Toole Barry, Gechtman Cecilia, Dreier Jens, Kuhn Joachim, Gutierrez Miguel Rueda, Barrett Alan, Niederau Christoph
Clin Lab. 2015;61(9):1303-15. doi: 10.7754/clin.lab.2015.150225.
Careful monitoring of the post-transplantation immunosuppressant drugs (ISDs) cyclosporine (CsA) and tacrolimus (TAC) in whole blood is essential to prevent adverse drug events. Immunoassays represent the most widely used methodology for therapeutic drug monitoring. In this study, the technical performance of the new automated electrochemiluminescence immunoassays (ECLIAs) for CsA and TAC measurement were assessed under field conditions.
Residual whole blood samples from patients undergoing CsA or TAC therapy following organ transplant were used to evaluate the assays at six independent laboratories across four countries. Experiments included within-run imprecision using PreciControl ISD controls and recovery of commercial external quality assurance (EQA) scheme samples. Both assays were compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS), using methods routinely employed at each investigational site, as well as with an equivalent commercial chemiluminescent microparticle immunoassay (CMIA) and enzyme multiplied immunoassay (EMIT).
Within-run imprecision testing gave coefficients of variation of ≤ 5% in the > 90.0 - 2000 ng/mL range for the CsA ECLIA and ≤ 4.2% in the 3.5 - 12 ng/mL range and ≤ 4.9% in the > 12 - 40 ng/mL range for the TAC ECLIA. EQA sample recovery by ECLIA gave a mean bias of 6.9% for CsA and 4.9% for TAC versus the spiked concentration or the mean LC-MS/MS value. Deming regression analysis of ECLIA method comparison to LC-MS/MS for all sites yielded a slope of 1.22, intercept 8.43 ng/mL and r = 0.97 for CsA and a slope of 1.22, intercept -0.51 ng/mL and r = 0.96 for TAC. Comparison with CMIA yielded a slope of 0.87, intercept 5.51 ng/mL and r = 0.97 for CsA and a slope of 0.98, intercept 0.12 ng/mL and r = 0.97 for TAC. Comparison with EMIT yielded a slope of 1.23, intercept -8.74 ng/mL and r = 0.96 for CsA.
The CsA and TAC ECLIA compare favorably with existing commercial immunoassays and with LC-MS/MS. They represent modern generation assays that meet the demands of monitoring drug concentrations in current immunosuppressive regimens. This study also highlights the importance of standardizing protocols and LC-MS/MS methods to give improved comparability between ISD assays.
密切监测移植后免疫抑制药物（ISD）环孢素（CsA）和他克莫司（TAC）的全血浓度对于预防药物不良事件至关重要。免疫测定法是治疗药物监测中使用最广泛的方法。在本研究中，在实际现场条件下评估了用于测量CsA和TAC的新型自动化电化学发光免疫测定法（ECLIA）的技术性能。
使用来自四个国家六个独立实验室的接受器官移植后接受CsA或TAC治疗患者的残余全血样本评估这些测定法。实验包括使用PreciControl ISD对照进行批内不精密度检测以及商业外部质量保证（EQA）计划样本的回收率检测。两种测定法均与液相色谱 - 串联质谱法（LC-MS/MS）进行比较，使用每个研究地点常规采用的方法，同时也与等效的商业化学发光微粒子免疫测定法（CMIA）和酶放大免疫测定法（EMIT）进行比较。
对于CsA ECLIA，批内不精密度检测在>90.0 - 2000 ng/mL范围内变异系数≤5%；对于TAC ECLIA，在3.5 - 12 ng/mL范围内变异系数≤4.2%，在>12 - 40 ng/mL范围内变异系数≤4.9%。与加标浓度或平均LC-MS/MS值相比，ECLIA对EQA样本的回收率显示，CsA的平均偏差为6.9%，TAC为4.9%。对所有研究地点的ECLIA方法与LC-MS/MS进行Deming回归分析，结果显示CsA的斜率为1.22，截距为8.43 ng/mL，r = 0.97；TAC的斜率为1.22，截距为 -0.51 ng/mL，r = 0.96。与CMIA比较，CsA的斜率为0.87，截距为5.51 ng/mL，r = 0.97；TAC的斜率为0.98，截距为0.12 ng/mL，r = 0.97。与EMIT比较，CsA的斜率为1.23，截距为 -8.74 ng/mL，r = 0.96。
CsA和TAC ECLIA与现有的商业免疫测定法以及LC-MS/MS相比具有优势。它们代表了满足当前免疫抑制方案中药物浓度监测需求的现代检测方法。本研究还强调了标准化方案和LC-MS/MS方法对于提高ISD检测之间可比性的重要性。
