The influence of 7-OH methotrexate metabolite on clinical relevance of methotrexate determination.

Abstract

The concentration of MTX < 1 micromol/L are overestimated due to the cross reactivity with metabolites 7-OHMTX and 2,4-diamino-N10-methylpteroic acid (DAMPA). The cross reaction may affect the therapy and lead to relapse in children with acute lymphoblastic leukemia.