Circulating miR-21 and miR-29a as Markers of Disease Severity and Etiology in Cholestatic Pediatric Liver Disease.

Circulating microRNAs have been investigated as markers of disease severity in a variety of conditions. We examined whether circulating miR-21 and miR-29a could serve as markers of hepatic fibrosis and disease etiology in children with various liver diseases. Circulating miR-21 and miR-29a were determined in 58 children (21 female, age 0.1-17.8 (median 9.8) years)) with chronic liver disease and compared to histological grading of hepatic fibrosis. 22 healthy children served as controls for circulating miRNAs. Levels of circulating miR-21 appeared to be age-dependent in healthy children. Children with biliary atresia had significantly higher levels of miR-21 compared both to healthy controls and to age-matched children with other cholestatic liver disease. Circulating miR-29a levels in biliary atresia children did not differ from healthy controls, but tended to be higher than in age-matched children with other cholestatic liver disease. Neither miR-21 nor miR-29a correlated well with hepatic fibrosis. Circulating miR-21 and miR-29a levels can potentially serve as non-invasive diagnostic markers to differentiate biliary atresia from other cholestatic disease in infancy. They do not appear suitable as non-invasive markers for the degree of hepatic fibrosis in an unselected cohort of children with various liver diseases. The discriminating effect regarding neonatal cholestasis should be followed up in a prospective longitudinal study.