GSTP1和SLCO1B1基因多态性对大剂量甲氨蝶呤化疗排泄延迟及不良反应的影响

目的 研究GSTP1和SLCO1B1基因多态性与儿童急性淋巴细胞白血病（ALL）患儿使用大剂量甲氨蝶呤（HD-MTX）化疗后出现排泄延迟及不良反应的相关性及预测价值。方法 选择2021年1月至2022年12月南京医科大学附属儿童医院80例ALL患儿为研究对象,采用聚合酶链式反应（PCR）法测定所有患儿GSTP1(rs1695、rs537387344)和SLCO1B1(rs2306283、rs4149056)等位点的基因多态性,采用均相酶扩大免疫分析（EMIT）法测定MTX血药浓度,记录在接受HD-MTX治疗过程中发生的不良反应。用单因素分析GSTP1和SLCO1B1基因多态性、HD-MTX排泄延迟及不良反应的相关性,并得出显著性因素;用多因素Logistic回归筛选出预测因子,绘制受试者工作特征（ROC）曲线评价预测价值。结果 SLCO1B1 rs4149056 TC与排泄延迟具有相关性;72 h血药浓度、GSTP1 rs1695 AA、SLCO1B1 rs4149056 TC基因型与MTX化疗后不良反应的发生具有相关性,差异有统计学意义（P <0.05）。ROC曲线分析结果表明...     

MTRR和SLCO1B1基因多态性与ALL患儿MTX血药浓度及HD-MTX致不良反应的相关性研究

目的:研究MTRR基因rs1801394位点、SLCO1B1基因rs11045879位点多态性与急性淋巴细胞白血病(ALL)患儿甲氨蝶呤(MTX)血药浓度及大剂量甲氨蝶呤(HD-MTX)致不良反应的相关性。方法:回顾性收集2015年10月-2018年9月四川省人民医院收治的接受HD-MTX治疗且处于巩固化疗期的四川地区汉族ALL住院患儿70例,采用均相酶扩大免疫法检测患儿给药后48、72 h时的血药浓度,采用实时荧光定量聚合酶链反应法检测其基因分型;分析MTRR、SLCO1B1基因多态性与MTX血药浓度[剂量校正浓度(c48 h/D,48 h)、不同血药浓度范围(≤0.1、>0.1μmol/L)患儿比例(72 h)]及不良反应(骨髓抑制、肝功能损害、胃肠道反应、黏膜损伤、皮疹等)的相关性;采用Wald渐进法对不同影响因素(基因多态性、MTX血药浓度、免疫分型、体质量指数等)与不良反应的相关性进行二元Logistic回归分析。结果:共检出MTRR基因AA、AG、GG型患儿31、32、7例,SLCO1B1基因TT、TC、CC型患儿23、37、10例,各基因型频率均符合Hardy-Weinberg平衡(P>0.05)。MTRR和SLCO1B1各基因型患儿c48 h/D(48 h)以及不同血药浓度范围患儿比例(72 h)比较差异均无统计学意义(P>0.05)。MTRR各基因型患儿肝功能损害发生率差异显著(P<0.05),且AA型显著高于AG+GG型(P<0.05);而MTRR基因多态性与其他不良反应发生率,SLCO1B1基因多态性与各不良反应发生率均不相关(P>0.05)。二元Logistic回归分析结果显示,ALL患儿肝功能损害与MTRR基因多态性相关,胃肠道反应与72 h血药浓度>0.1μmol/L与否相关,黏膜损伤与患儿免疫分型和体质量指数相关,皮疹与患儿体质量相关(P<0.05)。结论:MTRR基因rs1801394位点多态性可能与ALL患儿HD-MTX致肝功能损害的发生相关,但该多态性和SLCO1B1基因rs11045879位点多态性均与患儿体内MTX的血药浓度无关。     

多药耐药基因1 C3435T多态性与急性淋巴细胞白血病患儿甲氨蝶呤血清浓度的关系

目的考察多药耐药基因1(MDR1)C3435T多态性与急性淋巴细胞白血病(ALL)患儿甲氨蝶呤(MTX)血清浓度及化疗毒性的相关性。方法收集100例ALL患儿外周血,提取基因组DNA;用PCR-RFLP法,检测MDR1 C3435T基因型;用荧光偏振免疫法(FPIA),测定MTX血清浓度,同时观察化疗的疗效和毒性。结果 CC、CT和TT基因型的分布频率分别为33%,53%,14%;C和T等位基因的分布频率分别为59.5%和40.5%。肝功能异常ALL患儿,其24,42h MTX剂量校正的血清浓度(C/D比值)高于肝功能正常者;携带野生基因型(CC)ALL患儿的24,42 h MTX C/D比值高于突变基因型(CT+TT)携带者;携带野生基因型ALL患儿的未缓解、化疗毒性和排泄延迟发生率,高于突变基因型携带者。由于个体间的变异大,上述差异均无统计学意义(P>0.05)。结论多种因素影响MTX的药代与药效,MDR1 C3435T多态性与ALL患儿的MTX血清浓度和化疗毒性无显著相关关系。     

1例大剂量甲氨蝶呤化疗致急性肾损伤及甲氨蝶呤延迟排泄的病例分析

摘要：1例中枢弥漫大B细胞淋巴瘤患者入院后给予大剂量甲氨蝶呤(HD-MTX)化疗。尽管给予了充分水化、碱化及亚叶酸钙(CF)解救,患者仍出现急性肾损伤(AKI)及甲氨蝶呤(MTX)延迟排泄。临床药师参与对患者的救治过程及药学监护,提醒临床监测MTX血药浓度并根据MTX血药浓度调整CF剂量,并对患者4个MTX药物代谢基因进行检测。患者之后经大剂量CF解救、肾脏替代治疗及其他积极救治,虽然肾功能明显改善,但MTX延迟排泄改善困难,最终患者发生Ⅳ度骨髓抑制并死亡。药物代谢基因基因多态性检测结果显示患者MTHFR 1298、ABCB1 3435为杂合突变。此病例分析提示,HD-MTX易导致危及生命的AKI及MTX延迟排泄。充分的水化、碱化、及时进行MTX药代动力学指导的CF解救、以及对患者相关化疗风险的评估是保障HD-MTX化疗安全的重要因素。     

ALL患儿MTHFD1基因多态性与大剂量甲氨蝶呤血药浓度及不良反应的关系

目的:探讨亚甲基四氢叶酸脱氢酶1(MTHFD1)G1958A基因多态性与急性淋巴细胞白血病(ALL)患儿使用大剂量甲氨蝶呤(HD-MTX)化疗期间的MTX血药浓度及不良反应的关系。方法:收集70例急性淋巴细胞白血病患儿外周血,提取DNA,采用PCR技术和直接测序的方法分析MTHFD1基因的基因型;采用酶放大免疫法(EMIT)测定MTX给药后48 h的血药浓度;收集患者HD-MTX化疗期间的临床资料,统计不良反应相关信息,对化疗不良反应进行分级。分析MTHFD1基因多态性与MTX血药浓度及不良反应的关系。结果:MTHFD1 G1958A基因位点存在多态性,70例ALL患儿中GG、AG和AA基因型的分布频率分别为41.43%,52.86%,5.71%; G和A等位基因的分布频率分别为67.86%和32.14%。携带野生基因型(GG)ALL患儿的48hC/D值高于突变型基因型(GA+AA)携带者;携带野生基因型(GG)ALL患儿的骨髓抑制和肝脏损害不良反应发生率高于携带突变基因型(GA+AA)ALL患儿。由于个体间差异大,上述差异均无统计学意义( P>0.05)。结论:影响MTX的体内代谢和不良反应的因素复杂,MTHFD1 G1958A多态性尚不能作为ALL患儿HDMTX化疗所致骨髓移植和肝脏损害不良反应和预测MTX体内排泄的有效预测指标。     

临床药师参与处理1例大剂量甲氨蝶呤给药后期排泄延迟的案例分析

目的:使临床更加合理地使用甲氨蝶呤(MTX),减少不良反应发生。方法:对1例骨盆骨肉瘤患者行大剂量MTX治疗,以亚叶酸钙进行解毒治疗,并检测MTX的血药浓度,判断该患者发生了MTX后期清除延迟。另结合近期国内外相关文献,分析可能引起大剂量MTX排泄延迟的相关因素。结果与结论:患者生理状态、药物相互作用(如质子泵抑制剂)、药物代谢酶等多方面因素均可能导致MTX的排泄延迟。在临床应用中,应引起警惕,减少MTX排泄延迟的发生率,保证用药安全。     

基于群体药动学原理对1例甲氨蝶呤严重排泄延迟患儿的药学监护

目的:探讨群体药动学(PPK)在甲氨蝶呤(MTX)严重排泄延迟急性淋巴细胞白血病(ALL)患儿个体化解救过程中的价值,为临床药学服务提供参考。方法:临床药师参与1例MTX严重排泄延迟ALL患儿的临床解救过程。患儿接受大剂量MTX(HD-MTX)化疗后,出现MTX严重排泄延迟。临床药师借助PPK模型和贝叶斯反馈法预测患儿体内MTX血药浓度,并根据实测及预测结果在亚叶酸钙(CF)初始解救剂量(15 mg/m2,ivgtt,q6 h)的基础上,将入院第6、7天的CF解救剂量调整至160 mg/次,维持静脉滴注1 h;入院第8天,调整至42 mg/次;入院第9、10天,调整至21 mg/次;入院第11~16天,调整至10.5 mg/次;均为每天给药4次。考虑到患儿肾功能轻度受损,临床药师建议停用奥美拉唑,改用西咪替丁注射液0.2 g,ivgtt,qd护胃,并将注射用头孢他啶减量至0.4 g,ivgtt,tid;并嘱临床加强水化、碱化及口腔黏膜护理。结果:医师采纳临床药师建议。患儿体内MTX血药浓度预测值与实测值的差值不超过±0.32μmol/L,预测准确度良好。患儿在PPK模型指导下调整CF解救方案后,其体内MTX血药浓度降至0.13μmol/L,顺利完成此次化疗,于入院第18天出院。结论:PPK理论可为MTX严重排泄延迟ALL患者的临床解救提供参考,可作为临床药师开展药学服务的切入点之一。当患者出现MTX严重排泄延迟时,临床药师应充分掌握影响MTX排泄的因素,从患者的生理、病理情况,联合用药,体内血药浓度等多方面综合考虑,以确保解救的及时、有效。     

基于Logistic回归和ROC曲线对甲氨蝶呤消除延迟的预测分析

目的:应用Logistic回归模型和受试者操作特征(ROC)曲线探讨大剂量甲氨蝶呤化疗中引起消除延迟的危险因素,并对其发生风险进行预测。方法:82例急性淋巴细胞白血病患儿行大剂量甲氨蝶呤(HDMTX)化疗,MTX剂量为3~5g·m-2,24 h持续静脉滴注。PCR-RFLP法检测患儿有机阴离子转运多肽1B1(OATP1B1)的编码基因SLCO1B1 T521C的基因类型。固相萃取高效液相色谱法测定MTX用药后24,48,72 h血清中MTX浓度。采用残数法计算MTX给药48 h后药-时曲线下面积(AUC48-∞),按AUC48-∞值将病例分为消除延迟组和正常组。用单因素分析比较2组患儿在生物学特征、生化指标、基因位点变异等27个变量间的差异,找出显著性变量。用Logistic回归建立MTX消除延迟的最终预测模型。依据最终模型绘制ROC曲线以评估预测因子的预测效力。结果:单因素分析显示消除延迟组与正常组患儿在基因位点变异、48 h点7-OHMTX/MTX血药浓度比值分组(k48 h≤2)2个变量间存在显著性差异(P<0.05)。多因素Logistic回归分析显示,仅基因位点变异是发生MTX消除延迟的独立危险因素OR(95%CI)=14.545(4.391~48.181)。以SLCO1B1 521T>C作为预测因子绘制的ROC曲线AUC(95%CI)=0.751(0.627~0.875),具有显著性诊断意义(P<0.05)。结论:存在SLCO1B1 T521C基因位点变异的ALL患儿发生MTX消除延迟的风险较大,临床需加强血药浓度的监控以避免毒副反应的发生。     

大剂量甲氨蝶呤治疗儿童急性淋巴细胞白血病排泄延迟分析

目的观察大剂量甲氨蝶呤（HD-MTX）治疗儿童急性淋巴细胞白血病排泄延迟的发生率,探讨MTX排泄延迟与不良反应的关系。方法筛选101例ALL患儿,对其应用HD-MTX化疗的临床资料进行统计,对MTX排泄延迟及其不良反应加以分析。结果总体排泄延迟发生率为19.77%,两个剂量组排泄延迟发生率无显著性差异。发生排泄延迟的患儿MTX不良反应发生率较高,需增加甲酰四氢叶酸钙解救。结论MTX排泄延迟可增加其不良反应,临床应调整解救方案保证用药安全。     

1例大剂量甲氨蝶呤治疗白血病患儿排泄延迟的个体化治疗

摘要：本文报道1例白血病化疗中大剂量甲氨蝶呤排泄延迟患儿的个体化治疗实践,探讨在儿童白血病化疗中大剂量甲氨蝶呤排泄延迟解救的个体化治疗。临床药师利用药物基因检测预警甲氨蝶呤排泄延迟及不良反应风险,并提前做好相应预防措施,通过血药浓度监测指导亚叶酸钙解救,针对导致甲氨蝶呤排泄的危险因素(药物相互作用、尿液p H、尿液量、呕吐等)采取应对措施,为甲氨蝶呤排泄延迟患儿实施个体化解救,在保持化疗效果同时避免甲氨蝶呤毒性蓄积,可为同类患儿的甲氨蝶呤个体化治疗提供借鉴。     

1例SLCO1B1*5等位基因携带者服用辛伐他汀致横纹肌溶解症的案例分析

目的：探求他汀类相关肌病发生特点及易感因素。方法：报告1例服用辛伐他汀导致横纹肌溶解症,并对患者进行SLCO1B1基因型检测。结果：高龄、性别、肾功能不全、联合用药及携带SLCO1B1*5等位基因可能为该患者发生横纹肌溶解症的主要原因。结论：他汀类药物应采取个体化用药,肌病高危患者宜采取低剂量,并严密监测,通过基因检测可对患者进行风险筛查。     

儿童急性淋巴细胞白血病中ABCB1C3435T位点基因多态性对大剂量甲氨蝶呤血药浓度及不良反应的影响

目的 研究急性淋巴细胞白血病(ALL)儿童的ABCB1 C3435T位点(rs1045642)基因多态性与大剂量甲氨蝶呤(HD-MTX)化学治疗后血浆中甲氨蝶呤血药浓度和不良反应的相关性.方法 选取2015年8月至2019年6月于我院小儿血液内科住院治疗的132例ALL患儿,在接受HD-MTX治疗前应用聚合酶链反应(P...     

SLCO1B1基因多态性与阿托伐他汀的安全性及有效性相关性分析

目的 研究高脂血症患者SLCO1B1基因多态性与阿托伐他汀安全性及有效性的相关性。方法 收集金华市人民医院2017年4月—2018年4月在门诊确诊为高脂血症患者的基本资料,测定纳入患者的SLCO1B1 c.388A>G和c.521T>C的基因多态性,定期随访受试者,并定期测定其甘油三酯、胆固醇、低密度脂蛋白胆固醇及肌酸激酶等相关实验室检查指标。结果 纳入患者SLCO1B1 c.388A>G和c.521T>C等位基因频率分别为72.8%和15.9%。随访期结束后不同基因型患者的血清血脂指标变化率无明显差异。SLCO1B1 c.521T>C基因多态性与阿托伐他汀的安全性有相关性（P=0.005）。结论 SLCO1B1c.388A>G基因多态性对阿托伐他汀降脂疗效及安全性无影响。SLCO1B1 c.521T>C基因多态性与阿托伐他汀的降脂疗效无相关性,但对其安全性有一定影响。     

The effect of SLCO1B1*15 on the disposition of pravastatin and pitavastatin is substrate dependent: the contribution of transporting activity changes by SLCO1B1*15

OBJECTIVE: This study was addressed to understand the underlying mechanism of the substrate-dependent effect of genetic variation in SLCO1B1, which encodes OATP1B1 (organic anion transporting polypeptide) transporter, on the disposition of two OATP1B1 substrates, pravastatin and pitavastatin, in relation to their transport activities. METHODS: The uptake of pravastatin, pitavastatin, and fluvastatin was measured in oocytes overexpressing SLCO1B1*1a and SLCO1B1*15 to compare the alterations of in-vitro transporting activity. After 40-mg pravastatin or 4-mg pitavastatin was administered to 11 healthy volunteers with homozygous genotypes of SLCO1B1*1a/*1a and SLCO1B1*15/*15, the pharmacokinetic parameters of pravastatin and pitavastatin were compared among participants with SLCO1B1*1a/*1a and SLCO1B1*15/*15 genotypes. RESULTS: The uptake of pravastatin and pitavastatin in SLCO1B1*15 overexpressing oocytes was decreased compared with that in SLCO1B1*15, but no change occurred with fluvastatin. The fold change of in-vitro intrinsic clearance (Clint) for pitavastatin in SLCO1B1*15 compared with SLCO1B1*1a was larger than that of pravastatin (P<0.0001). The clearance (Cl/F) of pitavastatin was decreased to a greater degree in participant with SLCO1B1*15/*15 compared with that of pravastatin in vivo (P<0.01), consistent with in-vitro study. As a result, Cmax and area under the plasma concentration-time curve of these nonmetabolized substrates were increased by SLCO1B1*15 variant. The greater decrease in the transport activity for pitavastatin in SLCO1B1*15 variant compared with SLCO1B1*1a was, however, associated with the greater effect on the pharmacokinetics of pitavastatin compared with pravastatin in relation to the SLCO1B1 genetic polymorphism. CONCLUSION: This study suggests that substrate dependency in the consequences of the SLCO1B1*15 variant could modulate the effect of SLCO1B1 polymorphism on the disposition of pitavastatin and pravastatin.     

SLCO1B1 Polymorphism and Oral Antidiabetic Drugs

Abstract: Organic anion‐transporting polypeptide 1B1 (OATP1B1; gene: SLCO1B1) is an influx transporter expressed on the sinusoidal membrane of human hepatocytes, where it mediates the uptake of its substrates from blood into liver. In vitro, the SLCO1B1 c.521T > C (p.Val174Ala) single‐nucleotide polymorphism (SNP) has been associated with reduced and the c.388A > G (p.Asn130Asp) SNP with both enhanced and reduced transport activity of OATP1B1. In vivo in humans, the c.521C allele (present in SLCO1B1*5 and *15 haplotypes) is associated with decreased hepatic uptake and increased plasma concentrations of several OATP1B1 substrates. The SLCO1B1*1B (c.388G‐c.521T) haplotype is associated with enhanced hepatic uptake and decreased plasma concentrations of some OATP1B1 substrates. The SLCO1B1 c.521CC genotype has been associated with an about 60‐190% increased, and the SLCO1B1*1B/*1B genotype with an about 30% decreased area under the plasma concentration‐time curve of repaglinide. Moreover, SLCO1B1 polymorphism can affect the extent of interaction between OATP1B1 inhibitors and repaglinide. Accordingly, SLCO1B1 genotyping may help in choosing the optimal starting dose of repaglinide. In Chinese individuals, the SLCO1B1 c.521C allele has been associated with increased plasma concentrations of nateglinide, but the association could not be replicated in Caucasians. SLCO1B1 genotype has had no effect on the pharmacokinetics of rosiglitazone, pioglitazone or their metabolites. The hepatic uptake of metformin is mediated by organic cation transporters 1 and 3, and the liver is not important for the elimination or action of the dipeptidylpeptidase 4 inhibitors sitagliptin, vildagliptin and saxagliptin. Therefore, SLCO1B1 polymorphism unlikely affects the response to these antidiabetics. Possible effects of SLCO1B1 polymorphism on sulfonylureas remain to be investigated.     

Influence of SLCO1B1, 1B3, 2B1 and ABCC2 genetic polymorphisms on mycophenolic acid pharmacokinetics in Japanese renal transplant recipients

Objective We investigated the association between mycophenolic acid (MPA) pharmacokinetics and organic anion-transporting polypeptide (OATP/SLCO)1B1, 1B3, 2B1 and multidrug resistance-association protein 2 (MRP2/ABCC2) genetic polymorphisms and diarrhea. Methods Eighty-seven renal allograft recipients were given repeated doses of mycophenolate mofetil every 12 h at a designated time (09:00 and 21:00). The pharmacokinetics of MPA were analyzed on day 28 posttransplantation. Results The dose-adjusted area under the cuve (AUC)_6–12 of MPA, an estimate of enterohepatic recirculation, was greater in SLCO1B3 T334G GG (or G699A AA) carriers than in TT carriers (or G699A GG) (40 vs. 25 ng·h/mL per milligram, respectively, P = 0.0497). None of the polymorphism of SLCO1B1, SLCO2B1, or ABCC2 C-24T were associated with MPA pharmacokinetics or diarrhea. However, the oral clearance of MPA in recipients having both the SLCO1B3 T334G GG genotype and the ABCC2 C-24T T allele was significantly lower than in patients having both the SLCO1B3 T334G TT and ABCC2 C-24T CC genotypes (0.15 vs. 0.18 L/h per kilogram, respectively, P = 0.0010). Conclusions MPA excretion into bile in patients with SLCO1B3 T334G GG (or G699A AA) was higher than in those with T334G TT (or G699A GG), probably resulting in a higher AUC_6–12 value of MPA. MPA uptake into hepatocytes and excretion into bile at first pass may be greater in SLCO1B3 T334G GG carriers than in TT carriers. In addition, the ABCC2 C-24T polymorphism also seems to be associated with enhanced enterohepatic circulation of MPA. The SLCO1B3 and ABCC2 transporters rather than uridine diphosphate-glucuronosyltransferase (UGT) may partly affect interindividual variety in plasma MPA concentration.     

The effect of SLCO1B1 polymorphism on repaglinide pharmacokinetics persists over a wide dose range

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Organic anion transporting polypeptide 1B1 is an influx transporter expressed on the basolateral membrane of hepatocytes.
• A common single nucleotide polymorphism, c.521T→C (p.Val174Ala), of the SLCO1B1 gene has been associated with increased plasma repaglinide concentrations in healthy volunteers.
• Previous studies at low repaglinide doses have suggested that the effect of SLCO1B1 c.521T→C polymorphism on the pharmacokinetics of repaglinide could be dose-dependent.

WHAT THIS STUDY ADDS

• Repaglinide peak plasma concentration and area under the plasma concentration–time curve increased linearly along with repaglinide dose ranging from 0.25 to 2 mg in both the predominant c.521TT and rare c.521CC genotype group.
• The effect of SLCO1B1 c.521T→C polymorphism on repaglinide pharmacokinetics persists over a wide dose range.

AIMS

To establish whether the effect of SLCO1B1[encoding organic anion transporting polypeptide 1B1 (OATP1B1)] c.521T→C (p.Val174Ala) polymorphism on the pharmacokinetics of repaglinide is dose-dependent.

METHODS

Twelve healthy volunteers with the SLCO1B1 c.521TT genotype (controls) and eight with the c.521CC genotype ingested a single 0.25-, 0.5-, 1- or 2-mg dose of repaglinide in a dose-escalation study with a wash-out period of ≥1 week.

RESULTS

The mean area under the plasma concentration–time curve from time 0 to infinity (AUC_0–∞) of 0.25, 0.5, 1 or 2 mg repaglinide was 82% (95% confidence interval 47, 125), 72% (24, 138), 56% (24, 95) or 108% (59, 171) (P ≤ 0.001) larger in participants with the SLCO1B1 c.521CC genotype than in those with the c.521TT genotype, respectively. Repaglinide peak plasma concentration and AUC_0–∞ increased linearly along with repaglinide dose in both genotype groups (r > 0.88, P < 0.001). There was a tendency towards lower blood glucose concentrations after repaglinide administration in the participants with the c.521CC genotype than in those with the c.521TT genotype.

CONCLUSIONS

The effect of SLCO1B1 c.521T→C polymorphism on the pharmacokinetics of repaglinide persists throughout the clinically relevant dose range.     

Pharmacokinetics and response to pravastatin in paediatric patients with familial hypercholesterolaemia and in paediatric cardiac transplant recipients in relation to polymorphisms of the SLCO1B1 and ABCB1 genes

AIMS: Our aim was to investigate associations between the single nucleotide polymorphisms (SNPs) in the SLCO1B1 (encoding OATP1B1) and ABCB1 (encoding P-glycoprotein) genes with the pharmacokinetics and efficacy of pravastatin in children with heterozygous familial hypercholesterolaemia (HeFH) and in paediatric cardiac transplant recipients. METHODS: Twenty children with HeFH (aged 4.9-15.6 years) and 12 cardiac transplant recipients (aged 4.4-18.7 years and receiving triple immunosuppressive medication) who had participated in previous pharmacokinetic and pharmacodynamic studies with pravastatin were genotyped for the -11187G > A and 521T > C SNPs in the SLCO1B1 gene and for the 2677G > T/A and 3435C > T SNPs in the ABCB1 gene. RESULTS: Two HeFH patients with the -11187GA genotype had a 81% lower peak plasma pravastatin concentration (Cmax) (difference in means -13.9 ng ml(-1), 95% CI -21.1, -6.7; P < 0.001) and a 74% smaller area under the plasma concentration-time curve (AUC0, infinity) (-25.3 ng ml(-1) h, 95% CI -35.6, -15.0; P < 0.0001) and significantly greater increase in high density lipoprotein (HDL) cholesterol after 2 months treatment with pravastatin than patients with the reference genotype. No significant differences were seen in the pharmacokinetics or effects of pravastatin between HeFH patients with the SLCO1B1 521TC and 521TT genotypes. The cardiac transplant recipients with the SLCO1B1 521TC genotype (n = 3) had a 46% lower Cmax (-67.7 ng ml(-1), 95% CI -135.7, 0.3; P = 0.055) and 62% lower AUC(0,24 h) (-228.5 ng ml(-1) h, 95% CI -402.7, -54.3; P = 0.016) and a shorter half-life (t1/2) (0.9 +/- 0.1 vs. 1.3 +/- 0.4 h, P = 0.015) of pravastatin than those with the reference genotype. Decreases in total and low-density lipoprotein cholesterol by pravastatin were significantly smaller, and the increase in HDL-cholesterol was greater in the transplant recipients with the 521TC genotype compared with patients with the 521TT reference genotype. CONCLUSIONS: In children with HeFH and in paediatric cardiac transplant recipients receiving immunosuppressive medication, the -11187G > A and SLCO1B1 521T > C SNPs were associated with decreased plasma concentrations of pravastatin. These differences are opposite to those seen previously in healthy adults. The mechanisms underlying these phenomena are unclear and warrant further study.