目的　筛选肺炎支原体肺炎（MPP）患儿差异表达的血浆miRNAs，并予以验证。方法　入选36例MPP患儿， 27例健康对照儿童；对3例MPP患儿及3例对照儿童的血浆样本进行miRNA芯片筛选，获得miRNA表达谱；RT-qPCR法 检测全体研究对象外周血白细胞中miR-222-3p及miR-492的表达量并进行比较。结果　MPP患儿血浆中筛选出26条与 对照组有显著差异的miRNAs，其中19条miRNAs表达上调， 7条miRNAs表达下调；与对照组比较，MPP组miR-222-3p 及miR-492的表达上调，差异均有统计学意义（P<0.01）。 结论　MPP患儿部分miRNAs表达有变化，可能参与MPP的免 疫发病机制。

Objective　To identify the differentially expressed microRNAs（miRNA）in plasma of Mycoplasma pneumoniae pneumonia (MPP) by miRNA microarray. Methods　36 cases of hospitalized children with MPP were enrolled (MPP group). 27 cases of healthy children were enrolled as control group (NC group) in the same period. Microarray chip was used to find out differentially expressed miRNAs of plasma from 3 cases with MPP group and 3 cases with NC group.  Real-time quantitative PCR was chosen to detect the expression of miR-222-3p and miR-492 in leukocytes from MPP group (n=36) and NC group (n=27).  Results　26 miRNAs differentially expressed between the two groups were screened out by miRNA microarray assays, of which the expression of 19 miRNAs was elevated, while 7 miRNAs declined. Compared with NC group, the expression of miR-222-3p and miR-492 increased in the MPP group (P＜0.01).  Conclusions　Some miRNAs are differently expressed in peripheral blood of MPP patients, which may be involved in the immunopathogenesis of MPP. Key