Chronic Drug-Induced Liver Injury: Updates and Future Challenges

Chinese guideline for the diagnosis and treatment of drug-induced liver injury: an update

Drug-induced liver injury (DILI) is an important adverse drug reaction that can lead to acute liver failure or even death in severe cases. Currently, the diagnosis of DILI still follows the strategy of exclusion. Therefore, a detailed history taking and a thorough and careful exclusion of other potential causes of liver injury is the key to correct diagnosis. This guideline was developed based on evidence-based medicine provided by the latest research advances and aims to provide professional guidance to clinicians on how to identify suspected DILI timely and standardize the diagnosis and management in clinical practice. Based on the clinical settings in China, the guideline also specifically focused on DILI in chronic liver disease, drug-induced viral hepatitis reactivation, common causing agents of DILI (herbal and dietary supplements, anti-tuberculosis drugs, and antineoplastic drugs), and signal of DILI in clinical trials and its assessment.

Drug induced liver injury - a 2023 update

Drug-Induced Liver Injury (DILI) constitutes hepatic damage attributed to drug exposure. DILI may be categorized as hepatocellular, cholestatic or mixed and might also involve immune responses. When DILI occurs in dose-dependent manner, it is referred to as intrinsic, while if the injury occurs spontaneously, it is termed as idiosyncratic. This review predominately focused on idiosyncratic liver injury. The established molecular mechanisms for DILI include (1) mitochondria dysfunction, (2) increased reactive oxygen species levels, (3) presence of elevated apoptosis and necrosis, (4) and bile duct injuries associated with immune mediated pathways. However, it should be emphasized that the underlying mechanisms responsible for DILI are still unknown. Prevention strategies are critical as incidences occur frequently, and treatment options are limited once the injury has developed. The aim of this review was to utilize retrospective cohort studies from across the globe to gain insight into epidemiological patterns. This review considers (1) what is currently known regarding the mechanisms underlying DILI, (2) discusses potential risk factors and (3) implications of the coronavirus pandemic on DILI presentation and research. Future perspectives are also considered and discussed and include potential new biomarkers, causality assessment and reporting methods.

Highlighting the Use of the Hepatoprotective Nutritional Supplements among Patients with Chronic Diseases

Cross-sectional studies, while not considered glamorous endeavors, are firmly anchored in data and statistics, providing essential insights about public health. The aim of the study is to see the frequency of hepatoprotective (HP) nutritional supplement consumption among patients with chronic diseases (other than chronic liver disorders) and analyzes the habits related to the consumption of nutritional supplements among these patients. A total of 954 patients, seeking medical prescriptions for chronic diseases under various payment arrangements (compensated, gratuity, or full payment) were carefully selected over a 12-month period from four private pharmaceutical facilities. We examined the frequency of HP consumption in relation with a number of prescribed medications for chronic conditions. All these patients were invited to complete a questionnaire about their supplement consumption habits and were provided the option to participate in a nutritional status assessment. One hundred ninety-five patients consented to participate in the survey, and 65 patients agreed to undergo a nutritional status evaluation. Of the 954 patients, 77.2% incorporate HP into their regimen. The most frequent consumption (83.33%) was recorded in a group with seven drugs, followed by a group with three drugs (82.84%). Women have a higher usage rate of HP (80.58%; 444 from 551) compared to men (62.60%; 293 from 383), and most of the patients (59.5%) used extracts of Silybum marianum L. In the survey, 64.61% of participants were using supplements, with most (59.52%) consuming HP. Only 32.54% of patients rely on recommendations from healthcare professionals. Of the patients who use supplements, 55.56% reported improvements in their health status. Furthermore, patients who integrate supplements into their daily routine tend to achieve better overall nutritional status.

Autoimmunity associates with severity of illness in elderly patients with drug-induced liver injury

Background: Drug-induced liver injury (DILI) is a potentially serious adverse drug reaction. Due to the lack of definite etiology, specific clinical manifestations, and diagnostic methods, its prediction and diagnosis are challenging. Elderly individuals are deemed to be at high risk for DILI due to abnormal pharmacokinetics, aging tissue repair function, comorbidities, and taking multiple drugs. This study aimed to identify the clinical characteristics and explore the risk factors associated with the severity of illness in elderly patients with DILI. Methods: In the present study, the clinical characteristics at the time of liver biopsy of consecutive patients with biopsy-proven DILI who presented at our hospital from June 2005 to September 2022 were evaluated. Hepatic inflammation and fibrosis were assessed according to the Scheuer scoring system. The presence of autoimmunity was considered if IgG level >1.1 × ULN (1826 mg/dL), or high titer (>1:80) of ANA, or SMA. Results: In total, 441 patients were enrolled, and the median age was 63.3 years (IQR, 61.0-66.0); 122 (27.7%), 195 (44.2%), or 124 (28.1%) were classified as having minor, moderate, or severe hepatic inflammation, respectively; and 188 (42.6%), 210 (47.6%) or 43 (9.8%) patients presented minor, significant fibrosis or cirrhosis, respectively. Female sex (73.5%) and the cholestatic pattern (47.6%) were dominant in elderly DILI patients. Autoimmunity existed in 201 patients (45.6%). Comorbidities were not directly associated with the severity of DILI. PLT (OR: 0.994, 95% CI: 0.991-0.997; p < 0.001), AST (OR: 1.001, 95% CI: 1.000-1.003, p = 0.012), TBIL (OR: 1.006, 95% CI: 1.003-1.010, p < 0.001), and autoimmunity (OR: 1.831, 95% CI: 1.258-2.672, p = 0.002) were associated with the degree of hepatic inflammation. Meanwhile, PLT (OR: 0.990, 95% CI: 0.986-0.993, p < 0.001), TBIL (OR: 1.004, 95% CI: 1.000-1.007, p = 0.028), age (OR: 1.123, 95% CI: 1.067-1.183, p < 0.001), and autoimmunity (OR: 1.760, 95% CI: 1.191-2.608, p = 0.005) were associated with the stage of hepatic fibrosis. Conclusion: This study revealed that the presence of autoimmunity represents a more serious illness state of DILI, deserving more intensive monitoring and progressive treatment.

[A high relapse risk of chronic drug-induced liver injury is correlated with a greater severity of liver fibrosis]

OBJECTIVE

To construct a risk prediction model for relapse of chronic drug-induced liver injury (DILI) and explore the correlation between DILI relapse risk and liver fibrosis.

METHODS

We retrospectively collected the clinical data of 1138 patients with chronic DILI hospitalized from January, 2017 to January, 2022, including 154 patients with and 984 without DILI relapse. Based on the results of univariable and multivariable logistic regression analyses, a risk prediction model for DILI relapse was constructed, evaluated for its discrimination and calibration using AUC value and Hosmer-Lemeshow test, and verified with a 200 times 5, 10 and 20 folds cross validation method. Spearman correlation analysis was used to evaluate the correlation between the new model and liver fibrosis, and its diagnostic efficiency for liver fibrosis was assessed by comparison with APRI and FIB-4 using ROC curve.

RESULTS

The proportions of patients with S0, S1, S2, S3 and S4 liver fibrosis were 1.9%, 13.1%, 42.2%, 27.9% and 14.9% in the relapse group, respectively, as compared with 8.9%, 43.5%, 26.1%, 17.1% and 4.4% in the non-relapse group, respectively, showing severer liver fibrosis in patients with than those without DILI relapse. Multivariable logistic regression analysis identified LSM≥13.7 kPa (OR=4.35, 95%CI: 2.61-7.25, P < 0.001), CHE < 2500 U/L (OR=5.17, 95%CI: 2.13-12.53, P < 0.001), CHE of 2500-5000 U/L (OR=4.07, 95%CI: 2.75-6.01, P < 0.001), and AST > 2×ULN (OR=2.29, 95%CI: 1.38-3.80, P=0.001) as risk factors for relapse of chronic DILI. The ACLS model constructed based on these non-invasive indicators had an AUC value of 0.803 (95%CI: 0.78-0.83). The results of Hosmer-Lemeshow goodness of fit test (χ²=7.73, P=0.46) and the cross validation tests (average AUC of 0.803) all showed a good stability of the model. Spearman correlation analysis showed that ACLS score was positively correlated with the severity of liver fibrosis (rho=0.530, P < 0.001). At the optimal cut-off value of 3 points for diagnosing moderate liver fibrosis, the ACLS model had an AUC value of 0.78 (with specificity of 72.7% and sensitivity of 73.3%), demonstrating a better efficacy than that of APRI and FIB-4 (P < 0.001). At the cut-off value of 6 for severe liver fibrosis, the diagnostic efficacy of the model (AUC=0.83; specificity 75.7%, sensitivity 72.7%) was still better than that of APRI (P < 0.001) but comparable with that of FIB-4 (P=0.38).

CONCLUSION

The patients at high risks of chronic DILI relapse have severer liver fibrosis and should be followed up regularly for timely aggressive treatment.

In Vitro Models for Studying Chronic Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a major clinical problem in terms of patient morbidity and mortality, cost to healthcare systems and failure of the development of new drugs. The need for consistent safety strategies capable of identifying a potential toxicity risk early in the drug discovery pipeline is key. Human DILI is poorly predicted in animals, probably due to the well-known interspecies differences in drug metabolism, pharmacokinetics, and toxicity targets. For this reason, distinct cellular models from primary human hepatocytes or hepatoma cell lines cultured as 2D monolayers to emerging 3D culture systems or the use of multi-cellular systems have been proposed for hepatotoxicity studies. In order to mimic long-term hepatotoxicity in vitro, cell models, which maintain hepatic phenotype for a suitably long period, should be used. On the other hand, repeated-dose administration is a more relevant scenario for therapeutics, providing information not only about toxicity, but also about cumulative effects and/or delayed responses. In this review, we evaluate the existing cell models for DILI prediction focusing on chronic hepatotoxicity, highlighting how better characterization and mechanistic studies could lead to advance DILI prediction.

3,3',5-triiodo-l-thyronine inhibits drug-induced liver injury through activation of PPARα as revealed by network pharmacology and biological experimental verification

Drug-induced liver injury (DILI) has increased in recent years, leading to acute liver failure. 3,3',5-triiodo-l-thyronine (T3) has been reported to exert a potent hepatoprotective effect. However, the mechanism and efficacy of T3 on DILI remain undocumented. In this study, an MTT assay was used to detect the effect of T3 on hepatotoxicity of acetaminophen (APAP) in L02 cells. Then, we screened key targets and related biological pathways by network pharmacology. Finally, enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to verify the mechanism and key targets of T3 on DILI. The results of the MTT assay showed that T3 significantly decreased hepatocellular injury induced by APAP. Network pharmacology and bioinformatics analysis showed that 118 intersection targets of T3 and DILI were identified and the mechanism of T3 on DILI was related to cell proliferation and oxidative stress. ELISA results showed that T3 may be an effective treatment for DILI as biomarkers of hepatocellular injury such as AST, ALP were decreased compared to APAP only treated cells, and the mechanism of T3 may be mediated in part through improving redox balance. The topological parameter screening results suggested 12 key targets of T3 for DILI. Among them, PPARα is associated with DILI, and activation of PPARα can reduce oxidative stress and cell necrosis. Therefore, PPARα was identified as a target for verification. qRT-PCR analysis demonstrated that T3 could reverse the down-regulation of PPARα induced by APAP exposure. Taken together, we demonstrated for the first time that T3 could activate PPARα, promote cell proliferation and reduce oxidative stress, and play a vital role in the treatment of DILI, which provides a reference for T3 as a candidate treatment for DILI.

Prediction of biochemical nonresolution in patients with chronic drug-induced liver injury: A large multicenter study

BACKGROUND AND AIMS

To clarify high-risk factors and develop a nomogram model to predict biochemical resolution or biochemical nonresolution (BNR) in patients with chronic DILI.

APPROACH AND RESULTS

Retrospectively, 3655 of 5326 patients with chronic DILI were enrolled from nine participating hospitals, of whom 2866 underwent liver biopsy. All of these patients were followed up for over 1 year and their clinical characteristics were retrieved from electronic medical records. The endpoint was BNR, defined as alanine aminotransferase or aspartate aminotransferase >1.5× upper limit of normal or alkaline phosphatase >1.1× ULN, at 12 months from chronic DILI diagnosis. The noninvasive high-risk factors for BNR identified by multivariable logistic regression were used to establish a nomogram, which was validated in an independent external cohort. Finally, 19.3% (707 of 3655) patients presented with BNR. Histologically, with the increase in liver inflammation grades and fibrosis stages, the proportion of BNR significantly increased. The risk of BNR was increased by 21.3-fold in patients with significant inflammation compared to none or mild inflammation (p < 0.001). Biochemically, aspartate aminotransferase and total bilirubin, platelets, prothrombin time, sex, and age were associated with BNR and incorporated to construct a nomogram model (BNR-6) with a concordance index of 0.824 (95% CI, 0.798-0.849), which was highly consistent with liver histology. These results were successfully validated both in the internal cohort and external cohort.

CONCLUSIONS

Significant liver inflammation is a robust predictor associated with biochemical nonresolution. The established BNR-6 model provides an easy-to-use approach to assess the outcome of chronic DILI.

Mouse Models of Liver Parenchyma Injuries and Regeneration

Mice have genetic and physiological similarities with humans and a well-characterized genetic background that is easy to manipulate. Murine models have become the most favored, robust mammalian systems for experimental analyses of biological processes and disease conditions due to their low cost, rapid reproduction, a wealth of mouse strains with defined genetic conditions (both native ones as well as ones established experimentally), and high reproducibility with respect to that which can be done in experimental studies. In this review, we focus on murine models for liver, an organ with renown regenerative capacity and the organ most central to systemic, complex metabolic and physiological functions for mammalian hosts. Establishment of murine models has been achieved for all aspects of studies of normal liver, liver diseases, liver injuries, and regenerative repair mechanisms. We summarize key information on current mouse systems that partially model facets of clinical scenarios, particularly those associated with drug-induced acute or chronic liver injuries, dietary related, non-alcoholic liver disease (NAFLD), hepatitis virus infectious chronic liver diseases, and autoimmune hepatitis (AIH). In addition, we also include mouse models that are suitable for studying liver cancers (e.g., hepatocellular carcinomas), the aging process (senescence, apoptosis), and various types of liver injuries and regenerative processes associated with them.

Alteration of Bile Acids and Omega-6 PUFAs Are Correlated With the Progression and Prognosis of Drug-Induced Liver Injury

Background & Aims

Drug-induced liver injury (DILI) is one of the leading causes of liver failure with some of the patients progressed to chronic DILI. The mechanisms underlying the severity and chronicity of DILI are poorly elucidated and the biomarkers are limited. Metabolites and gut microbiota played a crucial role in the development of various liver diseases. Herein, a systematic analysis of serum metabolites and gut microbiota was performed in DILI patients, aiming to identify metabolites correlated with the progression and clinical prognosis of DILI.

Methods

Various serum metabolites were quantitated using a metabolite array technology in this prospective study. Gut microbiome compositions and the expression profiles of liver genes were determined in patients with DILI and healthy controls.

Results

Metabolomic analysis revealed that bile acids (BAs) and polyunsaturated fatty acids (PUFAs) were closely related to DILI severity and chronicity respectively. The ratios of serum primary/secondary BAs and omega-6/omega-3 PUFAs were elevated in DILI patients. A model established by adrenic acid (AdA) and aspartic acid (Asp) exerts good performance for predicting the chronicity of DLIL. Hepatic transcriptome revealed enhanced expression of PUFA peroxidation and supressed expression of BA synthesis related genes in DILI patients. In addition, Lactic acid bacteria and BA converting bacteria were increased in gut of DILI patients. Besides, elevated serum malondialdehyde (MDA) and fibroblast growth factor 19 (FGF19) was observed in DILI patients.

Conclusion

BAs and PUFAs could be potent markers for the severity and chronicity of DILI respectively. The panel of AdA and Asp could be ideal predictive model for the risk of chronicity at the acute stage of DILI. Gut microbiota might act as a negative feedback mechanism to maintain the homeostasis of BAs and PUFAs via FGF19 signalling and PUFA saturation, respectively. Our study revealed novel biomarkers for severe and chronic DILI and provided new therapeutic targets for DILI.

Corticosteroid plus glycyrrhizin therapy for chronic drug- or herb-induced liver injury achieves biochemical and histological improvements: a randomised open-label trial

BACKGROUND

Treatment of chronic drug-induced liver injury (DILI) or herb-induced liver injury(HILI) is an important and unresolved challenge. There is no consensus regarding the indications for corticosteroids for chronic DILI/HILI.

AIMS

To investigate the efficacy and safety of corticosteroid plus glycyrrhizin for patients with chronic DILI/HILI.

METHODS

This was a randomised open-label trial. Eligible patients with causality assessment using the updated RUCAM were randomly assigned (1:1) either to the steroid treatment group (48-week stepwise dose reduction of methylprednisolone plus glycyrrhizin) or control group (glycyrrhizin alone). Liver biopsies were performed at baseline and at the end of the 48-week treatment period. The primary outcome was the proportion of patients with sustained biochemical response (SBR). The secondary outcomes were improvement in liver histology, time to biochemical normalisation and safety.

RESULTS

Of 80 participants, 70 (87.5%) completed the trial. The patients were predominantly female (77.5%), aged >40 years (77.5%) and had a hepatocellular injury pattern of DILI (71.2%). Compared to the control group, the treatment group showed a higher proportion of SBR (94.3% vs. 71.4%, p = 0.023), shorter biochemical normalisation time and histological improvements in both histological activity and fibrosis. The DILI and HILI subgroups, as well as the autoimmune hepatitis (AIH)-like DILI and non-AIH-like subgroups, showed comparable responses. No severe adverse events were observed during the trial.

CONCLUSION

This study provides the first clinical evidence that corticosteroid plus glycyrrhizin therapy for chronic DILI with or without AIH-like features can achieve both biochemical response and histological improvements with good safety. (ClinicalTrials.gov, NCT02651350).

Novel Therapies for the Treatment of Drug-Induced Liver Injury: A Systematic Review

Many drugs with different mechanisms of action and indications available on the market today are capable of inducing hepatotoxicity. Drug-induced liver injury (DILI) has been a treatment challenge nowadays as it was in the past. We searched Medline (via PubMed), CENTRAL, Science Citation Index Expanded, clinical trials registries and databases of DILI and hepatotoxicity up to 2021 for novel therapies for the management of adult patients with DILI based on the combination of three main search terms: 1) treatment, 2) novel, and 3) drug-induced liver injury. The mechanism of action of novel therapies, the potential of their benefit in clinical settings, and adverse drug reactions related to novel therapies were extracted. Cochrane Risk of bias tool and Grading of Recommendations Assessment, Development and Evaluation (GRADE) assessment approach was involved in the assessment of the certainty of the evidence for primary outcomes of included studies. One thousand three hundred seventy-two articles were identified. Twenty-eight articles were included in the final analysis. Eight randomized controlled trials (RCTs) were detected and for six the available data were sufficient for analysis. In abstract form only we found six studies which were also anaylzed. Investigated agents included: bicyclol, calmangafodipir, cytisin amidophospate, fomepizole, livina-polyherbal preparation, magnesium isoglycyrrhizinate (MgIG), picroliv, plasma exchange, radix Paeoniae Rubra, and S-adenosylmethionine. The primary outcomes of included trials mainly included laboratory markers improvement. Based on the moderate-certainty evidence, more patients treated with MgIG experienced alanine aminotransferase (ALT) normalization compared to placebo. Low-certainty evidence suggests that bicyclol treatment leads to a reduction of ALT levels compared to phosphatidylcholine. For the remaining eight interventions, the certainty of the evidence for primary outcomes was assessed as very low and we are very uncertain in any estimate of effect. More effort should be involved to investigate the novel treatment of DILI. Well-designed RCTs with appropriate sample sizes, comparable groups and precise, not only surrogate outcomes are urgently welcome.

Targeted Metabolomics Analysis of Bile Acids in Patients with Idiosyncratic Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is rare but clinically important due to a high rate of mortality. However, specific biomarkers for diagnosing and predicting the severity and prognosis of DILI are lacking. Here, we used targeted metabolomics to identify and quantify specific types of bile acids that can predict the severity of DILI. A total of 161 DILI patients were enrolled in this prospective cohort study, as well as 31 health controls. A targeted metabolomics method was used to identify 24 types of bile acids. DILI patients were divided into mild, moderate, and severe groups according to disease severity. A multivariate analysis was performed to identify characteristic bile acids. Then the patients were divided into severe and non-severe groups, and logistic regression was used to identify bile acids that could predict DILI severity. Among the enrolled DILI patients, 32 were in the mild group, 90 were in the moderate group, and 39 were in the severe group. Orthogonal partial least squares-discriminant analysis (OPLS-DA) modeling clearly discriminated among the different groups. Among the four groups, glycochenodeoxycholate (GCDCA), taurochenodeoxycholate (TCDCA), deoxycholic acid (DCA), Nor Cholic acid (NorCA), glycocholic acid (GCA), and taurocholic acid (TCA) showed significant differences in concentration between at least two groups. NorCA, GCDCA, and TCDCA were all independent risk factors that differentiated severe DILI patients from the other groups. The area under the receiver operating characteristic curve (AUROC) of GCDCA, TCDCA, and NorCA was 0.856, 0.792, and 0.753, respectively. Together, these three bile acids had an AUROC of 0.895 for predicting severe DILI patients. DILI patients with different disease severities have specific bile acid metabolomics. NorCA, GCDTA, and TCDCA were independent risk factors for differentiating severe DILI patients from less-severe patients and have the potential to predict DILI severity.

The LAC Score Indicates Significant Fibrosis in Patients With Chronic Drug-Induced Liver Injury: A Large Biopsy-Based Study

Currently, there are no satisfactory noninvasive methods for the diagnosis of fibrosis in patients with chronic drug-induced liver injury (DILI). Our goal was to develop an algorithm to improve the diagnostic accuracy of significant fibrosis in this population. In the present study, we retrospectively investigated the biochemical and pathological characteristics of consecutive patients with biopsy-proven chronic DILI, who presented at our hospital from January 2013 to December 2017. A noninvasive algorithm was developed by using multivariate logistic regression, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA) to diagnose significant fibrosis in the training cohort, and the algorithm was subsequently validated in the validation cohort. Totally, 1,130 patients were enrolled and randomly assigned into a training cohort (n = 848) and a validation cohort (n = 282). Based on the multivariate analysis, LSM, CHE, and APRI were independently associated with significant fibrosis. A novel algorithm, LAC, was identified with the AUROC of 0.81, which was significantly higher than LSM (AUROC 0.78), CHE (AUROC 0.73), and APRI (AUROC 0.68), alone. The best cutoff value of LAC in the training cohort was 5.4. When the LAC score was used to diagnose advanced fibrosis and cirrhosis stages, the optimal cutoff values were 6.2 and 6.7, respectively, and the AUROC values were 0.84 and 0.90 in the training cohort and 0.81 and 0.83 in the validation cohort. This study proved that the LAC score can contribute to the accurate assessment of high-risk disease progression and the establishment of optimal treatment strategies for patients with chronic DILI.