Measurement of methotrexate polyglutamates in human erythrocytes by ion-pair UPLC-MS/MS.

Journal Article (Journal Article)

BACKGROUND: Low-dose methotrexate is used for the treatment of rheumatoid arthritis and juvenile idiopathic arthritis, but its effectiveness greatly varies between individuals. Therapeutic drug monitoring of intracellular methotrexate metabolites, the γ-polyglutamates (MTXGlu(n)), in human erythrocytes has shown promise in providing a basis for individualization of therapy. RESULTS: This work presents expedient methodology for the analysis of MTXGlu(1-7) in human erythrocytes by ion-pair UPLC with detection by tandem MS (UPLC-ESI-MS/MS). The use of N,N-dimethylheptylamine as an ion-pair agent was found to be favorable over others. Thermal extraction of erythrocyte lysates provides a simple one-step extraction procedure. The entire chromatographic run time is 6 min and the assay was validated within the therapeutic range of these metabolites CONCLUSION: The developed sample preparation procedure in combination with ion-pair UPLC-ESI-MS/MS analysis allowed for expedient quantitation of MTXGlu(1-7) in human erythrocytes. The rapid analysis time would enable therapeutic drug monitoring of MTXGlu(1-7) in the clinic.

Full Text

Duke Authors

Cited Authors

  • van Haandel, L; Becker, ML; Williams, TD; Leeder, JS; Stobaugh, JF

Published Date

  • December 2011

Published In

Volume / Issue

  • 3 / 24

Start / End Page

  • 2783 - 2796

PubMed ID

  • 22185278

Electronic International Standard Serial Number (EISSN)

  • 1757-6199

Digital Object Identifier (DOI)

  • 10.4155/bio.11.288


  • eng

Conference Location

  • England