ATIC和GSTP1基因多态性与大剂量甲氨蝶呤排泄延迟的相关性研究

Association of ATIC and GSTP1 genetic polymorphism with elimination delay in high dose methotrexate therapy in childhood acute lymphoblastic leukemia

目的探讨大剂量甲氨蝶呤(HD-MTX)治疗儿童急性淋巴细胞白血病(ALL),MTX排泄延迟与氨基咪唑氨甲酰转移酶(ATIC)、谷胱甘肽S-转移酶P1(GSTP1)基因多态性的关系。方法 67例接受HD-MTX化疗的ALL患儿,收集外周血用于检测ATIC、GSTP1基因型及MTX浓度。采用PCR技术和直接测序方法分析ATIC、GSTP1基因的基因型,采用酶放大免疫法(EMIT)测定MTX开始给药后48h的血药浓度。结果 MTX开始注射后48h血药浓度>1.0μmol/L为排泄延迟,根据MTX血药浓度高低分为轻度(1-2μmol/L)、中度(2～5μmol/L)、重度(5～10μmol/L)和极重度排泄延迟(>10μmol/L)四级。(1)34例患儿出现MTX排泄延迟(实验组):轻度12例(38.4%);中度9例(26.5%);重度7例(20.6%);极重度6例(17.6%)。(2)34例MTX排泄延迟者,ATIC T26293C的CC基因型20例(58.8%);CT基因型12例(35.3%);TT基因型2例(5.9%)。GSTP1 A313G的AA基因型24例(70.6%),GA基因型9例(26.5%);GG基因型1例(2.9%)。(3)同期未出现MTX排泄延迟的33例患儿中,ATIC T26293C的CC基因型18例,占54.5%;CT基因型14例,占42.4%;TT基因型1例,占3.0%。GSTP1 A313G的AA基因型23例,占69.7%,GA基因型9例,占27.3%;GG基因型1例,占3.0%。(4)34例MTX排泄延迟者各基因型改变与无MTX排泄延迟的33例比较,P值均>0.05,差异无显著性。结论 ATIC的T26293C位点、GSTP1的A313G位点的多态性与ALL患儿大剂量MTX排泄延迟无明显相关性。

Objective To investigate the relationship between polymorphism of ATIC and GSTP1 gene and elimination delay in high dose methotrexate therapy in childhood acute lymphoblastic leukemia. Methods Peripheral blood samples were obtained from 67 patients with acute lymphoblastic leukemia receiving high dose methotrexate therapy. Polymerase chain reaction direct sequencing was applied for the analysis of ATIC and GSTP1 genotype. Blood methotrexate concentration of 48 hours after administrationwas detected by enzyme multiplied immunoassay technique. Results （1）Elimination delay of methotrexate occurred in 34 patients. Blood methotrexate concentration in 12 （38.4%） patients was 1 - 2μmol/L （mildly delayed）, in 9 （26.5%） was 2 -5μmol/L （moderately delayed）, in 7 （20. 6% ） was 5 - 10μmol/L （ severely delayed ） , and in 6 （ 17.6% ） was 〉 10μmol/L （ extremely severely delayed）. （2） Among the 34 children with elimination delay, at the genetic locus ATIC T26293C, the proportions of genotype CC was 58.8% （20/34）, genotype CT was 35.3% （12/34） and genotype TF was 5.9% （2/34）. At the genetic locus GSTP1 A313G, the proportions of genotype AA, GA and GG were 70. 6% （24/34）, 26.5% （9/34） and 2.9% （1/34）, respectively. （3） Meanwhile, 33 patients were treated with the same regime but didn＇ t undergo elimination delay. Among them, the percentages of genotype CC, CT and TY were 54. 5% （ 18/33）, 42. 4% （14/33） and 3.0% （1/33） at the genetic locus ATIC T26293C, respectively. For genetic locus GSTP1 A313G, 23 （69.7%） patients had genotype AA, 9 （27.3 % ） had genotype GA, and the left 1 （3.0） had genotype GG. （4） There was no significant difference of the 34 patients with elimination delay comparing the 33 ones without elimination delay in genotypes. Conclusions There was no significant relationship between the ATIC and GSTP1 genetic polymorphisrn and elimination delay in high dose methotrexate therapy in childhood acute lymphoblastie leukemia.