University of Texas-Houston Medical School, Houston, TX, United States.
Adv Clin Chem. 2016;76:165-84. doi: 10.1016/bs.acc.2016.04.001. Epub 2016 Jun 11.
Mycophenolic acid (MPA) is an immunosuppressant requiring therapeutic drug monitoring. Although immunoassays are commercially available, there is significant positive bias using this approach when compared to high-performance liquid chromatography or LC combined with mass spectrometry (LC/MS) or tandem mass spectrometry (LC/MS/MS). Positive bias is due to variable cross-reactivity of MPA acyl glucuronide with antibodies traditionally used in immunoassay formats. As can be expected, the magnitude of bias varies considerably. MPA strongly binds albumin and, as a result, disproportionate increases in free MPA occur in patients with uremia, hypoalbuminemia, and hepatic dysfunction. As such, monitoring free MPA poses additional challenges. Because MPA inhibits inosine monophosphate dehydrogenase, monitoring this enzyme may provide an alternative approach.
霉酚酸（MPA）是一种需要治疗药物监测的免疫抑制剂。虽然免疫分析可商业化获得，但与高效液相色谱或 LC 结合质谱（LC/MS）或串联质谱（LC/MS/MS）相比，使用这种方法存在显著的正偏倚。正偏倚是由于 MPA 酰葡萄糖醛酸与传统免疫分析方法中使用的抗体的交叉反应性不同所致。可以预期，偏倚的程度差异很大。MPA 与白蛋白结合牢固，因此，在尿毒症、低白蛋白血症和肝功能障碍的患者中，游离 MPA 不成比例地增加。因此，监测游离 MPA 带来了额外的挑战。由于 MPA 抑制肌苷单磷酸脱氢酶，因此监测这种酶可能提供一种替代方法。
