[Effects of and gene polymorphisms on plasma concentrations and toxicity following high-dose methotrexate therapy in children with acute lymphoblastic leukemia].

Objectives: To investigate the effects of methylenetetrahydrofolate reductase () rs1801133 and γ-glutamyl hydrolase () rs11545078 gene polymorphisms on plasma concentrations and toxicity following high-dose methotrexate (MTX) therapy in children with acute lymphoblastic leukemia (ALL).

Methods: Children with ALL treated at the Xuzhou Children's Hospital of Xuzhou Medical University from January 2021 to April 2024 were selected for this study. Genotypes of rs1801133 and rs11545078 were determined using multiplex polymerase chain reaction. MTX plasma concentrations were measured by enzyme-multiplied immunoassay technique, and toxicity was graded according to the Common Terminology Criteria for Adverse Events version 5.0. The relationships between rs1801133 and rs11545078 genotypes and both MTX plasma concentrations and associated toxicities were analyzed.

Results: In the low-risk ALL group, the rs1801133 genotype was associated with increased MTX plasma concentrations at 72 hours (<0.05). In the intermediate- to high-risk group, the rs1801133 genotype was associated with increased MTX plasma concentrations at 48 hours (<0.05), and the rs11545078 genotype was associated with increased MTX plasma concentrations at 48 hours (<0.05). In the intermediate- to high-risk group, the rs1801133 genotype was associated with the occurrence of reduced hemoglobin (<0.05), and the rs11545078 genotype was associated with the occurrence of thrombocytopenia (<0.05).

Conclusions: Detection of rs1801133 and rs11545078 genotypes can be used to predict increased MTX plasma concentrations and the occurrence of toxic reactions in high-dose MTX treatment of ALL, enabling timely interventions to enhance safety.