MSP检测p15基因甲基化在儿童急性白血病微小残留病灶诊断中的价值

对探讨ｐ１５基因甲基化在儿童急性白血病(ＡＬ)微小残留病灶(ＭＲＤ)诊断中的价值,采用甲基化特异性聚合酶链反应(ＭＳＰ)研究４９例初治儿童ＡＬ(包括ＡＬＬ３１例及ＡＭＬ１８例)和２０例对照组的ｐ１５基因甲基化情况。动态观察４例ＡＬＬ及２例ＡＭＬ治疗前后ｐ１５基因甲基化的变化。结果显示,儿童ＡＬ患者ｐ１５基因甲基化阳性率为６７．３%,ＡＬＬ与ＡＭＬ的阳性率(分别为６１．３%和７７．７%),差异无显著性:对照组２０例均阴性。动态观察的６例儿童ＡＬ,初诊时均呈现ｐ１５基因甲基化;完全缓解时,４例仍呈现甲基化,其中３例分别于３个月、５个月、６个月后复发:另一例甲基化转为阴性,未复发:ＭＳＰ敏感度可达１０－３。因此,ＭＳＰ检测ｐ１５基因甲基化有助于检测儿童ＡＬ的ＭＲＤ。

VALUE OF EXAMINING P15 GENE METHYLATION WITH METHYLATION - SPECIFIC PCR (MSP) FOR DIAGNOSING MINIMAL RESIDUAL DISEASE IN CHILDHOOD WITH ACUTE LEUKEMIA

To explore the value of p15 gene methylatuon for diagnosing minimal residual disease (MRD) in childhood with acute leukemia, using p15 gene methylation from 49 cases of childhood with newly diagnosed AL (including 31 cases of ALL and 18 of AML) and 20 of controls was investigated with methylation -specific PCR (MSP) methods. Changes of p15 gene methylation from 4 cases of ALL and 2 of AML was observed dynamically during the cource of treatment. Results showed that p15 gene was methylated in 67.3% (33/49) of childhood with newly diagnosed AL, no difference between ALL and AML(61.3% and 77.7%, respectively) was observed, 20 of controls didn' t have p15 gene methylation, 6 cases of childhood with AL, who were observed dynamically, all had p15 gene methylation at diagnosis; 4 cases still had methylation in CR, in which 3 cases relapsed with in 3、5 and 6 months, respectively. Another one turned methylation into nonmethylation and didn't relapse. The sensitivity of MSP was 10-3. Therefore, the examination of p15 gene methylation with MSP methods may contribute to observe MRD in childhood with AL.