Analysis of mono-, di-, and triphosphates of thioguanosine and methylthioinosine in children with acute lymphoblastic leukemia by LC-MS/MS

• Published in: Journal of pharmaceutical and biomedical analysis 2022-08, Vol.217, p.114813-114813, Article 114813
• Main Authors: Han, Jiaqi, Xu, Jiamin, Sun, Ning, Jin, Siyao, Mei, Dong, Wang, Xiaoling, Zhao, Libo
• Format: Article
• Language: English
• Subjects: LC-MS/MS; Mercaptopurine; Method development and validation; Therapeutic drug monitoring
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2022.114813

Mercaptopurine (6-MP) is an indispensable, first-line, drug in the treatment of pediatric acute lymphoblastic leukemia (ALL). However, 6-MP has several intrinsic drawbacks, such as large individual variability in the drug response, undesirable adverse reactions, and drug resistance in patients with release ALL, which requires therapeutic drug monitoring (TDM). Several studies analyzed the total concentration of thiopurine nucleotides in red blood cells (RBCs) after hydrolysis, and two studies detected them separately and accurately by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, we developed a rapid and robust LC-MS/MS method for simultaneous quantitation of mono-, di-, and triphosphates of thioguanosine and methylthioinosine. Not only EDTA and DTT were added, but also EHT1864, a new Rac family small GTPases inhibitor, was innovatively added to ensure the stability of the analytes. Commercial availability and relatively low cost compound methotrexate-D3 was selected as internal standards. The linearity, accuracy, precision, recovery, matrix effect and stability of the method were all in line with the guidelines. This method provide an accurate and robust new solution for the determination of 6 metabolites of MP in RBCs from ALL patients with maintenance therapy. •The method provides a new solution to quantify 6 metabolites of mercaptopurine.•The method includes simple sample preparation and analysis from red blood cells.•The method innovatively adds EHT1864 to ensure the stability of the analytes.•Methotrexate-D3 is selected and validated as internal standards in the method.