目的：研究Bcl-2，MDR-1基因与儿童急性白血病耐药的关系及其临床意义。方法：采用逆转录多聚酶链式反应(RTPCR)技术，对36例急性白血病患儿及10例血小板减少性紫癜患儿(对照)骨髓单个核细胞中Bcl-2和MDR-1基因的表达进行检测。结果：①初治组、复发组Bcl-2基因表达明显高于对照组，差异均有显著性(P<0.05)。初治组、完全缓解组Bcl-2基因表达明显低于复发组，差异均有显著性(P<0.01)。复发组MDR-1基因的表达明显高于对照组、初治组、完全缓解组(P<0.01 或 0.05)。初治组与对照组间及完全缓解组与对照组间的MDR-1表达差异无显著性(P>0.05)。②Bcl-2和MDR-1基因的表达与白血病临床特征如性别、年龄、初诊时白细胞数、骨髓中幼稚细胞百分数及肝、脾、淋巴结肿大程度均无显著相关性(P>0.05)。③Bcl-2与MDR-1基因之间无显著相关性(rs=0.308，P>0.05)。结论：Bcl-2和MDR-1基因可能通过不同的机制导致白血病的耐药。

OBJECTIVE: To investigate the expression and significance of Bcl 2 and MDR 1 genes in children with acute leukemia. Methods The expressions of Bcl 2 and MDR 1 genes in 36 cases of acute leukemia and 10 cases of idiopathic thrombocytopenic purpura in the control group were examined by RT PCR. RESULTS: The expressions of Bcl 2 in the incipient group and relapsed group were higher than that of the control group (P< 0.05 ). While in the incipient group and complete remission group, they were lower than that of the relapsed group (P< 0.01 ). The expression of MDR 1 gene in the relapsed group was higher than those of control group, incipient group and complete remission group (P< 0.01 or 0.05 ). There was no difference of MDR 1 expression between the incipient group and the control group or the complete remission group and the control group (P> 0.05 ). There was no close relationship between the levels of Bcl 2 or MDR 1 and clinical features such as gender, age, initial WBC count, the percent of carcinocytes, hepatomegaly, splenomegaly and lymphadenhypertrophy (P> 0.05 ). The relationship between Bcl 2 and MDR 1 genes was not significant (r s= 0.308 , P> 0.05 ). CONCLUSIONS: Bcl 2 and MDR 1 genes were associated with drug resistance by different mechanisms.