E2A-PBX1融合基因的实时定量检测在小儿急性淋巴细胞白血病微小残留病监测中的应用

Real-time quantitative detection of E2A-PBX1 fusion gene in children with acute lymphoblastic leukemia and its clinical application in minimal residual disease monitoring

目的实时荧光定量PCR方法检测E2A-PBX1融合基因的表达水平,探讨其在监测急性淋巴细胞白血病(ALL)患儿微小残留病(MRD)及判断预后中的临床价值。方法采用实时荧光定量RT-PCR方法,动态检测11例E2A-PBX1融合基因阳性的ALL患儿在初治期(11例)、完全缓解期(11例)、复发期(3例)和10例同期骨髓细胞形态学正常的非血液及肿瘤疾病对照组患儿的E2A-PBX1融合基因表达水平。结果 11例ALL患儿初治期和复发期的E2A-PBX1基因表达水平均显著高于缓解期及对照组(P<0.01)。与诱导缓解治疗第33天E2A-PBX1水平表达阴性的患儿比较,表达阳性的患儿3年的复发率增高,无病生存率降低(均P<0.05)。结论实时荧光定量RT-PCR检测E2A-PBX1融合基因的表达水平是监测MRD、预测复发、指导个体化治疗的良好指标,诱导缓解第33天E2A-PBX1融合基因水平可用于判断预后。

Objective To establish a real-time reverse transcription-polymerase chain reaction （RT-PCR） for quantitative detection of E2A-PBXI fusion gene mRNA in acute lymphoblastic leukemia （ALL） children and to explore its clinical significance in minimal residual disease monitoring and prognosis evaluation. Methods Real-time RT-PCR was used to quantitatively detect the mRNA expression of E2A-PBX1 gene in 11 newly diagnosed ALL patients at diagnosis （ 11 cases）, complete remission （11 cases） and periods of relapse （3 cases）. Ten children with normal bone marrow cell morphology and without hematopathy or tumor diseases were used as the control group. Results The median expression levels of E2A-PBX1 fusion gene in the ALL group at diagnosis and the relapse group were significantly higher than in the control and complete remission groups （ P 〈 0. 01 ）. Compared with E2A-PBXI negative patients on day 33 during induction of remission, the recurrence rate increased and disease free survival rate at 3 year decreased significantly in E2A- PBX1 positive patients decreased （P 〈 0.05）. Conclusions Measurement of E2A-PBXI levels by real-time RT-PCR is useful for monitoing minimal residual disease, prediction of relapse and individual treatment . The expression level of E2A- PBX1 gene on day 33 during induction of remission can be used for prognosis evaluation.