实时定量RT-PCR方法监测急性髓系白血病患者造血干细胞移植后AML1-ETO融合基因mRNA水平的临床意义

目的 评价实时定量RT-PCR(Q-PCR)方法监测AML1-ETO(+)急性髓系白血病(AML)患者异基因造血干细胞移植(allo-HSCT)后AML1-ETO mRNA水平的表达及其临床意义.方法 采用基于TagMan探针的Q-PCR技术检测17例AML1-ETO(+)AML患者allo-HSCT后不同时间骨髓标本AML1-ETO mRNA的表达.AML1-ETO mRNA水平以内参基因abl进行归一化.采用荧光原位杂交(FISH)法评估HSCT后是否达到细胞遗传学完全缓解(CCyR).结果 Q-PCR实验可重复敏感度为5个拷贝.在16例CCyR患者中,1例死于移植物抗宿主病(GVHD),1例死于感染,其余14例中位随访时间为268(70～811)d,HSCT后1个月(+1月)AML1-ETO中位水平0(0～0.740),+2月为0.026(0～2.900),+3月为0.039(0～3.300).移植时间超过12个月的5例患者中,中位随访685(385～811)d,4例仍呈AML1-ETO阳性,中位值0.078(0.003～0.120).1例复发患者+1月为0,+2月为9.800,+3月为5.600,+110 d血液学复发,AML1-ETO mRNA为390.000,+382 d死亡.结论 1年内AML1-ETO持续低水平阳性不一定预示复发;对AML1-ETO(+)AML患者HSCT后定期动态监测AML1-ETO水平十分必要.

Monitoring AML1-ETO mRNA levels by real-time quantitative RT-PCR in t (8; 21) acute myeloid leukemia patients after hematopoietic stem cell transplantation

Objective To evaluate the value of real time quantitative RT-PCR(Q-PCR) for monitoring AML1-ETO mRNA levels in AMLI-ETO(+) acute myeloid leukemia (AML) patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods Quantification of AMLI-ETO (+) mRNA was performed serially on bone marrow samples from 17 patients with AML1-ETO (+) AML after HSCT. Q-PCR used the TagMan probe system. The AML1-ETO mRNA level was normalized by control gene abl. Cytogenetic response was evaluated by fluorescent in situ hybridization (FISH). Results The reproducible sensitivity of Q-PCR was 5 copies. Out of 16 patients who achieved sustained complete cytogenetic response (CCyR), one each died of graft-versus-host disease and infection. The median AML1-ETO mRNA levels in the rest of 14 CCyR patients were 0 (0 - 0.740), 0. 026 (0 - 2.900), 0.039 (0 - 3.300) at + 1, + 2, + 3 month post allo-HSCT, respectively and in 5 CCyR patients beyond 1 year following allo-HSCT (median follow-up 685 days) was 0.078(0.003 -0.120). The AML1-ETO mRNA levels in one relapsed patient were 0, 9.8 and 5.6 at + 1, + 2 and + 3 month post allo-HSCT, respectively and hematological relapse occurred at + 110 day, when the AML1-ETO mRNA levels increased dramatically from 5.600 to 390. 000. Conclusions Q-PCR is a sensitive technique in monitoring AML1-ETO (+) AML patients post allo-HSCT. Persistence of a low level within one year after allo-HSCT does not mean at risk of relapse. It is necessary to dynamic monitoring AML1-ETO mRNA after remission in t(8 ;21) AML patients.