Abstract：
Methotrexate is a common component of pediatric oncology treatment and delayed clearance increases risk of significant toxicities. Glucarpidase is indicated for patients with toxic plasma methotrexate concentrations with renal toxicity. Laboratory interference with immunoassay measurement post-glucarpidase administration is well established, with current product labeling indicating this persists for 48 h. However, recent experience in pediatric patients supports this discrepancy persists beyond 48 h. Three cases experienced delayed methotrexate clearance and received glucarpidase with subsequent measurement of methotrexate levels by liquid chromatography tandem mass spectrometry (LC-MS/MS) and/or immunoassay. Within this case series, discrepancies between LC-MS/MS and immunoassay levels persisted significantly longer than 48 h.
摘要：
甲氨蝶呤是儿科肿瘤治疗的常见成分，延迟清除会增加重大毒性的风险。葡萄糖苷酶适用于具有肾毒性的血浆甲氨蝶呤浓度的患者。葡萄糖苷酶给药后对免疫测定测量的实验室干扰是公认的，目前的产品标签表明这种情况持续48小时。然而，最近在儿科患者中的经验支持这种差异持续超过48小时。3例患者经历了甲氨蝶呤清除延迟,并接受了葡糖糖苷酶,随后通过液相色谱串联质谱(LC-MS/MS)和/或免疫测定测量甲氨蝶呤水平.在这个案例系列中，LC-MS/MS和免疫测定水平之间的差异持续超过48小时。
