中文摘要：

目的 探讨微小RNA-127-5p（miR-127-5p）在重症肺炎患者支气管肺泡灌洗液（BALF）中的表达变化及其对重症肺炎的诊断价值.方法 收集2015年1月至12月宁夏医科大学总医院重症医学科收治的30例重症肺炎患者及10例非呼吸道感染术后患者（需辅助通气）的BALF.采用miRNA芯片技术对两组患者BALF中的miRNA进行筛选,初步建立重症肺炎BALF的miRNA差异表达谱,筛选出其中有明显差异表达的miRNA,采用实时荧光定量聚合酶链反应（PCR）检测BALF中miR-127-5p的表达水平;绘制受试者工作特征曲线（ROC）,评估BALF中miR-127-5p表达对重症肺炎的诊断价值.结果 40例患者中无剔除病例,均纳入最终分析.初步分析筛选建立了重症肺炎患者BALF中miRNA差异表达谱,并筛选出其中40个表达上调的miRNA和113个表达下调的miRNA.重症肺炎患者BALF中miR-127-5p表达量明显低于非呼吸道感染术后患者（2-ΔΔCT：0.578±0.226比1.004±0.337）,差异有统计学意义（t=4.552,P=0.000）.ROC曲线分析显示,miR-127-5p诊断重症肺炎的ROC曲线下面积（AUC）为0.855〔95%可信区间（95%CI）=0.721~0.989,P=0.001〕;当临界值取0.840时,敏感度为86.7%,特异度为70.0%,阳性似然比为2.89,阴性似然比为0.19.结论 BALF中miR-127-5p可作为诊断重症肺炎的分子标志物.

英文摘要：

Objective To observe differential expressions of microRNA-127-5p （miR-127-5p） in bronchoalveolar lavage fluid （BALF） of patients with severe pneumonia and the value of miR-127-5p in the diagnosis of severe pneumonia. Methods Thirty severe pneumonia patients and 10 non-respiratory infection patients who needed mechanical ventilation after surgery admitted to Department of Critical Care Medicine of General Hospital of Ningxia Medical University from January to December in 2015 were enrolled, whose specimens of BALF were collected. The differential expressions of miRNA in BALF of patients in both groups were screened by miRNA chip technique to preliminarily establish miRNA differential expression profiles in BALF of severe pneumonia, and the miRNAs which were up-regulated and down-regulated were screened out. The expression levels of miR-127-5p were determined using a real-time fluorescent quantitative polymerase chain reaction （PCR）. The value of miR-127-5p expression in the diagnosis of severe pneumonia was evaluated with receiver-operating characteristic curve （ROC）. Results All of the 40 patients were enrolled in the final analysis. Differential expression spectrum of miRNA in severe pneumonia patients was initially built, in which 40 miRNAs were up-regulated and 113 miRNAs were down-regulated. Compared with non-respiratory infection patients, the expressions of miR-127-5p were significantly lowered in severe pneumonia patients （2-ΔΔCT： 0.578±0.226 vs. 1.004±0.337） with statistical difference （t = 4.552, P = 0.000）. ROC curve analysis showed that the area under ROC curve （AUC） of miR-127-5p for diagnosis of severe pneumonia was 0.855 [95% confidence interval （95%CI） = 0.721-0.989, P = 0.001], with the optimal sensitivity and specificity of 86.7%and 70.0% respectively with 0.840 as the critical value, and the positive likelihood ratio was 2.89, the negative likelihood ratio was 0.19. Conclusion miR-127-5p in BALF could be used as a new biomarker for the diagnosis of severe pn