May 27, 2021 Biomarker synthesized by Th17 cells appears to differentiate myocarditis from MI Differentiating acute myocarditis from myocardial infarction (MI) requires either an invasive biopsy or cardiac MRI—technology that is not always available—so the possibility that a microRNA biomarker in circulating T cells could be used to confirm myocarditis is appealing. Identifying that novel miRNA was the goal of Rafael Blanco-Dominguez, MSc, of the Vascular Pathophysiology Area, Centro Nacional de Investigaciones Cardiovasculares in Madrid, and a team of international researchers, who started by inducing autoimmune myocarditis or myocardial infarction in mice to identify the microRNA found in Th17 cells in plasma of mice with acute myocarditis—either autoimmune or virus-induced.