Alm S J, Engvall C, Asp J, Palmqvist L, Abrahamsson J, Fogelstrand L
Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
Ryhov County Hospital, Jonkoping, Sweden.
Int J Lab Hematol. 2017 Apr;39(2):121-128. doi: 10.1111/ijlh.12593. Epub 2016 Dec 22.
The translocation t(12;21)(p13;q22) resulting in the fusion gene ETV6-RUNX1, is the most frequent gene fusion in childhood B lymphoblastic leukemia. In the Nordic Society of Paediatric Haematology and Oncology ALL-2008 treatment protocol, treatment stratification in B-lineage ALL is based on results of minimal residual disease (MRD) analysis with fluorescence-activated cell sorting (FACS). In this study, we determined whether RT-qPCR of the ETV6-RUNX1 fusion transcript can be a reliable alternative for MRD analysis.
Seventy-eight bone marrow samples from 29 children at diagnosis and day 15, 29, and 78 during treatment were analyzed for MRD with FACS and with quantitative reverse transcription polymerase chain reaction (RT-qPCR). Fusion transcript MRD was defined as the ETV6-RUNX1/GUSB ratio at the follow-up time point (day 15/29/78) divided with the ETV6-RUNX1/GUSB ratio at diagnosis (%).
MRD analysis with FACS and with RT-qPCR of ETV6-RUNX1 fusion transcript showed strong correlation. All cases showed concordant results at the treatment stratifying time points day 29 and day 78, when comparing the two methods with a cutoff set to 0.1%.
RT-qPCR is a valuable addition and could also be an alternative to FACS in cases where FACS is not achievable for MRD analysis.
导致融合基因ETV6-RUNX1的t(12;21)(p13;q22)易位是儿童B淋巴细胞白血病中最常见的基因融合。在北欧儿科血液学和肿瘤学协会ALL-2008治疗方案中，B系急性淋巴细胞白血病的治疗分层基于荧光激活细胞分选（FACS）的微小残留病（MRD）分析结果。在本研究中，我们确定ETV6-RUNX1融合转录本的逆转录定量聚合酶链反应（RT-qPCR）是否可以作为MRD分析的可靠替代方法。
对29名儿童诊断时、第15天、第29天和治疗期间第78天的78份骨髓样本进行FACS和定量逆转录聚合酶链反应（RT-qPCR）分析以检测MRD。融合转录本MRD定义为随访时间点（第15天/第29天/第78天）的ETV6-RUNX1/GUSB比值除以诊断时的ETV6-RUNX1/GUSB比值（%）。
FACS和ETV6-RUNX1融合转录本的RT-qPCR MRD分析显示出很强的相关性。当将两种方法的临界值设定为0.1%进行比较时，所有病例在治疗分层时间点第29天和第78天显示出一致的结果。
RT-qPCR是一项有价值的补充方法，在无法进行FACS MRD分析的情况下也可作为FACS的替代方法。
