霉酚酸酯药代动力学与多重耐药基因1多态性的相关性研究

目的 研究肾移植受者术后早期霉酚酸酯(MMF)的药代动力学与人类多重耐药基因1(MDRI)多态性的相关性.方法 选择初次肾移植的汉族受者28例,肾移植术后2周时,于口服MMF之前及服药后0.5、1、1.5、2、4、6、8、10、12 h共10个时间点分别采集外周血,以高效液相色谱(HPLC)法测定全血霉酚酸酯(MMF)的活性成分霉酚酸(MPA)的浓度,直接观察其峰值浓度(Cmax)和达峰时间(Tmax).应用Winnolin 3.1软件计算MPA 0～12 h药物时间一浓度曲线下面积(AUC)和平均滞留时间(MRT).同时从外周血提取基因组DNA,应用多聚酶链反应-限制性片断长度多态性(PCR-RFLP)测定MDR1第12、21、26号外显子C1236 T、G2677 T/A、C3435 T单核苷酸多态性(SNP).比较3个SNP位点的不同基因型、单倍型间MMF药代动力学参数的差异;比较MPA高暴露组(MPA AUC≥60 mg·h-1·L-1)与MPA低暴露组(MPA AUC＜60 mg·h-1·L-1)间MDR1多态性差异.结果 MDR1第12、21、26号外显子SNP位点突变型纯合子基因型(1236 TT、2677 TT/AA、3435 TT)频率分别为0.368、0.184和0.211.1236 TT基因型受者MPA AUC水平显著高于1236 cc/CT受者,分别为(65.36±11.51)mg·h-1·L-1和(53.33±13.77)mg·h-1·L-1(P=0.032).MPA高暴露组第12号外显子SNP位点上,TT基因型频率显著高于低暴露组,分别为66.7%和15.8%(P=0.013,OR=2.526);T等位基因频率有高于低暴露组的趋势,分别为83.3%和53.3%(P=0.072).结论 具有MDR1第12号外显子TT等位基因的受者,肾移植早期MPA AUC显著高于同一位点其他基因型受者,是MPA高暴露的危险个体.

Multidrug resistance 1 gene polymorphism affects early mycophenolate mofetil exposure in Chinese renal transplant recipients

Objective To investigate the relationship between the polymorphism of human multidrug resistance 1 gene(MDR1)polymorphism and early MMF pharmacokinetics.Methods Twenty-eight Chinese primary renal transplant recipients were emrolled.On day 14 post-transplant,patients took the MMF orally on fast.Whole blood samples(2 ml)were obtained at the following time points:predose(G0)and 0.5,1,1.5,2,4,6,8,10 and 12 h(C0.5,C1,C1.5,G2,C4,C6,C8,C10,C12,respectively)postdose during the dosing interval.The MPA plasrna concentration was assayed by high performance liquid chromatography (HPLC).Pharmacokinetie parameters were determined by WINNOLIN 3.1.Three major single nucleotide polymorphisrrls(SNP),C1236 T,G2677 T/A,C3435 T of MDR1 were analyzed by PCR-RFLP.Pharmacokinetie parameters of MPA were compared between different MDR1 genotype and haplotype groups.Ailele frenqueneis were also compared in high(MPA area under concentratation-time curve 0～12 h,frequencies of 1236 TT,2677 TT/AA,3435 TT in three major MDR1 SNP positions,exons 12,21 and 26,were 0.368,0.184 and 0.211,respectively.MPA AUC was significantly higher in 1236 TT group than in 1236 CC/CT group(65.36±11.51 vs 53.33±13.77,P=0.032).On C1236 T SNP,TT genotype frequency showed significant difference between MPA high and low exposure groups(66.7%vs 15.4%,P=0.013,OR=2.526).T allele frequency was marginally higher in MPA high exposure group than that in low exposure group(83.3%vs 53.3%,P=0.072).Conclusion TT genotype on 1236 of MDR1 indicates a risk of early high exposure to MPA in Chinese renal transplant patients given by oral MMF,