The Latin American DILI Registry Experience: A Successful Ongoing Collaborative Strategic Initiative

Control compounds for preclinical drug-induced liver injury assessment: Consensus-driven systematic review by the ProEuroDILI network

BACKGROUND & AIMS

Idiosyncratic drug-induced liver injury (DILI) is a complex and unpredictable event caused by drugs, and herbal or dietary supplements. Early identification of human hepatotoxicity at preclinical stages remains a major challenge, in which the selection of validated in vitro systems and test drugs has a significant impact. In this systematic review, we analyzed the compounds used in hepatotoxicity assays and established a list of DILI-positive and -negative control drugs for validation of in vitro models of DILI, supported by literature and clinical evidence and endorsed by an expert committee from the COST Action ProEuroDILI Network (CA17112).

METHODS

Following 2020 PRISMA guidelines, original research articles focusing on DILI which used in vitro human models and performed at least one hepatotoxicity assay with positive and negative control compounds, were included. Bias of the studies was assessed by a modified 'Toxicological Data Reliability Assessment Tool'.

RESULTS

A total of 51 studies (out of 2,936) met the inclusion criteria, with 30 categorized as reliable without restrictions. Although there was a broad consensus on positive compounds, the selection of negative compounds lacked clarity. 2D monoculture, short exposure times and cytotoxicity endpoints were the most tested, although there was no consensus on drug concentrations.

CONCLUSIONS

Extensive analysis highlighted the lack of agreement on control compounds for in vitro DILI assessment. Following comprehensive in vitro and clinical data analysis together with input from the expert committee, an evidence-based consensus-driven list of 10 positive and negative control drugs for validation of in vitro models of DILI is proposed.

IMPACT AND IMPLICATIONS

Prediction of human toxicity early in the drug development process remains a major challenge, necessitating the development of more physiologically relevant liver models and careful selection of drug-induced liver injury (DILI)-positive and -negative control drugs to better predict the risk of DILI associated with new drug candidates. Thus, this systematic study has crucial implications for standardizing the validation of new in vitro models of DILI. By establishing a consensus-driven list of positive and negative control drugs, the study provides a scientifically justified framework for enhancing the consistency of preclinical testing, thereby addressing a significant challenge in early hepatotoxicity identification. Practically, these findings can guide researchers in evaluating safety profiles of new drugs, refining in vitro models, and informing regulatory agencies on potential improvements to regulatory guidelines, ensuring a more systematic and efficient approach to drug safety assessment.

Rechallenge in idiosyncratic drug-induced liver injury: An analysis of cases in two large prospective registries according to existing definitions

INTRODUCTION

Data on positive rechallenge in idiosyncratic drug-induced liver injury (DILI) are scarce. We aim to analyse the clinical presentation, outcome and drugs associated with positive rechallenge in two DILI registries.

METHODS

Cases from the Spanish and Latin American DILI registries were included. Demographics, clinical characteristics and outcome of cases with positive rechallenge according to CIOMS/RUCAM and current definitions were analysed.

RESULTS

Of 1418 patients with idiosyncratic DILI, 58 cases had positive rechallenge (4.1%). Patients with positive rechallenge had shorter duration of therapy (p=0.001) and latency (p=0.003). In patients with rechallenge, aspartate transaminase levels were increased (p=0.026) and showed a prolonged time to recovery (p=0.020), albeit no differences were seen in terms of fatal outcomes. The main drug implicated in rechallenge was amoxicillin-clavulanate (17%). The majority of re-exposure events were unintentional (71%). Using both existing definitions of positive rechallenge, there were four cases which exclusively fulfilled the current criteria and five which only meet the historical definition. All cases of positive rechallenge, irrespective of the pattern of damage, fulfilled the criteria of either alanine transaminase (ALT) ≥3 times the upper limit of normal (ULN) and/or alkaline phosphatase (ALP) ≥2 times ULN.

CONCLUSIONS

Episodes of rechallenge were characterised by shorter duration of therapy and latency, and longer time to resolution, but did not show an increased incidence of fatal outcome. Based on our findings, ALT ≥3 times ULN and/or ALP ≥2 times ULN, regardless of the pattern of damage, is proposed as a new definition of rechallenge in DILI.

The burden of liver disease in Latin America

Liver disease poses a substantial burden in Latin America. This burden is primarily attributed to a high level of alcohol consumption and the increasing prevalence of risk factors associated with metabolic dysfunction-associated steatotic liver disease (MASLD), such as sedentary lifestyles, easy access to ultra-processed foods, obesity, and type 2 diabetes mellitus. These epidemiological trends are cause for concern, especially considering that there are significant challenges in addressing them due to disparities in access to liver disease screening and care. In this article, we aim to provide an overview of the current situation regarding liver disease in Latin America. We also discuss recent multinational proposals designed to address the growing MASLD burden via its integration into existing non-communicable diseases policies, at both local and global levels. Additionally, we emphasize the urgent need to establish effective public health policies that target both MASLD risk factors and excessive alcohol consumption. Furthermore, we discuss the development of liver transplantation programs, areas for improvement in medical education and research capabilities, and how the fostering of extensive collaboration among all stakeholders is crucial for addressing liver disease in the region.

Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet

In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.

Characterization of drug-induced liver injury associated with drug reaction with eosinophilia and systemic symptoms in two prospective DILI registries

Idiosyncratic drug-induced liver injury (DILI) associated with drug reactions with eosinophilia and systemic symptoms (DRESS) is poorly characterized among patients of Western countries. We aimed to comprehensively assess the clinical characteristics, outcomes, and causative agents in a prospective, well-vetted cohort of DILI patients with DRESS (DILI-DRESS). We identified 53 DILI-DRESS cases from the Spanish DILI Registry and the Latin American DILI Network. For comparison purposes, we defined a group of DILI patients (n = 881). DILI-DRESS cases were younger (47 vs. 53 years, respectively; p = 0.042) and presented more frequently with cholestatic/mixed damage (p = 0.018). Most DILI-DRESS patients showed moderate liver injury, 13% developed severe damage, and only one patient (with hepatocellular injury due to anti-tuberculosis drugs) progressed to acute liver failure and died. DILI-DRESS cases showed a distinctive causative drug pattern compared to DILI cases. The most frequent drugs were carbamazepine (13%), anti-tuberculosis drugs (13%), amoxicillin-clavulanate (11%), and allopurinol and lamotrigine (7.6% each). Among all cases of DILI due to allopurinol and lamotrigine, 67% presented with a DILI-DRESS phenotype, respectively. Higher total bilirubin (TBL) levels at DILI recognition (odds ratio [OR] 1.23; 95% confidence interval [CI] 1.04-1.45) and absence of eosinophilia (OR 8.77; 95% CI 1.11-69.20) increased the risk for developing a severe-fatal injury in DILI-DRESS patients. DILI-DRESS patients have a more frequent cholestasis/mixed pattern of injury at presentation, with antiepileptics as distinctive causative drug class. Most of the lamotrigine and allopurinol cases present with this phenotype. Higher TBL levels and absence of eosinophilia at DILI recognition are markers of poor outcomes.

Prior drug allergies are associated with worse outcome in patients with idiosyncratic drug-induced liver injury: A machine learning approach for risk stratification

The impact of prior drug allergies (PDA) on the clinical features and outcomes of patients who develop idiosyncratic drug-induced liver injury (DILI) is largely unknown. We aimed to assess the clinical presentation and outcomes of DILI patients based on the presence or absence of PDA and explore the association between culprit drugs responsible for DILI and allergy. We analysed a well-vetted cohort of DILI cases enrolled from the Spanish DILI Registry. Bootstrap-enhanced least absolute shrinkage operator procedure was used in variable selection, and a multivariable logistic model was fitted to predict poor outcomes in DILI. Of 912 cases with a first episode of DILI, 61 (6.7%) had documented PDA. Patients with PDA were older (p = 0.009), had higher aspartate aminotransferase (AST) levels (p = 0.047), lower platelet count (p = 0.011) and higher liver-related mortality than those without a history of drug allergies (11% vs. 1.6%, p < 0.001). Penicillin was the most common drug associated with PDA in DILI patients (32%). A model including PDA, nR-based type of liver injury, female sex, AST, total bilirubin, and platelet count showed an excellent performance in predicting poor outcome in patients from the Spanish DILI Registry (area under the ROC curve [AUC] 0.887; 95% confidence interval [CI] 0.794 - 0.981) and the LATINDILI Network (AUC 0.932; 95% CI 0.884 - 0.981). Patients with suspected DILI should be screened for PDA as they would require a close monitoring for early detection of worsening clinical course.

Review of human risk factors for idiosyncratic drug-induced liver injury: latest advances and future goals

INTRODUCTION

Idiosyncratic drug-induced liver injury (DILI) is a common cause of acute liver injury and can lead to death from acute liver failure or require liver transplantation. Although the total burden of liver injury is high, the frequency of DILI caused by specific agents is often low. As the liver injury is by per definition idiosyncratic, the prediction of which patients will develop liver injury from specific drugs is currently a very difficult challenge.

AREAS COVERED

The current paper highlights the most important studies on prediction of DILI published in 2019-2023, including studies on genetic, metabolomic, and demographic risk factors, concomitant medication, and the role of comorbid liver diseases. Risk stratification using demographic, metabolomic, and multigenetic risk factors is discussed.

EXPERT OPINION

Great advances have been made in identifying genetic risk factors for DILI. Combining these risk factors with demographic information and other biomarkers into multigenetic risk models might become highly useful in risk stratifying patients exposed to DILI. However, a more detailed mapping of genetic risk factors is needed. Results of these studies need to be validated in the selected ethnic groups before applicability and cost-effectiveness can be determined.

Clinical presentation, causative drugs and outcome of patients with autoimmune features in two prospective DILI registries

BACKGROUND & AIMS

Idiosyncratic drug-induced liver injury (DILI) with autoimmune features is a liver condition with laboratory and histological characteristics similar to those of idiopathic autoimmune hepatitis (AIH), which despite being increasingly reported, remains largely undefined. We aimed to describe in-depth the features of this entity in a large series of patients from two prospective DILI registries.

METHODS

DILI cases with autoimmune features collected in the Spanish DILI Registry and the Latin American DILI Network were compared with DILI patients without autoimmune features and with an independent cohort of patients with AIH.

RESULTS

Out of 1,426 patients with DILI, 33 cases with autoimmune features were identified. Female sex was more frequent in AIH patients than in the other groups (p = .001). DILI cases with autoimmune features had significantly longer time to onset (p < .001) and resolution time (p = .004) than those without autoimmune features. Interestingly, DILI patients with autoimmune features who relapsed exhibited significantly higher total bilirubin and transaminases at onset and absence of peripheral eosinophilia than those who did not relapse. The likelihood of relapse increased over time, from 17% at 6 months to 50% 4 years after biochemical normalization. Statins, nitrofurantoin and minocycline were the drugs most frequently associated with this phenotype.

CONCLUSIONS

DILI with autoimmune features shows different clinical features than DILI patients lacking characteristics of autoimmunity. Higher transaminases and total bilirubin values with no eosinophilia at presentation increase the likelihood of relapse in DILI with autoimmune features. As the tendency to relapse increases over time, these patients will require long-term follow-up.

Drug-induced liver injury: Relation between the R ratio and histopathology

INTRODUCTION AND AIM

Drug-induced liver injury (DILI) is a diagnosis based on the ruling out of potential liver diseases and consolidated by establishing causality through the temporal relation between a potentially hepatotoxic substance and altered liver biochemistry. Incidence fluctuates greatly worldwide, with very few reports of causal agents of DILI in Colombia. A retrospective study on patients treated at the Centro de Estudios en Salud (CES), within the time frame of January 2015 and June 2020, was conducted to document the causal substances of DILI in patients with liver biopsy and to correlate the types of histologic patterns with the biochemical pattern of liver injury (R ratio).

RESULTS

Of the 254 adult patients with liver biopsy and no tumor etiology, 20 patients were identified as cases of DILI (7.87%). The two most frequently found causal substances were efavirenz, in three HIV-positive patients, and Moringa oleifera (moringa), in two patients. There was a statistically significant association between cholestatic patterns (p = 0.037) and mixed patterns (p = 0.031), in the comparison of the histopathologic categories and the R ratio.

CONCLUSION

To the best of our knowledge, there are no reports on DILI secondary to Moringa oleifera (moringa). The R ratio could be a useful tool, in relation to the histologic pattern of injury, in cases of mixed and cholestatic patterns.

Review article: clinical assessment of suspected drug-induced liver injury and its management

BACKGROUND

Idisyncratic drug-induced liver injury (DILI) is a rare instance of liver injury after exposure to an otherwise safe drug or herbal or dietary supplement. DILI can be associated with significant morbidity and mortality. Furthermore, it is an important consideration in drug development due to safety concerns.

AIMS AND METHODS

To highlight pearls and pitfalls to aid clinicians in diagnosing DILI and surmising the management options. We also share the best practices from personal insights developed from decades long participation in the causality assessment committee meetings of the DILI Network.

RESULTS

DILI lacks a diagnostic test and is currently diagnosed through a process of exclusion of competing aetiologies of liver injury. This requires a high degree of suspicion to consider the possibility of DILI, skill in ruling out the obvious and less obvious competing liver insults, and an understanding of the expected phenotypes of DILI. The facets of DILI cover multiple aspects, including the latency, liver injury pattern, course of injury, and associated autoimmune or immuno-allergic features. Care for patients with DILI is geared towards stopping the offending drug and symptom management that include the use of corticosteroids in select cases.

CONCLUSION

The diagnosis of DILI is challenging and is primarily made through a carefully crafted patient interview, temporal relationship with the implicated drug or supplement, and exclusion of competing aetiology. LiverTox is a useful resource for clinicians to review the literature and recognise the likelihood of the implicated agent in causing DILI.

Drug-induced Liver Injury in Pediatrics

Drug-induced liver injury (DILI) is a rare, underdiagnosed cause of liver disease in children. The incidence of DILI in the pediatric population is unknown but it represents around 10% of all DILI cases. The most common hepatotoxic drugs in children are antibiotics and antiepileptics. DILI is classified as intrinsic or idiosyncratic and it presents mostly with 2 patterns of injury: hepatocellular or cholestatic. Diagnosis can be done with help of the Roussel Uclaf Causality Assessment Method (RUCAM) casualty assessment. The mainstay of treatment is prompt withdrawal of the suspect drug.

Identification of New Toxicity Mechanisms in Drug-Induced Liver Injury through Systems Pharmacology

Among adverse drug reactions, drug-induced liver injury presents particular challenges because of its complexity, and the underlying mechanisms are still not completely characterized. Our knowledge of the topic is limited and based on the assumption that a drug acts on one molecular target. We have leveraged drug polypharmacology, i.e., the ability of a drug to bind multiple targets and thus perturb several biological processes, to develop a systems pharmacology platform that integrates all drug–target interactions. Our analysis sheds light on the molecular mechanisms of drugs involved in drug-induced liver injury and provides new hypotheses to study this phenomenon.

Drug-induced liver injury: Pathogenesis, epidemiology, clinical features, and practical management

Drug-induced liver injury (DILI) is an important but rare adverse event which can range from mild liver enzyme elevations to liver failure, transplantation or death. A large proportion of commonly used medications, in addition to herbal and dietary supplements, can cause liver injury. DILI has been categorized as direct or idiosyncratic but indirect liver injury has emerged as a third type of drug-induced liver injury. These types of liver injury may warrant different clinical approach and treatment. Associations of HLA genotypes and risk of DILI have highlighted the importance of the immune system in the pathogenesis of DILI. Furthermore, novel agents affecting the immune response can lead to liver injury, often associated with autoimmune features in serologic tests and liver biopsies. Overall, the diagnosis of DILI remains a challenge as it is requires detailed case evaluation in addition to reviewing the hepatotoxic potentials and clinical signatures of the implicated agents. Biochemical profiles vary between agents and although individual drugs tend to portray a consistent clinicopathologic signature, many drugs have multiple signatures. Thanks to multicenter prospective studies on DILI and websites in the public domain such as LiverTox, physicians are provided with tools to investigate suspected DILI cases to increase the likelihood of establishing adiagnosis. The pathogenesis of DILI, epidemiology and current challenges in the diagnosis and management of the disease are reviewed in the paper.

Herbal and Dietary Supplements-Induced Liver Injury in Latin America: Experience From the LATINDILI Network

BACKGROUND

Herbal and dietary supplements (HDS) consumption, a growing cause of hepatotoxicity, is a common practice among Latin-American populations.

OBJECTIVES

To evaluate clinical, laboratory features and outcome in HDS-hepatotoxicity included in the Latin America-Drug Induced Liver Injury (LATINDILI) Network.

METHODS

A total of 29 adjudicated cases of HDS hepatotoxicity reported to the LATINDILI Network from October 2011 through December 2019 were compared with 322 DILI cases due to conventional drugs and 16 due to anabolic steroids as well as with other series of HDS-hepatotoxicity.

RESULTS

From 367 DILI cases, 8% were attributed to HDS. An increasing trend in HDS-hepatotoxicity was noted over time (p = .04). Camellia sinensis, Herbalife® products, and Garcinia cambogia, mostly used for weight loss, were the most frequently adjudicated causative agents. Mean age was 45 years (66% female). Median time to onset was 31 days. Patients presented typically with hepatocellular injury (83%) and jaundice (66%). Five cases (17%) developed acute liver failure. Compared to conventional medications and anabolic steroids, HDS hepatotoxicity cases had the highest levels of aspartate and alanine transaminase (p = .008 and p = .021, respectively), had more re-exposure events to the culprit HDS (14% vs 3% vs 0%; p = .026), and had more severe and fatal/liver transplantation outcomes (21% vs 12% vs 13%; p = .005). Compared to other DILI cohorts, less HDS hepatotoxicity cases in Latin America were hospitalized (41%).

CONCLUSIONS

HDS-hepatotoxicity in Latin-America affects mainly young women, manifests mostly with hepatocellular injury and is associated with higher frequency of accidental re-exposure. HDS hepatotoxicity is more serious with a higher chance of death/liver transplantation than DILI related to conventional drugs.

Drug-induced liver injury: A management position paper from the Latin American Association for Study of the liver

Idiosyncratic drug-induced liver injury (DILI) caused by xenobiotics (drugs, herbals and dietary supplements) is an uncommon cause of liver disease presenting with a wide range of phenotypes and disease severity, acute hepatitis mimicking viral hepatitis to autoimmune hepatitis, steatosis, fibrosis or rare chronic vascular syndromes. Disease severity ranges from asymptomatic liver test abnormalities to acute liver failure. DILI has been traditionally classified in predictable or intrinsic (dose-related) or unpredictable (not dose-related) mechanisms. Few prospective studies are assessing the real prevalence and incidence of hepatotoxicity in the general population. DILI registries represent useful networks used for the study of liver toxicity, aimed at improving the understanding of causes, phenotypes, natural history, and standardized definitions of hepatotoxicity. Although most of the registries do not carry out population-based studies, they may provide important data related to the prevalence of DILI, and also may be useful to compare features from different countries. With the support of the Spanish Registry of Hepatotoxicity, our Latin American Registry (LATINDILI) was created in 2011, and more than 350 DILI patients have been recruited to date. This position paper describes the more frequent drugs and herbs-induced DILI in Latin America, mainly focusing on several features of responsible medicaments. Also, we highlighted the most critical points on the management of hepatotoxicity in general and those based on findings from our Latin American experience in particular.

Preclinical models of idiosyncratic drug-induced liver injury (iDILI): Moving towards prediction

Idiosyncratic drug-induced liver injury (iDILI) encompasses the unexpected harms that prescription and non-prescription drugs, herbal and dietary supplements can cause to the liver. iDILI remains a major public health problem and a major cause of drug attrition. Given the lack of biomarkers for iDILI prediction, diagnosis and prognosis, searching new models to predict and study mechanisms of iDILI is necessary. One of the major limitations of iDILI preclinical assessment has been the lack of correlation between the markers of hepatotoxicity in animal toxicological studies and clinically significant iDILI. Thus, major advances in the understanding of iDILI susceptibility and pathogenesis have come from the study of well-phenotyped iDILI patients. However, there are many gaps for explaining all the complexity of iDILI susceptibility and mechanisms. Therefore, there is a need to optimize preclinical human in vitro models to reduce the risk of iDILI during drug development. Here, the current experimental models and the future directions in iDILI modelling are thoroughly discussed, focusing on the human cellular models available to study the pathophysiological mechanisms of the disease and the most used in vivo animal iDILI models. We also comment about in silico approaches and the increasing relevance of patient-derived cellular models.

Overview on drug-induced liver injury in Brazil

Drug-induced liver injury (DILI) is an uncommon event in clinical practice, which makes knowing its true incidence difficult. Prospective, retrospective and registry-based studies are the most important methods to obtain epidemiological data on DILI. Latin America (LA) has a historical lack of prospective studies on this topic. New definitions and the creation of hepatotoxicity registries have significantly improved the epidemiological understanding of hepatic drug reactions in several regions of the world. The Latin American DILI network, referred to as LATINDILI, has been created in 2011, and recently published its own DILI recommendations describing the most relevant issues on the management of hepatotoxicity in general, and those based on findings from our own LA experience in particular. Although most of the registries do not carry out population-based studies, they may provide important data related to the prevalence of DILI. The joint work among researchers and the corresponding health and regulatory authorities should be stimulated due to the high impact that hepatotoxicity represents for public health.

Prevalence and clinical characteristics of antibiotics associated drug induced liver injury

Background

The use of antibiotics increases recently. Accordingly, the incidence of antibiotics associated with drug induced liver injury (DILI) also increases. The purpose of this study is to evaluate the proportion and the clinical characteristics of antibiotic associated with DILI.

Methods

This study is a retrospective study of analyzed adult patients who were referred to the department of hepatology for the elevation of liver function tests and the frequency of elevated liver enzyme of patients with prescribed antibiotics during the same period at outpatient setting as a validation set.

Results

Antibiotics associated with DILI (64.0%) are the most common reason agent among consulting to hepatology department. Rheumatoid arthritis related drugs (11.0%), health supplements (5.0%), herbal medicines (4.0%), anti-viral drugs, anti-inflammatory analgesics/acetaminophen and lipid-lowering agents (3.0%) were next common causative drug for DILI in inpatients setting (training set). The frequency of antibiotics associated with DILI was high in order of flomoxef, cetrazole, ceftriaxone, vancomycin, piperacillin/tazobactam and amoxicillin/clavulanate. In the same period, 32% of the patients who prescribed flomoxef showed elevated liver enzyme levels above the upper normal limit. The prevalence of flomoxef induced DILI (>3 folds of ALT) was 13% and liver enzyme levels were five times higher than upper normal limits in 5% of flomoxef groups. Hypertension or diabetes was the risk factor of flomoxef associated with DILI.

Conclusions

The Prevalence of antibiotics associated with DILI was 2-14%. Co-morbidity with diabetes and hypertension was the risk factor of flomoxef associated with DILI.

Drug properties and host factors contribute to biochemical presentation of drug-induced liver injury: a prediction model from a machine learning approach

Drug-induced liver injury (DILI) presentation varies biochemically and histologically. Certain drugs present quite consistent injury patterns, i.e., DILI signatures. In contrast, others are manifested as broader types of liver injury. The variety of DILI presentations by a single drug suggests that both drugs and host factors may contribute to the phenotype. However, factors determining the DILI types have not been yet elucidated. Identifying such factors may help to accurately predict the injury types based on drugs and host information and assist the clinical diagnosis of DILI. Using prospective DILI registry datasets, we sought to explore and validate the associations of biochemical injury types at the time of DILI recognition with comprehensive information on drug properties and host factors. Random forest models identified a set of drug properties and host factors that differentiate hepatocellular from cholestatic damage with reasonable accuracy (69-84%). A simplified logistic regression model developed for practical use, consisting of patient's age, drug's lipoaffinity, and hybridization ratio, achieved a fair prediction (68-74%), but suggested potential clinical usability, computing the likelihood of liver injury type based on two properties of drugs taken by a patient and patient's age. In summary, considering both drug and host factors in evaluating DILI risk and phenotypes open an avenue for future DILI research and aid in the refinement of causality assessment.

Worldwide Use of RUCAM for Causality Assessment in 81,856 Idiosyncratic DILI and 14,029 HILI Cases Published 1993-Mid 2020: A Comprehensive Analysis

Background: A large number of idiosyncratic drug induced liver injury (iDILI) and herb induced liver injury(HILI) cases of variable quality has been published but some are a matter of concern if the cases were not evaluated for causality using a robust causality assessment method (CAM) such as RUCAM (Roussel Uclaf Causality Assessment Method) as diagnostiinjuryc algorithm. The purpose of this analysis was to evaluate the worldwide use of RUCAM in iDILI and HILI cases. Methods: The PubMed database (1993-30 June 2020) was searched for articles by using the following key terms: Roussel Uclaf Causality Assessment Method; RUCAM; Idiosyncratic drug induced liver injury; iDILI; Herb induced liver injury; HILI. Results: Considering reports published worldwide since 1993, our analysis showed the use of RUCAM for causality assessment in 95,885 cases of liver injury including 81,856 cases of idiosyncratic DILI and 14,029 cases of HILI. Among the top countries providing RUCAM based DILI cases were, in decreasing order, China, the US, Germany, Korea, and Italy, with China, Korea, Germany, India, and the US as the top countries for HILI. Conclusion: Since 1993 RUCAM is certainly the most widely used method to assess causality in IDILI and HILI. This should encourage practitioner, experts, and regulatory agencies to use it in order to reinforce their diagnosis and to take sound decisions.

Drug and herb-induced liver injury: A critical review of Brazilian cases with proposals for the improvement of causality assessment using RUCAM

INTRODUCTION AND OBJECTIVES

Although hepatotoxicity accounts for 10% of adverse drug reactions, it remains poorly understood and underreported. This study aimed to summarize case reports of herb- and drug-induced liver injury in Brazil.

METHODOLOGY

Systematic review in the following databases: PubMed, SciELO, Science Direct, CAPES, and gray literature.

RESULTS

Twenty-seven studies reporting 32 cases were identified. Brazilian cases were primarily detected in hospitals, and occurred mainly in young males suffering from chronic diseases. Drugs (n=29) were a more frequent cause of liver injury than herbs (n=3). Almost a third of these drugs were anticonvulsants, and 15 appear in the Brazilian List of Essential Medicines. In 50% of the cases, clinical manifestations started within 30 days of drug ingestion. Regarding the decline of liver enzymes, 50% of the cases reached normality after drug withdrawal. However, 7 deaths and 2 liver transplantations were reported. Only one study assessed causality using RUCAM.

CONCLUSION

Given the severe outcomes of DILI and HILI, early detection and management of hepatotoxicity to increase drug safety are necessary, as well as pharmacotherapeutic monitoring of patients with chronic diseases. Moreover, the application of the RUCAM algorithm in clinical practice has to be further disseminated.

Profile of herbal and dietary supplements induced liver injury in Latin America: A systematic review of published reports

Hepatotoxicity related to HDS is a growing global health issue. We have undertaken a systematic review of published case reports and case series from LA from 1976 to 2020 to describe the clinical features of HDS related hepatotoxicity in this region. We search in PubMed, Web of Science, Scopus and specific LA databases according to PRISMA guidelines. Only HILI cases published in LA that met criteria for DILI definition were included. Duplicate records or reports that lacked relevant data that precluded establishing causality were excluded. Finally, 17 records (23 cases) were included in this review. Centella asiatica, Carthamus tinctorius, and Herbalife® were the most reported HDS culprit products, the main reason for HDS consumption was weight loss. The clinical characteristics of HDS hepatotoxicity in our study were compared to those of other studies in the USA, Europe and China showing a similar signature with predominance of young females, hepatocellular damage, a high rate of ALF and mortality, more frequent inadvertent re-challenge and chronic damage. This study underscores the challenge in causality assessment when multi-ingredients HDS are taken and the need for consistent publication practice when reporting hepatotoxicity cases due to HDS, to foster HDS liver safety particularly in LA.

Drug-Induced Liver Injury in GI Practice

Although drug-induced liver injury (DILI) is a rare clinical event, it carries significant morbidity and mortality, leaving it as the leading cause of acute liver failure in the United States. It is one of the most challenging diagnoses encountered by gastroenterologists. The development of various drug injury networks has played a vital role in expanding our knowledge regarding drug-related and herbal and dietary supplement-related liver injury. In this review, we discuss what defines liver injury, epidemiology of DILI, its biochemical and pathologic patterns, and management.

Drug induced liver injury: East versus West - a systematic review and meta-analysis

Drug induced liver injury (DILI) may be different in the East compared to the West due to differing disease prevalence, prescribing patterns and pharmacogenetic profiles. To review existing literature on causative agents of DILI in the East compared to the West, a comprehensive literature search was performed on electronic databases: MEDLINE/PubMed, Embase, Cochrane Library and China National Knowledge Infrastructure without language restrictions. Studies which involve patients having DILI and reported the frequency of causative agents were included. A random effects model was applied to synthesize the current evidence using prevalence of class-specific and agent-specific causative drugs with 95% confidence intervals. Of 6,914 articles found, 12 showed the distribution of drugs implicated in DILI in the East with a total of 33,294 patients and 16 in the West with a total of 26,069 DILI cases. In the East, the most common agents by class were anti-tuberculosis drugs (26.6%), herbal and alternative medications (25.3%), and antibiotics (15.7%), while in the West, antibiotics (34.9%), cardiovascular agents (17.3%), and non-steroidal anti-inflammatory drugs (12.5%) were the commonest. For individual agents, the most common agents in the East were isoniazid-rifampicin-pyrazinamide (25.4%), phenytoin (3.5%), and cephalosporin (2.9%) while in the West, amoxicillin-potassium clavulanate combination acid (11.3%), nimesulide (6.3%), and ibuprofen (6.1%) were the commonest. There was significant heterogeneity due to variability in single-centre compared to multi-centre studies. Differences in DILI in the East versus the West both in drug classes and individual agents are important for clinicians to recognize.

Ashwagandha-induced liver injury: A case series from Iceland and the US Drug-Induced Liver Injury Network

BACKGROUND & AIMS

Ashwagandha (Withania somnifera) is widely used in Indian Ayurvedic medicine. Several dietary supplements containing ashwagandha are marketed in the US and Europe, but only one case of drug-induced liver injury (DILI) due to ashwagandha has been published. The aim of this case series was to describe the clinical phenotype of suspected ashwagandha-induced liver injury.

METHODS

Five cases of liver injury attributed to ashwagandha-containing supplements were identified; three were collected in Iceland during 2017-2018 and two from the Drug-Induced Liver Injury Network (DILIN) in 2016. Other causes for liver injury were excluded. Causality was assessed using the DILIN structured expert opinion causality approach.

RESULTS

Among the five patients, three were males; mean age was 43 years (range 21-62). All patients developed jaundice and symptoms such as nausea, lethargy, pruritus and abdominal discomfort after a latency of 2-12 weeks. Liver injury was cholestatic or mixed (R ratios 1.4-3.3). Pruritus and hyperbilirubinaemia were prolonged (5-20 weeks). No patient developed hepatic failure. Liver tests normalized within 1-5 months in four patients. One patient was lost to follow-up. One biopsy was performed, showing acute cholestatic hepatitis. Chemical analysis confirmed ashwagandha in available supplements; no other toxic compounds were identified. No patient was taking potentially hepatotoxic prescription medications, although four were consuming additional supplements, and in one case, rhodiola was a possible causative agent along with ashwagandha.

CONCLUSIONS

These cases illustrate the hepatotoxic potential of ashwagandha. Liver injury is typically cholestatic or mixed with severe jaundice and pruritus, but self-limited with liver tests normalizing in 1-5 months.

Translating new knowledge on drug-induced liver injury into clinical practice

Drug-induced liver injury (DILI) is one of the main reasons for drug withdrawal from the market, and a cause of worldwide morbidity. Although several issues on DILI are still unsolved, there have been significant advances in new definitions and diagnosis tools. DILI is the result of a complex interaction between genetic and environmental factors, and constitutes an expanding area of investigation. DILI can mimic virtually all known hepatopathies, including vascular disorders and liver tumours. As part of this broad spectrum of clinical presentations, DILI severity ranges from asymptomatic elevations of aminotransferases to acute liver failure. Although biomarkers are emerging as valuable diagnostic tools, they are not available in clinical practice. Accurate DILI diagnosis is a challenging issue, particularly the establishing of causal relationships with the culprit agent and the exclusion of competing causes of liver injury. Given that the understanding of the mechanisms inducing DILI is growing, and both DILI causality assessment scales and the performance of international DILI networks have been improved, hepatotoxicity may be recognised earlier in clinical practice. In this review, advances and results obtained by DILI registries around the world, case characterisations, particularly those relevant to newer definitions in DILI, and the behaviour of chronic liver disease induced by drugs will be updated. In addition, recently published data on herbal and dietary supplements and new predictive scores for acute liver failure assessment will also be discussed.

Metabolic Comorbidities and Risk of Development and Severity of Drug-Induced Liver Injury

The incidence and rates of diagnosis of drug-induced liver injury (DILI) have been increasing in recent years as findings from basic research and the examination of clinical databases reveal information about the clinical course, etiology, and prognosis of this complex disease. The prevalence of metabolic comorbidities (e.g., diabetes mellitus, fatty liver, obesity, and metabolic syndrome (MetS)) has been increasing during the same period. The results of preclinical and clinical research studies indicate that characteristics of metabolic comorbidities are also factors that affect DILI phenotype and progression. The objective of this review is to present the evidence for DILI and hepatotoxicity mechanisms, incidence, and outcomes in patients with MetS and nonalcoholic fatty liver disease. Moreover, we also summarize the relationships between drugs used to treat metabolic comorbidities and DILI.

A closer look at the spectrum of drug-induced liver injury in sub-Saharan Africa

Introduction: Drug-induced liver injury (DILI) has become the most frequent cause of acute liver failure in high-income countries. However, little is known about the determinants of DILI in sub-Saharan Africa (SSA), where the prescription of antimicrobials and the use of potentially hepatotoxic traditional medicine are common. Areas covered: Based on an extensive literature search, we summarize current data available on the epidemiology and risk factors of DILI in SSA. We discuss the most likely causes of DILI in the region, including antimicrobial therapies and traditional medicine. We also highlight research gaps as well as barriers to diagnosis and management of the condition, and explore ways to address these important challenges. Expert opinion: DILI is underestimated in SSA and several factors challenge its early diagnosis, including lack of information on the causes of DILI in the region, sub-optimal knowledge about the condition among clinicians, and structural difficulties faced by health care systems. In order to better prevent the occurrence of DILI and its complications, it is crucial to enhance awareness among health care providers and patients, adapt drug prescription habits and regulations, and improve current knowledge on the main risk factors for DILI, including host genetic and environmental determinants.

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.

EASL Clinical Practice Guidelines: Drug-induced liver injury

Idiosyncratic (unpredictable) drug-induced liver injury is one of the most challenging liver disorders faced by hepatologists, because of the myriad of drugs used in clinical practice, available herbs and dietary supplements with hepatotoxic potential, the ability of the condition to present with a variety of clinical and pathological phenotypes and the current absence of specific biomarkers. This makes the diagnosis of drug-induced liver injury an uncertain process, requiring a high degree of awareness of the condition and the careful exclusion of alternative aetiologies of liver disease. Idiosyncratic hepatotoxicity can be severe, leading to a particularly serious variety of acute liver failure for which no effective therapy has yet been developed. These Clinical Practice Guidelines summarize the available evidence on risk factors, diagnosis, management and risk minimization strategies for drug-induced liver jury.

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.

Drug-Induced Liver Injury: Why is the Roussel Uclaf Causality Assessment Method (RUCAM) Still Used 25 Years After Its Launch?

Launched in 1993 and partially based on the results of an international consensus meeting organized under the auspices of the Council of International Organizations of Medical Sciences (CIOMS), the Roussel Uclaf Causality Assessment Method (RUCAM) is the most used causality assessment tool worldwide for the diagnosis of drug-induced liver injury (DILI) and herb-induced liver injury (HILI) in a large number of epidemiological studies, case reports, and case series. The 25-year experience of RUCAM use confirmed that the success was due to its objective, standardized, and liver-injury-specific approach structured with defined key elements derived from a series of DILI cases with positive rechallenge. Using this series, the validation procedure avoided arbitrary definitions and confirmed scores to key items. The algorithm provides a quantitative causality grading of highly probable, probable, possible, unlikely, or excluded relationship between the liver injury and the suspected product(s). Despite challenges, prospective use of RUCAM fosters case data completeness and transparent causality adjudication in real time, as opposed to subjective opinion resulting from several rounds by experts lacking defined key elements and scores. In 2016, RUCAM was updated with specification of alcohol use and Hepatitis E Virus (HEV) biomarkers and simplified item handling to further reduce inter-observer variability. RUCAM-based probable and highly probable DILI and HILI cases are essential for the detection of new hepatotoxins, confirmation of new biomarkers, description of clinical features and risk factors, and determination of incidence in pharmacoepidemiological studies. This article is intended to encourage systematic use of sophisticated causality assessment methods such as RUCAM to improve DILI and HILI case evaluation and to increase confidence in published cases.

Herbal and Dietary Supplement-Induced Liver Injuries in the Spanish DILI Registry

BACKGROUND & AIMS

There have been increasing reports of liver injury associated with use of herbal and dietary supplements, likely due to easy access to these products and beliefs among consumers that they are safer or more effective than conventional medications. We aimed to evaluate clinical features and outcomes of patients with herbal and dietary supplement-induced liver injuries included in the Spanish DILI Registry.

METHODS

We collected and analyzed data on demographic and clinical features, along with biochemical parameters, of 32 patients with herbal and dietary supplement-associated liver injury reported to the Spanish DILI registry from 1994 through 2016. We used analysis of variance to compare these data with those from cases of liver injury induced by conventional drugs or anabolic androgenic steroid-containing products.

RESULTS

Herbal and dietary supplements were responsible for 4% (32 cases) of the 856 DILI cases in the registry; 20 cases of DILI (2%) were caused by anabolic androgenic steroids. Patients with herbal and dietary supplement-induced liver injury were a mean age of 48 years and 63% were female; they presented a mean level of alanine aminotransferase 37-fold the upper limit of normal, 28% had hypersensitivity features, and 78% had jaundice. Herbal and dietary supplement-induced liver injury progressed to acute liver failure in 6% of patients, compared with none of the cases of anabolic androgenic steroid-induced injury and 4% of cases of conventional drugs. Liver injury after repeat exposure to the same product that caused the first DILI episode occurred in 9% of patients with herbal and dietary supplement-induced liver injury vs none of the patients with anabolic androgenic steroid-induced injury and 6% of patients with liver injury from conventional drugs.

CONCLUSION

In an analysis of cases of herbal and dietary supplement-induced liver injury in Spain, we found cases to be more frequent among young women than older patients or men, and to associate with hepatocellular injury and high levels of transaminases. Herbal and dietary supplement-induced liver injury is more severe than other types of DILI and re-exposure is more likely. Increasing awareness of the hepatoxic effects of herbal and dietary supplements could help physicians make earlier diagnoses and reduce the risk of serious liver damage.

Novel Approaches to Causality Adjudication in Drug-Induced Liver Disease

Purpose of Review

Drug induced liver injury (DILI) is a complex diagnosis dominantly based of exclusion.

Recent Findings

Currently available causality assessment instruments are considered to be suboptimal. Expert opinion appears to be best method to adjudicate causality, but is impractical to implement on a wide scale basis. Thus, new approaches are needed, for example improving the specificity of current scoring systems. A further option would be to develop a system that utilizes computer-based scoring - which would reduce human error. Additionally, it would be ideal to have available drug specific scoring systems, based on drugs' characteristic "phenotypes" (presentation and pattern of injury). Eventually, a validated system could be integrated within the electronic health information system.

Summary

This review highlights an avenue to an improved Causality Assessment Tool.

Hepatotoxicity of Herbal Supplements Mediated by Modulation of Cytochrome P450

Herbal supplements are a significant source of drug-drug interactions (DDIs), herb-drug interactions, and hepatotoxicity. Cytochrome P450 (CYP450) enzymes metabolize a large number of FDA-approved pharmaceuticals and herbal supplements. This metabolism of pharmaceuticals and supplements can be augmented by concomitant use of either pharmaceuticals or supplements. The xenobiotic receptors constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) can respond to xenobiotics by increasing the expression of a large number of genes that are involved in the metabolism of xenobiotics, including CYP450s. Conversely, but not exclusively, many xenobiotics can inhibit the activity of CYP450s. Induction of the expression or inhibition of the activity of CYP450s can result in DDIs and toxicity. Currently, the United States (US) Food and Drug Administration does not require the investigation of the interactions of herbal supplements and CYP450s. This review provides a summary of herbal supplements that inhibit CYP450s, induce the expression of CYP450s, and/or whose toxicity is mediated by CYP450s.

Highlights of drug - and herb- induced liver injury in the literature from 2016: how best to translate new information into clinical practice?

INTRODUCTION

Over 1500 papers on drug-induced liver injury (DILI) and herb-induced liver injury (HILI) were published in 2016, many of which have the potential to impact clinical practice. Areas covered: Clinical studies and case series that lent themselves to new concepts in diagnosing, and treating DILI were selected for inclusion. Epidemiology of DILI in large prospective registries was highlighted. Causality assessment of drug hepatotoxicity remains challenging, as seen with cases of OxyELITE Pro (OEP). In 2016 updates to the Roussel Uclaf Causality Assessment Method (RUCAM) were published to aid in the accuracy of diagnosing DILI/HILI. New reports of established hepatotoxins were again discussed in 2016, including genetic risk factors for DILI with respect to antituberculous agents. Expert opinion: 2016 marked a turning point in how much credence should be placed in the current causality assessment for DILI/HILI cases. Many recognized hepatotoxins are backed by a relatively few number of literature reports. Danan and Teschke make a strong case that an updated RUCAM should remain the gold standard for diagnosing DILI/HILI going forward, although the role of expert opinion is often still needed in cases where RUCAM falls short. The field of chemoinformatics continues to evolve while we await a truly predictive and diagnostic DILI biomarker.

Developing multicenter consortia in liver disease in Latin America: Challenges and opportunities

The development of consortia has been useful for exploring challenging scenarios and uncharted territories in liver disease treatments. Several consortia already developed in the United States and Europe have become key factors in patient care decision-making processes and medical education, and they have also impacted policy makers' decisions. In Latin America, the situation is different. As a result of a combination of different factors, our region has not been able to develop networking advantages in research and education in liver diseases. Thus far, most of the initial experiences focused on the development of collaborative groups established to investigate a particular topic, which were dissolved once the questions were answered. It is the aim of this review to describe those difficulties we confront in developing multicenter liver consortia in Latin America, to identify those challenges we face, and also to describe the opportunities we have for improvement. Liver Transplantation 23 1210-1215 2017 AASLD.

Liver toxicity mechanisms of herbs commonly used in Latin America

Mexico owns approximately 4500 medicinal plants species, a great diversity that position it at the second place after China. According to the Mexican health department, 90% of common population consumes them to treat various diseases. Additionally, herbal remedies in Latin America (LA) are considered a common practice, but the frequency of use and the liver damage related to its consumption is still unknown. Despite the high prevalence and indiscriminate herbal consumption, the exact mechanism of hepatotoxicity and adverse effects is not fully clarified and is still questioned. Some herb products associated with herb induced liver injury (HILI) are characterized by presenting a different chemical composition that may vary from batch to batch, also the biological activity of many medicinal plants and other natural products are directly related to their most active component and its concentration. There are two main biological components that are associated with liver damage, alkaloids, and flavonoids, which are frequent constituents of commonly used herbs. The interaction with the different cytochrome P-450 isoforms, inflammatory, and oxidative activities seem to be the main damage pathway involved in the liver. It is important to know the herbal adverse effects and mechanisms involved; therefore, this article is focused on the beneficial and deleterious effects as well as the possible toxicity mechanisms and interactions of the herbs that are frequently used in LA, since the herb-host interaction may not always be the expected or desired depending on the clinical context in which it is administered.

Drug-Induced Liver Injury: Cascade of Events Leading to Cell Death, Apoptosis or Necrosis

Drug-induced liver injury (DILI) can broadly be divided into predictable and dose dependent such as acetaminophen (APAP) and unpredictable or idiosyncratic DILI (IDILI). Liver injury from drug hepatotoxicity (whether idiosyncratic or predictable) results in hepatocyte cell death and inflammation. The cascade of events leading to DILI and the cell death subroutine (apoptosis or necrosis) of the cell depend largely on the culprit drug. Direct toxins to hepatocytes likely induce oxidative organelle stress (such as endoplasmic reticulum (ER) and mitochondrial stress) leading to necrosis or apoptosis, while cell death in idiosyncratic DILI (IDILI) is usually the result of engagement of the innate and adaptive immune system (likely apoptotic), involving death receptors (DR). Here, we review the hepatocyte cell death pathways both in direct hepatotoxicity such as in APAP DILI as well as in IDILI. We examine the known signaling pathways in APAP toxicity, a model of necrotic liver cell death. We also explore what is known about the genetic basis of IDILI and the molecular pathways leading to immune activation and how these events can trigger hepatotoxicity and cell death.

Epidemiology and Genetic Risk Factors of Drug Hepatotoxicity

Idiosyncratic drug-induced liver injury (DILI) from prescription medications and herbal and dietary supplements has an annual incidence rate of approximately 20 cases per 100,000 per year. However, the risk of DILI varies greatly according to the drug. In the United States and Europe, antimicrobials are the commonest implicated agents, with amoxicillin/clavulanate the most common, whereas in Asian countries, herbal and dietary supplements predominate. Genetic analysis of DILI is currently limited, but multiple polymorphisms of human leukocyte antigen genes and genes involved in drug metabolism and transport have been identified as risk factors for DILI.