A Retrospective Cohort Study: The Influence of MTHFR C677T and A1298C on the High-dose Methotrexate-Related Toxicities in Pediatric Patients With Non-Hodgkin Lymphoma

Patients received MTX therapy at the dose of 5g/m2 for 24 hours. Each dose of HD-MTX therapy was followed by 6\~7 times of leucovorin rescue 12 hours after the end of MTX infusion, at the dose of 15 mg/ m2 every 6 hours. The plasma MTX levels were monitored at 0, 24, 48, 72 hours from the initiation of HD-MTX infusion. To maintain the urine pH at approximately 7\~8, intravenous hydration and alkalization at the dose of 1,500ml/ m2 per day were achieved 12 hours prior to the initiation of HD-MTX administration (D0) and 3,000ml/ m2 per day lasted for the following 3 days (D1 to D3). CF was used to rinse mouth to prevent oral mucositis from D1 to D3. We closely monitored the volume and pH of the urine via routine test from D0 to D4.