Dong Wei-Chong, Gao Shuai-Shuai, Shi Bo, Li Hao-Ran, Jiang Ye, Guo Jia-Liang, Zhang Zhi-Qing, Zhang Ying-Ze
Department of Pharmacy, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, 050051, People's Republic of China.
The School of Medicine, Nankai University, Tianjin, 300071, People's Republic of China.
Drug Des Devel Ther. 2025 May 26;19:4383-4396. doi: 10.2147/DDDT.S516431. eCollection 2025.
High-dose methotrexate (HD-MTX) is seen as an effective therapy for acute lymphoblastic leukemia (ALL); however, it is extremely toxic. Monitoring the plasma concentrations of methotrexate (MTX) and its important metabolite, 7-hydroxy-methotrexate (7-OH-MTX), on a routine basis aids in dose modification of rescue medications and in avoiding toxicity. The pharmacologically active and toxic effects of drugs are due to the unbound portion, as most drugs are bound to plasma proteins to some degree. However, the simultaneous measurement of unbound plasma concentrations of MTX and 7-OH-MTX has not been reported.
We developed and validated a hollow fiber centrifugal ultrafiltration (HFCF-UF) technology to simultaneously analyze unbound MTX and 7-OH-MTX concentrations in human plasma. In total, 234 plasma samples from 58 children diagnosed with ALL who were administered HD-MTX were used in our study. We investigated the connection between unbound and total plasma concentrations of MTX and 7-OH-MTX, as well as how these concentrations relate to liver and renal function.
The method that was developed is both simple and accurate. A weak linear relationship was observed between the concentrations of unbound and total 7-OH-MTX ( = 0.732). The concentration of total MTX and unbound 7-OH-MTX were both positively correlated with creatinine (Cr) levels and negatively correlated with Creatinine clearance (CCr). There was a wide variation in the concentration ratios of 7-OH-MTX to MTX, both total and unbound, and these ratios were significantly lower in individuals with impaired liver function.
The total concentration of 7-OH-MTX is an unreliable predictor of unbound concentration, necessitating the monitoring of unbound levels. The concentration ratios of 7-OH-MTX to MTX (both total and unbound) could be more accurate and sensitive biomarkers for predicting hepatotoxicity.
大剂量甲氨蝶呤（HD-MTX）被视为急性淋巴细胞白血病（ALL）的有效治疗方法；然而，它具有极高的毒性。定期监测甲氨蝶呤（MTX）及其重要代谢产物7-羟基甲氨蝶呤（7-OH-MTX）的血浆浓度有助于调整救援药物的剂量并避免毒性。由于大多数药物在一定程度上与血浆蛋白结合，药物的药理活性和毒性作用归因于未结合部分。然而，尚未见同时测定MTX和7-OH-MTX未结合血浆浓度的报道。
我们开发并验证了一种中空纤维离心超滤（HFCF-UF）技术，用于同时分析人血浆中未结合的MTX和7-OH-MTX浓度。我们的研究共使用了58例接受HD-MTX治疗的ALL患儿的234份血浆样本。我们研究了MTX和7-OH-MTX未结合血浆浓度与总血浆浓度之间的关系，以及这些浓度与肝肾功能的关系。
所开发的方法既简单又准确。未结合的7-OH-MTX浓度与总浓度之间存在弱线性关系（r = 0.732）。总MTX浓度和未结合的7-OH-MTX浓度均与肌酐（Cr）水平呈正相关，与肌酐清除率（CCr）呈负相关。7-OH-MTX与MTX的浓度比（总浓度和未结合浓度）存在很大差异，肝功能受损个体的这些比值明显较低。
7-OH-MTX的总浓度不是未结合浓度的可靠预测指标，因此有必要监测未结合水平。7-OH-MTX与MTX的浓度比（总浓度和未结合浓度）可能是预测肝毒性更准确、更敏感的生物标志物。
