儿童t(8;21)急性髓系白血病的细胞遗传学特点及预后分析

目的探讨伴有t(8;21)的儿童急性髓系白血病(AML)的细胞遗传学特点及预后意义。方法回顾性分析我院检测的85例伴有t(8;21)的儿童AML的细胞遗传学及荧光原位杂交(FISH)结果,分析其与临床预后的关系。结果单纯t(8;21)(q22;q22)占25.9%(22/85),伴有附加异常74.1%(63/85)。附加异常中:单纯性染色体丢失占46.0%(29/63),9q-占15.9%(10/63),+4占6.3%(4/63),四倍体(4N)占7.9%(5/63),变异易位占12.7%(8/63),其它异常占11.1%(7/63)。85例中30例行FISH检测,结果均为阳性。23例信号特征显示典型的t(8;21)阳性信号(2Y1R1G),5例为变异易位信号(1Y2G2R)患者,2例为多倍体信号特点(4Y2G2R,3Y2G1R)。16例多次FISH结果中,阳性转阴性的12例,阴性转阳性的2例(初诊没做FISH),2例多次均为阳性。本组85例患者中,59例在本院接受治疗,55例患者获得完全缓解,患者的缓解率为93.2%(55/59),+4组和4N组的治疗效果较差。本组总的中位生存期为16个月。+4、4N和伴有其它异常的三组预后较差,中位生存期小于1年。4N组中位生存期明显短(P=0.0039)。四倍体核型在儿童组的发生率明显高于成人组(χ2=5.48,P<0.05)。结论附加异常中+4和四倍体的预后较差,四倍体核型在儿童患者中多见。核型和FISH检测可同时应用于儿童t(8;21)AML的诊断和预后监测。

Cytogenetic characteristics and clinical outcome of t(8;21) childhood acute myeloid leukemia

Objective To investigate the cytogenetic and prognostic significance of childhood acute myeloid leukemia(AML) with t(8;21). Methods A retrospective analysis including the cytogenetics ,FISH and clinical outcome was performed on 85 cases of childhood t(8;21) AML. Results 22 cases(25.9%) were t(8;21) without additional aberrations,63 cases(74.1%) were t(8;21) with additional aberrations. In the additional aberrations,loss of the sex chromosome were found in 29 cases(46.0%); Del(9q) was found in 10 cases (15.9%); +4was found in4 cases (6.3%); Tetraploidy clone(4N) was found in 5 cases (7.9%); Variant translocation was found in 8 cases(12.7%). 30 cases among 85 were studied by FISH,the results are all positive. Among these 30 cases,23 cases displayed typical FISH signal pattern,5 cases displayed variant signal,2 cases displayed multiple signal. The childhood t(8;21) AML had a high remission rate(93.2%),the median overall survival was 16 months. Curative effect of +4 and 4N were not good. The median overall survival of 4N was significantly shorter than other patients (P=0.0039). Tetraploid clone was significantly higher in children than in aldults (χ2=5.48,P<0.05). Conclusion t(8;21) AML is also frequently associated with additional chromosome aberrations,+4 and 4N were unfavorable prognostic factors,tetraploid clone was more frequent in children. Conventional cytogenetics and FISH can be applied to diagnose t(8;21)AML and monitor relapse.