Use of Hy's law and a new composite algorithm to predict acute liver failure in patients with drug-induced liver injury

Treatment options for nonalcoholic steatohepatitis - a safety evaluation

INTRODUCTION

There is an urgent as yet unmet need to develop highly effective and safe therapeutics for nonalcoholic fatty liver disease (NAFLD). The remarkable progress in understanding NAFLD pathogenesis allowed the identification of injury pathways which may be recruited as therapy targets. Areas covered: This article reviews the safety and tolerability data of the NAFLD therapies and explains the mechanistic basis for each of the established and investigational drugs. Treatment targets include: weight loss, anti-metabolic agents such as lipid lowering and anti-diabetic drugs, inflammation, fibrosis and others such as targeting gut microbiota, immune modulation and apoptosis. Expert opinion: Current therapies continue to remain suboptimal. Weight loss is effective but hard to achieve. Traditional and endoscopic bariatric procedures are promising although more randomized trials are needed and the long-term safety remains to be established. Clinical trials have demonstrated the efficacy of several drugs for the treatment of NASH. Of these, there remains some uncertainty about the long-term safety of vitamin E. Pioglitazone is associated with osteopenia, fluid retention and weight gain. Obeticholic acid causes pruritus in a substantial proportion of subjects and elafibranor has been associated with transient rises in creatinine. Several exciting therapies are under development and results of clinical and post-marketing trials will help elucidate their safety.

Drug-induced liver injury: recent advances in diagnosis and risk assessment

Idiosyncratic drug-induced liver injury (IDILI) is a rare but potentially severe adverse drug reaction that should be considered in patients who develop laboratory criteria for liver injury secondary to the administration of a potentially hepatotoxic drug. Although currently used liver parameters are sensitive in detecting DILI, they are neither specific nor able to predict the patient's subsequent clinical course. Genetic risk assessment is useful mainly due to its high negative predictive value, with several human leucocyte antigen alleles being associated with DILI. New emerging biomarkers which could be useful in assessing DILI include total keratin18 (K18) and caspase-cleaved keratin18 (ccK18), macrophage colony-stimulating factor receptor 1, high mobility group box 1 and microRNA-122. From the numerous in vitro test systems that are available, monocyte-derived hepatocytes generated from patients with DILI show promise in identifying the DILI-causing agent from among a panel of coprescribed drugs. Several computer-based algorithms are available that rely on cumulative scores of known risk factors such as the administered dose or potential liabilities such as mitochondrial toxicity, inhibition of the bile salt export pump or the formation of reactive metabolites. A novel DILI cluster score is being developed which predicts DILI from multiple complimentary cluster and classification models using absorption-distribution-metabolism-elimination-related as well as physicochemical properties, diverse substructural descriptors and known structural liabilities. The provision of more advanced scientific and regulatory guidance for liver safety assessment will depend on validating the new diagnostic markers in the ongoing DILI registries, biobanks and public-private partnerships.

CSH guidelines for the diagnosis and treatment of drug-induced liver injury

Drug-induced liver injury (DILI) is an important clinical problem, which has received more attention in recent decades. It can be induced by small chemical molecules, biological agents, traditional Chinese medicines (TCM), natural medicines (NM), health products (HP), and dietary supplements (DS). Idiosyncratic DILI is far more common than intrinsic DILI clinically and can be classified into hepatocellular injury, cholestatic injury, hepatocellular-cholestatic mixed injury, and vascular injury based on the types of injured target cells. The CSH guidelines summarized the epidemiology, pathogenesis, pathology, and clinical manifestation and gives 16 evidence-based recommendations on diagnosis, differential diagnosis, treatment, and prevention of DILI.

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.

Role of nonalcoholic fatty liver disease as risk factor for drug-induced hepatotoxicity

BACKGROUND

Obesity is often associated with nonalcoholic fatty liver disease (NAFLD), which refers to a large spectrum of hepatic lesions including fatty liver, nonalcoholic steatohepatitis (NASH) and cirrhosis. Different investigations showed or suggested that obesity and NAFLD are able to increase the risk of hepatotoxicity of different drugs. Some of these drugs could induce more frequently an acute hepatitis in obese individuals whereas others could worsen pre-existing NAFLD.

AIM

The main objective of the present review was to collect the available information regarding the role of NAFLD as risk factor for drug-induced hepatotoxicity. For this purpose, we performed a data-mining analysis using different queries including drug-induced liver injury (or DILI), drug-induced hepatotoxicity, fatty liver, nonalcoholic fatty liver disease (or NAFLD), steatosis and obesity. The main data from the collected articles are reported in this review and when available, some pathophysiological hypotheses are put forward.

RELEVANCE FOR PATIENTS

Drugs that could pose a potential risk in obese patients include compounds belonging to different pharmacological classes such as acetaminophen, halothane, methotrexate, rosiglitazone, stavudine and tamoxifen. For some of these drugs, experimental investigations in obese rodents confirmed the clinical observations and unveiled different pathophysiological mechanisms which could explain why these pharmaceuticals are particularly hepatotoxic in obesity and NAFLD. Other drugs such as pentoxifylline, phenobarbital and omeprazole might also pose a risk but more investigations are required to determine whether this risk is significant or not. Because obese people often take several drugs for the treatment of different obesity-related diseases such as type 2 diabetes, hyperlipidemia and coronary heart disease, it is urgent to identify the main pharmaceuticals that can cause acute hepatitis on a fatty liver background or induce NAFLD worsening.

Drug-Induced Liver Disease: Clinical Course

Drug-induced liver injury (DILI) is a term used to describe a spectrum of clinical presentations and severity that ranges from mild elevation of liver enzymes on routine blood work to acute liver failure and death. Approximately 10% of all patients with DILI develop acute liver failure resulting in death or liver transplantation. DILI may be prolonged with persistence of elevated liver enzymes for longer than 6 months in approximately 5% to 20% of cases. Cirrhosis and long-term liver-related morbidity and mortality have also been described but are rare, occurring in 1% to 3% of cases.

Adverse Drug Reactions: Type A (Intrinsic) or Type B (Idiosyncratic)

Hepatotoxic adverse drug reactions are associated with significant morbidity and mortality and are the leading cause of postmarketing regulatory action in the United States. They are classified as Type A (intrinsic) or Type B (idiosyncratic). Type A are predictable, dose-related toxicities, often identified in preclinical or clinical trials, and usually occur in overdose settings or with pre-existing hepatic impairment. Type B are not clearly related to increasing dose and are associated with drug-specific and patient-specific characteristics and environmental risks. Rare Type B reactions are often identified postmarketing. Identification and management, including electronic resources, has evolved.

Prediction of drug-induced liver injury using keratinocytes

Drug-induced liver injury (DILI) is one of the most common adverse drug reactions. DILI is often accompanied by skin reactions, including rash and pruritus. However, it is still unknown whether DILI-associated genes such as S100 calcium-binding protein A and interleukin (IL)-1β are involved in drug-induced skin toxicity. In the present study, most of the tested hepatotoxic drugs such as pioglitazone and diclofenac induced DILI-associated genes in human and mouse keratinocytes. Keratinocytes of mice at higher risk for DILI exhibited an increased IL-1β basal expression. They also showed a higher inducibility of IL-1β when treated by pioglitazone. Mice at higher risk for DILI showed even higher sums of DILI-associated gene basal expression levels and induction rates in keratinocytes. Our data suggest that DILI-associated genes might be involved in the onset and progression of drug-induced skin toxicity. Furthermore, we might be able to identify individuals at higher risk of developing DILI less invasively by examining gene expression patterns in keratinocytes. Copyright © 2017 John Wiley & Sons, Ltd.

Outcomes from massive paracetamol overdose: a retrospective observational study

LINKED ARTICLE

This article is commented on by Bateman DN and Dear JW. Should we treat very large paracetamol overdose differently? Br J Clin Pharmacol 2017; 83: 1163-5. https://doi.org/10.1111/bcp.13279 AIMS: Treatment of paracetamol (acetaminophen) overdose with acetylcysteine is standardized, with dose determined only by patient weight. The validity of this approach for massive overdoses has been questioned. We systematically compared outcomes in massive and non-massive overdoses, to guide whether alternative treatment strategies should be considered, and whether the ratio between measured timed paracetamol concentrations (APAP_pl ) and treatment nomogram thresholds at those time points (APAP_t ) provides a useful assessment tool.

METHODS

This is a retrospective observational study of all patients (n = 545) between 2005 and 2013 admitted to a tertiary care toxicology service with acute non-staggered paracetamol overdose. Massive overdoses were defined as extrapolated 4-h plasma paracetamol concentrations >250 mg l^-1 , or reported ingestions ≥30 g. Outcomes (liver injury, coagulopathy and kidney injury) were assessed in relation to reported dose and APAP_pl :APAP_t ratio (based on a treatment line through 100 mg l^-1 at 4 h), and time to acetylcysteine.

RESULTS

Ingestions of ≥30 g paracetamol correlated with higher peak serum aminotransferase (r = 0.212, P < 0.0001) and creatinine (r = 0.138, P = 0.002) concentrations. Acute liver injury, hepatotoxicity and coagulopathy were more frequent with APAP_pl :APAP_t  ≥ 3 with odds ratios (OR) and 95% confidence intervals (CI) of 9.19 (5.04-16.68), 35.95 (8.80-158.1) and 8.34 (4.43-15.84), respectively (P < 0.0001). Heightened risk persisted in patients receiving acetylcysteine within 8 h of overdose.

CONCLUSION

Patients presenting following massive paracetamol overdose are at higher risk of organ injury, even when acetylcysteine is administered early. Enhanced therapeutic strategies should be considered in those who have an APAP_pl :APAP_t  ≥ 3. Novel biomarkers of incipient liver injury and abbreviated acetylcysteine regimens require validation in this patient cohort.

Drug-induced liver injury: Towards early prediction and risk stratification

Drug-induced liver injury (DILI) is a hot topic for clinicians, academia, drug companies and regulators, as shown by the steadily increasing number of publications and agents listed as causing liver damage (http://livertox.nih.gov/). As it was the case in the past decade with drug-induced QT prolongation/arrhythmia, there is an urgent unmet clinical need to develop tools for risk assessment and stratification in clinical practice and, in parallel, to improve prediction of pre-clinical models to support regulatory steps and facilitate early detection of liver-specific adverse drug events. Although drug discontinuation and therapy reconciliation still remain the mainstay in patient management to minimize occurrence of DILI, especially acute liver failure events, different multidisciplinary attempts have been proposed in 2016 to predict and assess drug-related risk in individual patients; these promising, albeit preliminary, results strongly support the need to pursue this innovative pathway.

Drug-induced liver injury

Drug-induced liver injury (DILI) remains the most common cause of acute liver failure (ALF) in the western world. Excluding paracetamol overdose, nearly all DILI encountered in the clinical setting is idiosyncratic in nature because affected individuals represent only a small proportion of those treated with such drugs. In many cases, the mechanism for idiosyncrasy is immune-mediation and is often identified by genetic risk determined by human leukocyte antigen variants. In the absence of diagnostic tests and/or biomarkers, the diagnosis of DILI requires a high index of suspicion after diligently excluding other causes of abnormal liver tests. Antibiotics are the class of drugs most frequently associated with idiosyncratic DILI, although recent studies indicate that herbal and dietary supplements are an increasingly recognised cause. It is imperative that upon development of DILI the culprit drug be discontinued, especially in the presence of elevated transaminases (aspartate aminotransferase/alanine aminotransferase ratio ≥5 times the upper limit of normal) and/or jaundice. Risk factors for the development ALF include hepatocellular DILI and female gender, the treatment being supportive with some benefit of N-acetylcysteine in the early stages. In view of the poor transplant-free survival in idiosyncratic DILI, early consideration for liver transplant is mandatory.

Apixaban-induced liver injury

An 81-year-old woman with well-controlled hypertension presented to the emergency department with new-onset atrial fibrillation with rapid ventricular response. Treatment for atrial fibrillation was initiated, including rate control and anticoagulation with 5 mg of apixaban two times per day for primary stroke prophylaxis. Three days after initiation of apixaban, the patient noted new-onset abdominal pain, worsening shortness of breath and weakness. Laboratory results showed elevated liver enzymes. Workup for elevated transaminase did not reveal any underlying infectious or autoimmune process. Apixaban, a probable cause for the hepatocellular injury, was discontinued and replaced with intravenous unfractionated heparin to bridge anticoagulation with warfarin. The patient's symptoms resolved as her transaminases improved by discontinuation of apixaban. We illustrate this case of drug-induced hepatotoxicity secondary to treatment with apixaban. It is important for physicians to be aware of this rare adverse effect caused by a widely used novel oral anticoagulant.

Killer Immunoglobulin-Like Receptor Profiles Are not Associated with Risk of Amoxicillin-Clavulanate-Induced Liver Injury in Spanish Patients

Natural killer cells are an integral part of the immune system and represent a large proportion of the lymphocyte population in the liver. The activity of these cells is regulated by various cell surface receptors, such as killer Ig-like receptors (KIR) that bind to human leukocyte antigen (HLA) class I ligands on the target cell. The composition of KIR receptors has been suggested to influence the development of specific diseases, in particularly autoimmune diseases, cancer and reproductive diseases. The role played in idiosyncratic drug-induced liver injury (DILI) is currently unknown. In this study, we examined KIR gene profiles and HLA class I polymorphisms in amoxicillin-clavulanate (AC) DILI patients in search for potential risk associations. One hundred and two AC DILI patients and 226 controls were genotyped for the presence or absence of 16 KIR loci, including the two pseudogenes 2DP1 and 3DP1. No significant differences were found in the distribution of individual KIRs between patients and controls, which were comparable to previously reported KIR data from ethnically similar cohorts. The 21.6 and 21.2% of the patients and controls, respectively, were homozygous haplotype A carriers, while 78.4 and 78.8%, respectively, contained at least one B haplotype (Bx). The genotypes translated into 27 (AC DILI) and 46 (controls) different gene profiles, with 19 being present in both groups. The most frequent Bx gene profile containing KIRs 2DS2, 2DL2, 2DL3, 2DP1, 2DL1, 3DL1, 2DS4, 3DL2, 3DL3, 2DL4, and 3PD1 was present in 16% of the DILI patients and 14% of the controls. The distribution of HLA class I epitopes did not differ significantly between AC DILI patients and controls. The most frequent receptor-ligand combinations in the DILI patients were 2DL3 + epitope C1 (67%) and 3DL1 + Bw4 motif (67%), while 2DL1 + epitope C2 (69%) and 3DL1 + Bw4 motif (69%) predominated in the controls. This is to our knowledge the first analysis of KIR receptor-HLA ligand associations in DILI, although our findings do not support evidence of these genetic variations playing a major role in AC DILI development.

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.

Biomarkers in DILI: One More Step Forward

Despite being relatively rare, drug-induced liver injury (DILI) is a serious condition, both for the individual patient due to the risk of acute liver failure, and for the drug development industry and regulatory agencies due to associations with drug development attritions, black box warnings, and postmarketing withdrawals. A major limitation in DILI diagnosis and prediction is the current lack of specific biomarkers. Despite refined usage of traditional liver biomarkers in DILI, reliable disease outcome predictions are still difficult to make. These limitations have driven the growing interest in developing new more sensitive and specific DILI biomarkers, which can improve early DILI prediction, diagnosis, and course of action. Several promising DILI biomarker candidates have been discovered to date, including mechanistic-based biomarker candidates such as glutamate dehydrogenase, high-mobility group box 1 protein and keratin-18, which can also provide information on the injury mechanism of different causative agents. Furthermore, microRNAs have received much attention lately as potential non-invasive DILI biomarker candidates, in particular miR-122. Advances in “omics” technologies offer a new approach for biomarker exploration studies. The ability to screen a large number of molecules (e.g., metabolites, proteins, or DNA) simultaneously enables the identification of ‘toxicity signatures,’ which may be used to enhance preclinical safety assessments and disease diagnostics. Omics-based studies can also provide information on the underlying mechanisms of distinct forms of DILI that may further facilitate the identification of early diagnostic biomarkers and safer implementation of personalized medicine. In this review, we summarize recent advances in the area of DILI biomarker studies.

Acute Liver Failure: Diagnosis and Management

Acute liver failure is life threatening liver injury with coagulopathy and hepatic encephalopathy within 26 weeks and generally, in the absence of preexisting liver disease. Fulminant liver failure occurs when hepatic encephalopathy occurs within 8 weeks of jaundice. The majority of patients with ALF are women with the median age of 38 years. In the United States, drug induced liver injury including acetaminophen causes the majority of ALF cases. The etiology of ALF should be determined, if possible, because many causes have a specific treatment. The mainstay for ALF is supportive care and liver transplantation, if necessary. There are multiple prognostic criteria available. Prognosis can be poor and patients should be referred to a liver transplantation center as soon as possible.

Case Characterization, Clinical Features and Risk Factors in Drug-Induced Liver Injury

Idiosyncratic drug-induced liver injury (DILI) caused by xenobiotics (drugs, herbals and dietary supplements) presents with a range of both phenotypes and severity, from acute hepatitis indistinguishable of viral hepatitis to autoimmune syndromes, steatosis or rare chronic vascular syndromes, and from asymptomatic liver test abnormalities to acute liver failure. DILI pathogenesis is complex, depending on the interaction of drug physicochemical properties and host factors. The awareness of risk factors for DILI is arising from the analysis of large databases of DILI cases included in Registries and Consortia networks around the world. These networks are also enabling in-depth phenotyping with the identification of predictors for severe outcome, including acute liver failure and mortality/liver transplantation. Genome wide association studies taking advantage of these large cohorts have identified several alleles from the major histocompatibility complex system indicating a fundamental role of the adaptive immune system in DILI pathogenesis. Correct case definition and characterization is crucial for appropriate phenotyping, which in turn will strengthen sample collection for genotypic and future biomarkers studies.

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

Drug induced liver injury (DILI) is a rare but well recognized serious adverse reaction. Pre-marketing studies may not detect liver injury, and DILI becomes very often apparent after the drug is launched to the market. Specific biomarkers for DILI prediction or diagnosis are not available. Toxic liver reactions present with a wide spectrum of phenotypes and severity, and our knowledge on the mechanisms underlying idiosyncratic reactions and individual susceptibility is still limited. To overcome these limitations, country-based registries and multicenter research networks have been created in Europe and North America. Reliable epidemiological data on DILI in Latin America (LA), a region with a large variety of ethnic groups, were however lacking. Fortunately, a LA network of DILI was set up in 2011, with the support of the Spanish DILI Registry from the University of Malaga. The primary aim of the Latin DILI Network (LATINDILIN) Registry was to prospectively identify bona fide DILI cases and to collect biological samples to study genetic biomarkers. Physicians involved in the project must complete a structured report form describing the DILI case presentation and follow-up which is submitted to a Coordinator Center in each country, where it is further assessed for completeness. During the last four years, several LA countries (Argentina, Uruguay, Chile, Mexico, Paraguay, Brazil, Ecuador, Peru, Venezuela and Colombia) have joined the network and committed with this project. At that point, to identify both our strengths and weaknesses was a very important issue. In this review, we will describe how the LATINDILI Registry was created. The aims and methods to achieve these objectives will be discussed in depth. Additionally, both the difficulties we have faced and the strategies to solve them will be also pinpointed. Finally, we will report on our preliminary results, and discuss ideas to expand and to keep running this network.

Preventive use of a hepatoprotectant against anti-tuberculosis drug-induced liver injury: A randomized controlled trial

BACKGROUND AND AIM

Hepatoprotectants are routinely prescribed in China to prevent anti-tuberculosis drug-induced liver injury (ATLI). However, their biological mechanisms have not yet been clearly demonstrated. This study aims to evaluate the preventive effects of Silybum marianum against drug-induced liver injury among tuberculosis patients and to provide clinical guidelines for tuberculosis management in China.

METHODS

A randomized controlled trial was performed in Jiangsu, China. Tuberculosis patients were randomly allocated to the experimental group (anti-tuberculosis therapy plus S. marianum capsule) or the control group (anti-tuberculosis therapy plus vitamin C tablet). The primary outcomes were the occurrence of probable and possible ATLI, the peak aspartate aminotransferase/alanine aminotransferase ratio and the maximum altered alkaline phosphatase or gamma-glutamyl transferase.

RESULTS

The final analysis comprised 183 cases in the experiment group and 187 cases in the control group. The risk of developing probable ATLI was not significantly different between the two groups. During the follow-up period, 43.72% of cases in the experiment group and 35.83% of cases in the control group were determined to have possible ATLI (relative risk = 1.23, 95% confidence interval: 0.94-1.54). When using a more strict definition of possible ATLI, the adjusted relative risk (95% confidence interval) was 1.76 (1.14-2.56). The risks of adverse drug reactions, prolonged treatment length, taking second-line tuberculosis drugs, and the clearance of tuberculosis bacteria were similar between the two groups.

CONCLUSIONS

No significant preventive effect of silymarin was found for either lowering the risk of liver injury or boosting the positive outcomes. Worse, we even found a potential risk of liver damage caused by the hepatoprotectant.

Risk of Acute Liver Failure in Patients With Drug-Induced Liver Injury: Evaluation of Hy's Law and a New Prognostic Model

BACKGROUND & AIMS

Few studies have evaluated the ability of laboratory tests to predict risk of acute liver failure (ALF) among patients with drug-induced liver injury (DILI). We aimed to develop a highly sensitive model to identify DILI patients at increased risk of ALF. We compared its performance with that of Hy's Law, which predicts severity of DILI based on levels of alanine aminotransferase or aspartate aminotransferase and total bilirubin, and validated the model in a separate sample.

METHODS

We conducted a retrospective cohort study of 15,353 Kaiser Permanente Northern California members diagnosed with DILI from 2004 through 2010, liver aminotransferase levels above the upper limit of normal, and no pre-existing liver disease. Thirty ALF events were confirmed by medical record review. Logistic regression was used to develop prognostic models for ALF based on laboratory results measured at DILI diagnosis. External validation was performed in a sample of 76 patients with DILI at the University of Pennsylvania.

RESULTS

Hy's Law identified patients that developed ALF with a high level of specificity (0.92) and negative predictive value (0.99), but low level of sensitivity (0.68) and positive predictive value (0.02). The model we developed, comprising data on platelet count and total bilirubin level, identified patients with ALF with a C statistic of 0.87 (95% confidence interval [CI], 0.76-0.96) and enabled calculation of a risk score (Drug-Induced Liver Toxicity ALF Score). We found a cut-off score that identified patients at high risk patients for ALF with a sensitivity value of 0.91 (95% CI, 0.71-0.99) and a specificity value of 0.76 (95% CI, 0.75-0.77). This cut-off score identified patients at high risk for ALF with a high level of sensitivity (0.89; 95% CI, 0.52-1.00) in the validation analysis.

CONCLUSIONS

Hy's Law identifies patients with DILI at high risk for ALF with low sensitivity but high specificity. We developed a model (the Drug-Induced Liver Toxicity ALF Score) based on platelet count and total bilirubin level that identifies patients at increased risk for ALF with high sensitivity.

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.

The value of serum aspartate aminotransferase and gamma-glutamyl transpetidase as biomarkers in hepatotoxicity

BACKGROUND & AIMS

The current definition of the pattern of liver injury in hepatotoxicity (DILI) is given by the R (ratio) value, dividing alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in upper limits of normal at DILI onset. We aimed to explore the validity of using aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) as biomarkers of hepatocelullar and cholestatic damage, respectively, when calculating the R value.

METHODS

Clinical, laboratory and histological data from 588 DILI episodes included in the Spanish DILI Registry were analyzed. Linear regression analysis was performed to establish the most appropriate cut-off points for hepatocellular and cholestatic patterns when calculating R with AST and GGT.

RESULTS

The overall agreement between ALT/ALP and AST/ALP was 76%, with 96%, 61% and 41% agreement in the hepatocellular (R ≥ 5), cholestatic (R ≤ 2) and mixed groups respectively (P < 0.001). Classified by the causative drug, the agreement was higher (87-95%) among drug classes that mainly present with hepatocellular damage and lower (48-58%) for those in which cholestatic-mixed injury predominate (P < 0.001)). The overall agreement between ALT/ALP and ALT/GGT was weak (59%), except for in hepatocellular cases that showed a good agreement (94%) (P = 0.001). Pattern of injury according to liver histology demonstrated 65%, 68% and 47% agreement for ALT/ALP, AST/ALP and ALT/GGT ratios respectively.

CONCLUSIONS

AST can reliably replace ALT when calculating pattern of liver injury in DILI, while GGT can only substitute ALP when the R value scores as hepatocellular. The biochemical signature of causative drugs does influence the validity of the ratios with AST or GGT.

Sorting out cirrhosis: mechanisms of non-response to hepatitis C therapy

Although cirrhosis has long been recognized as an important negative predictor of treatment response for hepatitis C virus (HCV) therapy, the mechanisms underlying this association remain relatively poorly understood. Treatment has progressed rapidly with the introduction of highly effective all-oral therapies, with promising outcomes even in patients with advanced cirrhosis. However, even with the new therapies, it is clear that patients with cirrhosis require special attention. Efficacy continues to be somewhat reduced compared to non-cirrhotic patients and safety is an important concern. In this review, we explore the reasons for treatment non-response in patients with cirrhosis. We focus on how cirrhosis impacts on four important areas including drug delivery, drug uptake and metabolism, immune responses and drug toxicity with examples from the clinical and basic literature. Fortunately, as treatment continues to progress, many of the challenges of treating patients with cirrhosis will become less and less problematic.

Drug-induced liver injury: Interactions between drug properties and host factors

Idiosyncratic drug-induced liver injury (DILI) is a common cause for drug withdrawal from the market and although infrequent, DILI can result in serious clinical outcomes including acute liver failure and the need for liver transplantation. Eliminating the iatrogenic "harm" caused by a therapeutic intent is a priority in patient care. However, identifying culprit drugs and individuals at risk for DILI remains challenging. Apart from genetic factors predisposing individuals at risk, the role of the drugs' physicochemical and toxicological properties and their interactions with host and environmental factors need to be considered. The influence of these factors on mechanisms involved in DILI is multi-layered. In this review, we summarize current knowledge on 1) drug properties associated with hepatotoxicity, 2) host factors considered to modify an individuals' risk for DILI and clinical phenotypes, and 3) drug-host interactions. We aim at clarifying knowledge gaps needed to be filled in as to improve risk stratification in patient care. We therefore broadly discuss relevant areas of future research. Emerging insight will stimulate new investigational approaches to facilitate the discovery of clinical DILI risk modifiers in the context of disease complexity and associated interactions with drug properties, and hence will be able to move towards safety personalized medicine.

Drug-induced liver disease: Types and mechanisms of action of liver-protecting drugs

Drug-induced liver disease is one of the adverse reactions of clinical drugs. Acute liver injury is the most common form of drug-induced liver disease and even could cause life-threatening liver failure. It is not easy to diagnose, and the diagnosis can be established only after other diagnoses excluded. In most cases, patients usually are prescribed several drugs together, which makes it even harder to distinguish and give standardized treatment. This review summarizes the pathological category of Drug-induced liver disease and the mechanisms of action of liver-protecting drugs.

Drug- and herb-induced liver injury: Progress, current challenges and emerging signals of post-marketing risk

Drug-induced liver injury (DILI) and herb-induced liver injury is a hot topic for clinicians, academia, drug companies and regulators, as shown by the steadily increasing number of publications in the past 15 years. This review will first provide clues for clinicians to suspect idiosyncratic (unpredictable) DILI and succeed in diagnosis. Causality assessment remains challenging and requires careful medical history as well as awareness of multifaceted aspects, especially for herbs. Drug discontinuation and therapy reconciliation remain the mainstay in patent's management to minimize occurrence of acute liver failure. The second section will address novel agents associated with liver injury in 2014 (referred to as "signals"), especially in terms of clinical, research and drug development implications. Insights will be provided into recent trends by highlighting the contribution of different post-marketing data, especially registries and spontaneous reporting systems. This literature scrutiny suggests: (1) the importance of post-marketing databases as tools of clinical evidence to detect signals of DILI risk; and (2) the need for joining efforts in improving predictivity of pre-clinical assays, continuing post-marketing surveillance and design ad hoc post-authorization safety studies. In this context, ongoing European/United States research consortia and novel pharmaco-epidemiological tools (e.g., specialist prescription event monitoring) will support innovation in this field. Direct oral anticoagulants and herbal/dietary supplements appear as key research priorities.

Population-representative incidence of drug-induced acute liver failure based on an analysis of an integrated health care system

BACKGROUND & AIMS

Medications are a major cause of acute liver failure (ALF) in the United States, but no population-based studies have evaluated the incidence of ALF from drug-induced liver injury. We aimed to determine the incidence and outcomes of drug-induced ALF in an integrated health care system that approximates a population-based cohort.

METHODS

We performed a retrospective cohort study using data from the Kaiser Permanente Northern California (KPNC) health care system between January 1, 2004, and December 31, 2010. We included all KPNC members age 18 years and older with 6 months or more of membership and hospitalization for potential ALF. The primary outcome was drug-induced ALF (defined as coagulopathy and hepatic encephalopathy without underlying chronic liver disease), determined by hepatologists who reviewed medical records of all KPNC members with inpatient diagnostic and laboratory criteria suggesting potential ALF.

RESULTS

Among 5,484,224 KPNC members between 2004 and 2010, 669 had inpatient diagnostic and laboratory criteria indicating potential ALF. After medical record review, 62 (9.3%) were categorized as having definite or possible ALF, and 32 (51.6%) had a drug-induced etiology (27 definite, 5 possible). Acetaminophen was implicated in 18 events (56.3%), dietary/herbal supplements in 6 events (18.8%), antimicrobials in 2 events (6.3%), and miscellaneous medications in 6 events (18.8%). One patient with acetaminophen-induced ALF died (5.6%; 0.06 events/1,000,000 person-years) compared with 3 patients with non-acetaminophen-induced ALF (21.4%; 0.18/1,000,000 person-years). Overall, 6 patients (18.8%) underwent liver transplantation, and 22 patients (68.8%) were discharged without transplantation. The incidence rates of any definite drug-induced ALF and acetaminophen-induced ALF were 1.61 events/1,000,000 person-years (95% confidence interval, 1.06-2.35) and 1.02 events/1,000,000 person-years (95% confidence interval, 0.59-1.63), respectively.

CONCLUSIONS

Drug-induced ALF is uncommon, but over-the-counter products and dietary/herbal supplements are its most common causes.

Model for end-stage liver disease score as a predictor of short-term outcome in patients with drug-induced liver injury

OBJECTIVES

The purposes of this study were to investigate the clinical presentation, cause and outcome of drug-induced liver injury (DILI) and to evaluate the predictive value of the model for end-stage liver disease (MELD) score in DILI.

METHODS

Patients diagnosed with DILI between January 1, 2010 and December 31, 2012 in the Emergency Department at Asan Medical Center in Seoul, Korea were analyzed retrospectively. The primary end point was poor outcome, defined as liver transplantation or death within 30 days of the initial hospital visit.

RESULTS

Of 213 patients, 13.1% had a 30-day poor outcome. Folk remedies were the most common cause of DILI in 147 patients (69%). Univariate logistic regression analysis showed that multiple drugs (odds ratio [OR] 2.30, 95% confidence interval [CI]: 1.03-5.15), concurrent alcohol consumption (OR 3.69, 95% CI: 1.03-13.18), white blood cell (WBC) count (OR 1.17, 95% CI: 1.07-1.28), hemoglobin (Hb) (OR 0.60, 95% CI: 0.49-0.74), platelet count (OR 0.993, 95% CI: 0.987-0.998), total bilirubin (OR 1.09, 95% CI: 1.06-1.13) and MELD (OR 1.23, 95% CI: 1.15-1.32) were significantly associated with 30-day poor outcomes. Multivariate analysis showed that the MELD (OR 1.21, 95% CI: 1.12-1.30) and Hb (OR 0.77, 95% CI: 0.61-0.98) were independent predictors of poor outcome. For 30-day mortality, the c-statistics for MELD alone and for combination of MELD and Hb were 0.93 (95% CI: 0.89-0.97) and 0.94 (95% CI: 0.90-0.97), respectively.

CONCLUSION

The outcome of patients with DILI was poor. MELD score and Hb were reliable predictors of short-term outcome in patients with DILI.

Distinct phenotype of hepatotoxicity associated with illicit use of anabolic androgenic steroids

BACKGROUND

We have observed an increase in hepatotoxicity (DILI) reporting related to the use of anabolic androgenic steroids (AAS) for bodybuilding.

AIM

To characterise phenotype presentation, outcome and severity of AAS DILI.

METHODS

Data on 25 cases of AAS DILI reported to the Spanish (20) and Latin-American (5) DILI Registries were collated and compared with previously published cases.

RESULTS

AAS DILI increased from representing less than 1% of the total cases in the Spanish DILI Registry in the period 2001-2009 to 8% in 2010-2013. Young men (mean age 32 years), requiring hospitalisation, hepatocellular injury and jaundice were predominating features among the AAS cases. AAS DILI caused significantly higher bilirubin values independent of type of damage when compared to other drug classes (P = 0.001). Furthermore, the cholestatic AAS cases presented significantly higher mean peak bilirubin (P = 0.029) and serum creatinine values (P = 0.0002), compared to the hepatocellular cases. In a logistic regression model, the interaction between peak bilirubin values and cholestatic damage was associated with the development of AAS-induced acute kidney impairment (AKI) [OR 1.26 (95% CI: 1.035-1.526); P = 0.021], with 21.5 ×ULN being the best bilirubin cut-off point for predicting AKI risk (AUCROC 0.92). No fatalities occurred.

CONCLUSIONS

Illicit recreational AAS use is a growing cause of reported DILI that can lead to severe hepatic and renal injury. AAS DILI is associated with a distinct phenotype, characterised by considerable bilirubin elevations independent of type of damage. Although hepatocellular injury predominates, acute kidney injury develops in cholestatic cases with pronounced jaundice.