Micro-RNA-122 levels in acute liver failure and chronic hepatitis C

MicroRNA‐122 (miR‐122) is the foremost liver‐related micro‐RNA, but its role in the hepatocyte is not fully understood. To evaluate whether circulating levels of miR‐122 are elevated in chronic‐HCV for a reason other than hepatic injury, we compared serum level in patients with chronic hepatitis C to other forms of liver injury including patients with acute liver failure and healthy controls. MiR‐122 was quantitated using sera from 35 acute liver failure patients (20 acetaminophen‐induced, 15 other etiologies), 39 chronic‐HCV patients and 12 controls. In parallel, human genomic DNA (hgDNA) levels were measured to reflect quantitatively the extent of hepatic necrosis. Additionally, six HIV–HCV co‐infected patients, who achieved viral clearance after undergoing therapy with interferon and ribavirin, had serial sera miR‐122 and hgDNA levels measured before and throughout treatment. Serum miR‐122 levels were elevated approximately 100‐fold in both acute liver failure and chronic‐HCV sera as compared to controls (P