Differential miRNA expression in pleural effusions derived from extracellular vesicles of patients with lung cancer, pulmonary tuberculosis, or pneumonia

MicroRNAs (miRNAs) have been found to play important regulatory roles in various physiological and pathological processes. MiRNAs also exhibit high stability and are present at high concentrations in human bodily fluids. Consequently, miRNAs may represent attractive and novel diagnostic biomarkers for certain clinical conditions. Recently, the capacity for extracellular vesicles, including microvesicles and exosomes, to carry miRNAs that participate in cell-to-cell communication has been described. In the present study, the miRNA expression patterns for three kinds of pleural effusions that were obtained from patients with pneumonia (group A), pulmonary tuberculosis (group B), and lung cancer (group C) were detected with high-throughput sequencing. When the expression levels of these miRNAs were compared among the three groups, three differentially expressed miRNAs were detected between groups A and B, while 27 differentially expressed miRNAs were detected between groups A and C. Notably, miR-378i was significantly elevated only in group B, while miR-205-5p and miR-200b were markedly increased only in group C (p < 0.01). Further studies are needed to confirm whether these differentially expressed miRNAs may serve as prospective diagnostic markers for pulmonary diseases.