Expressions of microRNA-127-5p in bronchoalveolar lavage fluid of patients with severe pneumonia and its diagnostic value / 中华危重病急救医学

ABSTRACT

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 pneumonia.