Erythrocyte Methotrexate–Polyglutamate Concentrations in Pediatric Inflammatory Bowel Disease

Intracellular MTX–polyglutamates (PG1–5), which accumulate over time, have not been assessed in pediatric inflammatory bowel disease (IBD). This study aimed to evaluate erythrocyte MTX-PG as a potential TDM tool in pediatric IBD.