Circulating extracellular vesicle‐encapsulated microRNA‐557 induces a proinflammatory immune response and serves as a diagnostic or relapse marker in autoimmune hepatitis

Aim This study investigated serum microRNAs (miRNAs/miRs) in autoimmune hepatitis (AIH) and the relationship of these molecules with diagnostic and relapse markers. Methods Initially, extracellular vesicle‐encapsulated miRNAs (EV‐miRNAs) in serum with altered expression in AIH relative to healthy control (HC) samples were identified using microarray analysis. To validate the microarray results, the expression levels of selected EV‐miRNAs were determined. Results Among the 2569 mature miRNAs evaluated in the microarray, EV‐miR‐557 discriminated patients with AIH from healthy controls (HCs). Validation by digital polymerase chain reaction indicated that serum EV‐miR‐557 levels were higher in patients with AIH (7.75 copies/μl) than in patients with non‐alcoholic steatohepatitis (1.60 copies/μl; p