Pharmaceutical Sciences Research Center, Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China.
School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Jun 1;1240:124154. doi: 10.1016/j.jchromb.2024.124154. Epub 2024 May 10.
Cyclosporine A (CsA) is a widely used immunosuppressive drug with a narrow therapeutic index and large individual differences. Its therapeutic and toxic effects are closely related to blood drug concentrations, requiring routine therapeutic drug monitoring (TDM). The current main methods for TDM of CsA are enzyme multiplied immunoassay technique (EMIT) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). However, few study on the method comparison of the EMIT and LC-MS/MS for the measurement of whole blood CsA concentration in children has been reported. In this study, we developed a simple and sensitive LC-MS/MS assay for the determination of CsA, and 657 cases of CsA concentrations were determined from 197 pediatric patients by a routine EMIT assay and by the validated in-house LC-MS/MS method on the same batch of samples, aimed to address the aforementioned concern. Consistency between the two assays was evaluated using linear regression and Bland-Altman analysis. The linear range of LC-MS/MS was 0.500-2000 ng/mL and that of the EMIT was 40-500 ng/mL, respectively. Overall, the correlation between the two methods was significant (r-value ranging from 0.8842 to 0.9441). Unsatisfactory consistency was observed in the concentrations < 40 ng/mL (r = 0.7325) and 200-500 ng/mL (r = 0.6851). Bland-Altman plot showed a mean bias of -18.0 % (±1.96 SD, -73.8 to 37.8 %) between EMIT and LC-MS/MS. For Passing-Bablok regression between EMIT and LC-MS/MS did not differ significantly (p > 0.05). In conclusion, the two methods were closely correlated, but the CsA concentration by LC-MS/MS assay was slightly higher than that by EMIT method. Switching from the EMIT assay to the LC-MS/MS method was acceptable, and the LC-MS/MS method will receive broader application in clinical settings due to its better analytical capabilities, but the results need to be further verified in different laboratories.
环孢素 A（CsA）是一种广泛使用的免疫抑制剂，治疗指数较窄，个体差异较大。其治疗效果和毒性与血药浓度密切相关，需要常规进行治疗药物监测（TDM）。目前，CsA 的 TDM 主要方法有酶放大免疫测定技术（EMIT）和液相色谱-串联质谱法（LC-MS/MS）。然而，关于 EMIT 和 LC-MS/MS 测定儿童全血 CsA 浓度的方法比较的研究较少。本研究建立了一种简单灵敏的 LC-MS/MS 测定方法，并对同批次样本进行了常规 EMIT 测定和验证的内 LC-MS/MS 方法，共检测了 197 例儿科患者的 657 例 CsA 浓度，旨在解决上述问题。采用线性回归和 Bland-Altman 分析评价两种方法的一致性。LC-MS/MS 的线性范围为 0.500-2000ng/mL，EMIT 的线性范围为 40-500ng/mL。总体而言，两种方法的相关性显著（r 值在 0.8842 到 0.9441 之间）。在浓度 <40ng/mL（r=0.7325）和 200-500ng/mL（r=0.6851）时，观察到不一致的一致性。Bland-Altman 图显示 EMIT 和 LC-MS/MS 之间的平均偏差为-18.0%（±1.96 SD，-73.8 至 37.8%）。EMIT 和 LC-MS/MS 之间的 Passing-Bablok 回归没有显著差异（p>0.05）。结论：两种方法相关性密切，但 LC-MS/MS 测定的 CsA 浓度略高于 EMIT 方法。从 EMIT 测定法切换到 LC-MS/MS 测定法是可以接受的，由于其更好的分析能力，LC-MS/MS 方法将在临床环境中得到更广泛的应用，但需要在不同实验室进一步验证结果。
