Ethanol consumption produces a small increase in circulating miR-122 in healthy individuals

Introduction: MicroRNA 122 (miR-122) is a new circulating biomarker for liver injury, which increases earlier than conventional markers in patients with acetaminophen hepatotoxicity. However, as co-ingestion of ethanol is common with drug overdose, a confounding effect of acute ethanol consumption on serum miR-122 must be examined. Methods: Blood was collected from healthy volunteers before and after recreational consumption of ethanol. Routine biochemistry and haematology measurements were performed, and serum miR-122 was measured by qPCR. The primary outcome was the difference in serum miR-122 with ethanol consumption. Results: We recruited 18 participants (72% male). Their mean serum ethanol concentration was 113mg/dl (95% confidence interval [CI] 91-135mg/dl) after consuming ethanol. Serum miR-122 increased from a mean of 71.3 million (95% CI 29.3-113.2 million) to 139.1 million (95% CI 62.6-215.7 million) copies/ml (2.2-fold increase). There was no significant difference in serum alanine aminotransferase activity before and after ethanol consumption. Conclusion: miR-122 increased with moderate ethanol consumption, but the fold change was modest. As increases with acetaminophen toxicity are 100- to 10 000-fold, moderate ethanol intoxication is unlikely to confound the use of this biomarker of hepatotoxicity.