochrome P450 3A (CYP3A) subfamily members are the most abundant and important drug-metabolizing enzymes in humans, and wide interindividual variability in CYP3A expression and function is present. CYP3A4 alone cannot fully explain the observed constitutive variability because its genetic variants are relatively uncommon and have limited functional significance, whereas CYP3A5 expression in humans is highly variable and may be contributory. However, it is difficult to delineate the relative contribution of CYP3A4 and CYP3A5, and to differentiate their effects on drug metabolism as their protein structure, function and substrates are so similar. By contrast, molecular biology methods provide the ability to identify CYP3A4 and CYP3A5 genotypes with certainty. This review collates currently available data on CYP3A5 polymorphisms, provides information on the population frequency of each genetic variant in major ethnic groups, and describes in vitro and in vivo studies that have attempted to identify genotype-phenotype associations.     

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.