Profiling of circulating microRNAs in human drug-induced liver injury identifies novel signatures of toxicity

ADB Vliegenthart1, JM Schaffer2, LEJ Peeters1, DN Bateman1, DM Wood3,4, PI Dargan3,4, A Caporali1, DJ Webb1, MA Bailey1, E Lader1, KJ Simpson5, JW Dear1. 1Pharmacology, Toxicology and Therapeutics, University/BHF Centre for Cardiovascular Science, Edinburgh University, Edinburgh, UK, 2Qiagen, Fredrick, Maryland, USA, 3Clinical Toxicology, Guy’s and St Thomas’ NHS Foundation Trust, London, UK, 4King’s College London, London, UK, 5Scottish Liver Transplantation Unit, Royal Infirmary of Edinburgh, Edinburgh, UK

Paracetamol is the commonest cause of drug-induced liver injury in the Western world. Circulating microRNAs (miRNAs) are promising biomarkers, with microRNA-122 (miR-122) undergoing qualification and validation for adoption into clinical practice as a biomarker for liver injury. Our objective was to comprehensively profile the changes in circulating miRNA that accompany human paracetamol toxicity.

Plasma miRNAs were quantified using PCR-based arrays in paracetamol overdose patients with (APAP-TOX) (N=27) and without (APAP no TOX) (N=27) organ toxicity defined as peak ALT activity greater than 3x the upper limit of normal (ULN;>150 U/L). Using random forest analysis, classifier miRNA models were developed then tested in a separate patient cohort (‘test cohort’ N=81). Stable internal miRNA normalizers were discovered and selected normalized miRNAs were compared with miR-122 and serum alanine aminotransferase (ALT) activity with regard to the stratification of patients at first presentation to hospital (APAP-early, N=67).

Out of 1805 miRNA species, 75 were more than 3 fold increased with APAP-TOX versus APAP no TOX. The largest median (inter quartile range) increased circulating miRNAs were miR-122 68 (11-277), miR-885 57 (17-372), miR-151a 57 (16-360), miR-1290 45 (11-226) and miR-1915 17 (7-89) (all P<0.001). A classifier model consisting of 16 miRNA species was derived that separated APAP-TOX and APAP no TOX patients in the test cohort with high accuracy. Receiver operator curve (ROC) analysis demonstrated that miR-122 predicted liver injury (defined as peak ALT > 3x ULN) at first presentation to hospital and was more accurate than ALT (ROC AUC: miR-122 0.92 (0.9-1); ALT: 0.81 (0.65-0.97)).

These new miRNA panels report human organ toxicity with high accuracy and include novel miRNAs not previously described as toxicology biomarkers. For patient stratification at first presentation to hospital microRNAs are lead candidates for clinical development.