Assessment of a panel of miRNAs in serum and pleural fluid for the differential diagnosis of malignant and benign pleural effusion.

Background: Differential diagnosis between malignant pleural effusion (MPE) and benign pleural effusion (BPE) remains a clinical challenge.

Objective: The aim of the study is to assess the efficacy of the serum and pleural fluid (PF) miRNA panels in distinguishing MPE from BPE.

Methods: Fourteen candidate miRNAs which were shown aberrant expression in lung cancer based on previous studies were tested by quantitative real-time PCR (qRT-PCR) in 20 MPE patients and 20 BPE patients. Significantly aberrantly expressed miRNAs were further assessed by qRT-PCR in all patients enrolled in this study. A receiver operating characteristic (ROC) curve was constructed, and the area under the ROC curve (AUC) was calculated to evaluated the diagnostic performance of the miRNAs.

Results: miR-21, miR-29c and miR-182 were found to be significantly aberrantly expressed in the serum and PF of MPE patients. The AUCs for the combination of miR-21, miR-29c and miR-182 in serum and PF were 0.832 and 0.89 respectively in distinguishing MPE from infection-associated PE including tuberculous pleurisy and parapneumonia PE, and 0.866 and 0.919 respectively for differentiating MPE from heart failure-associated PE, which were superior to AUC of each individual miRNAs.

Conclusions: miR-21, miR-29c and miR-182 in serum and PF could be useful biomarkers for diagnosis of MPE.