BackgroundD-dimer tests have been widely used to rule-out deep venous thrombosis (DVT), but with low specificity. Circulating microRNAs (miRNAs) are novel promising biomarkers in diverse diseases. The purpose of our study was to identify the diagnostic abilities of circulating miRNA-320a/b and to assess their correlation with plasma D-dimer in DVT and post-thrombotic syndrome (PTS) patients.Material/MethodsPlasma samples were taken from 30 DVT patients, 30 PTS patients, and 30 age- and sex-matched healthy volunteers. Quantitative real-time PCR (qPCR) assay and turbidimetric immunoassay were conducted to assess the concentrations of miRNA-320a/b and D-dimer in plasma.ResultsCirculating miRNA-320a and miRNA-320b were significantly upregulated in DVT patients with fold changes of 1.58 and 1.79, respectively. The receiver operating characteristic (ROC) curve analysis showed area under the curve (AUC) values of 0.70 (95% CI: 0.56–0.83) for miRNA-320a and 0.79 (95% CI: 0.67–0.90) for miRNA-320b. Moreover, plasma levels of miRNA-320b were associated with D-dimer values (r=0.52, 95% CI: 0.19–0.74) in DVT. However, no significant changes in plasma miRNA-320a/b and D-dimer were detected in PTS patients.ConclusionsCompared with controls, circulating miRNA-320a/b was differentially expressed in DVT. Simultaneous detection of miRNA-320a/b with D-dimer may improve diagnostic accuracy of DVT.