急性白血病伴11q23/MLL基因易位和扩增临床特点

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[摘要] 目的 研究急性白血病（AL）伴混合系列白血病（MLL）基因易位和擴增的临床特点。

方法 初治成人AL病人112例，取其骨髓细胞经24 h短期培养，常规方法制备染色体标本，R显带行染色体核型分析;使用位点特异性识别（LSI）11q23/MLL双色分离DNA探针行间期荧光原位杂交（FISH），对异常信号者行中期FISH确定11q23/MLL异常。分析MLL基因易位和扩增者临床特征。

结果 FISH显示112例AL病人中9例（8.04%）存在11q23/MLL基因易位，8例（7.14%）存在MLL基因扩增。两者显示相似的临床特点：髓外浸润发生率高，对细胞毒药物敏感性低，治疗后早期复发率高，生存期短，预后不良。病人通常诊断为B-祖细胞急性淋巴细胞白血病、急性单核细胞白血病或双表型急性白血病。急性淋巴细胞白血病高表达CD34，急性髓系白血病高表达CD117、CD56、CD11b和CD64并有明显骨髓病态造血。MLL基因扩增病人发病年龄较大、外周血白细胞计数较低，有更明显的病态造血。

结论 11q23/MLL基因易位和扩增的成人AL病人具有相似的临床特点，MLL基因在AL发病中为功能获得性异常。

[关键词] 白血病，双表型，急性;易位，遗传;基因扩增

[中图分类号] R733.71

[文献标志码] A

[文章编号]  2096-5532（2019）06-0679-06

doi：10.11712/jms201906012

[开放科学（资源服务）标识码（OSID）]

CLINICAL FEATURES OF ACUTE LEUKEMIA WITH 11Q23/MLL TRANSLOCATIONS OR AMPLIFICATIONS

ZHAO Xichen， SUN Xiaoyun， YI Li′an， ZHAO Li， JU Bo， ZHAO Hongguo

（Department of Hematology， Qingdao West Coast New Area Central Hospital， Qingdao， 266555， China）

[ABSTRACT] Objective To investigate the clinical features of acute leukemia （AL） with mixed-lineage leukemia （MLL） gene translocations or amplifications.

Methods Bone marrow cells were collected from 112 previously untreated adult patients with AL， and then cultured for a short period of 24 h followed by conventional chromosome preparation. The R-banding technique was applied for karyotype analysis. Interphase-fluorescence in situ hybridization （FISH） was used to detect gene abnormalities using the locus-specific identifier 11q23/MLL dual-color break-apart probe. Abnormal signals of the 11q23/MLL screened out by interphase-FISH would be further determined by metaphase-FISH. The clinical features of the patients with MLL translocations or amplifications were analyzed.

Results The 11q23/MLL translocations were observed in 9 cases （8.04%） and MLL amplifications in 8 cases （7.14%） of all the 112 AL patients according to FISH. There were similar clinical features between the patients with 11q23/MLL translocations and those with 11q23/MLL amplifications： a high incidence of extramedullary infiltration， a low sensitivity to cytotoxic drugs， a high early recurrence rate after treatment， a short survival time， and a poor prognosis. The patients with MLL gene abnormalities were frequently diagnosed with B-progenitor acute lymphoblastic leukemia， acute monocytic leukemia， or biphenotypic acute leukemia. A high expression of CD34 was observed in acute lymphoblastic leukemia， while a high expression of CD117， CD56， CD11b， and CD64 along with obvious dysplasia was observed in acute myeloid leukemia. The patients with MLL amplifications had an older age of onset， a relatively low white blood cell count， and more obvious dysplasia.