目的 探讨microRNA-155在初诊急性髓性血病（AML）患儿和非白血病对照儿童之间的差异表达情况，分析其意义。 方法 随机抽取我院标本库中自2012至2013年间收集的19例初诊AML骨髓标本以及20例非白血病对照儿童标本，利用Taqman探针实时荧光定量聚合酶链反应 (qRT-PCR)法检测microRNA-155的相对表达水平（结果以2-△△Ct表示）。结果 microRNA-155的表达水平在AML患儿和对照组之间有显著差异（AML患儿组增高）（ z=-4.382;P=0.001）；在预后分组中，不良组、中等组和良好组之间microRNA-155的表达水平无明显差异（P>0.05）；在早期治疗反应分组中，缓解组和未缓解组之间表达水平无显著差异（P>0.05）。结论 与对照组相比，microRNA-155在初诊小儿AML中发生显著的差异高表达现象，过表达的microRNA-155与危险度分组和早期治疗反应、预后等无显著相关性。microRNA-155有希望成为小儿AML的一个早期诊断标记物，但对于预后的意义尚有待于进一步的深入研究。

Objective To investigate the differential expression of microRNA-155 in new diagnosed pediatric acute myeloid leukemia (AML) and its clinical significances. Methods 19 AML children and 20 non-leukemia controlled children were included. Real-time quantitative PCR (TaqMan）was applied to validate the expression of microRNA-155 in bone marrow samples. Results The expressions of microRNA-155 in AML children were significantly higher than those in controls (p=0.001). The levels of microRNA-155 had no significant differences in Karyotype groups, response to treatment groups and risk groups (p>0.05). The microRNA-155 levels in AML childen were increased comparing with controls, but there were no distinctions in clinical groups associated with the outcome of disease. Conclusion The microRNA-155 may be used as one of biomarkers in the early diagnosis of childhood AML in the near future.