Identification of Reduced ERAP2 Expression and a Novel HLA Allele as Components of a Risk Score for Susceptibility to Liver Injury Due to Amoxicillin-Clavulanate.

BACKGROUND & AIMS: Drug-induced liver injury (DILI) due to amoxicillin-clavulanate (AC) has been associated with HLA-A∗02:01, HLA-DRB1∗15:01, and rs2476601, a missense variant in PTPN22. The aim of this study was to identify novel risk factors for AC-DILI and to construct a genetic risk score (GRS). METHODS: Transcriptome-wide association study and genome-wide association study analyses were performed on 444 AC-DILI cases and 10,397 population-based controls of European descent. Associations were confirmed in a validation cohort (n = 133 cases and 17,836 population-based controls). Discovery and validation AC-DILI cases were also compared with 1358 and 403 non-AC-DILI cases. RESULTS: Transcriptome-wide association study revealed a significant association of AC-DILI risk with reduced liver expression of ERAP2 (P = 3.7 × 10-7), coding for an aminopeptidase involved in antigen presentation. The lead eQTL single nucleotide polymorphism, rs1363907 (G), was associated with AC-DILI risk in the discovery (odds ratio [OR], 1.68; 95% CI, 1.23-1.66; P = 1.7 × 10-7) and validation cohorts (OR, 1.2; 95% CI, 1.04-2.05; P = .03), following a recessive model. We also identified HLA-B∗15:18 as a novel AC-DILI risk factor in both discovery (OR, 4.19; 95% CI, 2.09-8.36; P = 4.9 × 10-5) and validation (OR, 7.78; 95% CI, 2.75-21.99; P = .0001) cohorts. GRS, incorporating rs1363907, rs2476601, HLA-B∗15:18, HLA-A∗02:01, and HLA-DRB1∗15:01, was highly predictive of AC-DILI risk when cases were analyzed against both general population and non-AC-DILI control cohorts. GRS was the most significant predictor in a regression model containing known AC-DILI clinical risk characteristics and significantly improved the predictive model. CONCLUSIONS: We identified novel associations of AC-DILI risk with ERAP2 low expression and with HLA-B∗15:18. GRS based on the 5 risk variants may assist AC-DILI causality assessment and risk management.

ERAP-1 and ERAP-2 Variants in Liver Injury After COVID-19 mRNA Vaccination: A US Multicenter Study.

INTRODUCTION: The aim of this study is to describe the presenting features, genetic factors, and outcomes of 23 adults who developed liver injury after coronavirus disease 2019 (COVID-19) mRNA vaccination. METHODS: Patients with suspected COVID-19 vaccine hepatitis were enrolled into the Drug-Induced Liver Injury Network. Causality was assessed using the Drug-Induced Liver Injury Network expert opinion score. High-resolution HLA sequencing was undertaken using Illumina platform. RESULTS: Amongst the 16 high causality cases, median time to onset was 16 days, median age was 63 years, and 75% were female. The injury was hepatocellular in 75% with a median alanine aminotransferase of 497 U/L, and 37% had jaundice. An antinuclear antibody and smooth muscle antibody were detectable in 27% and 36%, but only 12% had an elevated immunoglobulin G level. During follow-up, 37% received a short course of corticosteroids, and 88% fully recovered by 6 months with no deaths observed. HLA alleles associated with autoimmune hepatitis were not overrepresented compared with controls, but an ERAP-2 variant (rs1263907) and the ERAP-1 Hap6 haplotype were significantly overrepresented in the high causality cases vs controls ( P = 0.026 and 5 × 10 -5 , respectively). DISCUSSION: Acute liver injury may arise within 8 weeks of COVID-19 mRNA vaccination that is generally mild and self-limited in most patients. The absence of an association with the AIH HLA alleles combined with the significant ERAP-2 and ERAP-1 Hap6 haplotype associations implicates a unique but very rare host immune response to vaccine-derived antigens in the pathogenesis of COVID-19 vaccine hepatotoxicity.

Human Leukocyte Antigen B*14:01 and B*35:01 Are Associated With Trimethoprim-Sulfamethoxazole Induced Liver Injury.

BACKGROUND AND AIMS: Trimethoprim (TMP)-sulfamethoxazole (SMX) is an important cause of idiosyncratic drug-induced liver injury (DILI), but its genetic risk factors are not well understood. This study investigated the relationship between variants in the human leukocyte antigen (HLA) class 1 and 2 genes and well-characterized cases of TMP-SMX DILI. APPROACH AND RESULTS: European American and African American persons with TMP-SMX DILI were compared with respective population controls. HLA sequencing was performed by Illumina MiSeq (Illumina, San Diego, CA) for cases. The HLA genotype imputation with attribute bagging program was used to impute HLA alleles for controls. The allele frequency difference between case patients and controls was tested by Fisher's exact tests for each ethnic group. For European Americans, multivariable logistic regression with Firth penalization was used to test the HLA allelic effect after adjusting for age and the top two principal components. Molecular docking was performed to assess HLA binding with TMP and SMX. The European American subset had 51 case patients and 12,156 controls, whereas the African American subset had 10 case patients and 5,439 controls. Four HLA alleles were significantly associated in the European American subset, with HLA-B*14:01 ranking at the top (odds ratio, 9.20; 95% confidence interval, 3.16, 22.35; P = 0.0003) after covariate adjustment. All carriers of HLA-B*14:01 with TMP-SMX DILI possessed HLA-C*08:02, another significant allele (P = 0.0026). This pattern was supported by HLA-B*14:01-HLA-C*08:02 haplotype association (P = 1.33 × 10-5 ). For the African American patients, HLA-B*35:01 had 2.8-fold higher frequency in case patients than in controls, with 5 of 10 patients carrying this allele. Molecular docking showed cysteine at position 67 in HLA-B*14:01 and phenylalanine at position 67 in HLA-B*35:01 to be the predictive binding sites for SMX metabolites. CONCLUSIONS: HLA-B*14:01 is associated with TMP-SMX DILI in European Americans, and HLA-B*35:01 may be a potential genetic risk factor for African Americans.

Incidence and Etiology of Drug-Induced Liver Injury in Mainland China.

BACKGROUND & AIMS: We performed a nationwide, retrospective study to determine the incidence and causes of drug-induced liver injury (DILI) in mainland China. METHODS: We collected data on a total of 25,927 confirmed DILI cases, hospitalized from 2012 through 2014 at 308 medical centers in mainland China. We collected demographic, medical history, treatment, laboratory, disease severity, and mortality data from all patients. Investigators at each site were asked to complete causality assessments for each case whose diagnosis at discharge was DILI (n = 29,478) according to the Roussel Uclaf Causality Assessment Method. RESULTS: Most cases of DILI presented with hepatocellular injury (51.39%; 95% confidence interval [CI] 50.76-52.03), followed by mixed injury (28.30%; 95% CI 27.73-28.87) and cholestatic injury (20.31%; 95% CI 19.80-20.82). The leading single classes of implicated drugs were traditional Chinese medicines or herbal and dietary supplements (26.81%) and antituberculosis medications (21.99%). Chronic DILI occurred in 13.00% of the cases and, although 44.40% of the hepatocellular DILI cases fulfilled Hy's Law criteria, only 280 cases (1.08%) progressed to hepatic failure, 2 cases underwent liver transplantation (0.01%), and 102 patients died (0.39%). Among deaths, DILI was judged to have a primary role in 72 (70.59%), a contributory role in 21 (20.59%), and no role in 9 (8.82%). Assuming the proportion of DILI in the entire hospitalized population of China was represented by that observed in the 66 centers where DILI capture was complete, we estimated the annual incidence in the general population to be 23.80 per 100,000 persons (95% CI 20.86-26.74). Only hospitalized patients were included in this analysis, so the true incidence is likely to be higher. CONCLUSIONS: In a retrospective study to determine the incidence and causes of DILI in mainland China, the annual incidence in the general population was estimated to be 23.80 per 100,000 persons; higher than that reported from Western countries. Traditional Chinese medicines, herbal and dietary supplements, and antituberculosis drugs were the leading causes of DILI in mainland China.

A Missense Variant in PTPN22 is a Risk Factor for Drug-induced Liver Injury.

BACKGROUND & AIMS: We performed genetic analyses of a multiethnic cohort of patients with idiosyncratic drug-induced liver injury (DILI) to identify variants associated with susceptibility. METHODS: We performed a genome-wide association study of 2048 individuals with DILI (cases) and 12,429 individuals without (controls). Our analysis included subjects of European (1806 cases and 10,397 controls), African American (133 cases and 1,314 controls), and Hispanic (109 cases and 718 controls) ancestry. We analyzed DNA from 113 Icelandic cases and 239,304 controls to validate our findings. RESULTS: We associated idiosyncratic DILI with rs2476601, a nonsynonymous polymorphism that encodes a substitution of tryptophan with arginine in the protein tyrosine phosphatase, nonreceptor type 22 gene (PTPN22) (odds ratio [OR] 1.44; 95% confidence interval [CI] 1.28-1.62; P = 1.2 × 10-9 and replicated the finding in the validation set (OR 1.48; 95% CI 1.09-1.99; P = .01). The minor allele frequency showed the same effect size (OR > 1) among ethnic groups. The strongest association was with amoxicillin and clavulanate-associated DILI in persons of European ancestry (OR 1.62; 95% CI 1.32-1.98; P = 4.0 × 10-6; allele frequency = 13.3%), but the polymorphism was associated with DILI of other causes (OR 1.37; 95% CI 1.21-1.56; P = 1.5 × 10-6; allele frequency = 11.5%). Among amoxicillin- and clavulanate-associated cases of European ancestry, rs2476601 doubled the risk for DILI among those with the HLA risk alleles A*02:01 and DRB1*15:01. CONCLUSIONS: In a genome-wide association study, we identified rs2476601 in PTPN22 as a non-HLA variant that associates with risk of liver injury caused by multiple drugs and validated our finding in a separate cohort. This variant has been associated with increased risk of autoimmune diseases, providing support for the concept that alterations in immune regulation contribute to idiosyncratic DILI.

HLA associations with infliximab-induced liver injury.

Biomarkers that are able to identify patients at risk of drug-induced liver injury (DILI) after treatment with infliximab could be important in increasing the safety of infliximab use. We performed a genetic analysis to identify possible human leukocyte antigen (HLA) associations with DILI in European Caucasian users of infliximab in a retrospective study of 16 infliximab-DILI patients and 60 matched controls. In infliximab-associated liver injury, multiple potentially causal individual HLA associations were observed, as well as possible haplotypes. The strongest associated HLA allele was HLA-B*39:01 (P = 0.001; odds ratio [OR] 43.6; 95% confidence interval [CI] 2.8-infinity), which always appeared with another associated allele C*12:03 (P = 0.032; OR 6.1; 95% CI 0.9-47.4). Other associations were observed with HLAs DQB1*02:01 (P = 0.007; OR 5.7; 95% CI 1.4-24.8), DRB1*03:01 (P = 0.012; OR 4.9; 95% CI 1.2-20.5), and B*08:01 (P = 0.048; OR 3.4; 95% CI 0.9-13.2), which also appeared together whenever present in cases. Additional associations were found with HLA-DPB1*10:01 (P = 0.042; OR 20.9; 95% CI 0.7-infinity) and HLA-DRB1*04:04 (P = 0.042; OR 20.9; 95% CI 0.7-infinity). A strong association with HLA-B*39:01 was identified as a potentially causal risk factor for infliximab-induced DILI. Future work should aim to validate this finding and explore possible mechanisms through which the biologic interacts with this particular allele.

Best practices for detection, assessment and management of suspected immune-mediated liver injury caused by immune checkpoint inhibitors during drug development.

Immune checkpoint inhibitors (ICIs) have shown significant efficacy in patients with various malignancies, however, they are associated with a wide range of immune-related toxicities affecting many organs, including the liver. Immune-mediated liver injury caused by checkpoint inhibitors (ILICI) is a distinctive form of drug induced liver injury (DILI), that differs from most DILI types in presumed underlying mechanism, incidence, and response to therapeutic interventions. Despite increased awareness of ILICI and other immune-related adverse effects of ICIs reflected by recent guidelines for their management in post marketing clinical practice, there is lack of uniform best practices to address ILICI risk during drug development. As efforts to develop safer and more effective ICIs for additional indications grow, and as combination therapies including ICIs are increasingly investigated, there is a growing need for consistent practices for ILICI in drug development. This publication summarizes current best practices to optimize the monitoring, diagnosis, assessment, and management of suspected ILICI in clinical trials using ICI as a single agent and in combination with other ICIs or other oncological agents. It is one of several publications developed by the IQ DILI Initiative in collaboration with DILI experts from academia and regulatory agencies. Recommended best practices are outlined pertaining to hepatic inclusion and exclusion criteria, monitoring of liver tests, ILICI detection, approach to a suspected ILICI signal, causality assessment, hepatic discontinuation rules and additional medical treatment.

Candidate biomarkers for the diagnosis and prognosis of drug-induced liver injury: An international collaborative effort.

Current blood biomarkers are suboptimal in detecting drug-induced liver injury (DILI) and predicting its outcome. We sought to characterize the natural variabilty and performance characteristics of 14 promising DILI biomarker candidates. Serum or plasma from multiple cohorts of healthy volunteers (n = 192 and n = 81), subjects who safely took potentially hepatotoxic drugs without adverse effects (n = 55 and n = 92) and DILI patients (n = 98, n = 28, and n = 143) were assayed for microRNA-122 (miR-122), glutamate dehydrogenase (GLDH), total cytokeratin 18 (K18), caspase cleaved K18, glutathione S-transferase α, alpha-fetoprotein, arginase-1, osteopontin (OPN), sorbitol dehydrogenase, fatty acid binding protein, cadherin-5, macrophage colony-stimulating factor receptor (MCSFR), paraoxonase 1 (normalized to prothrombin protein), and leukocyte cell-derived chemotaxin-2. Most candidate biomarkers were significantly altered in DILI cases compared with healthy volunteers. GLDH correlated more closely with gold standard alanine aminotransferase than miR-122, and there was a surprisingly wide inter- and intra-individual variability of miR-122 levels among healthy volunteers. Serum K18, OPN, and MCSFR levels were most strongly associated with liver-related death or transplantation within 6 months of DILI onset. Prediction of prognosis among DILI patients using the Model for End-Stage Liver Disease was improved by incorporation of K18 and MCSFR levels. Conclusion: GLDH appears to be more useful than miR-122 in identifying DILI patients, and K18, OPN, and MCSFR are promising candidates for prediction of prognosis during an acute DILI event. Serial assessment of these biomarkers in large prospective studies will help further delineate their role in DILI diagnosis and management.

Safety and tolerability of ubrogepant following intermittent, high-frequency dosing: Randomized, placebo-controlled trial in healthy adults.

BACKGROUND: Ubrogepant is a novel, oral calcitonin gene-related peptide (CGRP) receptor antagonist in development for the acute treatment of migraine. This trial evaluated the safety and tolerability of ubrogepant, focusing on hepatic safety, when administered intermittently with high-frequency dosing to healthy participants. METHODS: In this phase 1, multicenter, double-blind, parallel-group trial, healthy adults (age 18-50 years) were randomized 1:1 to placebo or ubrogepant. Ubrogepant was dosed at 100 mg (2 × 50 mg tablets) on 2 consecutive days followed by 2 consecutive days of placebo, alternating for 8 weeks. Primary outcome measures were safety and tolerability. RESULTS: Of participants randomized (n = 518), 516 were included in the safety population (n = 260 placebo; n = 256 ubrogepant). Treatment-emergent adverse events were reported in 45% of placebo and 44% of ubrogepant participants. The most common was headache (10% placebo; 11% ubrogepant). Overall, seven cases of alanine aminotransferase and/or aspartate aminotransferase levels ≥ 3 × the upper limit of normal (five placebo, two ubrogepant) were reported and adjudicated by a panel of independent liver experts blinded to treatment. Four cases were judged unlikely related to treatment. Two cases (one placebo, one ubrogepant) were judged possibly related, and one (ubrogepant) probably related. Alanine aminotransferase increases to ≥ 3 × the upper limit of normal in the two ubrogepant cases (possibly or probably related) were transient and resolved with continued dosing; both cases were asymptomatic, with no concurrent bilirubin elevation. CONCLUSION: Ubrogepant was well tolerated following intermittent, high-frequency dosing in healthy participants, with no clinically relevant signal of hepatotoxicity. TRIAL REGISTRATION: NA.

Analyzing the Mechanisms Behind Macrolide Antibiotic-Induced Liver Injury Using Quantitative Systems Toxicology Modeling.

PURPOSE: Macrolide antibiotics are commonly prescribed treatments for drug-resistant bacterial infections; however, many macrolides have been shown to cause liver enzyme elevations and one macrolide, telithromycin, has been pulled from the market by its provider due to liver toxicity. This work seeks to assess the mechanisms responsible for the toxicity of macrolide antibiotics. METHODS: Five macrolides were assessed in in vitro systems designed to test for bile acid transporter inhibition, mitochondrial dysfunction, and oxidative stress. The macrolides were then represented in DILIsym, a quantitative systems pharmacology (QST) model of drug-induced liver injury, placing the in vitro results in context with each compound's predicted liver exposure and known biochemistry. RESULTS: DILIsym results suggest that solithromycin and clarithromycin toxicity is primarily due to inhibition of the mitochondrial electron transport chain (ETC) while erythromycin toxicity is primarily due to bile acid transporter inhibition. Telithromycin and azithromycin toxicity was not predicted by DILIsym and may be caused by mechanisms not currently incorporated into DILIsym or by unknown metabolite effects. CONCLUSIONS: The mechanisms responsible for toxicity can be significantly different within a class of drugs, despite the structural similarity among the drugs. QST modeling can provide valuable insight into the nature of these mechanistic differences.

Determination of fasiglifam-induced liver toxicity: Insights from the data monitoring committee of the fasiglifam clinical trials program.

BACKGROUND: Different approaches to safety event collection influence the determination of liver toxicity within drug development programs. Herein, a description of how fasiglifam-induced liver injury was detected is provided. METHODS: This eight-trial drug development program was intended to evaluate fasiglifam (25 mg, 50 mg) against placebo or active comparators (glimepiride, sitagliptin) in approximately 11,000 suboptimally controlled patients with type 2 diabetes (terminated Dec 2013 due to liver toxicity). Liver safety had been pre-identified as a concern, and within the phase 3 trials, was measured through (1) adverse event reporting, (2) central predefined liver monitoring schedule with various thresholds for potential drug-induced liver injury, and (3) blinded adjudication of serious liver toxicity by a panel of experts in drug-induced liver injury. A single data monitoring committee provided safety oversight across all trials within the program. FINDINGS: Prior to program termination, 7595 of 7602 (99.9%) randomized participants across the eight trials received at least one dose of the study drug (fasiglifam, placebo, or active control). No concerning trends were noted in adverse or serious adverse event frequency, suspected unexpected serious adverse reaction, alanine or aspartate transaminase elevations, or hepatobiliary or gastrointestinal adverse events as reported by local site investigators. However, the predefined central liver safety measurements revealed a greater frequency of possible Hy's Law cases (5 vs 2) and a 3- to 7-fold greater relative risk in alanine or aspartate transaminase elevation (with respect to upper limit of normal) within fasiglifam recipients compared with placebo/active control: alanine or aspartate transaminase > 3×: relative risk 3.34 (95% confidence interval 2.29-4.90), alanine or aspartate transaminase > 5×: relative risk 6.60 (95% confidence interval 3.03-14.38), alanine or aspartate transaminase > 8×: relative risk 6.14 (95% confidence interval 2.18-17.27), and alanine or aspartate transaminase > 10×: relative risk 6.74 (95% confidence interval 2.05, 22.14). All elevations resolved on study drug discontinuation. Drug-induced liver injury was adjudicated as highly likely or probably related in 0.64% of fasiglifam-treated versus 0.06% placebo or active control-treated patients. CONCLUSION: In spite of clear liver toxicity detected with a systematic surveillance program, liver safety signals were not identified from investigator adverse event reporting alone. By integrating key safety monitoring processes within the randomized design of adequately sized clinical trials, the rare but serious liver toxicity signal became clear, leading to timely program termination.

Association of Liver Injury From Specific Drugs, or Groups of Drugs, With Polymorphisms in HLA and Other Genes in a Genome-Wide Association Study.

BACKGROUND & AIMS: We performed a genome-wide association study (GWAS) to identify genetic risk factors for drug-induced liver injury (DILI) from licensed drugs without previously reported genetic risk factors. METHODS: We performed a GWAS of 862 persons with DILI and 10,588 population-matched controls. The first set of cases was recruited before May 2009 in Europe (n = 137) and the United States (n = 274). The second set of cases were identified from May 2009 through May 2013 from international collaborative studies performed in Europe, the United States, and South America. For the GWAS, we included only cases with patients of European ancestry associated with a particular drug (but not flucloxacillin or amoxicillin-clavulanate). We used DNA samples from all subjects to analyze HLA genes and single nucleotide polymorphisms. After the discovery analysis was concluded, we validated our findings using data from 283 European patients with diagnosis of DILI associated with various drugs. RESULTS: We associated DILI with rs114577328 (a proxy for A*33:01 a HLA class I allele; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.9-3.8; P = 2.4 × 10-8) and with rs72631567 on chromosome 2 (OR, 2.0; 95% CI, 1.6-2.5; P = 9.7 × 10-9). The association with A*33:01 was mediated by large effects for terbinafine-, fenofibrate-, and ticlopidine-related DILI. The variant on chromosome 2 was associated with DILI from a variety of drugs. Further phenotypic analysis indicated that the association between DILI and A*33:01 was significant genome wide for cholestatic and mixed DILI, but not for hepatocellular DILI; the polymorphism on chromosome 2 was associated with cholestatic and mixed DILI as well as hepatocellular DILI. We identified an association between rs28521457 (within the lipopolysaccharide-responsive vesicle trafficking, beach and anchor containing gene) and only hepatocellular DILI (OR, 2.1; 95% CI, 1.6-2.7; P = 4.8 × 10-9). We did not associate any specific drug classes with genetic polymorphisms, except for statin-associated DILI, which was associated with rs116561224 on chromosome 18 (OR, 5.4; 95% CI, 3.0-9.5; P = 7.1 × 10-9). We validated the association between A*33:01 terbinafine- and sertraline-induced DILI. We could not validate the association between DILI and rs72631567, rs28521457, or rs116561224. CONCLUSIONS: In a GWAS of persons of European descent with DILI, we associated HLA-A*33:01 with DILI due to terbinafine and possibly fenofibrate and ticlopidine. We identified polymorphisms that appear to be associated with DILI from statins, as well as 2 non-drug-specific risk factors.

The transformation in biomarker detection and management of drug-induced liver injury.

Drug-induced liver injury (DILI) is a major concern for patients, care givers and the pharmaceutical industry. Interpretation of the serum biomarkers routinely used to detect and monitor DILI, which have not changed in almost 50 years, can be improved with recently proposed models employing quantitative systems pharmacology. In addition, several newer serum biomarkers are showing great promise. Studies in rodents indicate that the ratio of the caspase cleaved fragment of cytokeratin 18 to total K18 in serum (termed the "apoptotic index") estimates the relative proportions of apoptosis vs necrosis during drug-induced liver injury. Glutamate dehydrogenase can reliably differentiate liver from muscle injury and, when serum is properly prepared, may also detect mitochondrial toxicity as a mechanism of liver injury. MicroRNA-122 is liver-specific, but recent data suggests it can be actively released from hepatocytes in the absence of overt toxicity limiting enthusiasm for it as a DILI biomarker. Finally, damage associated molecular patterns, particularly high mobility group box 1 and its various modified forms, are promising biomarkers of innate immune activation, which may be useful in distinguishing benign elevations in aminotransferases from those that portend clinically important liver injury. These new biomarkers are already being measured in early clinical trials, but broad acceptance will require widespread archiving of serum from diverse clinical trials and probably pre-competitive analysis efforts. We believe that utilization of a panel of traditional and newer biomarkers in conjunction with quantitative systems pharmacology modelling approaches will transform DILI detection and risk management.

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.

Elevated levels of circulating CDH5 and FABP1 in association with human drug-induced liver injury.

BACKGROUND & AIMS: The occurrence of drug-induced liver injury (DILI) is a major issue in all phases of drug development. To identify novel biomarker candidates associated with DILI, we utilised an affinity proteomics strategy, where antibody suspension bead arrays were applied to profile plasma and serum samples from human DILI cases and controls. METHODS: An initial screening was performed using 4594 randomly selected antibodies, representing 3450 human proteins. Resulting candidate proteins together with proposed DILI biomarker candidates generated a DILI array of 251 proteins for subsequent target analysis and verifications. In total, 1196 samples from 241 individuals across four independent cohorts were profiled: healthy volunteers receiving acetaminophen, patients with human immunodeficiency virus and/or tuberculosis receiving treatment, DILI cases originating from a wide spectrum of drugs, and healthy volunteers receiving heparins. RESULTS: We observed elevated levels of cadherin 5, type 2 (CDH5) and fatty acid-binding protein 1 (FABP1) in DILI cases. In the two longitudinal cohorts, CDH5 was elevated already at baseline. FABP1 was elevated after treatment initiation and seemed to respond more rapidly than alanine aminotransferase (ALT). The elevations were verified in the DILI cases treated with various drugs. In the heparin cohort, CDH5 was stable over time whereas FABP1 was elevated. CONCLUSIONS: These results suggest that CDH5 may have value as a susceptibility marker for DILI. FABP1 was identified as a biomarker candidate with superior characteristics regarding tissue distribution and kinetics compared to ALT but likely with limited predictive value for the development of severe DILI. Further studies are needed to determine the clinical utility of the proposed markers.

Features and Outcomes of 899 Patients With Drug-Induced Liver Injury: The DILIN Prospective Study.

BACKGROUND & AIMS: The Drug-Induced Liver Injury Network is conducting a prospective study of patients with DILI in the United States. We present characteristics and subgroup analyses from the first 1257 patients enrolled in the study. METHODS: In an observational longitudinal study, we began collecting data on eligible individuals with suspected DILI in 2004, following them for 6 months or longer. Subjects were evaluated systematically for other etiologies, causes, and severity of DILI. RESULTS: Among 1257 enrolled subjects with suspected DILI, the causality was assessed in 1091 patients, and 899 were considered to have definite, highly likely, or probable DILI. Ten percent of patients died or underwent liver transplantation, and 17% had chronic liver injury. In the 89 patients (10%) with pre-existing liver disease, DILI appeared to be more severe than in those without (difference not statistically significant; P = .09) and mortality was significantly higher (16% vs 5.2%; P < .001). Azithromycin was the implicated agent in a higher proportion of patients with pre-existing liver disease compared with those without liver disease (6.7% vs 1.5%; P = .006). Forty-one cases with latency ≤7 days were caused predominantly by antimicrobial agents (71%). Two most common causes for 60 DILI cases with latency >365 days were nitrofurantoin (25%) or minocycline (17%). There were no differences in outcomes of patients with short vs long latency of DILI. Compared with individuals younger than 65 years, individuals 65 years or older (n = 149) were more likely to have cholestatic injury, although mortality and rate of liver transplantation did not differ. Nine patients (1%) had concomitant severe skin reactions; implicated agents were lamotrigine, azithromycin, carbamazepine, moxifloxacin, cephalexin, diclofenac, and nitrofurantoin. Four of these patients died. CONCLUSIONS: Mortality from DILI is significantly higher in individuals with pre-existing liver disease or concomitant severe skin reactions compared with patients without. Additional studies are needed to confirm the association between azithromycin and increased DILI in patients with chronic liver disease. Older age and short or long latencies are not associated with DILI mortality.

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

BACKGROUND & AIMS: Little is known about the incidence of drug-induced liver injury (DILI) and risk factors for adverse outcomes. We evaluated short-term outcomes of a large cohort of patients with DILI enrolled in an ongoing multicenter prospective study. METHODS: Data were collected from 660 adults with definite, highly likely, or probable DILI. Regression methods were used to identify risk factors for early liver-related death or liver transplantation and chronic liver injury. RESULTS: Patients' median age was 51.4 years; 59.5% were female and 59.1% required hospitalization. Within 6 months of DILI onset, 30 patients received liver transplants (4.5%; 95% confidence interval [CI], 3.0%-6.1%) and 32 died (5%; 95% CI, 3.2%-6.5%); 53% of the deaths were liver related. Asian race, absence of itching, lung disease, low serum albumin levels, low platelet counts, and high serum levels of alanine aminotransferase and total bilirubin at presentation were independent risk factors for reduced times to liver-related death or liver transplantation (C-statistic = 0.87). At 6 months after DILI onset, 18.9% of the 598 evaluable subjects had persistent liver damage. African-American race, higher serum levels of alkaline phosphatase, and prior heart disease or malignancy requiring treatment were independent risk factors for chronic DILI (C-statistic = 0.71). CONCLUSIONS: Nearly 1 in 10 patients die or undergo liver transplantation within 6 months of DILI onset and nearly 1 in 5 of the remaining patients have evidence of persistent liver injury at 6 months. The profile of liver injury at presentation, initial severity, patient's race, and medical comorbidities are important determinants of the likelihood of death/transplantation or persistent liver injury within 6 months.

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

OBJECTIVES: The long-term outcomes of patients with drug induced liver injury (DILI) are not well described. The aim of this study was to determine the frequency and severity of persistent liver biochemistry abnormalities in DILI patients followed over 2 years. METHODS: Subjects with evidence of liver injury at 6 months after DILI onset were offered a month 12 and 24 study visit. RESULTS: Amongst the 99 patients with definite, probable, or very likely DILI and available laboratory data at 12 months after DILI onset, 74 (75%) had persistent liver injury (persisters) defined as a serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >1.5 × upper limit of normal (ULN) or an alkaline phosphatase >ULN, while 25 (25%) had resolved liver injury (resolvers). On multivariate analysis, month 12 persisters were significantly older (52.6 vs. 43.7 years, P=0.01) and more likely to have a cholestatic lab profile at DILI onset (54 vs. 20%, P<0.01) than resolvers. The month 12 persisters also had significantly poorer SF-36 physical summary scores at DILI onset and throughout follow-up compared with the resolvers (P<0.01). Amongst the 17 subjects with a liver biopsy obtained at a median of 387 days after DILI onset, 9 had chronic cholestasis, 3 had steatohepatitis, and 3 had chronic hepatitis. CONCLUSIONS: In all, 75% of subjects with liver injury at 6 months after DILI onset have laboratory evidence of persistent liver injury during prolonged follow-up. Higher serum alkaline phosphatase levels at presentation and older patient age were independent predictors of persistent liver injury. Subjects with persistent liver injury at 12 months after DILI onset should be carefully monitored and assessed for liver disease progression.