The natural history of histologically proved drug induced liver disease

Clinical Characteristics and Outcomes of Patients With Antithyroid Drug-Related Liver Injury

Context

Antithyroid drugs (ATDs) are the cornerstone of hyperthyroidism management. Hepatotoxicity due to ATDs can range from mild transaminase elevation to liver transplantation requirement and mortality.

Objective

The primary objective of the systematic review was to assess the clinical characteristics and outcomes of patients with drug induced liver injury (DILI) due to ATDs.

Methods

We conducted a systematic review of PUBMED, SCOPUS, and EMBASE on characteristics and outcomes of adults (>18 years) with DILI due to ATDs. We defined DILI as bilirubin ≥2.5 mg/dL or international normalized ratio >1.5 with any rise in alanine aminotransferase (ALT), aminotransferase (AST), or alkaline phosphatase (ALP), or an elevation of ALT or AST >5 times or ALP >2 times the upper limit of normal without jaundice/coagulopathy.

Results

The review included 100 articles describing 271 patients; 148 (70.8%) were female (N = 209). Mean age was 42.9 ± 17.2 years. Graves' disease was the most common indication for ATDs. Carbimazole/methimazole (CBM/MMI) was the most common offending agent (55.7%). DILI pattern was hepatocellular in 41.8%, cholestatic in 41.3%, and mixed in 16.9%. Outcomes included death in 11.8%, liver transplantation in 6.4%, partial improvement in 2.2%, and complete resolution in 79.6% with a median time (IQR) to resolution of 45 (20-90) days. Patients in the propylthiouracil (PTU) group had higher initial bilirubin, initial AST, initial ALT, peak ALT, peak AST, severe and fatal DILI, liver transplantation, and mortality than CBM/MMI. Rechallenge of antithyroid medication was infrequently reported (n = 16) but was successful in 75%.

Conclusion

DILI due to ATDs can present with different patterns and should prompt immediate drug discontinuation. Referral to a hepatologist should be considered if severe as transplantation is sometimes required. PTU-induced DILI may have worse outcomes than CBM/MMI.

Advances in Idiosyncratic Drug-Induced Liver Injury Issues: New Clinical and Mechanistic Analysis Due to Roussel Uclaf Causality Assessment Method Use

Clinical and mechanistic considerations in idiosyncratic drug-induced liver injury (iDILI) remain challenging topics when they are derived from mere case narratives or iDILI cases without valid diagnosis. To overcome these issues, attempts should be made on pathogenetic aspects based on published clinical iDILI cases firmly diagnosed by the original RUCAM (Roussel Uclaf Causality Assessment Method) or the RUCAM version updated in 2016. Analysis of RUCAM-based iDILI cases allowed for evaluating immune and genetic data obtained from the serum and the liver of affected patients. For instance, strong evidence for immune reactions in the liver of patients with RUCAM-based iDILI was provided by the detection of serum anti-CYP 2E1 due to drugs like volatile anesthetics sevoflurane and desflurane, partially associated with the formation of trifluoroacetyl (TFA) halide as toxic intermediates that form protein adducts and may generate reactive oxygen species (ROS). This is accompanied by production of anti-TFA antibodies detected in the serum of these patients. Other RUCAM-based studies on serum ANA (anti-nuclear antibodies) and SMA (anti-smooth muscle antibodies) associated with AIDILI (autoimmune DILI) syn DIAIH (drug-induced autoimmune hepatitis) provide additional evidence of immunological reactions with monocytes as one of several promoting immune cells. In addition, in the blood plasma of patients, mediators like the cytokines IL-22, IL-22 binding protein (IL-22BP), IL-6, IL-10, IL 12p70, IL-17A, IL-23, IP-10, or chemokines such as CD206 and sCD163 were found in DILI due to anti-tuberculosis drugs as ascertained by the prospective updated RUCAM, which scored a high causality. RUCAM-based analysis also provided compelling evidence of genetic factors such as HLA (human leucocyte antigen) alleles contributing to initiate iDILI by a few drugs. In conclusion, analysis of published RUCAM-based iDILI cases provided firm evidence of immune and genetic processes involved in iDILI caused by specific drugs.

Sex disparity and drug-induced liver injury

Drug-induced liver injury (DILI) is a potentially serious clinical condition that remains a major problem for patients, physicians and those involved in the development of new drugs. Population and hospital-based studies have reported incidences of DILI varying from 1.4 to 19.1/100.000. Overall, females have a 1.5- to 1.7-fold greater risk of developing adverse drug reactions and the female/male ratio increases after the age of 49 years, suggesting a clear susceptibility of DILI after menopause. Sex differences in pharmacokinetics and pharmacodynamic, sex-specific hormonal effects or interaction with signalling molecules that can influence drug efficacy and safety and differences in abnormal immune response following drug exposure are the main probable causes of the higher vulnerability observed among female patients. A novel phenotype of autoimmune-mediated DILI following the use of check-point inhibitors in oncology and haematology has been recently described. Finally, there have been increasing reports of DILI associated with use of herbal and dietary supplements that is more frequently reported in women.

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).

Long-term sequelae of drug-induced liver injury

Drug-induced liver injury (DILI) has a very variable clinical and biochemical phenotype and differs widely in severity, from mild injury to life-threatening liver failure. Chronic injury has also been reported to occur at a variable frequency, ranging from 3.4% to 39%, 6-12 months after discontinuing the implicated agent. This wide range is probably related to various definitions of chronic liver injury and variable selection of patients. The long-term sequalae of this chronic injury in terms of morbidity and mortality are unclear, although rare vanishing bile duct syndrome is associated with an unfavourable prognosis, with increased risk of chronic liver failure and need for liver transplantation. Other forms of long-term sequalae associated with DILI are progressive fibrosis, autoimmune-like hepatitis, secondary sclerosing cholangitis, sinusoidal obstruction syndrome and, as a common final stage, the development of cirrhosis, portal hypertension and its complications. Immune checkpoint inhibitors, which can cause an autoimmune-like phenotype have also recently been shown to cause sclerosing cholangitis with cytotoxic T CD8+ cell infiltration in biliary tracts. DILI has been shown to have a significant impact on health-related quality of life but very little is known about its psychological consequences in the long-term. Further investigations with structured long-term follow-up and periodic quality of life surveys are needed to assess the impact of DILI on psychological outcomes, particularly in those with chronic sequelae.

Evaluation of drug-induced liver injury as etiology for acute liver failure in Brazil

INTRODUCTION AND OBJECTIVES

Little is known about the etiology of acute liver failure (ALF) in Latin America. The objective of this paper is to investigate the main etiologies of ALF in Brazil, including Drug Induced Liver Injury (DILI) using stringent causality criteria.

PATIENTS OR MATERIAL AND METHODS

All the cases of individuals who underwent liver transplantation (LT) in 12 centers in Brazil for ALF were reviewed. When DILI was stated as the cause of ALF, causality criteria were applied on site by the main investigator in order to rule out other etiologies.

RESULTS

325 individuals had ALF mainly for unknown reasons (34%), DILI (27%) and AIH (18%). Reassessment of the 89 cases of DILI, using stringent causality criteria, revealed that in only 42 subjects could DILI be confirmed as the cause of ALF. Acetaminophen (APAP) toxicity (n = 3) or DILI due to herbal and dietary supplements (HDS) (n = 2) were not commonly observed.

CONCLUSIONS

Undetermined etiology and DILI are the main causes of ALF in Brazil. However, APAP toxicity and DILI due to HDS are mostly uncommon.

Pharmacotherapies for Drug-Induced Liver Injury: A Current Literature Review

Drug-induced liver injury (DILI) has become a serious public health problem. For the management of DILI, discontinuation of suspicious drug or medicine is the first step, but the treatments including drugs and supporting approaches are needed. Reference to clinical patterns and disease severity grades of DILI, the treatment drugs were considered to summarize into hepatoprotective drugs (N-acetylcysteine and Glutathione, Glycyrrhizin acid preparation, Polyene phosphatidylcholine, Bicyclol, Silymarin), anticholestatic drug (Ursodeoxycholic acid, S-adenosylmethionine, Cholestyramine), immunosuppressants (Glucocorticoids) and specific treatment agents (L-carnitine, Anticoagulants). The current article reviewed the accumulated literature with evidence-based medicine researches for DILI in clinical practice. Also the drawbacks of the clinical studies involved in the article, unmet needs and prospective development for DILI therapy were discussed.

The LiverTox Paradox-Gaps between Promised Data and Reality Check

The LiverTox database compiles cases of idiosyncratic drug-induced liver injury (iDILI) with the promised aims to help identify hepatotoxicants and provide evidence-based information on iDILI. Weaknesses of this approach include case selection merely based on published case number and not on a strong causality assessment method such as the Roussel Uclaf Causality Assessment Method (RUCAM). The aim of this analysis was to find out whether the promised aims have been achieved by comparison of current iDILI case data with those promised in 2012 in LiverTox. First, the LiverTox criteria of likelihood categories applied to iDILI cases were analyzed regarding robustness. Second, the quality was analyzed in LiverTox cases caused by 46 selected drugs implicated in iDILI. LiverTox included iDILI cases of insufficient quality because most promised details were not fulfilled: (1) Standard liver injury definition; (2) incomplete narratives or inaccurate for alternative causes; and (3) not a single case was assessed for causality with RUCAM, as promised. Instead, causality was arbitrarily judged on the iDILI case number presented in published reports with the same drug. All of these issues characterize the paradox of LiverTox, requiring changes in the method to improve data quality and database reliability. In conclusion, establishing LiverTox is recognized as a valuable effort, but the paradox due to weaknesses between promised data quality and actual data must be settled by substantial improvements, including, for instance, clear definition and identification of iDILI cases after evaluation with RUCAM to establish a robust causality grading.

Elevated bilirubin, alkaline phosphatase at onset, and drug metabolism are associated with prolonged recovery from DILI

BACKGROUND & AIMS

Although most drug-induced liver injury (DILI) cases resolve after the offending medication is discontinued, time to recovery varies among patients, with 6 -12% developing a chronic disease. Herein, we investigated clinical factors and drug properties as potential risk determinants that influence the time course for DILI recovery and developed a model to predict its trajectory.

METHODS

We applied an accelerated failure time model to 294 cases collected by the International Drug-Induced Liver Network Consortium (iDILIC). Factors included in the multivariate recovery score model were selected through univariate analysis. The model was externally validated using 257 cases from the Spanish DILI Registry and 191 cases from the LiverTox database.

RESULTS

Higher serum bilirubin and alkaline phosphatase (ALP) at DILI onset, a longer time to onset, and non-significant drug metabolism were associated with a longer recovery and were included in the recovery score model. We defined high- and low-risk groups based on the scores assigned by the model. The estimated probability of recovery by 6 months was 0.46 (95% CI 0.26-0.61) for the high-risk group and 0.93 (95% CI 0.58-0.99) for the low-risk group in the iDILIC. Model performance was validated in both validation sets. The high- and low-risk cases identified by the model showed a significantly different time course for recovery, with a majority of low-risk cases recovering sooner.

CONCLUSION

The trajectory of biochemical recovery from DILI is predicted by the extent of drug metabolism, serum bilirubin and ALP at DILI onset. The model can be used to compute an estimated DILI recovery and, when a significant delay is predicted, clinicians may consider additional investigations such as histologic evaluation or extended follow-up.

LAY SUMMARY

In this study, we investigated whether drug properties and clinical factors are associated with the time it takes to recover from drug-induced liver injury (DILI). We found that total bilirubin, alkaline phosphatase level at DILI onset, time to onset, and extent of drug metabolism were consistently associated with recovery time. Using these factors, we built a model to predict the trajectory of recovery from DILI and validated this model in 2 independent cohorts. Our findings offer important insights into the factors influencing the trajectory of recovery from DILI. Additional investigations and longer follow-ups can be planned in those for whom a delayed recovery is predicted.

Chronic Drug-Induced Liver Injury: Updates and Future Challenges

Chronic drug-induced liver injury (DILI), defined as DILI with persistent liver injury more than one year after the first onset by the latest European guidelines, is a notable challenge globally with big issues of defining causality and establishing effective treatment. About 20% of patients with DILI develop into chronic DILI. Chronic DILI manifests as persistent or repeated inflammatory or diminishing bile ducts, even progresses to cirrhosis and needs liver transplantation eventually. However, research on chronic DILI over the last decades is still lacking, and the incidence, phenotypes, mechanisms, risk factors, and treatment have not been fully understood. In this paper, we reviewed the definition of chronic DILI, updated clinical studies in terms of incidence, special manifestations, and promising risk factors of chronic DILI, along with the recent progress and challenges in glucocorticoid therapy.

Drug-induced liver injury: Asia Pacific Association of Study of Liver consensus guidelines

Idiosyncratic drug-induced liver injury mimics acute and chronic liver disease. It is under recognized and underrecognised because of the lack of pathognomonic diagnostic serological markers. Its consequences may vary from being asymptomatic to self-limiting illness to severe liver injury leading to acute liver failure. Its incidence is likely to be more common in Asia than other parts of the world, mainly because of hepatotoxicity resulting from the treatment of tuberculosis disease and the ubiquitous use of traditional and complimentary medicines in Asian countries. This APASL consensus guidelines on DILI is a concise account of the various aspects including current evidence-based information on DILI with special emphasis on DILI due to antituberculosis agents and traditional and complementary medicine use in Asia.

Drug induced liver injury: an update

Drug induced liver injury (DILI) is a relatively rare hepatic condition in response to the use of medications, illegal drugs, herbal products or dietary supplements. It occurs in susceptible individuals through a combination of genetic and environmental risk factors believed to modify drug metabolism and/or excretion leading to a cascade of cellular events, including oxidative stress formation, apoptosis/necrosis, haptenization, immune response activation and a failure to adapt. The resultant liver damage can present with an array of phenotypes, which mimic almost every other liver disorder, and varies in severity from asymptomatic elevation of liver tests to fulminant hepatic failure. Despite recent research efforts specific biomarkers are not still available for routine use in clinical practice, which makes the diagnosis of DILI uncertain and relying on a high degree of awareness of this condition and the exclusion of other causes of liver disease. Diagnostic scales such as the CIOMS/RUCAM can support the causality assessment of a DILI suspicion, but need refinement as some criteria are not evidence-based. Prospective collection of well-vetted DILI cases in established DILI registries has allowed the identification and validation of a number of clinical variables, and to predict a more severe DILI outcome. DILI is also in need of properly designed clinical trials to evaluate the efficacy of new DILI treatments as well as older drugs such as ursodeoxycholic acid traditionally used to ameliorate cholestasis or corticosteroids now widely tried in the oncology field to manage the emergent type of hepatotoxicity related to immune checkpoint inhibitors.

Epidemiology of drug-induced liver injury in a University Hospital from Colombia: Updated RUCAM being used for prospective causality assessment

INTRODUCTION AND AIM

Epidemiological information regarding drug-induced liver injury in some Latin American countries remains limited. Therefore, disease prevention and health promotion strategies are imperative to reduce drug-induced liver injuries and its fatal outcomes. This study aimed to collect epidemiological data regarding drug-induced liver injury and identify associated factors in patients admitted to a university hospital in Colombia.

METHODS AND PATIENTS

A prospective study was conducted for 1 year to assess the incidence of drug-induced liver injury in patients aged >18 years who showed elevated values in liver tests. Data were collected after obtaining informed consent from the patients. The updated Roussel Uclaf Causality Assessment Method was applied to assess the causality of drug-induced liver injury.

RESULTS

The study included 286 patients with elevated values in liver tests, 18 of whom presented with drug-induced liver injury. The mean age of patients was 54.7±19.1 years. The associated pharmacological groups were anti-infectives and anticonvulsants (isoniazid, rifampicin, nitrofurantoin, phenytoin, and valproic acid), with a total of 15 drugs. The affected patients presented with cytopenia, jaundice, nausea, vomiting, or hepatomegaly. The most common type of liver injury was hepatocellular, and most patients recovered satisfactorily. The number of patients who had highly probable and probable causality grading was 1 and 9, respectively.

CONCLUSION

The incidence of drug-induced liver injury in a university hospital in Colombia was 6%. Comorbidities and concomitant drugs are risk factors for drug-induced liver injury.

TRIAL REGISTRATION

Registered in The Cuban Public Registry of Clinical Trials (identifier RPCEC00000242).

Isoniazid and Rifampicin Produce Hepatic Fibrosis through an Oxidative Stress-Dependent Mechanism

METHODS

A combined dose of INH (50 mg) and RMP (100 mg) per kg body weight per day was administered to mice by oral gavage, 6 days a week, for 4 to 24 weeks for the assessment of liver injury, oxidative stress, and development of hepatic fibrosis, including demonstration of changes in key fibrogenesis linked pathways and mediators.

RESULTS

Progressive increase in markers of hepatic stellate cell (HSC) activation associated with changes in matrix turnover was observed between 12 and 24 weeks of INH-RMP treatment along with the elevation of liver collagen content and significant periportal fibrosis. These were associated with concurrent apoptosis of the hepatocytes, increase in hepatic cytochrome P450 2E1 (CYP2E1), NADPH oxidase (NOX) activity, and development of hepatic oxidative stress.

CONCLUSIONS

INH-RMP can activate HSC through generation of NOX-mediated oxidative stress, leading to the development of liver fibrosis.

Prolonged interval of total bilirubin decline is an early independent predictive factor of chronic persistent drug-induced liver injury

AIM

Chronic drug-induced liver injury (DILI) with persistent abnormal liver function tests (LFTs) >6 months after cessation of the insulting drugs could progress to cirrhosis. The aim of the present study was to identify the risk factors of chronic DILI for early recognition and better management.

METHODS

History of drug intake and results of LFTs were retrospectively retrieved for patients with a discharge diagnosis of DILI for at least 1-year follow up. The risk factors independently associated with chronic DILI were analyzed by multiple logistic regression analyses.

RESULTS

A total of 33 of the 140 DILI patients had persistent abnormal LFTs >6 months, which were considered as chronic DILI. It was found that the time intervals of alanine aminotransferase and total bilirubin decline from the peak to their half peak (T_0.5ALT , T_0.5TBIL ) were significantly longer in the chronic DILI group than that in the recovered group (P = 0.001 and P < 0.001). The risk factors associated with chronic DILI independently were T_0.5TBIL (OR 1.315, 95% CI 1.038-1.668), longer period of insulting drug(s) intake (OR 1.018, 95% CI 1.003-1.033), mixed/cholestatic pattern (OR 97.159, 95% CI 1.866-5005.994). More importantly, receiver operating characteristic curve analysis showed that the prognostic value of T_0.5TBIL for chronic DILI had a sensitivity of 60.0% at a specificity of 90.7% with the threshold of 16 days.

CONCLUSIONS

The time intervals of total bilirubin decline from its peak to half of its peak (T_0.5TBIL ) was an early independent predictive factor of chronic DILI, suggesting that T_0.5TBIL might serve as an indicator for chronicity.

Vanishing bile duct syndrome arising in a patient with HIV infection sequentially treated with trimethoprim/sulfamethoxazole and dapsone

Trimethoprim/sulfamethoxazole is well known to cause intra-hepatic cholestasis which in rare instances can be prolonged and lead to vanishing bile duct syndrome. The risk regarding the potential for cross-reactivity between structurally related molecules such as dapsone and trimethoprim/sulfamethoxazole in causing hepatotoxicity is scarce. Herein, we report a case of vanishing bile duct syndrome following dapsone use in a patient with HIV infection and a recent history of trimethoprim/sulfamethoxazole-induced cholestasis. The patient had severe and protracted cholestasis during 2 years of follow-up and eventually died of liver failure.

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 drug-induced liver injury in patients: Detection, severity assessment, and regulatory implications

Idiosyncratic Drug-Induced Liver Injury (IDILI) is a rare but potentially life-threatening event that is caused by drugs that, at usual therapeutic doses, do not cause any biochemical or clinical evidence of liver injury in the majority of treated patients. The most common clinical phenotypes of IDILI are "acute hepatitis," "mixed hepatocellular-cholestatic hepatitis," and "cholestatic hepatitis" and these are distinguished by clinical, biochemical and histologic characteristics. Anti-microbials, herbals and dietary supplements are now the agents most often implicated in the US Drug-Induced Liver Injury Network registry. There are several scales that have been used to characterize the severity of IDILI events. There are no reliable means to accurately predict the course of an IDILI event at presentation. In clinical trials, the "gold standard" liver safety signal is the occurrence of "Hy's Law Cases." Making the diagnosis of IDILI, and when a patient is taking multiple drugs, identifying the most likely culprit can be challenging, but many drugs cause IDILI with characteristic clinical and biochemical presentations, or "signatures." In a clinical trial, it is sometimes possible to identify an overlooked "signature" of IDILI by characterizing more minor, asymptomatic, and transient elevations in liver chemistries. This observation can be helpful in assessing causation in rare serious liver events occurring in the clinical trial, or first recognized post-marketing.

The diagnosis and management of idiosyncratic drug-induced liver injury

Drug-induced liver injury (DILI) is an uncommon but important cause of liver disease that can arise after exposure to a multitude of drugs and herbal and dietary supplements. The severity of idiosyncratic DILI varies from mild serum aminotransferase elevations to the development of severe liver injury that can progress to acute liver failure resulting in death or liver transplantation within days of DILI onset. Chronic liver injury that persists for more than 6 months after DILI onset is also becoming increasingly recognized in up to 20% of DILI patients. Host demographic (age, gender, race), clinical and laboratory features at DILI onset have been associated with the severity and outcome of liver injury in DILI patients. In addition to cessation of the suspect drug, other medical interventions including the use of N-acetylcysteine and corticosteroids in selected patients have shown some clinical benefit, but additional prospective studies are needed. A number of promising diagnostic, prognostic and mechanistic serum and genetic biomarkers may help improve our understanding of the pathogenesis and treatment of idiosyncratic DILI.

Top-ranking drugs out of 3312 drug-induced liver injury cases evaluated by the Roussel Uclaf Causality Assessment Method

INTRODUCTION

A list presenting a valid ranking of drugs most commonly implicated is hardly to be found. Areas covered: Published cases of drug-induced liver injury (DILI) with verified causality using RUCAM (Roussel Uclaf Causality Assessment Method) were used for a ranking of drugs most commonly implicated in causing DILI. Expert opinion: RUCAM-based DILI cases were retrieved from 15 reports published by six international databases of DILI registries and three large medical centers, which provided 3312 cases. Overall 48 drugs with the highest number of DILI cases were listed. Among the top 10 ranking drugs implicated in causing DILI were, in decreasing order: amoxicillin-clavulanate, flucloxacilllin, atorvastatin, disulfiram, diclofenac, simvastatin, carbamazepine, ibuprofen, erythromycin, and anabolic steroids as bodybuilding agents. For these 10 drugs, respective DILI case numbers were highest for Amoxicillin-clavulanate (n=333) and lowest for anabolic steroids (n=26). The author classifies the databases of national DILI registries and large medical centers as best sources of drugs implicated in DILI. Presently discouraged is the use of the LiverTox website because many cases were derived from published cases of poor quality and could previously not be classified as DILI, calling for the inclusion of DILI cases with established causality by the updated RUCAM.

Chronic liver injury induced by drugs and toxins

Drug-induced liver injury (DILI) occurs in a small fraction of individuals exposed to drugs, herbs or dietary supplements and is a relatively rare diagnosis compared with other liver disorders. DILI can be serious, resulting in hospitalization and even life-threatening liver failure, death or need for liver transplantation. Toxic liver damage usually presents as an acute hepatitis viral-like syndrome or as an acute cholestasis that resolves upon drug discontinuation. However, un-resolving chronic outcome after acute DILI can ensue in some subjects, the mechanisms and risk factors for this particular evolution being yet scarcely known. Furthermore, the definition of chronicity after acute DILI is controversial, regarding both the time frame of liver injury persistence and the magnitude of the abnormalities required. Besides this, in some instances the phenotypes and pathological manifestations are those of chronic liver disease at the time of DILI diagnosis. These include non-alcoholic fatty liver disease, vascular lesions, drug-induced autoimmune hepatitis, chronic cholestasis leading to vanishing bile duct syndrome and even cirrhosis, and some drugs such as amiodarone or methotrexate have been frequently implicated in some of these forms of chronic DILI. In addition, all of these DILI phenotypes can be indistinguishable from those related to other etiologies, making the diagnosis particularly challenging. In this manuscript we have critically reviewed the more recent data on chronicity in DILI with a particular focus on the epidemiology, mechanisms and risk factors of atypical chronic DILI phenotypes.

Long-Term Outcomes After Drug-Induced Liver Injury

Purpose of the review

This review serves to update the reader on emerging data regarding a spectrum of drug-induced liver injury (DILI) outcomes that lie between complete resolution and acute liver failure. Such outcomes can range from mild chronic injury to late liver failure and mortality.

Recent findings

Several large registries are maturing with large numbers of DILI cases thus shedding light on outcomes including chronic injury and late fatality. We cover definitions commonly used to describe resolution versus chronic injury and mortality due to DILI. We look at rates of occurrence for these different outcomes in major registries. Three specific types of chronic DILI that are illustrative but also easily missed by clinicians are also described.

Summary

A small but important proportion of DILI cases do not resolve, going on to develop chronic injury and even liver failure. Defining and recognizing these cases is a challenge because DILI is rare, and chronic injury rarer still. Large registries are beginning to define these previously overlooked long term outcomes.

Drug induced liver injury with analysis of alternative causes as confounding variables

AIMS

Drug-induced liver injury (DILI) is rare compared to the worldwide frequent acute or chronic liver diseases. Therefore, patients included in series of suspected DILI are at high risk of not having DILI, whereby alternative causes may confound the DILI diagnosis. The aim of this review is to evaluate published case series of DILI for alternative causes.

METHODS

Relevant studies were identified using a computerized search of the Medline database for publications from 1993 through 30 October 2017. We used the following terms: drug hepatotoxicity, drug induced liver injury, hepatotoxic drugs combined with diagnosis, causality assessment and alternative causes.

RESULTS

Alternative causes as variables confounding the DILI diagnosis emerged in 22 published DILI case series, ranging from 4 to 47%. Among 13 335 cases of suspected DILI, alternative causes were found to be more likely in 4555 patients (34.2%), suggesting that the suspected DILI was probably not DILI. Biliary diseases such as biliary obstruction, cholangitis, choledocholithiasis, primary biliary cholangitis and primary sclerosing cholangitis were among the most missed diagnoses. Alternative causes included hepatitis B, C and E, cytomegalovirus, Epstein-Barr virus, ischemic hepatitis, cardiac hepatopathy, autoimmune hepatitis, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, and alcoholic liver disease.

CONCLUSIONS

In more than one-third of published global DILI case series, alternative causes as published in these reports confounded the DILI diagnosis. In the future, published DILI case series should include only patients with secured DILI diagnosis, preferentially established by prospective use of scored items provided by robust diagnostic algorithms such as the updated Roussel Uclaf causality assessment method.

Diagnosis and Management of Drug-Induced Liver Injury (DILI) in Patients with Pre-Existing Liver Disease

The relationship between drugs and pre-existing liver disease is complex, particularly when increased liver tests (LTs) or new symptoms emerge in patients with pre-existing liver disease during drug therapy. This requires two strategies to assess whether these changes are due to drug-induced liver injury (DILI) as a new event or due to flares of the underlying liver disease. Lacking a valid diagnostic biomarker, DILI is a diagnosis of exclusion and requires causality assessment by RUCAM, the Roussel Uclaf Causality Assessment Method, to establish an individual causality grading of the suspected drug(s). Flares of pre-existing liver disease can reliably be assessed in some hepatotropic virus infections by polymerase chain reaction (PCR) and antibody titers at the beginning and in the clinical course to ascertain flares during the natural course of the disease. Unfortunately, flares cannot be verified in many other liver diseases such as alcoholic liver disease, since specific tests are unavailable. However, such a diagnostic approach using RUCAM applied to suspected DILI cases includes clinical and biological markers of pre-existing liver diseases and would determine whether drugs or underlying liver diseases caused the LT abnormalities or the new symptoms. More importantly, a clear diagnosis is essential to ensure effective disease management by drug cessation or specific treatment of the flare up due to the underlying disease.

"Autoimmune(-Like)" Drug and Herb Induced Liver Injury: New Insights into Molecular Pathogenesis

Idiosyncratic drug-induced liver injury (DILI) and hepatic injury due to herbal and dietary supplements (HDS) can adapt clinical characteristics of autoimmune hepatitis (AIH), such as the appearance of autoantibodies and infiltration of the liver by immune competent cells. To describe these cases of DILI/HDS, the poorly-defined term "autoimmune(-like)" DILI/HDS came up. It is uncertain if these cases represent a subgroup of DILI/HDS with distinct pathomechanistic and prognostic features different from "classical" DILI/HDS. Besides, due to the overlap of clinical characteristics of "immune-mediated" DILI/HDS and AIH, both entities are not easy to differentiate. However, the demarcation is important, especially with regard to treatment: AIH requires long-term, mostly lifelong immunosuppression, whereas DILI/HDS does not. Only through exact diagnostic evaluation, exclusion of differential diagnoses and prolonged follow-up can the correct diagnosis reliably be made. Molecular mechanisms have not been analysed for the subgroup of "autoimmune(-like)" DILI/HDS yet. However, several pathogenetic checkpoints of DILI/HDS in general and AIH are shared. An analysis of these shared mechanisms might hint at relevant molecular processes of "autoimmune(-like)" DILI/HDS.

Profiles of miRNAs in serum in severe acute drug induced liver injury and their prognostic significance

BACKGROUND & AIMS

Drug induced liver injury (DILI) is challenging because of the lack of biomarkers to predict mortality. Our aim was to describe miRNA changes in sera of subjects with acute idiosyncratic DILI and determine if levels of miRNAs were associated with 6 month mortality.

METHODS

Clinical data and sera were collected from subjects enrolled in the Drug Induced Liver Injury Network prospective study. miRNAs were isolated from serum obtained from 78 subjects within 2 weeks of acute DILI and followed up for 6 months or longer. miRNAs were compared to 40 normal controls and 6 month survivors vs non-survivors.

RESULTS

The mean age of the DILI cohort was 48 years, and 55% were female. Eleven (14.1%) subjects died, 10 within 6 months of DILI onset, 5 (45%) liver related. Lower levels of miRNAs-122, -4463 and -4270 were associated with death within 6 months (P<.05). None of the subjects with miRNA-122 greater than the median value died within 6 months for a sensitivity of 100% and specificity of 57%. In subjects with a serum albumin <2.8 g/dL and miR-122<7.89 RFU the sensitivity, specificity, positive and negative predictive values for death within 6 months were 100%, 57%, 38% and 100% respectively.

CONCLUSIONS

Serum miRNA-122 combined with albumin accurately identified subjects who died within 6 months of drug induced liver injury. If confirmed prospectively, miRNA-122 and albumin may be useful in identifying patients at high risk for mortality or liver transplantation.

Drug-induced liver injury: Do we know everything?

Interest in drug-induced liver injury (DILI) has dramatically increased over the past decade, and it has become a hot topic for clinicians, academics, pharmaceutical companies and regulatory bodies. By investigating the current state of the art, the latest scientific findings, controversies, and guidelines, this review will attempt to answer the question: Do we know everything? Since the first descriptions of hepatotoxicity over 70 years ago, more than 1000 drugs have been identified to date, however, much of our knowledge of diagnostic and pathophysiologic principles remains unchanged. Clinically ranging from asymptomatic transaminitis and acute or chronic hepatitis, to acute liver failure, DILI remains a leading causes of emergent liver transplant. The consumption of unregulated herbal and dietary supplements has introduced new challenges in epidemiological assessment and clinician management. As such, numerous registries have been created, including the United States Drug-Induced Liver Injury Network, to further our understanding of all aspects of DILI. The launch of LiverTox and other online hepatotoxicity resources has increased our awareness of DILI. In 2013, the first guidelines for the diagnosis and management of DILI, were offered by the Practice Parameters Committee of the American College of Gastroenterology, and along with the identification of risk factors and predictors of injury, novel mechanisms of injury, refined causality assessment tools, and targeted treatment options have come to define the current state of the art, however, gaps in our knowledge still undoubtedly remain.

Involvement of Reactive Metabolites of Diclofenac in Cytotoxicity in Sandwich-Cultured Rat Hepatocytes

Background and Objectives:

Diclofenac (DIC) is metabolized to reactive metabolites such as diclofenac acyl-β-d-glucuronide (DIC-AG). It is possible that such reactive metabolites could cause tissue damage by formation of covalent protein adducts and other modification of cellular proteins or by induction of immune responses against its covalent protein adducts. However, the detailed mechanisms of idiosyncratic drug-induced liver injury (DILI) have been unclear. The objective is to clarify the involvement of DIC-AG and 4′hydroxydiclofenac (4′OH-DIC) in acute DILI.

Methods:

We examined the effects of inhibiting DIC-AG and 4′OH-DIC production on covalent protein adduct formation and lactate dehydrogenase leakage using sandwich-cultured rat hepatocytes (SCRHs).

Results:

After pretreatment of SCRH with (−)-borneol (BOR, a uridine diphosphate (UDP)-glucuronosyltransferase inhibitor) or sulfaphenazole (SUL, a cytochrome P450 2C9 inhibitor) for 30 minutes, intracellular concentrations of DIC, DIC-AG, and 4′OH-DIC were determined after further treating cells with 300 μM DIC for 3 hours. The decreased levels of reactive metabolites caused by BOR or SUL pretreatment resulted in decreased lactate dehydrogenase leakage from SCRH, although the formation of covalent protein adducts was not affected.

Conclusion:

These results suggested that both DIC-AG and 4′OH-DIC may be involved in acute cytotoxicity by DIC.

Drug Metabolism, Drug Interactions, and Drug-Induced Liver Injury in Living Donor Liver Transplant Patients

Living donor liver transplant (LDLT) fills a critically needed gap in the number of livers available for transplant. However, little is known about the functional recovery of the liver in the donor and in the recipient after surgery. Given that both donor and recipients are treated with several drugs, it is important to characterize the time course of recovery of hepatic synthetic, metabolic, and excretory function in these patients. In the absence of data from LDLT, information on the effect of liver disease on the pharmacokinetics of medications can be used as guidance for drug dosing in LDLT patients.

The pathogenesis of drug-induced liver injury

Drugs can induce liver injury when taken as an over-dose, or even at therapeutic doses in susceptible individuals. Although severe drug-induced liver injury (DILI) is a relatively uncommon clinical event, it is a potentially life threatening adverse drug reaction and is the most common indication for the drug withdrawal. Areas covered: However, the diagnosis of DILI remains a significant challenge, because the establishment of causality is very difficult, and the histopathologic findings of DILI may be indistinguishable from those of other hepatic disorders, such as viral and alcoholic hepatitis. In this review, we provide an overview of recent advances in identification of serologic markers of diagnosis and prognosis, etiologic factors for susceptibility and diagnostic evaluation of DILI, with a focus on its pathogenic mechanisms and the role of liver biopsy. Expert commentary: Further studies of divergent research platforms, using a systems biology approach such as genomics and transcriptomics, may provide a deeper understanding of human drug metabolism and the causes, risk factors, and pathogenesis of DILI.

Monocyte-derived hepatocyte-like cells for causality assessment of idiosyncratic drug-induced liver injury

BACKGROUND

Idiosyncratic drug-induced liver injury (iDILI) is a frequent cause of acute liver injury and a serious problem in late stage drug-development. Its diagnosis is one of the most challenging in hepatology, since it is done by exclusion and relies on expert opinion. Until now no reliable in vitro test exists to support the diagnosis of iDILI. In some instances it is impossible to determine the causative drug in polymedicated patients.

AIM

To investigate if monocyte-derived hepatocyte-like (MH) cells might be a tool supporting clinical judgment for iDILI diagnosis and causality assessment.

METHODS

This prospective study included 54 patients with acute liver injury and intake of at least one drug. Thirty-one patients were diagnosed with iDILI based on causality likelihood. MH cells were generated from every patient and in vitro toxicity of the respective drugs was assessed by lactate-dehydrogenase release. The results from MH cells and RUCAM, the most widely used scoring system as methods to support clinical judgement were compared.

RESULTS

MH cells showed enhanced toxicity in 29 of the 31 patients with iDILI, similar to RUCAM score. MH cells exhibited negative results in the 23 non-DILI cases, whereas RUCAM indicated possible iDILI in six cases. Analysis of the comedications also showed superior specificity of MH cells. No MH cell toxicity of the drugs showing toxicity in patients with iDILI was observed in MH cells of healthy donors.

CONCLUSIONS

In this pilot study in vitro testing using MH cells derived from patients with acute liver injury was able to identify patients with iDILI with an excellent sensitivity and a higher specificity than RUCAM, the most widely used current causality assessment score. Therefore, MH cells could be useful to identify the causative drugs even in polymedicated patients by adding objective data to causality assessment.

TRIAL REGISTRATION NUMBER

NCT02353455.

Definition and risk factors for chronicity following acute idiosyncratic drug-induced liver injury

BACKGROUND & AIMS

Chronic outcome following acute idiosyncratic drug-induced liver injury (DILI) is not yet defined. This prospective, long-term follow-up study aimed to analyze time to liver enzyme resolutions to establish the best definition and risk factors of DILI chronicity.

METHODS

298 out of 850 patients in the Spanish DILI registry with no pre-existing disease affecting the liver and follow-up to resolution or ⩾1year were analyzed. Chronicity was defined as abnormal liver biochemistry, imaging test or histology one year after DILI recognition.

RESULTS

Out of 298 patients enrolled 273 (92%) resolved ⩽1year from DILI recognition and 25 patients (8%) were chronic. Independent risk factors for chronicity were older age [OR: 1.06, p=0.011], dyslipidemia [OR: 4.26, p=0.04] and severe DILI [OR: 14.22, p=0.005]. Alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TB) median values were higher in the chronic group during follow-up. Values of ALP and TB >1.1 x upper limit of normal (xULN) and 2.8 xULN respectively, in the second month from DILI onset, were found to predict chronic DILI (p<0.001). Main drug classes involved in chronicity were statins (24%) and anti-infectives (24%). Histological examination in chronic patients demonstrated two cases with ductal lesion and seven with cirrhosis.

CONCLUSIONS

One year is the best cut-off point to define chronic DILI or prolonged recovery, with risk factors being older age, dyslipidemia and severity of the acute episode. Statins are distinctly related to chronicity. ALP and TB values in the second month could help predict chronicity or very prolonged recovery.

LAY SUMMARY

Drug-induced liver injury (DILI) patients who do not resolve their liver damage during the first year should be considered chronic DILI patients. Risk factors for DILI chronicity are older age, dyslipidemia and severity of the acute episode. Chronic DILI is not a very common condition; normally featuring mild liver profile abnormalities and not being an important clinical problem, with the exception of a small number of cases of early onset cirrhosis.

Causes, Features, and Outcomes of Drug-Induced Liver Injury in 69 Children from China

Background/Aims

Drug-induced liver injury (DILI) is a frequent cause of pediatric liver disease; however, the data on DILI are remarkably limited.

Methods

All 69 children hospitalized with DILI between January 2009 and December 2011 were retrospectively studied.

Results

A total of 37.7% of the children had medical histories of respiratory infection. The clinical injury patterns were as follows: hepatocellular 89.9%, cholestatic 2.9%, and mixed 7.2%. Liver biopsies from 55 children most frequently demonstrated chronic (47.3%) and acute (27.3%) hepatitis. Hypersensitivity features, namely, fever (31.9%), rash (21.7%), and eosinophilia (1.4%), were found. Twenty-four children (34.8%) developed chronic DILI. Antibiotics (26.1%) were the most common Western medicines (WMs) causing DILI, and the major implicated herbs were Ephedra sinica and Polygonum multiflorum. Compared with WM, the children whose injuries were caused by Chinese herbal medicine (CHM) showed a higher level of total bilirubin (1.4 mg/dL vs 16.6 mg/dL, p=0.004) and a longer prothrombin time (11.8 seconds vs 17.3 seconds, p=0.012), but they exhibited less chronic DILI (2/15 vs 18/39, p=0.031).

Conclusions

Most cases of DILI in children are caused by antibiotics or CHM used to treat respiratory infection and present with hepatocellular injury. Compared with WM, CHM is more likely to cause severe liver injury, but liver injury caused by CHM is curable.

The Art and Science of Diagnosing and Managing Drug-induced Liver Injury in 2015 and Beyond

Drug-induced liver injury (DILI) remains a leading reason why new compounds are dropped from further study or are the subject of product warnings and regulatory actions. Hy's Law of drug-induced hepatocellular jaundice causing a case-fatality rate or need for transplant of 10% or higher has been validated in several large national registries, including the ongoing, prospective U.S. Drug-Induced Liver Injury Network. It serves as the basis for stopping rules in clinical trials and in clinical practice. Because DILI can mimic all known causes of acute and chronic liver disease, establishing causality can be difficult. Histopathologic findings are often nonspecific and rarely, if ever, considered pathognomonic. A daily drug dose >50-100 mg is more likely to be hepatotoxic than does <10 mg, especially if the compound is highly lipophilic or undergoes extensive hepatic metabolism. The quest for a predictive biomarker to replace alanine aminotransferase is ongoing. Markers of necrosis and apoptosis such as microRNA-122 and keratin 18 may prove useful in identifying patients at risk for severe injury when they initially present with a suspected acetaminophen overdose. Although a number of drugs causing idiosyncratic DILI have HLA associations that may allow for pre-prescription testing to prevent hepatotoxicity, the cost and relatively low frequency of injury among affected patients limit the current usefulness of such genome-wide association studies. Alanine aminotransferase monitoring is often recommended but has rarely been shown to be an effective method to prevent serious DILI. Guidelines on the diagnosis and management of DILI have recently been published, although specific therapies remain limited. The LiverTox Web site has been introduced as an interactive online virtual textbook that makes the latest information on more than 650 agents available to clinicians, regulators, and drug developers alike.

Persistent liver biochemistry abnormalities are more common in older patients and those with cholestatic drug induced liver injury

OBJECTIVES

The long-term outcomes of patients with drug induced liver injury (DILI) are not well described. The aim of this study was to determine the frequency and severity of persistent liver biochemistry abnormalities in DILI patients followed over 2 years.

METHODS

Subjects with evidence of liver injury at 6 months after DILI onset were offered a month 12 and 24 study visit.

RESULTS

Amongst the 99 patients with definite, probable, or very likely DILI and available laboratory data at 12 months after DILI onset, 74 (75%) had persistent liver injury (persisters) defined as a serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >1.5 × upper limit of normal (ULN) or an alkaline phosphatase >ULN, while 25 (25%) had resolved liver injury (resolvers). On multivariate analysis, month 12 persisters were significantly older (52.6 vs. 43.7 years, P=0.01) and more likely to have a cholestatic lab profile at DILI onset (54 vs. 20%, P<0.01) than resolvers. The month 12 persisters also had significantly poorer SF-36 physical summary scores at DILI onset and throughout follow-up compared with the resolvers (P<0.01). Amongst the 17 subjects with a liver biopsy obtained at a median of 387 days after DILI onset, 9 had chronic cholestasis, 3 had steatohepatitis, and 3 had chronic hepatitis.

CONCLUSIONS

In all, 75% of subjects with liver injury at 6 months after DILI onset have laboratory evidence of persistent liver injury during prolonged follow-up. Higher serum alkaline phosphatase levels at presentation and older patient age were independent predictors of persistent liver injury. Subjects with persistent liver injury at 12 months after DILI onset should be carefully monitored and assessed for liver disease progression.

Chinese Herbal Medicine-induced Liver Injury

The widespread use of Chinese herbal medicine (CHM) and the associated adverse reactions has attracted the attention of researchers and physicians. Reports have shown that several types of CHM can cause liver injury, with increasing numbers of cases reported every year. The difficulty in characterizing CHM-induced liver injury stems from clinical manifestations, diagnosis and pathogenesis. The clinical manifestations are varied, but gastrointestinal symptoms are the majority. The Council for International Organizations of Medical Sciences scale is currently the most commonly used method for assessing causality in cases of medicine-induced liver injury with excellent sensitivity, specificity and predictive validity. However, the pathogenesis of CHM-induced liver injury is not well understood. The classic view encompasses a contribution from "toxic metabolites" that either elicit an immune response or directly affect cellular biochemical processes or functions. In addition, poor quality and inappropriate clinical use of CHMs contribute to safety concerns. To ensure the safe use of CHMs and decrease the number of hepatotoxic cases, clinicians, researchers and pharmaceutical companies should share responsibility by regulating clinical use, strengthening basic toxicology research and establishing a strict quality control system.

Idiosyncratic drug-induced liver injury is associated with substantial morbidity and mortality within 6 months from onset

BACKGROUND & AIMS

Little is known about the incidence of drug-induced liver injury (DILI) and risk factors for adverse outcomes. We evaluated short-term outcomes of a large cohort of patients with DILI enrolled in an ongoing multicenter prospective study.

METHODS

Data were collected from 660 adults with definite, highly likely, or probable DILI. Regression methods were used to identify risk factors for early liver-related death or liver transplantation and chronic liver injury.

RESULTS

Patients' median age was 51.4 years; 59.5% were female and 59.1% required hospitalization. Within 6 months of DILI onset, 30 patients received liver transplants (4.5%; 95% confidence interval [CI], 3.0%-6.1%) and 32 died (5%; 95% CI, 3.2%-6.5%); 53% of the deaths were liver related. Asian race, absence of itching, lung disease, low serum albumin levels, low platelet counts, and high serum levels of alanine aminotransferase and total bilirubin at presentation were independent risk factors for reduced times to liver-related death or liver transplantation (C-statistic = 0.87). At 6 months after DILI onset, 18.9% of the 598 evaluable subjects had persistent liver damage. African-American race, higher serum levels of alkaline phosphatase, and prior heart disease or malignancy requiring treatment were independent risk factors for chronic DILI (C-statistic = 0.71).

CONCLUSIONS

Nearly 1 in 10 patients die or undergo liver transplantation within 6 months of DILI onset and nearly 1 in 5 of the remaining patients have evidence of persistent liver injury at 6 months. The profile of liver injury at presentation, initial severity, patient's race, and medical comorbidities are important determinants of the likelihood of death/transplantation or persistent liver injury within 6 months.

Drug-drug interactions with oral anti-HCV agents and idiosyncratic hepatotoxicity in the liver transplant setting

Studies of boceprevir and telaprevir based antiviral therapy in liver transplant (LT) recipients with hepatitis C genotype 1 infection have demonstrated dramatic increases in tacrolimus, cyclosporine, and mTOR inhibitor exposure. In addition to empiric dose reductions, daily monitoring of immunosuppressant blood levels is required when initiating as well as discontinuing the protease inhibitors to maximize patient safety. Although improved suppression of HCV replication is anticipated, 20 to 40% of treated subjects have required early treatment discontinuation due to various adverse events including anemia (100%), infection (30%), nephrotoxicity (20%) and rejection (5 to 10%). Simeprevir and faldaprevir will likely have improved efficacy and safety profiles but potential drug interactions with other OATP1B1 substrates and unconjugated hyperbilirubinemia are expected. In contrast, sofosbuvir and daclatasvir based antiviral therapy are not expected to lead to clinically significant drug-drug interactions in LT recipients but confirmatory studies are needed. Liver transplant recipients may also be at increased risk of developing drug induced liver injury (DILI). Establishing a diagnosis of DILI in the transplant setting is very difficult with the variable latency, laboratory features and histopathological manifestations of hepatotoxicity associated with a given drug, the need to exclude competing causes of allograft injury, and the lack of an objective and verifiable confirmatory test. Nonetheless, a heightened awareness of the possibility of DILI is warranted in light of the large number of medications used in LT recipients and the potential adverse impact that DILI may have on patient outcomes.

Drug and herb induced liver injury: Council for International Organizations of Medical Sciences scale for causality assessment

Causality assessment of suspected drug induced liver injury (DILI) and herb induced liver injury (HILI) is hampered by the lack of a standardized approach to be used by attending physicians and at various subsequent evaluating levels. The aim of this review was to analyze the suitability of the liver specific Council for International Organizations of Medical Sciences (CIOMS) scale as a standard tool for causality assessment in DILI and HILI cases. PubMed database was searched for the following terms: drug induced liver injury; herb induced liver injury; DILI causality assessment; and HILI causality assessment. The strength of the CIOMS lies in its potential as a standardized scale for DILI and HILI causality assessment. Other advantages include its liver specificity and its validation for hepatotoxicity with excellent sensitivity, specificity and predictive validity, based on cases with a positive reexposure test. This scale allows prospective collection of all relevant data required for a valid causality assessment. It does not require expert knowledge in hepatotoxicity and its results may subsequently be refined. Weaknesses of the CIOMS scale include the limited exclusion of alternative causes and qualitatively graded risk factors. In conclusion, CIOMS appears to be suitable as a standard scale for attending physicians, regulatory agencies, expert panels and other scientists to provide a standardized, reproducible causality assessment in suspected DILI and HILI cases, applicable primarily at all assessing levels involved.

Idiosyncratic drug hepatotoxicity: a 2008 update

Pharmaceutical preparations, and also herbal products and dietary supplements, are emerging contributors to severe forms of liver disease. Although acetaminophen intoxication is still the reason for many cases of drug-induced liver injury (DILI) in Western countries, the bulk of hepatic reactions to drugs are idiosyncratic. Only a small fraction of individuals exposed to a drug associated with liver injury will develop hepatotoxicity. Indeed, the rarity of this serious adverse event prevents its detection in clinical trials. The pathogenesis of idiosyncratic DILI is not well known because of a lack of reliable animal models, although it probably involves the metabolism of the drug and/or activation of the immune system. Different databases have described antibiotics, NSAIDs and anticonvulsants as the main group of drugs incriminated in DILI. Clinical presentation of DILI includes predominantly a hepatocellular type of damage, yet cholestatic and mixed types are also common; the determinants of the type of damage induced by a given drug are poorly understood. Analysis of pooled data has recently underlined the influence of older age in the cholestatic/mixed expression of liver injury, as well as the independent association of female gender, older age, aspartate aminotransferase levels with hepatocellular type of damage and high bilirubin levels with the risk of fulminant liver failure/death. In the long term (providing the patient survives the initial episode), persistent damage may occur in at least 6% of patients, with the cholestatic mixed type of damage more prone to becoming chronic, while in the hepatocellular pattern the severity is greater, with further likelihood of evolution to cirrhosis. Cardiovascular and CNS drugs are the main groups leading to chronic liver damage. The diagnosis of hepatotoxicity remains a difficult task owing to the lack of reliable markers for use in general clinical practice. Diagnostic algorithms may add consistency to clinical judgment by translating a suspicion into a quantitative score. Currently, the Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method instrument is considered the gold standard in causality assessment of hepatotoxicity, although there is probably room for improvement. Current efforts in collecting bona fide cases will make refinements of existing scales feasible. Efforts should also be directed towards the development of an abridged instrument for use in evaluating suspected drug-induced hepatotoxicity at the very beginning of the diagnosis and treatment process when clinical decisions need to be taken. The treatment of idiosyncratic DILI is largely supportive. Early suspicion and withdrawal of the offending agent is the most important therapeutic measure.

Idiosyncratic drug-induced liver injury: an update on the 2007 overview

INTRODUCTION

Idiosyncratic drug induced liver injury (DILI) is rare, with an incidence of approximately 19 per 100,000 treated individuals.

AREAS COVERED

An update on the epidemiology, pathogenic mechanisms, diagnosis, outcome, risk factors for idiosyncratic drug-induced hepatotoxicity, specific classes of drug hepatotoxicity and biomarkers to predict DILI are covered. Cumulative drug exposure and HLA phenotypes play an important role in the pathogenesis of DILI. Patients who present with suspected DILI and jaundice should have biliary obstruction and acute viral hepatitis, including hepatitis E excluded. Immune-mediated DILI will respond to steroid therapy. Patients with an elevated bilirubin and a hepatocellular pattern of liver function tests have severe liver injury with a mortality of greater than 10% and a risk of acute liver failure. Women have an increased risk of hepatocellular DILI. Antibiotics, anticonvulsants, and antidepressant therapy remain the commonest causes of DILI in the Western Hemisphere. Statin therapy rarely causes severe liver injury.

EXPERT OPINION

The establishment of prospective registries for DILI has provided valuable data on the pathogenesis and outcome of DILI. Drug-specific computerised causality assessment tools should improve the diagnosis of DILI. The clinical utility of genetic polymorphisms associated with drug-specific DILI is limited.

Drug- and Herb-Induced Liver Injury in Clinical and Translational Hepatology: Causality Assessment Methods, Quo Vadis?

Drug-induced liver injury (DILI) and herb-induced liver injury (HILI) are typical diseases of clinical and translational hepatology. Their diagnosis is complex and requires an experienced clinician to translate basic science into clinical judgment and identify a valid causality algorithm. To prospectively assess causality starting on the day DILI or HILI is suspected, the best approach for physicians is to use the Council for International Organizations of Medical Sciences (CIOMS) scale in its original or preferably its updated version. The CIOMS scale is validated, liver-specific, structured, and quantitative, providing final causality grades based on scores of specific items for individual patients. These items include latency period, decline in liver values after treatment cessation, risk factors, co-medication, alternative diagnoses, hepatotoxicity track record of the suspected product, and unintentional re-exposure. Provided causality is established as probable or highly probable, data of the CIOMS scale with all individual items, a short clinical report, and complete raw data should be transmitted to the regulatory agencies, manufacturers, expert panels, and possibly to the scientific community for further refinement of the causality evaluation in a setting of retrospective expert opinion. Good-quality case data combined with thorough CIOMS-based assessment as a standardized approach should avert subsequent necessity for other complex causality assessment methods that may have inter-rater problems because of poor-quality data. In the future, the CIOMS scale will continue to be the preferred tool to assess causality of DILI and HILI cases and should be used consistently, both prospectively by physicians, and retrospectively for subsequent expert opinion if needed. For comparability and international harmonization, all parties assessing causality in DILI and HILI cases should attempt this standardized approach using the updated CIOMS scale.

Herbal hepatotoxicity: suspected cases assessed for alternative causes

BACKGROUND AND OBJECTIVES

Alternative explanations are common in suspected drug-induced liver injury (DILI) and account for up to 47.1% of analyzed cases. This raised the question of whether a similar frequency may prevail in cases of assumed herb-induced liver injury (HILI).

METHODS

We searched the Medline database for the following terms: herbs, herbal drugs, herbal dietary supplements, hepatotoxic herbs, herbal hepatotoxicity, and herb-induced liver injury. Additional terms specifically addressed single herbs and herbal products: black cohosh, Greater Celandine, green tea, Herbalife products, Hydroxycut, kava, and Pelargonium sidoides. We retrieved 23 published case series and regulatory assessments related to hepatotoxicity by herbs and herbal dietary supplements with alternative causes.

RESULTS

The 23 publications comprised 573 cases of initially suspected HILI; alternative causes were evident in 278/573 cases (48.5%). Among them were hepatitis by various viruses (9.7%), autoimmune diseases (10.4%), nonalcoholic and alcoholic liver diseases (5.4%), liver injury by comedication (DILI and other HILI) (43.9%), and liver involvement in infectious diseases (4.7%). Biliary and pancreatic diseases were frequent alternative diagnoses (11.5%), raising therapeutic problems if specific treatment is withheld; pre-existing liver diseases including cirrhosis (9.7%) were additional confounding variables. Other diagnoses were rare, but possibly relevant for the individual patient.

CONCLUSION

In 573 cases of initially assumed HILI, 48.5% showed alternative causes unrelated to the initially incriminated herb, herbal drug, or herbal dietary supplement, calling for thorough clinical evaluations and appropriate causality assessments in future cases of suspected HILI.

Genetic characterization to improve interpretation and clinical management of hepatotoxicity caused by tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKIs) represent important therapeutic alternatives to, or combinations with, traditional cytotoxic chemotherapy. Despite their selective molecular targeting and demonstrated clinical benefit, TKIs produce a range of serious adverse events, including drug-induced liver injury, that require careful patient management to maintain treatment benefit without harm. Genetic characterization of serious adverse events can identify mechanisms of injury and improve safety risk management. This review presents pharmacogenetic comparisons of two approved TKIs, lapatinib and pazopanib, which reveal different mechanisms of injury and inform the characteristics and risk of serious liver injury in treated patients. The data presented demonstrate the utility of genetic studies to investigate drug-induced liver injury and potentially support its management in patients.

Clinical and causality assessment in herbal hepatotoxicity

INTRODUCTION

Herbal hepatotoxicity represents a poorly understood, neglected and multifaceted disease with numerous confounding variables and missing established causality in the majority of cases. This review discusses overt shortcomings in its clinical and causality assessment and suggests improvements.

AREAS COVERED

A selective literature search of PubMed using the terms herbal hepatotoxicity, herb-induced liver injury, drug hepatotoxicity and drug-induced liver injury was performed to identify published case reports, spontaneous case reports, case series and review articles regarding hepatotoxicity due to herbs, herbal drugs and herbal dietary supplements. Covered areas focused on confounding variables related to the documentation of the herbal product and the clinical course, hepatotoxicity and reexposure criteria, temporal association, comedication and alternative causes with special attention to preexisting diseases of the liver, bile ducts and the pancreas. Of particular interest were recent discussions of approaches designed and validated for hepatotoxicity causality, such as the scale of CIOMS (Council for International Organizations of Medical Sciences).

EXPERT OPINION

The authors call for substantial improvements in data quality of herbal products and case characteristics and strongly recommend using the CIOMS scale to assess causality in suspected herbal hepatotoxicity.