儿童急性淋巴细胞白血病伴有TEL-AML1融合基因表达的免疫表型特点分析

Immunophenotypic Characteristics of Children with Acute Lymphoblastic Leukemia Carrying TEL-AML1 Fusion Gene

为了探讨伴有TEL-AML1融合基因表达的儿童急性淋巴细胞白血病(ALL)的免疫表型及其它临床特点,采用三色流式细胞术(FCM)检测免疫表型,用巢式逆转录聚合酶链反应(RT-PCR)检测TEL-AML1融合基因的表达;同时在FAB分型基础之上进行形态学(M)、免疫学(I)、细胞遗传学(C)分型。结果显示①儿童B系ALL中TEL-AML1+占18.5%(22/119),主要以L2亚型为主,糖原(PAS)染色阳性率和积分值均数分别为65%和121,均高于TEL-AML1-组(P<0.05);②与儿童B系ALLTEL-AML1-组相比,TEL-AML1+年龄、性别、白细胞计数、外周血中幼稚细胞数目均未见有统计学差异;③TEL/AML1+组中,普通淋巴细胞表型占95.5%(21/22);与TEL/AML1-组比较,CD13表达率增高(59.1%,13/22),CD20表达率减低(22.7%,5/22)(P<0.05);CD10及HLA-DR的平均荧光指数(MFI值)增高,分别为92.80及53.61(P<0.05)。结论儿童伴TEL-AML1融合基因表达在儿童ALL中较常见,且具有特殊的免疫表型特点,该特点可作为儿童白血病微量残留病的辅助检测。

To investigate the immunilogical and O.her clinical characteristics in TEL/AML1^＋ childhoot B-acute lymphoblastic leukemia （B-ALL）, immunophenotyping was performed with three-color flow cytometry, and the expression of TEL-AML1 fusion gene was detected with nested RT-PCR. Diagnosis was made according to FAB and MIC criteria. The results showed that （1） among 119 children with B-AlL, 22 （18.5%） were TEL-AML1 positive and classified as Lz morphological subtype. In TEL- AML1^＋ group, positive rate and score of PAS, which were 65% and 121 respectively,were all higher than that of TEL-AML1 - group （P 〈0.05）; （2） compared with TEL-AML1^- group, no significant difference was found in age, gender, white cell count and blasts count in peripheral blood of TEL-AML1 ^＋ ; （3） in TEL-AML1 ^＋ group, 21 out of 22 （95.5%） were common ALL, as compared with TEL-AML1^- group, the positive rate of CD13 was higher （59. 1%, 13/22） and the positive rate of CD20 was low- er （22.7%, 5/22） than that in TEL-AMLI- group, respectively （P 〈0.05）, and the mean fluorescence index of CD10 and HLA- DR significantly increased to 92.80 and 53.61, respectively （P 〈0.05）. It is concluded that TEL-AML1 rearrangement is a frequent molecular abnormality in childhood ALL. Leukemic blasts with this anomaly have special immunophenotypic characteris- tics. These characteristics may be useful in detection of minimal residual leukemia.