西罗莫司不同血药浓度对肾移植患者肝肾功能的影响

目的探讨西罗莫司不同血药浓度对肾移植患者肝肾功能的影响。方法 45例肾移植术后服用西罗莫司治疗的患者,采用高效液相色谱法(HPLC法)检测西罗莫司的血液浓度,比较分析不同血药浓度下肝肾指标的变化情况。结果西罗莫司血药浓度≤8 ng/ml组患者的天门冬氨酸肌转酶(AST)、丙氨酸氨基转移酶(ALT)、直接胆红素(DBIL)分别为(65.26±12.68)U/L、(70.19±13.66)U/L、(11.05±9.64)μmol/L,显著低于>8 ng/ml组,差异均具有统计学意义(P<0.05);西罗莫司血药浓度为4~8 ng/ml组患者的内生肌酐清除率(Ccr)为(82.64±17.32)ml/(min·70 kg),显著高于<4 ng/ml组、>8 ng/ml组,差异具有统计学意义(P<0.05)。结论肾移植术后采用西罗莫司行免疫抑制治疗时,血药浓度控制在4~8 ng/ml最佳。     

肾移植受者应用西罗莫司治疗窗的临床研究

目的:探讨西罗莫司应用于国内肾移植受者的治疗窗范围。方法:采用多中心、开放性临床研究,来自国内4家移植中心的首次肾移植病人共100例。免疫抑制方案为西罗莫司联合环孢素和皮质激素的三联疗法。移植后48h内开始服用西罗莫司,首次负荷剂量为6mg·d-1,维持剂量为2mg·d-1,采用高效液相色谱法测定西罗莫司浓度。结果:100例病人西罗莫司总的全血谷浓度为(6.6±s2.8)μg·L-1,10及90百分位数浓度分别为3.2μg·L-1和10.26μg·L-1。肾移植后6mo内急性排斥发生率为10%(8/84),此8例病人急性排斥时的西罗莫司浓度明显低于非排斥时浓度(P<0.01)。主要不良反应为肝功能损害和高脂血症,三酰甘油浓度与西罗莫司浓度相关(r=0.276,P<0.01)。结论:西罗莫司浓度维持在4～8μg·L-1范围内较为合适,定期监测血药浓度,合理调整用量,可增加西罗莫司应用的有效性及安全性。     

肾移植患者西罗莫司的群体药动学研究

目的:建立中国肾移植患者西罗莫司的群体药动学模型,为实施个体化用药提供理论支持。方法:选择47名肾移植术后采用西罗莫司+泼尼松+环孢素或他克莫司或霉酚酸酯(MMF)三联免疫抑制治疗的患者为研究对象,回顾性收集47名患者服药后的101个西罗莫司稳态血药浓度及相应的试验室检查数据,运用Winnonmix药动学软件,采用非线性混合效应模型(NONMEM)分析体重、年龄、性别、给药剂量、合并用药、肌酐清除率等对药动学参数的影响。最终模型的验证采用Jackknife法进行内部验证。结果:西罗莫司符合无滞后时间的一级消除动力学一室模型。固定效应结果量子,合用MMF和体重可影响药物清除率。最终模型公式为:CL/F(L·h-1)=11.01×0.14MMF+0.089×W。CL/F和Vd/F的群体典型值分别是11.01L·h-1和3616L,个体间变异分别为62.82%和85.07%。观测值和预测值间的残差(SD)和相关系数(r)分别是1.0ng·mL-1和0.94。结论:所建立的群体药动学模型能较好地估算服用西罗莫司的肾移植患者的个体及群体药动学参数,对指导临床个体化用药具有重要意义。     

儿童患者西罗莫司血药浓度监测及临床应用分析

目的:探讨西罗莫司在儿童患者中的血药浓度,考察血药浓度与相关实验室指标的关系,为西罗莫司的合理应用提供更多的临床依据.方法:选择54例使用西罗莫司治疗的患儿,记录基本信息、西罗莫司全血谷浓度(CSRL)、肝功能和中性粒细胞计数(NEU)等相关信息.结果:儿童患者西罗莫司血药浓度为(8.7±5.9) ng/mL,16.7...     

他克莫司治疗风湿免疫病患者安全性分析*

回顾分析93例他克莫司治疗风湿免疫病患者剂量、血药浓度和不良反应的相关性。他克莫司血药浓度与剂量呈正相关（P<0.05）,其血药浓度范围在5.4~14 ng·mL-1时,尿素氮（BUN）显著升高（P<0.05）,血糖略升高（P>0.05）,高血糖发生率显著上升至26.1%（6/23）（P<0.05）。以上结果表明,他克莫司血药浓度范围在0.2~5.3 ng·mL-1,安全性较高,当血药浓度范围在5.4~14 ng·mL-1时,需要监测患者BUN和血糖。     

人工神经网络模型在肾移植患者西罗莫司个体化给药中的应用

目的:建立人工神经网络用于估算西罗莫司血药浓度的方法。方法:收集56例肾移植患者口服西罗莫司的182份全血浓度数据,采用遗传算法配合动量法优化网络参数,建立人工神经网络,并对测试数据进行处理,验证测试结果。结果:人工神经网络平均预测误差(MPE)与平均绝对误差(MAE)分别为(0.31±1.14)、(0.89±0.77)ng·mL-1,32例/次(88.9%)血药浓度数据绝对预测误差≤2.0ng·mL-1。人工神经网络模型准确性及精密度优于多元线性回归及非线性混合效应模型。结论:人工神经网络模型可用于预测西罗莫司血药浓度,指导个体化给药。     

肾移植病人西罗莫司血药浓度/剂量比与CYP3A5基因多态性的关系

目的:研究肾移植术后病人CYP3A5基因多态性与免疫抑制剂西罗莫司临床个体化给药剂量的关系。方法:采用聚合酶链反应(PCR)和限制性内切片段多态性(RFLP)的方法对105例健康受试者和50例肾移植术后病人进行CYP3A5基因分型。使用高效液相色谱(HPLC)测定病人的西罗莫司血药浓度。比较不同基因型之间的西罗莫司的血药浓度与每千克体重的剂量(C/D)比值的差异。结果:健康受试者和肾移植病人的CYP3A5 A6986G SNPs,CYP3A5*3的发生频率分别为72.9％和71％,差异无显著意义(P>0.05)。肾移植*1/*3型病人的C/D比值(362±s108)μg·L~(-1)per mg·kg~(-1)和*3/*3型病人的C/D比值(375±123)μg·L~(-1)per mg·kg~(-1)差异无显著意义(P>0.05),但两者C/D值均明显高于*1/*1型病人(199±65)μxg·L~(-1)per mg·kg~(-1),差异具有显著意义(P<0.05)。结论:肾移植病人的CYP3A5基因多态性与西罗莫司血药浓度具有相关性,*1/*3型和*3/*3型病人拟取得相似的血药浓度要比*1/*1型病人服用更低剂量的西罗莫司。研究肾移植病人的CYP3A5基因型,有利于肾移植病人术后西罗莫司个体化用药方案的制定。     

中国肾移植患者中不同的CYP3A5*3基因型与西罗莫司血药浓度的关系

回顾性收集了服用西罗莫司的80例肾移植患者病例,建立了四引物法检测其CYP3A5基因型,并以聚合酶链反应-限制性片段长度多态性(PCR-RFLP)法进行对照.采用微粒子化学发光免疫法测定患者西罗莫司的谷浓度.80位患者的CYP3A5*3基因频率为79%.*1/*1基因型患者有3人(3.75%),*1/*3基因型有28人(35%),*3/*3基因型有49人(61.25%).三种基因型患者西罗莫司平均血药谷浓度分别为(4.17±0.90)、(5.96±2.43)和(6.39±2.86)ng/ml.表明不同CYP3A5基因型患者西罗莫司血药浓度差异显著,含有CYP3A5*1等位基因患者的西罗莫司血药浓度明显低于*3/*3组(P<0.05).     

他克莫司血药浓度与肾病综合征的临床疗效相关性研究

目的 研究他克莫司治疗肾病综合征(NS)的临床疗效与其血药浓度的相关性。方法 34例 NS患者服用他克莫司达稳态血药浓度后,用酶增强免疫分析法(EMIT)测定他克莫司全血谷浓度,对患者进行随访,观察药物的治疗效果及不良反应,并应用统计学软件SPSS 13.0分析他克莫司血药浓度与临床疗效的相关性。结果 完全缓解(CR)组的血药浓度为(8.11±3.23)ng·mL^-1,部分缓解(PR)组的血药浓度为为(6.08±1.15)ng·mL^-1,无反应(NR)组为(3.25±0.96)ng·mL^-1,缓解率82.4%。他克莫司血药浓度与临床疗效进行Spearmen等级相关系数分析,rs=0.611>0.5>0,P<0.01,t(α/2)=0.01,呈正相关,相关性密切。结论 他克莫司治疗肾病综合征的临床疗效与血药浓度密切相关,他克莫司全血谷浓度在4.88~11.34 ng·mL^-1内,可达到满意的治疗效果。     

中国肾移植病人西罗莫司基因多态性研究

目的研究肾移植术后病人MDR1和CYP3A5基因多态性与免疫抑制剂西罗莫司临床个体化给药剂量的关系。方法采用聚合酶链反应(PCR)和限制性内切片段多态性(RFLP)的方法对105例健康受试者和50例肾移植术后的病人进行MDR1和CYPA5基因分型。使用高效液相色谱(HPLC)测定病人的西罗莫司血药浓度。比较不同基因型之间的西罗莫司的血药浓度与每公斤体重的剂量比值(c/D)的差异。结果健康受试者和肾移植病人的CYP3A5 A6986G SNPs,CYP3A5*3的发生频率分别为72.9%和71%;MDR1 C3435T SNPs的发生频率分别为51.0%和44.0%,差异均无显著意义(P>0.05)。肾移植*1/*3型病人的c/D比(362±108)μg·L~(-1)per mg·kg~(-1)和*3/*3型病人的c/D比(375±123)μg·L~(-1) per mg·kg~(-1),差异无显著意义(P>0.05),但两者c/D值均明显高于*1/*1型病人(199±65)μg·L~(-1) per mg·kg~(-1),差异具有显著意义(P<0.05)。而MDR1不同基因型对c/D的差异无显著意义。结论肾移植病人的CYP3A5基因多态性与西罗莫司血药浓度具有相关性,*1/*3型和*3/*3型病人拟取得相似的血药浓度要比*1/*1型病人服用更低剂量的西罗莫司。研究肾移植病人的CYP3A5基因型,有利于肾移植病人术后西罗莫司个体化用药方案的制定。     

Relationships between sirolimus dosing, concentration and outcomes in renal transplant recipients

AIM: To explore relationships between sirolimus dosing, concentration and clinical outcomes. METHODS: Data were collected from 25 kidney transplant recipients (14 M/11 F), median 278 days after transplantation. Outcomes of interest were white blood cell (WBC) count, platelet (PLT) count, and haematocrit (HCT). A naive pooled data analysis was performed with outcomes dichotomized (Mann-Whitney U-tests). RESULTS: Several patients experienced at least one episode when WBC (n = 9), PLT (n = 12), or HCT (n = 21) fell below the lower limits of the normal range. WBC and HCT were significantly lower (P < 0.05) when sirolimus dose was greater than 10 mg day(-1), and sirolimus concentration greater than 12 microg l(-1). No relationship was shown for PLT and dichotomized sirolimus dose or concentration. CONCLUSIONS: Given this relationship between sirolimus concentration and effect, linked population pharmacokinetic-pharmacodynamic modelling using data from more renal transplant recipients should now be used to quantify the time course of these relationships to optimize dosing and minimize risk of these adverse outcomes.     

Long-term pharmacokinetic study of the novel combination of tacrolimus and sirolimus in de novo renal allograft recipients

It was recently shown in two randomized studies that combining sirolimus (rapamycin) and tacrolimus is very efficient in renal transplantation. However, little is known about the long-term pharmacokinetics of this combination. We performed simultaneous AUC measurements (area under the concentration curves) of sirolimus and tacrolimus at 1, 3, and 12 months posttransplantation in nine de novo recipients treated with this drug combination to characterize the evolution of the pharmacokinetics of both drugs and to investigate possible interactions between the two compounds. Patients were treated with a standard-dose tacrolimus or with a reduced-dose tacrolimus in combination with sirolimus and corticosteroids. This long-term pharmacokinetic study has shown that when sirolimus is combined with tacrolimus, dose changes of sirolimus are reflected by pharmacokinetic exposure parameters. Patients taking a low dose of sirolimus in combination with a standard dose tacrolimus might require sirolimus dose increments over time to maintain constant exposure to sirolimus. Further prospective dose-controlled studies are necessary to investigate a possible effect of a standard-dose tacrolimus on long-term sirolimus bioavailability and/or metabolism. Dose reductions of tacrolimus in both study groups were reflected by concordant decreasing pharmacokinetic exposure parameters, which illustrates the common clinical practice of reducing the dose of calcineurin inhibitor as time elapses after transplantation.     

Trimethoprim-sulphamethoxazole does not affect the pharmacokinetics of sirolimus in renal transplant recipients

AIMS: The influence of the trimethoprim-sulphamethoxazole combination on the steady-state pharmacokinetics of sirolimus, a potent macrocyclic immunosuppressant, was studied in renal transplant recipients. METHODS: Fifteen kidney transplant recipients were treated with sirolimus 8-23 mg m(-2) in combination with azathioprine and prednisolone from the day of transplantation. Whole blood sirolimus AUC and C(max) were determined on days 6 and 7 after transplantation. On day 7, sirolimus was coadministered with the first dose of trimethoprim (80 mg) and sulphamethoxazole (400 mg). RESULTS: On day 6, the mean (95% confidence interval) whole blood sirolimus AUC((0-24 h)) was 1040 (846, 1234) ng ml(-1) and mean C(max) was 109 (88, 129) ng ml(-1). Corresponding values on day 7 were AUC((0-24 h)) 1060 (826, 1293) ng ml(-1) and C(max) mean 107 (87, 127) ng ml(-1). The mean difference in the dose-corrected AUC((0-24 h)) was 0.40% (-9.4, +10). CONCLUSIONS: A single dose of trimethoprim-sulphamethoxazole does not affect the pharmacokinetics of sirolimus in renal transplant patients.     

Mechanisms and management of proteinuria in kidney transplant patients

Proteinuria is a common complication occurring after kidney transplantation. It is associated with an increased risk of renal failure and patient death. Treatment with ACE inhibitors or angiotensin receptor antagonists (blockers) has been shown to reduce proteinuria after kidney transplantation, as well as improve both graft and patient survival. An increase in proteinuria has been observed in some patients after initiation of sirolimus therapy. Although the mechanism of this remains unclear, high proteinuria at baseline and poor renal function at baseline have been identified as potential risk factors for the development of proteinuria after conversion to sirolimus. Initiation of sirolimus therapy is not recommended in patients with early histological indicators of glomerular damage; however, in patients with healthy grafts, sirolimus may prevent future glomerulosclerosis. Early treatment with an ACE inhibitor and sirolimus, prior to the appearance of glomerular changes, may result in better outcomes.     

Sirolimus: a new option in transplantation

This review of immunosuppression in renal transplantation has allowed us to highlight the deleterious effect of calcineurin inhibitor nephrotoxicity and to emphasise the importance of sirolimus. Now, a whole new set of possibilities has opened up in immunosuppression: sirolimus-based immunosuppression without calcineurin inhibitors; sirolimus in combination with calcineurin inhibitors in reduced doses; early calcineurin inhibitor withdrawal from a regimen that combines sirolimus, calcineurin inhibitors and steroids; and calcineurin inhibitor conversion to sirolimus when the first signs of graft nephrotoxicity appear. These new strategies in immunosuppression in renal transplantation are associated with good results in graft and patient survival in year 1, and with better renal function. Therefore, we can hope for better long-term results in transplantation, with a significant increase in the graft half-life and in the patient survival.     

Correlation between pretransplantation test dose cyclosporine pharmacokinetic profiles and posttransplantation sirolimus blood levels in renal transplant recipients

We sought to determine whether pretransplantation test dose pharmacokinetic measurements of cyclosporine (CsA) concentrations would forecast the posttransplantation blood concentrations of sirolimus in renal transplant patients treated de novo with CsA, sirolimus, and prednisone. All 44 renal transplant recipients enrolled in Phase I/II studies of de novo posttransplantation therapy with sirolimus, CsA, and prednisone underwent pretransplantation pharmacokinetic profiling after having received paired intravenous (i.v.) and oral test doses of CsA. After transplantation, all patients were treated with CsA on a once- or twice-daily schedule (according to a concentration-controlled regimen), with tapering doses of prednisone, and with fixed doses of sirolimus on a once-daily schedule. Patients were divided into four cohorts based on the deviation of their pretransplantation CsA clearance or bioavailability values from the mean. Patients with high pretransplantation CsA clearance rates displayed a significantly lower mean posttransplantation value of sirolimus trough concentrations than patients with low pretransplantation CsA clearance rates. In contrast, values for pretransplantation absolute oral CsA bioavailability failed to correlate with the mean posttransplantation concentration of sirolimus but did predict posttransplantation CsA bioavailability. Therefore, pretransplantation CsA clearance rate estimates may forecast posttransplantation sirolimus concentrations, possibly guiding use of sirolimus therapy to achieve an optimal ratio of concentration-dependent immunosuppressive versus toxic effects.