Serum exosome microRNA panel as a noninvasive biomarker for molecular diagnosis of fulminant myocarditis

Exosome-derived microRNAs (miRNAs) are potential diagnostic biomarkers. However, little is known about their effectiveness as diagnostic biomarkers of fulminant myocarditis (FM). This study aimed to explore serum exosomal miRNAs as potential biomarkers for FM diagnosis. Peripheral blood samples were collected from 99 patients with FM, 32 patients with nonfulminant myocarditis (NFM), and 105 healthy controls (HCs). The miRNA expression profiles of serum exosomes were determined using next-generation sequencing, and differentially expressed miRNAs were further analyzed by quantitative reverse transcriptase polymerase chain reaction. A logistic regression model was constructed using a training cohort (n = 120) and then validated using an independent cohort (n = 106). The area under the receiver operating characteristic curve was used to evaluate diagnostic accuracy. In FM patients, hsa-miR-30a, hsa-miR-192, hsa-miR-146a, hsa-miR-155, and hsa-miR-320a were validated as significantly and differentially expressed candidates that could serve as potential markers for diagnosing FM. In addition, the miRNA panel (hsa-miR-155 and hsa-miR-320a) from the multivariate logistic regression model demonstrated high accuracy in the diagnosis of FM and was able to distinguish FM from HCs and NFM. Moreover, the diagnostic value of the miRNA panel was greater than that of CRP and cTn alone or together. The miRNA panel provided the excellent diagnostic capability for FM.