Update on Advances in Research on Idiosyncratic Drug-Induced Liver Injury

An integrative lipidomics and transcriptomics study revealing Bavachin and Icariin synergistically induce idiosyncratic liver injury

Objectives: Reports of traditional Chinese medicine (TCM)-related liver injury have increased over recent years; however, identifying susceptibility-related components and biomarkers remains challenging due to the heterogeneous nature of TCM and idiosyncratic drug-induced liver injury (IDILI). Psoraleae Fructus (PF) and Epimedii Folium (EF), commonly found in TCM prescriptions, have been implicated in IDILI, but their constituents and underlying mechanisms are poorly understood.

Methods: In this study, we identified bavachin (Bav) and icariin (Ica) as susceptibility components for IDILI in PF and EF using a TNF-α-mediated mouse model. Lipidomics and transcriptomics were used to investigate their related mechanism.

Results: Liver biochemistry and histopathology analyses revealed that co-exposure to Bav, Ica, and a non-toxic dose of TNF-α prestimulation induced significant liver injury, while Bav and Ica alone did not. Lipidomics identified seven differentially abundant metabolites in the Bav/Ica/TNF-α group compared to the Ica/TNF-α or Bav/TNF-α groups, mainly enriched in alpha-linolenic acid (ALA), arachidonic acid (AA), and linoleic acid (LA) metabolic pathways. Additionally, transcriptomics revealed 49 differentially expressed genes (DEGs) in the Bav/TNF-α vs Bav/Ica/TNF-α and Ica/TNF-α vs Bav/Ica/TNF-α groups, primarily associated with the PI3K/AKT/mTOR signaling pathway and sphingolipid metabolism. Integrative lipidomics and transcriptomics analyses identified significant positive correlations between five differential metabolites (DMs) - PC (O-16:0_14:1), PG (22:1_20:3), PI (16:0_14:1), PS (18:0_19:2), and TG (17:0_18:2_22:5) - and ten DEGs - Nr0b2, Btbd19, Btg2, Fam222a, Fam83f, Gtse1, Anln, Gja4, Srrm4, and Zfp13.

Conslusions: Collectively, these results suggest that alterations in intracellular metabolism and gene expression levels may contribute to the synergistic induction of IDILI by the incompatible pair Bav and Ica in the presence of TNF-α.

Idiosyncratic DILI: Analysis of 46,266 Cases Assessed for Causality by RUCAM and Published From 2014 to Early 2019

One of the most difficult challenges in clinical hepatology is the diagnosis of a drug-induced liver injury (DILI). The timing of the events, exclusion of alternative causes, and taking into account the clinical context should be systematically assessed and scored in a transparent manner. RUCAM (Roussel Uclaf Causality Assessment Method) is a well-established diagnostic algorithm and scale to assess causality in patients with suspected DILI. First published in 1993 and updated in 2016, RUCAM is now the worldwide most commonly used causality assessment method (CAM) for DILI. The following manuscript highlights the recent implementation of RUCAM around the world, by reviewing the literature for publications that utilized RUCAM, and provides a review of “best practices” for the use of RUCAM in cases of suspected DILI. The worldwide appreciation of RUCAM is substantiated by the current analysis of 46,266 DILI cases, all tested for causality using RUCAM. These cases derived from 31 reports published from 2014 to early 2019. Their first authors came from 10 countries, with China on top, followed by the US, and Germany on the third rank. Importantly, all RUCAM-based DILI reports were published in high profile journals. Many other reports were published earlier from 1993 up to 2013 in support of RUCAM. Although most of the studies were of high quality, the current case analysis revealed shortcomings in few studies, not at the level of RUCAM itself but rather associated with the work of the users. To ensure in future DILI cases a better performance by the users, a list of essential elements is proposed. As an example, all suspected DILI cases should be evaluated 1) by the updated RUCAM to facilitate result comparisons, 2) according to a prospective study protocol to ensure complete data sets, 3) after exclusion of cases with herb induced liver injury (HILI) from a DILI cohort to prevent confounding variables, and 4) according to inclusion of DILI cases with RUCAM-based causality gradings of highly probable or probable, in order to increase the specificity of the results. In conclusion, RUCAM benefits from its high appreciation and performs well provided the users adhere to published recommendations to prevent confounding variability.

Idiosyncratic DILI: Analysis of 46,266 Cases Assessed for Causality by RUCAM and Published From 2014 to Early 2019

One of the most difficult challenges in clinical hepatology is the diagnosis of a drug-induced liver injury (DILI). The timing of the events, exclusion of alternative causes, and taking into account the clinical context should be systematically assessed and scored in a transparent manner. RUCAM (Roussel Uclaf Causality Assessment Method) is a well-established diagnostic algorithm and scale to assess causality in patients with suspected DILI. First published in 1993 and updated in 2016, RUCAM is now the worldwide most commonly used causality assessment method (CAM) for DILI. The following manuscript highlights the recent implementation of RUCAM around the world, by reviewing the literature for publications that utilized RUCAM, and provides a review of "best practices" for the use of RUCAM in cases of suspected DILI. The worldwide appreciation of RUCAM is substantiated by the current analysis of 46,266 DILI cases, all tested for causality using RUCAM. These cases derived from 31 reports published from 2014 to early 2019. Their first authors came from 10 countries, with China on top, followed by the US, and Germany on the third rank. Importantly, all RUCAM-based DILI reports were published in high profile journals. Many other reports were published earlier from 1993 up to 2013 in support of RUCAM. Although most of the studies were of high quality, the current case analysis revealed shortcomings in few studies, not at the level of RUCAM itself but rather associated with the work of the users. To ensure in future DILI cases a better performance by the users, a list of essential elements is proposed. As an example, all suspected DILI cases should be evaluated 1) by the updated RUCAM to facilitate result comparisons, 2) according to a prospective study protocol to ensure complete data sets, 3) after exclusion of cases with herb induced liver injury (HILI) from a DILI cohort to prevent confounding variables, and 4) according to inclusion of DILI cases with RUCAM-based causality gradings of highly probable or probable, in order to increase the specificity of the results. In conclusion, RUCAM benefits from its high appreciation and performs well provided the users adhere to published recommendations to prevent confounding variability.