急性混合谱系融合基因阳性急性白血病患儿的临床特点

Clinical Features of Acute Leukemia with Positive Mixed Lineage Leukemia Fusion Gene in Children

目的分析混合谱系白血病(MLL)融合基因阳性的急性白血病(AL)患儿临床特点,探讨其治疗措施及其预后相关因素。方法选取细胞形态学、分子生物学、免疫分型及巢式反转录聚合酶链反应(RT-PCR)检测MLL融合基因阳性AL患儿51例,对其临床表现、治疗及预后进行回顾性分析。结果51例MLL融合基因阳性AL患儿中急性淋巴细胞白血病(ALL)37例,急性髓细胞白血病(AML)14例。42例涉及11号染色体改变;RT-PCR检测有36例MLL基因重排,15例为串联重复。32例接受正规治疗的AL患儿中24例完全缓解,其中ALL19例,AML5例;缓解时间持续2 a以上者ALL5例,AML仅1例;持续缓解存活者仅16例,ALL12例,AML4例;10例MLL融合基因已转阴,并持续存活。在随访6 a中,32例中复发6例,均为骨髓复发,死亡6例。结论MLL融合基因阳性AL患儿发生率低,化疗效果差,易复发,预后差。少数对化疗敏感的AL患儿MLL融合基因可转阴,并持续存活。

Objective To analyze the clinical features of acute leukemia （AL） with positive mixed lineage leukemia （MLL） fusion gene in children, and explore their treatment protocols, prognosis factors, and so on. Methods Clinical features, treatment protocols, and prognosis factors were studied retrospectively among 51 AL patients with MLL fusion gene. MLL fusion gene was detected by morphology immunology, cytogenetics,molecul arbiology and reverse transcrption polymerase chain reaction （ RT - PCR）. Results Fifty - one AL patients with MLL fusion gene positive,included 37 cases of acute lymphoblastic leukemia （ALL） and 14 cases of acute myelocytie leukemia （AML）. Forty - two patients exhibited abnormal clonal chromosome 11. MLL fusion gene rearrangements and MLL fusion gene partial tandem duplication were found among 36 cases and 15 cases, respectively. Thirty - two cases who received regular chemotherapy were followed up. Twenty - four cases including 19 cases of ALL and 5 cases of AML had achieved complete remission（CR）. Six cases including 5 cases of ALL and 1 cases of AML had achieved more than 2 years CR. Sixteen cases were alive update including 12 cases of ALL and 4 cases of AML. Ten cases of positive MLL fusion gene were turning negative. Up to now,6 cases relapsed and 6 cases were dead. Conclusions The incidence of AL children with positive MLL fusion gene is low. It has some features, such as, high replapse rate and poor prognosis. A few patients sensitive to chemotherapies can achieve CR. They live with constant negative MLL fusion gene.