Albertioni F, Rask C, Eksborg S, Poulsen J H, Pettersson B, Beck O, Schroeder H, Peterson C
Department of Clinical Pharmacology, Karolinska Hospital, Stockholm, Sweden.
Clin Chem. 1996 Jan;42(1):39-44.
Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with postcolumn derivatization and fluorometric detection. About 200 clinical plasma samples from 13 children with acute lymphoblastic leukemia who received 5-8 g/m2 MTX as 24-h infusions were analyzed. The fraction of measured concentrations of MTX that were within 75-125% of the values obtained by HPLC were 64.5% for enzyme inhibition assay, 56.4% for fluorescence polarization immunoassay with polyclonal antibodies (FPIA1; Abbott), 58.9% for FPIA2 (with monoclonal antibodies; Abbott), and 46.4% for enzyme-multiplied immunoassay (Emit; Syva). All nonchromatographic procedures were subject to interferences from MTX plasma metabolites or endogenous substances. The interference from 7-OHMTX was, however, somewhat less pronounced for FPIA2 (monoclonal) than for FPIA1 (polyclonal).
通过高效液相色谱法（HPLC）作为比较方法，对高剂量治疗期间常用于监测血浆甲氨蝶呤（MTX）的四种常规检测方法进行了验证。采用柱后衍生化和荧光检测的高效液相色谱法对MTX及其主要代谢物7-羟基甲氨蝶呤（7-OHMTX）进行分析。分析了13例接受5-8 g/m² MTX 24小时静脉输注的急性淋巴细胞白血病儿童的约200份临床血浆样本。酶抑制法检测的MTX浓度在HPLC法所得值的75%-125%范围内的比例为64.5%，用多克隆抗体的荧光偏振免疫分析法（FPIA1；雅培公司）为56.4%，用单克隆抗体的FPIA2（雅培公司）为58.9%，酶放大免疫分析法（Emit；希瓦公司）为46.4%。所有非色谱法均受到MTX血浆代谢物或内源性物质的干扰。然而，7-OHMTX对FPIA2（单克隆）的干扰比对FPIA1（多克隆）的干扰稍弱。
