Aizawa Kenichi, Kimura Natsuka, Goda Takahiro, Nishida Sho, Sakuma Yasunaru, Iwami Daiki, Nagai Ryozo
Division of Translational Research, Clinical Research Center, Jichi Medical University Hospital, Shimotsuke 329-0498, Tochigi, Japan.
Clinical Pharmacology Center, Jichi Medical University Hospital, Shimotsuke 329-0498, Tochigi, Japan.
Int J Mol Sci. 2025 Jul 1;26(13):6358. doi: 10.3390/ijms26136358.
Immunosuppressants are essential for preventing allograft rejection; however, they require therapeutic drug monitoring to maintain efficacy and to prevent severe complications such as opportunistic infections. Calcineurin inhibitors (CIs) are primarily distributed in red blood cells, whereas mycophenolic acid (MPA) and its metabolites are found in plasma. These differences necessitate separate analyses for each drug, increasing laboratory workload, analytical complexity, and patient burden. We developed a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of CIs such as tacrolimus (Tac), everolimus (Eve), sirolimus (Sir), cyclosporine A (CycA) and MPA in 2.8-µL whole-blood samples, with a hematocrit-based correction to estimate plasma-equivalent MPA concentrations. Performance of this method was assessed by comparison with conventional immunoassay results using linear regression and Bland-Altman analyses, demonstrating excellent agreement, with strong linearity (R > 0.995) at <2 to 35 ng/mL for three CIs, 26.0 to 1866 ng/mL for CycA, and 0.1 to 50 μg/mL for MPA. Furthermore, MPA and tacrolimus concentrations closely aligned with routine clinical results (R > 0.900), indicating high accuracy and reproducibility. This new approach may be particularly beneficial for hospitalized patients with limited venous access, pediatric populations, and in remote care settings where frequent blood sampling is challenging because of simultaneous quantification and fewer sample volume requirements.
免疫抑制剂对于预防同种异体移植排斥反应至关重要；然而，它们需要进行治疗药物监测以维持疗效并预防诸如机会性感染等严重并发症。钙调神经磷酸酶抑制剂（CIs）主要分布于红细胞中，而霉酚酸（MPA）及其代谢产物则存在于血浆中。这些差异使得每种药物都需要单独分析，从而增加了实验室工作量、分析复杂性和患者负担。我们开发了一种液相色谱 - 串联质谱法，用于同时定量检测2.8 μL全血样本中的他克莫司（Tac）、依维莫司（Eve）、西罗莫司（Sir）、环孢素A（CycA）等CIs以及MPA，并基于血细胞比容进行校正以估算血浆等效MPA浓度。通过使用线性回归和Bland - Altman分析与传统免疫测定结果进行比较，评估了该方法的性能，结果显示一致性良好，三种CIs在<2至35 ng/mL时线性关系强（R>0.995），CycA在26.0至1866 ng/mL时线性关系强，MPA在0.1至50 μg/mL时线性关系强。此外，MPA和他克莫司浓度与常规临床结果密切相符（R>0.900），表明具有高准确性和可重复性。这种新方法对于静脉通路有限的住院患者、儿科人群以及在因同时定量和样本量需求较少而频繁采血具有挑战性的远程护理环境中可能特别有益。
