肝肾联合移植患者免疫抑制剂的应用

背景:不同单一器官移植后调动机体免疫反应的力度各不相同,故其免疫抑制剂的应用种类及剂量有所差异,多器官联合移植工作中,免疫抑制剂的应用则更为复杂,是移植工作者需要逐步总结的经验之一。目的:探讨肝肾联合移植患者合理的免疫抑制剂应用方案。方法:选择解放军第309医院器官移植中心2002-04/2009-07肝肾联合移植患者10例,以单独肝移植及肾移植患者为对照。3组患者术后早期抗排斥治疗均采用以他克莫司为基础的三联免疫抑制方案,在此方案基础上同时应用巴利昔单抗诱导疗法。肝肾联合移植组和肝移植组患者术中给予甲基泼尼松龙500mg冲击,术后第1天激素用量为160mg,分2次给药,此后每日递减40mg,术后第5天改为20mg泼尼松口服,术后2个月停用激素,术后6个月停用霉酚酸酯,仅应用他克莫司抗排斥治疗;肾移植组术中给予甲基泼尼松龙1000mg冲击,术后前3d应用甲基泼尼松龙500mg,此后每日50mg泼尼松口服,逐渐递减至每日10mg长期维持,术后长期应用他克莫司、霉酚酸酯和糖皮质激素。结果与结论:肝肾联合移植患者术后早期及术后6个月他克莫司用量同肝移植患者相近(P0.05),但低于肾移植患者(P0.05,P0.01);肝肾联合移植和肝移植患者激素和霉酚酸酯用量亦明显低于肾移植患者,并且均在半年内停用激素和霉酚酸酯,肾移植患者需长期应用。3组病例1年后维持用药逐渐体现出个体差异现象。肝肾联合移植组均未出现远期肝功能异常,同时低剂量抗排斥药物对患者免疫系统影响较小,围手术期感染发生率明显减低。说明肝肾联合移植患者免疫抑制剂早期的应用参考单肝移植患者即可达到满意的治疗效果,激素和霉酚酸酯可在6个月内停药,他克莫司用量可低于单肾脏移植患者。     

肾移植受者CYP3A5基因多态性对他克莫司血药浓度及疗效的影响*

背景：关于欧美人群中CYP3A5基因与他克莫司血药浓度之间关系已有报道,然而这些研究的数据多来自于移植后1个   月~1年,缺乏移植后早期的资料。 目的：探讨CYP3A 基因多态性与肾移植受者他克莫司血药浓度的关系,分析CYP3A5基因型对肾移植后排斥反应和毒性及不良反应的影响。 方法：按CYP3A5基因多态性将45例采用他克莫司+霉酚酸酯+泼尼松三联免疫抑制方案的肾移植患者分为*1/*1型组(11例)、*1/*3型组(15例)和*3/*3型组(19例),他克莫司初始剂量均为0.15 mg/(kg•d),1周后根据目标浓度调整他克莫司剂量。 结果与结论：术后7 d,1个月,3个月* 3/* 3型组他克莫司血药浓度/剂量比显著高于* 1/*3型组和*1/*1型组(P < 0.05) ;3个月内*1/*1型组急性排斥反应的比例显著高于*1/*3型组和*3/*3型组(P < 0.05)。3个月内*3/*3型组高血糖、神经及肾毒性等不良反应显著高于*1/*1型组。结果可见*1/*1基因型患者在肾移植早期难以达到有效目标血药浓度,使该组3个月内的急性排斥反应发生率明显升高,不合适采用目前他克莫司的初始剂量方案作为早期的抗排斥反应方案;*3/*3基因型患者他克莫司血药浓度明显升高,使3个月内毒性及不良反应发生率也明显升高。因此,根据CYP3A5 基因多态性作为他克莫司个体化用药的依据,既能使* 1 /* 1型患者早期急性排斥反应的发生率下降,又能使* 3 /*3型患者的药物不良反应减少,提高肾移植的临床效果。      

肾移植后他克莫司与五酯胶囊合用致高血钾症1例

背景：肾移植患者由于免疫抑制剂的药物肝毒性,肝功能异常发生率高,对临床出现肝功能异常者,需护肝治疗。但合用护肝药必须监测免疫抑制剂浓度。 目的：探讨肾移植患者他克莫司与五酯胶囊合用对他克莫司浓度及血生化的的影响。 方法：回顾性分析1例以他克莫司为免疫抑制剂的肾移植患者加服及停用五酯胶囊时他克莫司浓度及肾功能、血生化变化。患者因“慢性肾小球肾炎,慢性肾功能不全”于1998-06起行血液透析治疗。2000-08行同种异体尸体肾移植,移植后免服他克莫司+吗替麦考酚酯+泼尼松。移植后4个月患者出现肝功能异常,加用联苯双酯。2010-07-25患者停用联苯双酯,改服五酯胶囊。2010-07-29患者停用五酯胶囊。 结果与结论：服用他克莫司的肾移植受者,合用五酯胶囊,他克莫司血浓度显著升高。由5.3 ng/L升至24.7 ng/L,并合并高血钾症,停用五酯胶囊1周,他克莫司浓度由24.7 ng/L降至6.1 ng/L,血钾由6.4 mmol/L降至4.6 mmol/L。提示移植肾功能稳定的肾移植受者,在加用五酯胶囊,必须严密监测他克莫司血浓度及肝肾功能、电解质,及时调整他克莫司用量,保护移植肾功能。     

肝移植后他克莫司血药浓度对外周血单个核细胞内HBV DNA的影响

背景：肝移植后他克莫司等免疫抑制剂的长期应用导致机体细胞免疫功能降低,并有可能影响机体对乙肝病毒的清除。 目的：分析乙肝相关肝移植患者后不同浓度他克莫司对外周血单个核细胞中的HBV DNA含量的影响。 方法：纳入乙肝相关终末期肝病肝移植受者23例,根据移植后12周清晨空腹他克莫司血药浓度,分为高浓度组(≥ 10 μg/L) 9例和低浓度组(< 10 μg/L)14例,同时用荧光标记单克隆抗体结合流式细胞技术检测外周血T细胞亚群的百分比,用实时荧光定量PCR检测外周血单个核细胞内的HBV DNA。 结果与结论：用多元线性回归分析外周血单个核细胞内的HBV DNA含量与CD8⁺CD152⁺呈正相关,与CD8⁺CD28⁺呈负相关。高血药浓度他克莫司的患者外周血单个核细胞内的HBV DNA高于低浓度组,其改变与反映细胞免疫功能的指标CD8⁺CD152⁺和CD8⁺CD28⁺的变化有关。     

他克莫司对肾移植受者外周血NK和NKT细胞比例的影响及临床意义

他克莫司(Tacrolimus)是一种强效免疫抑制剂,现已广泛应用于肾脏、肝脏及心脏移植,有效减低了排异反应的发生,提高了移植受者的存活率.但是他克莫司个体药代动力学差异大,不同个体对其血药浓度的敏感性及耐受性有差异,故单纯依靠血药浓度监测不能有效反映移植受者的免疫状态.因此如何了解移植受者的免疫状态,指导免疫抑制剂的个体化应用,在免疫抑制不足及免疫过度之间寻找平衡,成为困扰移植医生的问题.NK细胞(natrural killer cell)是天然免疫系统的主要效应细胞.     

两种免疫法联合肾功能指标测定他克莫司血药浓度的比较

背景：不同免疫法测定的他克莫司血药浓度,对免疫抑制作用及毒性反应的预测能力是否有差异,在肾功能异常时是否能够更加敏感的反映患者血药浓度,是值得研究的问题。目的：联合肾功能指标,分析酶联免疫吸附技术和酶增强免疫技术测定他克莫司血药浓度的相关性。方法：收集133例应用他克莫司治疗的肾移植患者血样,分别用酶联免疫吸附技术、酶增强免疫技术测定血药浓度。分析两种方法测定的相同浓度范围内肾功能异常的发生率;分析不同浓度范围内,两种方法测定结果的相关性。结果与结论：在肾功能异常时,比较两种方法测定的浓度,酶联免疫吸附法测定结果均值较高,且波动较大。酶联免疫吸附法测定他克莫司血药浓度5-20 μg/L范围内,肾功能异常发生率较酶增强免疫法少,分析显示两种方法测定结果总体差异无显著性意义(r=0.904 5,P > 0.05)。以酶联免疫吸附法为标准,在他克莫司血药浓度< 2.0 μg/L时,酶增强免疫法测定结果明显较高(P < 0.01)。在血药浓度为≥2.0 μg/L时,两种方法测定结果差异无显著性意义(P > 0.05)。说明酶增强免疫法与酶联免疫吸附法相关性较好,均适合于临床常规测定他克莫司的血药浓度,建议结合肾功能指标,细化区分两种测定方法的参考范围。同时,在患者血药浓度极低(< 2.0 μg/L)时,不建议采用酶增强免疫法。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

环孢素A和他克莫司对肾移植受者血脂的影响

背景:高血脂为肾移植后常见的并发症,常用的免疫抑制剂包括环孢素A,泼尼松和他克莫司都会对患者血脂产生影响。目的:探讨他克莫司与环孢素对肾移植术后患者血脂的影响。方法:按照不同的服药方案将肾移植后的患者随机分成2组:环孢素A组(n=20),免疫抑制剂方案为环孢素A+麦考酚酸莫酯+泼尼松;他克莫司组(n=23),免疫抑制剂方案为他克莫司+麦考酚酸莫酯+泼尼松。于移植前,移植后1个月及6个月对患者抽血化验,观察两组患者总胆固醇、三酰甘油、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇的变化。结果与结论:两组各项指标移植前后比较均有差异,两组间比较,移植后1个月和6个月总胆固醇和低密度脂蛋白胆固醇差异显著(P0.05);高密度脂蛋白胆固醇和三酰甘油之间差异不显著。结果表明:对肾移植后肾功能稳定的患者实施以环孢素A为免疫抑制剂的方案,三酰甘油和低密度脂蛋白胆固醇更易升高,他克莫司在脂类代谢方面表现出更少的不良反应。与环孢素A相比,肾移植后患者应用他克莫司高脂血症的发病率明显降低。     

MDR1基因多态性对肝移植受体普乐可复治疗的影响

目的探讨普乐可复（Tacrolimus，FK506）服用剂量和血药浓度的个体差异与供受体多药耐药基因1（multidrug resistance gene 1，MDR1）多态性的关系。方法监测50例口服普乐可复的肝移植受体体重、服药剂量、全血谷浓度，用PCR-限制性片段长度多态性分析的方法检测供受体MDR1第3435位C／T基因型，计算每日每公斤体重的FK506用量和血药浓度与每日每公斤体重的FX505用量的比值，并分析与供受体MDR1基因型的关系。结果在各50例供受体研究中，23％为MDR1 CC基因型，54％为CT基因型，13％为TT基因型。MDR1 CC基因型受体的每日每公斤体重的FK506用量明显高于CT和TT基因型受体，前者血药浓度与每日每公斤体重的FK506用量的比值显著低于后两者，供体MDR1基因型对此无明显影响。结论普乐可复服用剂量和血药浓度与受体的MDR1第3435位点基因多态性相关。MDRI多态性分析可指导肝移植受体普乐可复临床用药的个体化。     

他克莫司和西罗莫司对行肝癌肝移植患者Foxp3+调节性T细胞产生及肝癌复发的影响

背景：通过促进调节性T细胞的产生及增强其功能的发挥已成为维持移植物免疫耐受的有效手段。 目的：探讨他克莫司和西罗莫司对行肝移植的肝癌患者Foxp3⁺调节性T细胞产生及肝癌复发的影响。 方法：纳入符合米兰标准的肝癌肝移植患者40例,随机分为西罗莫司组和他克莫司组,每组20例,移植后第2~12个月间每月抽取受试者外周血检测Foxp3⁺调节性T细胞,并行彩超和外周血检测甲胎蛋白,必要时肝穿刺活检观察排斥反应及肿瘤的复发情况。 结果与结论：流式细胞仪检测结果显示,西罗莫司组外周血Foxp3⁺调节性T细胞阳性率明显高于他克莫司组(P < 0.05),移植肝穿刺活检证实西罗莫司组排斥反应与他克莫司组差异无显著性意义(P > 0.05),而移植肝彩超、外周血甲胎蛋白检测及移植肝穿刺活检或手术亦证实在肝癌复发率方面西罗莫司组明显低于他克莫司组(P < 0.05)。说明西罗莫司在肝癌肝移植中对肿瘤复发的抑制作用方面优于他克莫司,且排斥反应较他克莫司并未增加,甚至有更好的免疫耐受效果。     

多药耐药基因1 C3435T基因多态性对环孢素A药物动力学影响的Meta分析

背景：多药耐药基因1 C3435T基因多态性影响着P-糖蛋白的功能和表达,从而影响环孢素A血药浓度,产生个体差异。目前多药耐药基因1 C3435T基因多态性对环孢素A药物动力学影响的研究结果不一。 目的：基于国内外报道的国内相关研究,系统评价多药耐药基因1 C3435T基因多态性与环孢素A药物动力学的关系。 方法：计算机检索Cochrane图书馆、Medline、Plumbed、CNKI、万方等数据库,并辅以文献追溯的方法,收集国内外公开发表的国内相关病例对照、队列研究。检索年限均为从建库至2011-12-31。按纳入、排除标准筛选文献并评价纳入研究的质量后,采用RevMan 5.1软件进行Meta分析。 结果与结论：共纳入9篇文献,合计893例患者。Meta分析结果表明,多药耐药基因1 3435CC的环孢素A剂量调整谷浓度显著低于CT基因型(P=0.007)和TT基因型(P=0.000 6);亚组分析显示,肾移植后患者多药耐药基因1 3435CC的环孢素A剂量调整谷浓度显著低于CT基因型 (P < 0.000 01)及TT基因型(P=0.000 3);血液系统疾病患者多药耐药基因1 3435CC的环孢素A剂量调整谷浓度显著低于TT基因型(P=0.004)。多药耐药基因1 3435CC的环孢素A剂量调整峰浓度显著低于TT基因型(P=0.005)。提示多药耐药基因1 C3435T基因多态性对环孢素A血药浓度有影响,CC基因型患者血药浓度低于TT基因型。还需要大样本、前瞻性研究来探讨多药耐药基因1 C3435T基因多态性与环孢素A药物动力学的关系。     

Influence of CYP3A5 and ABCB1 gene polymorphisms and other factors on tacrolimus dosing in Caucasian liver and kidney transplant patients

Tacrolimus is a substrate of cytochrome P4503A (CYP3A) enzymes as well as of the drug transporter ABCB1. We have investigated the possible influence of CYP3A5 and ABCB1 single nucleotide polymorphisms (SNPs) and other factors (e.g. albumin, hematocrit and steroids) on tacrolimus blood levels achieved in a population of Caucasian liver (n=51) and kidney (n=50) transplant recipients. At 1, 3 and 6 months after transplantation, tacrolimus doses (mg/kg/day) and trough blood levels (C0) were recorded and the weight-adjusted tacrolimus dosage (mg/kg/day) was calculated. Polymerase chain reaction followed by restriction fragment length polymorphism analysis was used for genotyping CYP3A5*1 and *3 [6986A>G] as well as ABCB1 at exons 21 [2677G>T/A] and 26 [3435C>T] in both liver transplant donors and recipients and in kidney transplant recipients. Of the 152 subjects studied, 84.9% showed a CYP3A5*3/*3 genotype. The total frequency of the allelic variant *3 was 93%. For the G2677T/A and C3435T polymorphisms the total frequencies of the allelic variants T/A and T were 44.7 and 46.7%, respectively. At 1, 3 and 6 months after transplantation the dose-adjusted C0 levels were significantly lower in patients with one copy of the *1 allele compared to those homozygous for the *3 allele. In the case of liver transplant patients the tacrolimus dose requirements were dominantly influenced by the polymorphisms of the CYP3A5 gene in the donors. With regard to the ABCB1 SNPs, in general they did not show any appreciable influence on tacrolimus dosing requirements; however, kidney transplant recipients carrying the 2677T/A allele required significantly higher daily tacrolimus doses than subjects homozygous for the wild-type allele. Identification of CYP3A5 single nucleotide polymorphisms prior to transplantation could contribute to evaluate the appropriate initial dosage of tacrolimus in the patients.     

Identifying candidate causal variants responsible for altered activity of the ABCB1 multidrug resistance gene

The difficulty of fine localizing the polymorphisms responsible for genotype-phenotype correlations is emerging as an important constraint in the implementation and interpretation of genetic association studies, and calls for the definition of protocols for the follow-up of associated variants. One recent example is the 3435C>T polymorphism in the multidrug transporter gene ABCB1, associated with protein expression and activity, and with several clinical conditions. Available data suggest that 3435C>T may not directly cause altered transport activity, but may be associated with one or more causal variants in the poorly characterized stretch of linkage disequilibrium (LD) surrounding it. Here we describe a strategy for the follow-up of reported associations, including a Bayesian formalization of the associated interval concept previously described by Goldstein. We focus on the region of high LD around 3435C>T to compile an exhaustive list of variants by (1) using a relatively coarse set of marker typings to assess the pattern of LD, and (2) resequencing derived and ancestral chromosomes at 3435C>T through the associated interval. We identified three intronic sites that are strongly associated with the 3435C>T polymorphism. One of them is associated with multidrug resistance in patients with epilepsy (chi2 = 3.78, P = 0.052), and sits within a stretch of significant evolutionary conservation. We argue that these variants represent additional candidates for influencing multidrug resistance due to P-glycoprotein activity, with the IVS 26+80 T>C being the best candidate among the three intronic sites. Finally, we describe a set of six haplotype tagging single-nucleotide polymorphisms that represent common ABCB1 variation surrounding 3435C>T in Europeans.     

Therapeutic drug monitoring of immunosuppresants

The pharmacokinetics and pharmacodynamics of tacrolimus were evaluated in the pediatric recipients of living-related liver transplant. The mean clearance for tacrolimus was estimated with large interindividual variability and was shown to change as a function of days after operation. The therapeutic blood concentration of tacrolimus ranges were concerned from nearly 10 to 20 ng/ml. We have examined whether the expression levels of the intestinal absorptive barriers, MDR1 gene product P-glycoprotein and cytochrome P450 IIIA4(CYP3A4), correlate with the trough levels of orally administered tacrolimus in a recipient of small bowel transplant for 4 months. Both the MDR1 and CYP3A4 mRNA levels changed markedly through out this period. The tacrolimus concentration/dose ratio correlated well with the mRNA expression level of MDR1, but not CYP3A4. Intestinal P-glycoprotein rather than CYP3A4 is a good probe to predict the intraindividual variation in the tacrolimus pharmacokinetics.     

Association of abcb1 polymorphisms and ulcerative colitis susceptibility

Objective: Multi-drug resistance gene 1 (ABCB1) is closely related to bowel diseases. Therefore, our study was aimed to evaluate the correlation between ABCB1 polymorphisms (C1236T and C3435T) and ulcerative colitis (UC) susceptibility. Methods: A total of 61 UC patients and 64 healthy people participated in the study. Genotyping was conducted with the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). χ² test was used to evaluate the association of ABCB1 gene polymorphisms (C1236T and C3435T) and UC susceptibility. Results: For ABCB1 C1236T polymorphism, the frequencies of CC genotype and C allele were found higher in the cases than those in the controls (CC: 36.1% vs. 20.3%; C: 58.2% vs. 41.4%), which indicated that the CC genotype and C allele might increase the risk for UC (OR = 3.39, 95% CI = 1.28-8.97; OR = 1.97, 95% CI = 1.19-3.26). However, there were no statistical differences in the genotype or allele distribution of ABCB1 C3435T between the case and control group. Conclusion: The CC genotype and C allele of ABCB1 C1236T polymorphisms are significantly associated with UC susceptibility, so we conclude that ABCB1 C1236T polymorphisms might serve as genetic-susceptibility factors for UC. While, no remarkable relationship is observed between ABCB1 C3435T polymorphisms and UC.     

ABCB1 polymorphisms associated with osteonecrosis of the femeral head

Aims: This case-control study was conducted to investigate the relation of ATP-binding cassette subfamily B member 1 (ABCB1) C1236T and C3435T polymorphisms and non-traumatic osteonecrosis of the femeral head (ONFH). Methods: We gathered 113 ONFH patients and 116 controls in the study. The polymorphisms of ABCB1 were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Odds ratio (OR) with 95% confidence interval (CI) were adopted to analyze the correlation between ABCB1 polymorphisms and ONFH. Results: In the study, we found that the frequency of C3435T TT genotype was much lower in case group, compared with that of controls (17.7% vs. 23.3%). Moreover, OR and 95% CI values indicated that C3435T TT genotype served as a protective factor for ONFH (OR=0.34, 95% CI=0.15-0.75). Meanwhile, the risk for the T allele carriers was much lower than C allele (OR=0.60, 95% CI=0.42-0.87). However, C1236T polymorphism showed no significant effects on the pathogenesis of ONFH. In the haplotype analysis, T-T haplotype appeared to be an inhibitor for ONFH (OR=0.45, 95% CI=0.23-0.87). Conclusions: Based on the results, ABCB1 polymorphisms were associated with the risk for ONFH.     

Effect of CYP3A4, CYP3A5, and ABCB1 Polymorphisms on Intravenous Tacrolimus Exposure and Adverse Events in Adult Allogeneic Stem Cell Transplant Patients

Pharmacogenetics influences oral tacrolimus exposure; however, little data exist regarding i.v. tacrolimus. We investigated the impact of genetic polymorphisms in CYP3A4, CYP3A5, and ABCB1 on i.v. tacrolimus exposure and toxicity in adult patients receiving an allogeneic hematopoietic stem cell transplant for hematologic malignancies. Germline DNA was extracted from buccal swabs and genotyped for CYP3A4, CYP3A5, and ABCB1 polymorphisms. Continuous i.v. infusion of tacrolimus .03 mg/kg/day was initiated on day +5 post-transplant, and steady-state blood concentrations were measured 4days later. We evaluated the association between phenotypes and prevalence of nontherapeutic target concentrations (below or above 5 to 15 ng/mL) as well as tacrolimus-related toxicities. Of 63 patients, 28.6% achieved the target concentration; 71.4% were >15ng/mL, which was more common in CYP3A4 intermediate/normal metabolizers (compared with rapid) and those with at least 1 ABCB1 C2677T loss-of-function allele (P < .05). ABCB1 C2677T was significantly associated with concentrations >15ng/mL (odds ratio, 6.2; 95% confidence interval, 1.8 to 23.6; P = .004) and tacrolimus-related toxicities (odds ratio, 7.5; 95% confidence interval, 1.6 to 55.2; P = .02). ABCB1 C2677T and CYP3A4 are important determinants of i.v. tacrolimus exposure, whereas ABCB1 C2677T also impacts tacrolimus-related toxicities in stem cell transplants.