Loor Rueyming, Pope Lisa, Boyd Rose, Wood Kristopher, Bodepudi Vani
Microgenics Corporation, Fremont, CA 94538, USA.
Ther Drug Monit. 2004 Feb;26(1):58-67. doi: 10.1097/00007691-200402000-00013.
A nonextraction homogeneous immunoassay (CEDIA Cyclosporine Plus Assay) has been developed for the measurement of cyclosporine in predose (trough) and post-dose (C2 to C8) whole-blood samples. The method includes a low-range assay that measures cyclosporine from 25 to 450 ng/mL in pre-dose samples and a high-range assay that detects cyclosporine from 450 to 2000 ng/mL in post-dose samples. The high-range assay allows a direct measurement of post-dose samples without a dilution step. Alternatively, post-dose samples can be correctly measured by the low-range assay following a twofold dilution. Using an NCCLS precision protocol, the assay exhibited less than 10% CV or error less than the functional sensitivity. Functional sensitivity of the low-range assay was demonstrated at 20 ng/mL cyclosporine. Cross-reactivity was measured in the presence of cyclosporine and was found to be 4.4%, 19.8%, 16.4%, 0.9%, 1.0%, and 1.6% for metabolites AM1, AM9, AM4n, AM19, AM4n9, and AM1c, respectively. When 53 samples were evaluated using an HPLC method, the three most significant cross-reactive metabolites, AM1, AM4n, and AM9, exhibited an average concentration profile of 123%, 19%, and 0.06% of the parent cyclosporine, respectively. The average total contribution to cyclosporine quantification from these metabolites was estimated at 7.2% based on the percentage cross-reactivity of each metabolite in the CEDIA assay and the concentration of each metabolite as determined by HPLC. The method comparison study revealed a linear regression correlation of CEDIA = 1.095 x HPLC + 6.6, r = 0.972, for the low-range assay, and CEDIA = 1.018 x HPLC - 36.4, r = 0.968, for the high-range assay. In conclusion, the CEDIA Cyclosporine Plus Assay is a precise and accurate method for quantification of cyclosporine in pre-dose and post-dose samples.
已开发出一种非提取均相免疫测定法（CEDIA环孢素加测定法），用于测定给药前（谷值）和给药后（C2至C8）全血样本中的环孢素。该方法包括一个低范围测定法，用于测量给药前样本中环孢素浓度为25至450 ng/mL，以及一个高范围测定法，用于检测给药后样本中环孢素浓度为450至2000 ng/mL。高范围测定法无需稀释步骤即可直接测量给药后样本。或者，给药后样本经两倍稀释后可用低范围测定法正确测量。采用NCCLS精密度方案，该测定法的变异系数小于10%或误差小于功能灵敏度。低范围测定法的功能灵敏度在环孢素浓度为20 ng/mL时得到验证。在存在环孢素的情况下测量交叉反应性，发现代谢物AM1、AM9、AM4n、AM19、AM4n9和AM1c的交叉反应性分别为4.4%、19.8%、16.4%、0.9%、1.0%和1.6%。当使用高效液相色谱法评估53个样本时，三种最主要的交叉反应性代谢物AM1、AM4n和AM9，其平均浓度分别为母体环孢素的123%、19%和0.06%。根据CEDIA测定法中各代谢物的交叉反应百分比以及高效液相色谱法测定的各代谢物浓度，估计这些代谢物对环孢素定量的平均总贡献为7.2%。方法比较研究显示，低范围测定法的线性回归相关性为CEDIA = 1.095×高效液相色谱法 + 6.6，r = 0.972；高范围测定法的线性回归相关性为CEDIA = 1.018×高效液相色谱法 - 36.4，r = 0.968。总之，CEDIA环孢素加测定法是一种精确且准确的方法，用于定量给药前和给药后样本中的环孢素。
