Circulating miR-122 as a potential biomarker of liver disease

Aim: Expression profiles indicate that miR-122 is specifically and abundantly expressed in liver. This study sought to determine miR-122 plasma concentrations in 15 apparently healthy subjects and 30 patients with liver disease, and clarify whether plasma miR-122 correlates with ALT. Materials & methods: miR-122 was measured by quantitative PCR in healthy volunteers and patients with liver disease. Results: ALT was increased in two out of 15 (13%) apparently healthy subjects and 17 out of 30 (57%) liver disease patients. In healthy subjects, median miR-122 plasma concentration was 51.7 copies/20 pg RNA (range 16.0-312.0). In liver disease patients, median miR-122 was significantly elevated to 202.3 copies/20 pg RNA (range 20.9-1160.0; Mann-Whitney test between median concentrations; p = 0.0016). Conclusion: This small proof-of-principle study suggests that miR-122 may be a potential plasma biomarker of liver damage.