目的 明确亚甲基四氢叶酸还原酶（MTHFR）C677T、A1298C基因多态性与成人患者使用大剂量甲氨蝶呤（MTX）治疗急性淋巴细胞白血病（ALL）毒性反应和24、48、72 h MTX血药浓度关系。方法 收集2014年6月—2020年6月就诊于新疆医科大学第一附属医院成人急性淋巴细胞白血病75例患者血样检测MTHFR C677T及A1298C基因多态性, 根据抗癌药物常见毒性反应分级标准对毒性反应进行分级,采用非条件Logistic回归分析MTHFR C677T、A1298C基因多态性与HD-MTX毒性反应及血药浓度的关系。结果 MTHFR 677TT型发生贫血风险显著高于CC型（P=0.027, OR=4.694, 95%CI：1.195~18.438）; 未发现MTHFR C677T与白细胞减少、血小板计数减少、中性粒细胞计数减少、淋巴粒细胞计数减少、骨髓抑制、谷丙转氨酶升高、谷草转氨酶升高、肝功能损伤、急性肾损伤及黏膜损伤、24 h、48 h及72 h MTX血药浓度有相关性（P>0.05）; 未发现MTHFR A1298C与HD-MTX毒性反应及血药浓度有相关性（P>0.05）。结论 MTHFR C677T基因多态性与成人急性淋巴细胞白血病患者大剂量MTX化学治疗后血液毒性存在相关性。

Objective To determine the relationship among C677T and A1298C gene polymorphisms of methyltetrahydrofolate reductase（MTHFR）and adult acute lymphocytic leukemia（ALL）, the relationship between the toxicity of high-dose methotrexate（HD-MTX）after chemotherapy and the MTX blood concentration of 24 h, 48 h and 72 h in patients with ALL．Methods Blood samples were collected from 75 adult patients with ALL who were treated at the First Affiliated Hospital of Xinjiang Medical University from June 2014 to June 2020．The samples were used to detect the genetic polymorphisms of MTHFR C677T and A1298C, and the toxic reactions were graded according to the common toxic reaction classification criteria of anti-cancer drugs．Unconditional Logistic regression was used to analyze the relationship between MTHFR C677T and A1298C gene polymorphisms and HD-MTX toxic reactions and blood drug concentration．Results The risk of anemia in MTHFR 677TT was significantly higher than that in CC type（P=0.027, OR=4.694, 95% CI：1.195-18.438）．No correlation was found between MTHFR C677T and leukopenia, thrombocytopenia, neutropenia, lymphogranulocytopenia, bone marrow suppression, elevated alanine aminotransferase, elevated aspartate aminotransferase, liver function injury, acute kidney injury and mucosal injury, 24 h, 48 h and 72 h MTX plasma concentrations（>0.05）．No correlation was found among MTHFR A1298C and HD-MTX toxicity and blood concentration（P>0.05）．Conclusions MTHFR C677T gene polymorphism is associated with hematotoxicity after HD-MTX chemotherapy in adult patients with ALL．