Incidence, presentation, and outcomes in patients with drug-induced liver injury in the general population of Iceland

Risk of drug-induced liver injury from tumor necrosis factor antagonists

BACKGROUND & AIMS

Antagonists of tumor necrosis factor (anti-TNF agents) can cause drug-induced liver injury (DILI), yet little is known about the level of risk.

METHODS

We identified cases of DILI caused by anti-TNF agents in Iceland, from 2009 through 2013, at the National University Hospital of Iceland (n = 11). We collected data on the total use of the drugs by patients with DILI, and outcomes, compared with patients who received anti-TNF agents but who did not develop DILI (controls, n = 22).

RESULTS

Of the 11 cases of DILI identified (8 women; mean age, 46 y), 9 cases were caused by infliximab. DILI developed in 1 of 120 patients who received infliximab, 1 in 270 patients who received adalimumab, and 1 in 430 patients who received etanercept. Most patients with infliximab-associated DILI developed this disorder after 4 infusions (n = 6). Four patients had jaundice at diagnosis of DILI, and 8 patients had hepatocellular liver injury. The mean peak level of alanine aminotransferase was 704 U/L, of aspartate aminotransferase was 503 U/L, of alkaline phosphatase was 261 U/L, and of bilirubin was 47 μmol/L. Seven patients with DILI were tested for antinuclear antibodies before therapy with an anti-TNF agent and 3 had positive test results, compared with 5 of the 14 controls tested. At DILI diagnosis, 8 of 11 patients tested positive for antinuclear antibodies. Of liver biopsy specimens collected from 5 patients with DILI, 3 showed signs of severe acute hepatitis. Only 9% of the patients who developed DILI received methotrexate during anti-TNF therapy, compared with 59% of controls (P = .009). DILI was treated with steroids in 5 patients, and in 4 cases steroid therapy was discontinued without relapse. Eight patients with DILI went on to receive treatment with different TNF antagonists without developing DILI.

CONCLUSIONS

Of anti-TNF agents, infliximab is associated most frequently with DILI, developing in 1 of 120 patients who received this drug. Fifty percent of patients with anti-TNF-associated DILI required steroid therapy, but most did not need long-term treatment. The addition of methotrexate to anti-TNF therapy might reduce the risk of DILI.

No contribution of the ABCB11 p.444A polymorphism in Japanese patients with drug-induced cholestasis

European studies have revealed that the ABCB11 c.1331T>C (V444A) polymorphism (rs2287622) C-allele frequency is higher among patients with drug-induced cholestasis. Given the low incidence of this disease, however, this association has not been sufficiently elucidated. We aimed to investigate the significance of this polymorphism in Japanese patients. We determined ABCB11 V444A polymorphism frequencies and HLA genotypes in two independent drug-induced cholestasis cohorts. Expression and taurocholate transport activity of proteins from 444A variants were analyzed using Madin-Darby canine kidney II cells. In cohort 1 (n = 40), the V444A polymorphism C-allele frequency (66%) was lower than that in controls (n = 190, 78%), but this difference was not significant (P = 0.09). In cohort 2 (n = 119), comprising patients with cholestatic (n = 19), hepatocellular (n = 74), and mixed (n = 26) liver injuries, the C-allele frequency was lower among patients with cholestatic liver injury (68%) than among those with hepatocellular (75%) or mixed liver injury (83%), although this difference was not significant. In cohort 1, HLA-A*0201 was observed more frequently in patients (22%) than in controls [11%; P = 0.003; odds ratio, 2.4 (95% confidence interval, 1.4-4.0)]. Taurocholate transport activity of 444A-encoded protein was significantly lower than that of 444V-encoded protein (81% of 444V, P < 0.05) because of the reduced protein stability. In conclusion, ABCB11 444A had slightly reduced transport activity, but it did not contribute to the occurrence of drug-induced cholestasis in Japanese patients. Therefore, genetic susceptibility to acquired cholestasis may differ considerably by ethnicity.

3D Cultivation Techniques for Primary Human Hepatocytes

One of the main challenges in drug development is the prediction of in vivo toxicity based on in vitro data. The standard cultivation system for primary human hepatocytes is based on monolayer cultures, even if it is known that these conditions result in a loss of hepatocyte morphology and of liver-specific functions, such as drug-metabolizing enzymes and transporters. As it has been demonstrated that hepatocytes embedded between two sheets of collagen maintain their function, various hydrogels and scaffolds for the 3D cultivation of hepatocytes have been developed. To further improve or maintain hepatic functions, 3D cultivation has been combined with perfusion. In this manuscript, we discuss the benefits and drawbacks of different 3D microfluidic devices. For most systems that are currently available, the main issues are the requirement of large cell numbers, the low throughput, and expensive equipment, which render these devices unattractive for research and the drug-developing industry. A higher acceptance of these devices could be achieved by their simplification and their compatibility with high-throughput, as both aspects are of major importance for a user-friendly device.

Drug-induced liver injury: an overview over the most critical compounds

There has been a substantial interest in drug-induced liver injury (DILI) recently. National Institutes of Health has sponsored a multicenter study in the USA for the last 10 years, which has collected valuable information in this context. Idiosyncratic DILI is like other adverse effects of drugs underestimated and underreported in most epidemiological studies. A recent prospective population-based study from Iceland found a crude incidence of approximately 19 cases per 100,000 and year. Antibiotic is the class of drugs most commonly implicated in patients with DILI. Amoxicillin-clavulanate continues to be the most commonly implicated agent occurring in approximately 1 out of 2,300 users. Drugs with the highest risk of DILI in the Icelandic study were azathioprine and infliximab. Although rare, statin-induced hepatotoxicity has been well documented. Liver injury associated with the use of herbal medicines and dietary supplements seems to be increasing. Information on the documented hepatotoxicity of drugs has recently been made easier by a website available in the public domain: LiverTox ( http://livertox.nlm.nih.gov ). Unfortunately, at the current time, pre-therapy risk assessment for DILI in the individual patient is difficult but previous well-documented hepatotoxicity is usually a contraindication for a subsequent treatment with the same drug.

A new animal model for Polygonum multiflorum Thunb-induced liver injury in rats and its potential mechanisms

The model is established successfully with the activation of LPS. Its pathogenesis is associated with the expression of mTLR4 in rats' liver. MicroRNA-122 is certificated to be an ideal potential serum biomarker for this model.

Metabonomics and drug development

Metabolites as an end product of metabolism possess a wealth of information about altered metabolic control and homeostasis that is dependent on numerous variables including age, sex, and environment. Studying significant changes in the metabolite patterns has been recognized as a tool to understand crucial aspects in drug development like drug efficacy and toxicity. The inclusion of metabonomics into the OMICS study platform brings us closer to define the phenotype and allows us to look at alternatives to improve the diagnosis of diseases. Advancements in the analytical strategies and statistical tools used to study metabonomics allow us to prevent drug failures at early stages of drug development and reduce financial losses during expensive phase II and III clinical trials. This chapter introduces metabonomics along with the instruments used in the study; in addition relevant examples of the usage of metabonomics in the drug development process are discussed along with an emphasis on future directions and the challenges it faces.

Human leukocyte antigen genetic risk factors of drug-induced liver toxicology

INTRODUCTION

Drug-induced liver injury (DILI) is a rare adverse drug reaction, which impacts significantly on patients. Human leukocyte antigen (HLA) risk alleles have been found to be associated with DILI supporting an immunological basis to DILI pathogenesis.

AREAS COVERED

HLA alleles associated with risk of liver injury induced by specific therapeutic drugs are described. The evidence for a role of the adaptive immune system in DILI is presented; case-control studies showing an association between DILI and HLA alleles are reviewed. Clinical applications of pharmacogenomics are considered.

EXPERT OPINION

Increasing evidence points to a crucial role for the adaptive immune system in the pathogenesis of DILI. Identification of specific HLA alleles as risk factors through large genome-wide association studies has been instrumental in this and in vitro analyses have facilitated improved understanding of the molecular mechanisms. This provides the basis for developing clinical pharmacogenomic applications. Already, genotyping for hypersensitivity HLA risk alleles has been implemented and opportunities for pre-prescription testing in DILI identified. However, although associations are strong, the rarity of DILI means routine testing has not been formally evaluated. Nevertheless, enhanced understanding of how HLA alleles contribute to injury risk is valuable for drug development. Translation of this research into effective pre-emption and primary prevention remains the goal.

Whole genome transcript profiling of drug induced steatosis in rats reveals a gene signature predictive of outcome

Drug induced steatosis (DIS) is characterised by excess triglyceride accumulation in the form of lipid droplets (LD) in liver cells. To explore mechanisms underlying DIS we interrogated the publically available microarray data from the Japanese Toxicogenomics Project (TGP) to study comprehensively whole genome gene expression changes in the liver of treated rats. For this purpose a total of 17 and 12 drugs which are diverse in molecular structure and mode of action were considered based on their ability to cause either steatosis or phospholipidosis, respectively, while 7 drugs served as negative controls. In our efforts we focused on 200 genes which are considered to be mechanistically relevant in the process of lipid droplet biogenesis in hepatocytes as recently published (Sahini and Borlak, 2014). Based on mechanistic considerations we identified 19 genes which displayed dose dependent responses while 10 genes showed time dependency. Importantly, the present study defined 9 genes (ANGPTL4, FABP7, FADS1, FGF21, GOT1, LDLR, GK, STAT3, and PKLR) as signature genes to predict DIS. Moreover, cross tabulation revealed 9 genes to be regulated ≥10 times amongst the various conditions and included genes linked to glucose metabolism, lipid transport and lipogenesis as well as signalling events. Additionally, a comparison between drugs causing phospholipidosis and/or steatosis revealed 26 genes to be regulated in common including 4 signature genes to predict DIS (PKLR, GK, FABP7 and FADS1). Furthermore, a comparison between in vivo single dose (3, 6, 9 and 24 h) and findings from rat hepatocyte studies (2 h, 8 h, 24 h) identified 10 genes which are regulated in common and contained 2 DIS signature genes (FABP7, FGF21). Altogether, our studies provide comprehensive information on mechanistically linked gene expression changes of a range of drugs causing steatosis and phospholipidosis and encourage the screening of DIS signature genes at the preclinical stage.

Competency of different cell models to predict human hepatotoxic drugs

INTRODUCTION

The liver is the most important target for drug-induced toxicity. This vulnerability results from functional liver features and its role in the metabolic elimination of most drugs. Drug-induced liver injury is a significant leading cause of acute, chronic liver disease and an important safety issue when developing new drugs.

AREAS COVERED

This review describes the advantages and limitations of hepatic cell-based models for early safety risk assessment during drug development. These models include hepatocytes cultured as monolayer, collagen-sandwich; emerging complex 3D configuration; liver-derived cell lines; stem cell-derived hepatocytes.

EXPERT OPINION

In vitro toxicity assays performed in hepatocytes or hepatoma cell lines can potentially provide rapid and cost-effective early feedback to identify toxic candidates for compound prioritization. However, their capacity to predict hepatotoxicity depends critically on cells' functional performance. In an attempt to improve and prolong functional properties of cultured cells, different strategies to recreate the in vivo hepatocyte environment have been explored. 3D cultures, co-cultures of hepatocytes with other cell types and microfluidic devices seem highly promising for toxicological studies. Moreover, hepatocytes derived from human pluripotent stem cells are emerging cell-based systems that may provide a stable source of hepatocytes to reliably screen metabolism and toxicity of candidate compounds.

Liver injury from herbals and dietary supplements in the U.S. Drug-Induced Liver Injury Network

The Drug-Induced Liver Injury Network (DILIN) studies hepatotoxicity caused by conventional medications as well as herbals and dietary supplements (HDS). To characterize hepatotoxicity and its outcomes from HDS versus medications, patients with hepatotoxicity attributed to medications or HDS were enrolled prospectively between 2004 and 2013. The study took place among eight U.S. referral centers that are part of the DILIN. Consecutive patients with liver injury referred to a DILIN center were eligible. The final sample comprised 130 (15.5%) of all subjects enrolled (839) who were judged to have experienced liver injury caused by HDS. Hepatotoxicity caused by HDS was evaluated by expert opinion. Demographic and clinical characteristics and outcome assessments, including death and liver transplantation (LT), were ascertained. Cases were stratified and compared according to the type of agent implicated in liver injury; 45 had injury caused by bodybuilding HDS, 85 by nonbodybuilding HDS, and 709 by medications. Liver injury caused by HDS increased from 7% to 20% (P < 0.001) during the study period. Bodybuilding HDS caused prolonged jaundice (median, 91 days) in young men, but did not result in any fatalities or LT. The remaining HDS cases presented as hepatocellular injury, predominantly in middle-aged women, and, more frequently, led to death or transplantation, compared to injury from medications (13% vs. 3%; P < 0.05).

CONCLUSIONS

The proportion of liver injury cases attributed to HDS in DILIN has increased significantly. Liver injury from nonbodybuilding HDS is more severe than from bodybuilding HDS or medications, as evidenced by differences in unfavorable outcomes (death and transplantation). (Hepatology 2014;60:1399-1408).

Liver injury associated with ketoconazole: review of the published evidence

The azole antifungal agent ketoconazole has been available since 1981 for the treatment of fungal infections. In 2013, the American Food and Drug Administration and the European Medicines Agency issued warnings or prohibitions against the clinical use of oral ketoconazole due to the risk of liver injury which may lead to liver transplantation or death. From the available published evidence it is difficult to determine the actual incidence or prevalence of liver injury during clinical use of ketoconazole as an antifungal. Hepatic injury, when it occurs, is generally evident as asymptomatic and reversible abnormalities of liver function tests. However, serious liver injury has been reported. Alternatives to ketoconazole (such as itraconazole, fluconazole, voriconazole, and terbinafine) are available, but improved safety with respect to liver injury risk is not clearly established. We are not aware of published reports of significant ketoconazole-associated liver injury in volunteer study participants when ketoconazole has been used as a CYP3A inhibitor in the context of clinical research on drug metabolism. Possible alternatives to ketoconazole as prototype CYP3A inhibitors include ritonavir and potentially itraconazole, but not clarithromycin.

Miscellaneous adverse events with biologic agents (excludes infection and malignancy)

Anti-tumor necrosis factor-α (anti-TNF) agents are frequently used in the treatment of inflammatory bowel disease (IBD). Currently, there are 4 anti-TNF therapies that are Food and Drug Administration-approved for moderate to severe IBD: infliximab, adalimumab, golimumab, and certolizumab pegol. For most noninfectious, nonmalignant adverse events, cessation of anti-TNF therapy typically leads to improvement or resolution of drug-induced complications. In this article, the current knowledge regarding the noninfectious and nonmalignant toxicities associated with anti-TNF agents is summarized.

Stem Cell Strategies to Evaluate Idiosyncratic Drug-induced Liver Injury

The host-dependent nature of idiosyncratic drug-induced liver injury (iDILI) suggests that rare genetic polymorphisms may contribute to the disease. Indeed, a few mutations in key genes have already been identified using conventional human genetics approaches. Over 50 commonly used drugs can precipitate iDILI, making this a substantial medical problem. Only recently have human induced pluripotent stem cells been used as a research tool to discover novel iDILI genes and to study the mechanisms of iDILI in vitro. Here we review the current state of stem cell use in the investigation of iDILI, with a special focus on genetics. In addition, the concerns and difficulties associated with genetics and animal model research are discussed. We then present the features of patient-specific pluripotent stem cells (which may be derived from iDILI patients themselves), and explain why these cells may be of great utility. A variety of recent approaches to produce hepatocyte-like cells from pluripotent cells and the associated advantages and limitations of such cells are discussed. Future directions for the use of stem cell science to investigate iDILI include novel ways to identify new iDILI genes, a consideration of epigenetic impacts on iDILI, and the development of new and improved strategies for the production of hepatocytes from human pluripotent cells.

Predicting idiosyncratic drug-induced liver injury: some recent advances

Drug-induced liver injury (DILI) is a major challenge for the pharmaceutical industry, regulatory authorities, and clinicians. It is usually categorized into 'intrinsic' and 'idiosyncratic', but DILI caused by most drugs is of an idiosyncratic nature and usually cannot be predicted from the regulatory required animal toxicity studies. Unfortunately, some individuals exposed to therapeutic dose will develop idiosyncratic DILI that might involve severe clinical outcome, and no biomarker is available to identify the susceptible patients prior to drug treatment. In this editorial, we summarized the recent advances in predicting idiosyncratic DILI and provided the perspectives to improve the prediction.

Risk of hepatobiliary cancer after solid organ transplant in the United States

BACKGROUND & AIMS

Studies of liver cancer risk in recipients of solid organ transplants generally have been small, yielding mixed results, and little is known about biliary tract cancers among transplant recipients.

METHODS

We identified incident hepatobiliary cancers among 201,549 US recipients of solid organs, from 1987 through 2008, by linking data from the US transplant registry with 15 cancer registries. We calculated standardized incidence ratios (SIRs), comparing risk relative to the general population. We also calculated incidence rate ratios (RRs), comparing risk for hepatocellular carcinoma (HCC) and total (intrahepatic and extrahepatic) cholangiocarcinoma among subgroups of recipients.

RESULTS

Of transplant recipients, 165 developed hepatobiliary cancers (SIR, 1.2; 95% confidence interval [CI], 1.0-1.4). HCC risk was increased among liver recipients (SIR, 1.5; 95% CI, 1.0-2.2), especially 5 or more years after transplant (SIR, 1.8; 95% CI, 1.0-3.0). Cholangiocarcinoma was increased among liver (SIR, 2.9; 95% CI, 1.6-4.8) and kidney recipients (SIR, 2.1; 95% CI, 1.3-3.1). HCC was associated with hepatitis B virus (RR, 3.2; 95% CI, 1.3-6.9), hepatitis C virus (RR, 10; 95% CI, 5.9-16.9), and non-insulin-dependent diabetes (RR, 2.5; 95% CI, 1.2-4.8). Cholangiocarcinoma was associated with azathioprine maintenance therapy (RR, 2.0; 95% CI, 1.1-3.7). Among liver recipients, primary sclerosing cholangitis was associated with an increased risk of cholangiocarcinoma, compared with the general population (SIR, 21; 95% CI, 8.2-42) and compared with liver recipients without primary sclerosing cholangitis (RR, 12.3; 95% CI, 4.1-36.4).

CONCLUSIONS

Risks for liver and biliary tract cancer are increased among organ transplant recipients. Risk factors for these cancers include medical conditions and potentially medications taken by recipients.

Cephalexin induced cholestatic jaundice

Cephalexin is a very commonly prescribed orally administered antibiotic which has many potential side effects. Amongst these cholestatic jaundice has been infrequently reported as an adverse reaction. We present a case of a 57-year-old male who exhibited features of cholestatic jaundice including elevated liver function tests (LFTs) after taking cephalexin and showed improvement on removal of the offending agent. During this time he was symptomatically treated with cholestyramine. Complete resolution of LFTs was seen in four weeks. Cephalexin induced cholestasis is rare and hence requires a high degree of clinical suspicion for prompt diagnosis and treatment.

Spectrum of statin hepatotoxicity: experience of the drug-induced liver injury network

The HMG-CoA reductase inhibitors (statins) are widely prescribed for patients with hyperlipidemia and are generally well tolerated. Mild elevations in serum aminotransferases arise in up to 3% of treated patients, but clinically apparent drug-induced liver injury is rare. The aim of this study is to report the presenting features and outcomes of 22 patients with clinically apparent liver injury due to statins. Among 1,188 cases of drug-induced liver injury enrolled between 2004 and 2012 in a prospective registry by the U.S. Drug Induced Liver Injury Network, 22 were attributed to a statin. All patients were evaluated in a standard fashion and followed for at least 6 months after onset. The median age was 60 years (range 41-80), and 15 (68%) were female. The latency to onset of liver injury ranged from 34 days to 10 years (median = 155 days). Median peak levels were alanine aminotransferase 892 U/L, alkaline phosphatase 358 U/L, and total bilirubin 6.1 mg/dL. Nine patients presented with cholestatic hepatitis and 12 patients presented with hepatocellular injury, of which six had an autoimmune phenotype. Nine patients were hospitalized, four developed evidence of hepatic failure, and one died. All commonly used statins were implicated. Four patients developed chronic liver injury, of which three had an autoimmune phenotype of liver injury.

CONCLUSION

Drug-induced liver injury from statins is rare and characterized by variable patterns of injury, a range of latencies to onset, autoimmune features in some cases, and persistent or chronic injury in 18% of patients, most of whom have an autoimmune phenotype.

Ascertainment of acute liver injury in two European primary care databases

PURPOSE

The purpose of this study was to ascertain acute liver injury (ALI) in primary care databases using different computer algorithms. The aim of this investigation was to study and compare the incidence of ALI in different primary care databases and using different definitions of ALI.

METHODS

The Clinical Practice Research Datalink (CPRD) in UK and the Spanish "Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria" (BIFAP) were used. Both are primary care databases from which we selected individuals of all ages registered between January 2004 and December 2009. We developed two case definitions of idiopathic ALI using computer algorithms: (i) restrictive definition (definite cases) and (ii) broad definition (definite and probable cases). Patients presenting prior liver conditions were excluded. Manual review of potential cases was performed to confirm diagnosis, in a sample in CPRD (21%) and all potential cases in BIFAP. Incidence rates of ALI by age, sex and calendar year were calculated.

RESULTS

In BIFAP, all cases considered definite after manual review had been detected with the computer algorithm as potential cases, and none came from the non-cases group. The restrictive definition of ALI had a low sensitivity but a very high specificity (95% in BIFAP) and showed higher rates of agreement between computer search and manual review compared to the broad definition. Higher incidence rates of definite ALI in 2008 were observed in BIFAP (3.01 (95% confidence interval (CI) 2.13-4.25) per 100,000 person-years than CPRD (1.35 (95% CI 1.03-1.78)).

CONCLUSIONS

This study shows that it is feasible to identify ALI cases if restrictive selection criteria are used and the possibility to review additional information to rule out differential diagnoses. Our results confirm that idiopathic ALI is a very rare disease in the general population. Finally, the construction of a standard definition with predefined criteria facilitates the timely comparison across databases.

Atypical causes of cholestasis

Cholestatic liver disease consists of a variety of disorders. Primary sclerosing cholangitis and primary biliary cirrhosis are the most commonly recognized cholestatic liver disease in the adult population, while biliary atresia and Alagille syndrome are commonly recognized in the pediatric population. In infants, the causes are usually congenital or inherited. Even though jaundice is a hallmark of cholestasis, it is not always seen in adult patients with chronic liver disease. Patients can have “silent” progressive cholestatic liver disease for years prior to development of symptoms such as jaundice and pruritus. In this review, we will discuss some of the atypical causes of cholestatic liver disease such as benign recurrent intrahepatic cholestasis, progressive familial intrahepatic cholestasis, Alagille Syndrome, biliary atresia, total parenteral nutrition induced cholestasis and cholestasis secondary to drug induced liver injury.

Estimating heritability of drug-induced liver injury from common variants and implications for future study designs

Recent genome-wide association studies identified certain human leukocyote antigen (HLA) alleles as the major risk factors of drug-induced liver injuries (DILI). While these alleles often cause large relative risk, their predictive values are quite low due to low prevalence of idiosyncratic DILI. Finding additional risk factors is important for precision medicine. However, optimal design of further genetic studies is hindered by uncertain overall heritability of DILI. This is a common problem for low-prevalence pharmacological traits, since it is difficult to obtain clinical outcome data in families. Here we estimated the heritability (h²) of DILI from case-control genome-wide single nucleotide polymorphism data using a method based on random effect models. We estimated the proportion of h² captured by common SNPs for DILI to be between 0.3 and 0.5. For co-amoxiclav induced DILI, chromosome 6 explained part of the heritability, indicating additional contributions from common variants yet to be found. We performed simulations to assess the robustness of the h² estimate with limited sample size under low prevelance, a condition typical to studies on idiosyncratic pharmacological traits. Our findings suggest that common variants outside of HLA contribute to DILI susceptability; therefore, it is valuable to conduct further GWAS with expanded case collection.

Review article: Herbal hepatotoxicity--an update on traditional Chinese medicine preparations

BACKGROUND

Although evidence for their therapeutic efficacy is limited, herbal traditional Chinese medicine (TCM) preparations increasingly gain popularity. In contrast to other herbal products, adverse effects by herbal TCM including liver toxicity were rarely reported. In recent years, more cases were published, providing new clinical challenges.

AIM

To summarise comprehensively the literature on herbal TCM hepatotoxicity since 2011.

METHODS

PubMed was searched using key words related to TCM, the results were restricted to full English-language publications and abstracts published since 2011. In addition, the database of the National Institutes of Health (NIH) and LiverTox was accessed under the topic 'Drug record: Chinese and other Asian herbal medicines'.

RESULTS

Since 2011, new case reports and case series provided evidence for herbal hepatotoxicity by TCM, focusing on nine TCM herbal mixtures and four individual TCM herbs with potential health hazards. These were the TCM products Ban Tu Wan, Chai Hu, Du Huo, Huang Qin, Jia Wei Xia Yao San, Jiguja, Kamishoyosan, Long Dan Xie Gan Tang, Lu Cha, Polygonum multiflorum products, Shan Chi, 'White flood' containing the herbal TCM Wu Zhu Yu and Qian Ceng Ta, and Xiao Chai Hu Tang. Other developments include the establishment of a new and early diagnostic serum marker for hepatotoxicity caused by pyrrolizidine alkaloids, assessed using ultra performance liquid chromatography-mass spectrometry analysis, and new regulatory details to improve herbal TCM product quality and safety.

CONCLUSION

Stringent evaluation of the risk/benefit ratio is essential to protect traditional Chinese medicines users from health hazards including liver injury.

ACG Clinical Guideline: the diagnosis and management of idiosyncratic drug-induced liver injury

Idiosyncratic drug-induced liver injury (DILI) is a rare adverse drug reaction and it can lead to jaundice, liver failure, or even death. Antimicrobials and herbal and dietary supplements are among the most common therapeutic classes to cause DILI in the Western world. DILI is a diagnosis of exclusion and thus careful history taking and thorough work-up for competing etiologies are essential for its timely diagnosis. In this ACG Clinical Guideline, the authors present an evidence-based approach to diagnosis and management of DILI with special emphasis on DILI due to herbal and dietary supplements and DILI occurring in individuals with underlying liver disease.

[Liver diseases in the elderly]

Liver diseases in the elderly have aroused less interest than diseases of other organs, since the liver plays a limited role in aging. There are no specific liver diseases of old age, but age-related anatomical and functional modifications of the liver cause changes in the frequency and clinical behavior of some liver diseases compared with those in younger patients. This review discusses the most important features of liver function in the healthy elderly population, as well as the features of the most prevalent liver diseases in this age group, especially the diagnostic approach to the most common liver problems in the elderly: asymptomatic elevation of serum transaminases and jaundice.

Traditional Chinese Medicine Induced Liver Injury

Traditional Chinese Medicine (TCM) is popular around the world and encompasses many different practices with particular emphasis on herbal TCM. Using the PubMed database, a literature search was undertaken to assess the extent herbal TCM products exert rare hepatotoxicity. Analysis of reported cases revealed numerous specified herbal TCM products with potential hepatotoxicity. Among these were An Shu Ling, Bai Fang, Bai Xian Pi, Ban Tu Wan, Bo He, Bo Ye Qing Niu Dan, Bofu Tsu Sho San, Boh Gol Zhee, Cang Er Zi, Chai Hu, Chaso, Chi R Yun, Chuan Lian Zi, Ci Wu Jia, Da Chai Hu Tang, Da Huang, Du Huo, Gan Cao, Ge Gen, Ho Shou Wu, Hu Bohe You, Hu Zhang, Huang Qin, Huang Yao Zi, Hwang Geun Cho, Ji Gu Cao, Ji Ji, Ji Xue Cao, Jiguja, Jin Bu Huan, Jue Ming Zi, Kamishoyosan, Kudzu, Lei Gong Teng, Long Dan Xie Gan Tang, Lu Cha, Ma Huang, Mao Guo Tian Jie Cai, Onshido, Polygonum multiflorum, Qian Li Guang, Ren Shen, Sairei To, Shan Chi, Shen Min, Shi Can, Shi Liu Pi, Shou Wu Pian, Tian Hua Fen, White flood, Wu Bei Zi, Xi Shu, Xiao Chai Hu Tang, Yin Chen Hao, Zexie, Zhen Chu Cao, and various unclassified Chinese herbal mixtures. Causality was firmly established for a number of herbal TCM products by a positive reexposure test result, the liver specific scale of CIOMS (Council for International Organizations of Medical Sciences), or both. Otherwise, the quality of case data was mixed, especially regarding analysis of the herb ingredients because of adulteration with synthetic drugs, contamination with heavy metals, and misidentification. In addition, non-herbal TCM elements derived from Agaricus blazei, Agkistrodon, Antelope, Bombyx, Carp, Fish gallbladder, Phellinus, Scolopendra, Scorpio, and Zaocys are also known or potential hepatotoxins. For some patients, the clinical course was severe, with risks for acute liver failure, liver transplantation requirement, and lethality. In conclusion, the use of few herbal TCM products may rarely be associated with hepatotoxicity in some susceptible individuals, necessitating a stringent pretreatment evaluation of the risk/benefit ratio, based on results of multicenter, randomized, double-blind, placebo-controlled clinical trials.

An Update on Treatment of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) has been linked to more than 1,000 medications and remains the most common cause of acute liver failure in the United States. Here, we review the most current literature regarding treatment and make recommendations for the management of this relatively common disease. Since treatment of DILI remains largely elusive, recent studies have attempted to define new management strategies for these difficult patients. Early diagnosis and withdrawal of the suspected medication is the mainstay of treatment of DILI. For acetaminophen and Amanita mushroom poisoning, there are specific therapies in use. Finally, there are other possible management modalities for DILI, including corticosteroids and ursodeoxycholic acid.

Review article: permanent drug withdrawal is desirable and achievable for autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis can be rendered treatment-free, but the difficulty, frequency and risks associated with the pursuit of this outcome are unclear.

AIM

To describe the frequency that autoimmune hepatitis can be rendered treatment-free, identify the features that characterise these patients, examine the pathogenic pathways that may sustain or terminate the disease and indicate management protocols that can obtain this result.

METHODS

Studies cited in Pub Med from 1972-2014 for autoimmune hepatitis, treatment, relapse, remission and outcome were selected.

RESULTS

The frequency of a treatment-free state varies from 19% to 40% in patients observed for ≥3 years after drug withdrawal. Complete laboratory resolution and reversion to normal liver tissue prior to drug withdrawal favours this response. The development of cirrhosis during therapy may increase treatment-dependence. Persistent liver damage and the generation of neo-antigens during the apoptosis of hepatocytes may perpetuate the disease. Genetic and age-related effects on the vigour of the immune response may also contribute. Reversion to normal liver tissue is achieved in only 22% of patients during conventional corticosteroid therapy, and the emerging pharmacological and biological interventions may improve this frequency. A management strategy designed to achieve a treatment-free state accommodates all candidates for this outcome, and it can be modified to a long-term maintenance strategy as warranted by the clinical response.

CONCLUSIONS

Permanent drug withdrawal is a treatment outcome that is desirable and achievable in patients with autoimmune hepatitis. Normalisation of liver tests and liver tissue during treatment enhances this occurrence.

Drug-induced liver injury: what was new in 2013?

INTRODUCTION

The year 2013 continued to highlight numerous aspects of drug-induced liver injury (DILI), with new information communicated via > 1500 publications. New reports of DILI were described and FDA warnings and alerts were issued for a number of products, emphasizing the risks related to hepatotoxicity.

AREAS COVERED

We provide a summary of the year's published reports of new causes of DILI, along with reviews and reports of established hepatotoxins, new and expanded DILI registries and the continuing emphasis placed on genetic and other risk factors. Several new analyses of data generated from the US DILI Network are included.

EXPERT OPINION

The clinical usefulness of pharmacogenetic testing remains to be determined; the number of patients who must be tested is large and the overall risk of DILI is quite small. The role that dose and hepatic metabolism play in causing idiosyncratic DILI was reviewed; daily doses > 50 - 100 mg of medications with high lipophilicity appear to be most predictive of severe DILI, but not in all cases. Restricting access to paracetamol in certain parts of the UK continues to demonstrate a successful reduction in the number of acute liver failure cases and patients listed for liver transplant.

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.

Mechanisms of isoniazid-induced idiosyncratic liver injury: emerging role of mitochondrial stress

Idiosyncratic drug-induced liver injury (DILI) is a significant adverse effect of antitubercular therapy with isoniazid (INH). Although the drug has been used for many decades, the underlying mode of action (both patient-specific and drug-specific mechanisms) leading to DILI are poorly understood. Among the patient-specific determinants of susceptibility to INH-associated DILI, the importance of HLA genetic variants has been increasingly recognized, whereas the role of polymorphisms of drug-metabolizing enzymes (NAT2 and CYP2E1) has become less important and remains controversial. However, these polymorphisms are merely correlative, and other molecular determinants of susceptibility have remained largely unknown. Regarding the drug-specific mechanisms underlying INH-induced liver injury, novel concepts have been emerging. Among these are covalent protein adduct formation via novel reactive intermediates, leading to hapten formation and a potential immune response, and interference with endogenous metabolism. Furthermore, INH and/or INH metabolites (e.g. hydrazine) can cause mitochondrial injury, which can lead to mitochondrial oxidant stress and impairment of energy homeostasis. Recent studies have revealed that underlying impairment of complex I function can trigger massive hepatocellular injury induced by otherwise nontoxic concentrations of INH superimposed on these mitochondrial deficiencies. This review discusses these emerging new paradigms of INH-induced DILI and highlights recent insights into the mechanisms, as well as points to the existing large gaps in our understanding of the pathogenesis.

Pathogenesis of idiosyncratic drug-induced liver injury and clinical perspectives

Idiosyncratic drug-induced liver injury (DILI) is a rare disease that develops independently of drug dose, route, or duration of administration. Furthermore, idiosyncratic DILI is not a single disease entity but rather a spectrum of rare diseases with varying clinical, histological, and laboratory features. The pathogenesis of DILI is not fully understood. Standardization of the DILI nomenclature and methods to assess causality, along with the information provided by the LiverTox Web site, will harmonize and accelerate research on DILI. Studies of new serum biomarkers such as glutamate dehydrogenase, high mobility group box protein 1, and microRNA-122 could provide information for use in diagnosis and prognosis and provide important insights into the mechanisms of the pathogenesis of DILI. Single nucleotide polymorphisms in the HLA region have been associated with idiosyncratic hepatotoxicity attributed to flucloxacillin, ximelagatran, lapatinib, and amoxicillin-clavulanate. However, genome-wide association studies of pooled cases have not associated any genetic factors with idiosyncratic DILI. Whole genome and whole exome sequencing analyses are under way to study cases of DILI attributed to a single medication. Serum proteomic, transcriptome, and metabolome as well as intestinal microbiome analyses will increase our understanding of the mechanisms of this disorder. Further improvements to in vitro and in vivo test systems should advance our understanding of the causes, risk factors, and mechanisms of idiosyncratic DILI.

Herbal hepatotoxicity: analysis of cases with initially reported positive re-exposure tests

BACKGROUND

Positive re-exposure tests are diagnostic hallmarks for hepatotoxicity.

OBJECTIVE

To test validity of positive re-exposures in herb induced liver injury.

METHODS

We searched Medline database for cases of herb induced liver injury with positive re-exposures and analysed 34 cases for positive re-exposure test criteria of baseline alanine aminotransferase< 5N before re-exposure, and re-exposure alanine aminotransferase ≥ 2× baseline alanine aminotransferase. Re-exposure test was negative, if baseline alanine aminotransferase< 5N combined with re-exposure alanine aminotransferase< 2× baseline alanine aminotransferase, or if baseline alanine aminotransferase≥ 5N regardless of the re-exposure alanine aminotransferase including no available re-exposure alanine aminotransferase result.

RESULTS

In 21/34 cases (61.8%), criteria for a positive re-exposure were fulfilled, with negative tests in 6/34 cases (17.6%) or uninterpretable ones in 7/34 cases (20.6%). Confirmed positive re-exposure tests established potential of herb induced liver injury for Aloe, Chaparral, Chinese herbal mixtures, Chinese Jin Bu Huan, Chinese Syo Saiko To, Germander, Greater Celandine, Green tea, Kava, Mistletoe, Polygonum multiflorum, and Senna, with up to 4 case reports per herb.

CONCLUSIONS

Among 34 cases of herb-induced liver injury with initially reported positive re-exposure tests, 61.8% of the cases actually fulfilled established test criteria and provided firm diagnoses of herb induced liver injury by various herbs.

The impact of obesity and metabolic syndrome on chronic hepatitis B and drug-induced liver disease

Steatosis and insulin resistance (IR) are no more frequent in chronic hepatitis B (CHB) than in the general population. Although experimental studies suggest that the HBx protein induces liver fat, human studies have shown that steatosis and IR are related to coexistent metabolic risk factors, thus epidemiologically linked rather than virally induced. Diabetes and obesity are associated with advanced fibrosis and increased risk of hepatocellular carcinoma in CHB. Despite abundant experimental data showing that fatty liver is more susceptible to liver injury, drug-induced liver disease seems no more frequent in NAFLD patients, except, possibly, a higher incidence but not severity of acetaminophen hepatotoxicity.

Molecular mechanisms of hepatic apoptosis

Apoptosis is a prominent feature of liver diseases. Causative factors such as alcohol, viruses, toxic bile acids, fatty acids, drugs, and immune response, can induce apoptotic cell death via membrane receptors and intracellular stress. Apoptotic signaling network, including membrane death receptor-mediated cascade, reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress, lysosomal permeabilization, and mitochondrial dysfunction, is intermixed each other, but one mechanism may dominate at a particular stage. Mechanisms of hepatic apoptosis are complicated by multiple signaling pathways. The progression of liver disease is affected by the balance between apoptotic and antiapoptotic capabilities. Therapeutic options of liver injury are impacted by the clear understanding toward mechanisms of hepatic apoptosis.

Molecular mechanisms of hepatic apoptosis

Apoptosis is a prominent feature of liver diseases. Causative factors such as alcohol, viruses, toxic bile acids, fatty acids, drugs, and immune response, can induce apoptotic cell death via membrane receptors and intracellular stress. Apoptotic signaling network, including membrane death receptor-mediated cascade, reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress, lysosomal permeabilization, and mitochondrial dysfunction, is intermixed each other, but one mechanism may dominate at a particular stage. Mechanisms of hepatic apoptosis are complicated by multiple signaling pathways. The progression of liver disease is affected by the balance between apoptotic and antiapoptotic capabilities. Therapeutic options of liver injury are impacted by the clear understanding toward mechanisms of hepatic apoptosis.

Drug-induced liver injury

Drug hepatoxicity can be nonidiosyncratic (predictable), as in the case of acetaminophen, or idiosyncratic (unpredictable). This review article focuses primarily on idiosyncratic drug-induced liver injury (DILI). New epidemiologic data suggest that approximately 20 new cases of DILI per 100,000 persons occur each year. Idiosyncratic DILI accounts for 11% of the cases of acute liver failure in the United States. Risk factors for DILI include medication dose, drug lipophilicity, and extent of hepatic metabolism. There is mixed evidence to support the role of host factors such as age, sex, and chronic liver disease in the development of DILI. For specific drugs, a genetic predisposition appears to be a risk factor for DILI. Suspected cases of idiosyncratic DILI should be categorized as hepatitic, cholestatic, or mixed on the basis of the degree/ratio of abnormalities in the alanine aminotransferase and alkaline phosphatase. A careful evaluation for other causes of liver disease should be performed, though a liver biopsy is rarely needed. There is evidence that some patients with DILI may actually have hepatitis E and this diagnosis should be considered. Amoxicillin/clavulanate isoniazid, and nonsteroidal anti-inflammatory drugs are among the most common causes of DILI. Drug discontinuation or dechallenge should lead to an improvement in liver biochemistries in most patients, though a bilirubin value of more than 3 g/dL is associated with mortality of at least 10%. New biomarkers for DILI using proteomics and micro RNA appear promising but require further study. New studies on drugs with potential for causing DILI are reviewed herein, including tumor necrosis factor-alpha antagonists, fluoroquinolones, tyrosine kinase inhibitors, statins, and supplements. PubMed was used with search terms of drug induced liver injury OR DILI with filter settings of "English language" and "humans" and custom date range of "January 1, 2000." The authors also manually searched bibliographies from key references and included seminal references before the year 2000.

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.

Liver complications in inflammatory bowel diseases

Diseases of the liver and the biliary tract are commonly observed in patients with inflammatory bowel diseases (IBD). Besides primary sclerosing cholangitis (PSC), drug-induced hepatotoxicity and non-alcoholic fatty liver disease (NAFLD) are the most frequent liver complications in IBD. PSC is a chronic inflammatory and commonly progressive disorder of unknown etiology associated with fibrosis and stricture development in the intrahepatic and extrahepatic biliary tree. Interestingly, this form of liver disease is mainly associated with ulcerative colitis. Development of PSC is highly relevant for IBD patients as cholestasis-associated problems increase over time resulting in biliary strictures, cholangitis, cholangiocarcinoma and importantly these patients also have a higher risk to develop colon cancer. Another major aspect regarding IBD and liver disease refers to drug-induced hepatotoxicity. Clinically, most relevant is liver toxicity caused by immunosuppressants such as azathioprine. Azathioprine and its derivate 6-mercaptopurine can cause a spectrum of liver injuries ranging from asymptomatic elevated liver enzymes to cholestasis and nodular regenerative hyperplasia. The third common IBD-associated liver disease is NAFLD, and first studies suggest that NAFLD might appear in IBD patients independent of classical risk factors such as obesity or insulin resistance. Overall, liver complications are observed in 10-20% of IBD patients, and therefore physicians have to be familiar with these complications to improve and to optimize patient care.