Drug-Induced Liver Injury Network Research Articles

Refinement of Hy's Law using the Drug-Induced Liver Injury Network Database.

Hyman Zimmerman observed that hepatocellular (HC) drug-induced liver injury (DILI) with jaundice had a mortality rate of ≥10% (Hy's Law). Hy's Law does not specify the timing of liver tests nor the definition of HC DILI versus cholestatic or mixed (C/M) DILI. We aimed to assess the validity of Hy's Law in the prospective Drug-Induced Liver Injury Network (DILIN) cohort. Drugs with ≥10 confirmed DILI cases with jaundice were analyzed. Four permutations of Hy's Law were applied: R≥ 5 using initial (1) or peak (2) ALT, AST and Alk P levels, and the FDA associated criteria of ALT or AST ≥ 3x ULN with Alk P ≤ 2x ULN using initial (3) or peak values (4). Mortality was death or liver transplant adjudicated to be due to DILI. Using initial R values, mortality was 11.1% for HC vs 2.0% for C/M (p<0.001); using peak R values, mortality was 10.3% vs 1.6% (p<0.001). Using FDA associated definition, mortality was 7.9% vs 3.9% (p=0.04) using initial values and 7.9% vs 3.0% (p=0.01) using peak values. Using initial R values, drugs that frequently caused HC injury generally had mortality rates ≥ 10%; while drugs that typically caused C/M injury all had rates <10%. Occasional agents that caused HC injury with jaundice were associated with low mortality. Initial R values were the most reliable means of identifying Hy's Law cases. There were some drugs that caused HC injury with jaundice but with mortality rates <10%. Refinement of Hy's Law is warranted.

Investigation of the Role of Chemical Analysis in Causality Assessment of Herbal and Dietary Supplement-Induced Liver Injury.

The attribution of drug-induced liver injury (DILI) to specific herbal and dietary supplements (HDS) is confounded by inaccurate labels and undisclosed ingredients. The US Drug-Induced Liver Injury Network (DILIN) determines the attribution of injury to an agent through its structured expert opinion causality assessment process, but without the use of chemical analysis data of HDS. We aimed to determine the impact of chemical analysis of HDS products on prior causality assessment scores. Obtained samples of HDS consumed by DILIN-enrolled patients were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Chemical analysis data were compared to label accuracy and detect whether the product contained botanical and non-botanical compounds. A comparison of the causality scores reassessed with chemical analysis was compared with the original scores. A total of 54 previously adjudicated cases with chemical analysis available were reassessed for causality with chemical analysis data; reviewers were blinded to original causality scores. Using the chemical analysis data, 37% (n = 20) of the 54 cases were scored with a higher likelihood of DILI compared with the original causality scores; 14 of the 20 (70%) moved from probable to highly likely; 52% had no change in causality score; and 11% of cases were scored as a lower likelihood of DILI. Our study demonstrates that there is value in using HDS chemical analysis data in the causality assessment process for DILI. In more than a third of cases, chemical analysis of products led to an increased confidence in DILI attribution to HDS. These findings suggest that chemical analysis is an important tool in causality assessment for HDS agents, specifically in challenging situations, and further studies are needed to confirm its applicability in clinical practice.

Time to use the right classification to predict the severity of checkpoint inhibitor-induced liver injury, as assessed for causality using the updated RUCAM.

While immune checkpoint inhibitors (ICIs) are revolutionising cancer therapy, checkpoint inhibitor-induced liver injury is a significant immune-related side effect of this immunotherapy. This study focuses on the severity classifications and characteristics of patients with checkpoint inhibitor-induced hepatitis. A retrospective analysis of patients with severe Checkpoint Inhibitor-induced hepatitis grade 3 and 4 according to the recommended Common Terminology Criteria for Adverse Events (CTCAE) classification was conducted. Data on clinicobiological characteristics, treatment and outcomes were collected from 3 university hospitals, and causality was assessed by using the updated Roussel Uclaf Causality Assessment Method. The severity of hepatitis was assessed using the Model for End-stage Liver Disease score, the Drug-Induced Liver Injury Network, and the Drug-Induced Liver Injury International Expert Working Group classifications. We retrospectively included 100 patients presenting various hepatitis patterns with a median time to onset of 20 days after checkpoint inhibitors. Severity grading varied significantly among the classifications used. A lower incidence of severe cases was observed when using the Drug-Induced Liver Injury classifications instead of the recommended CCTCAE classification, and this was correlated with outcomes. This retrospective study challenges the efficacy of the CTCAE classification in defining the severity of Checkpoint Inhibitor-induced hepatitis and suggests that the traditional hepatology-focused scores may be more relevant. The CTCAE classification is inconsistent and gives equal weight to jaundice and elevated transaminases, which leads to steroid overtreatment and limits the rechallenge of ICIs.

Incidence of Idiosyncratic Drug-Induced Liver Injury Caused by Prescription Drugs.

The incidence of drug-induced liver injury (DILI) is not known for most prescription medications. We aimed to estimate the incidence of DILI for commonly prescribed outpatient drugs. To establish a baseline estimate of DILI incidence, we used the estimated incidence (EI) of amoxicillin/clavulanate DILI from a previous population-based study in Iceland. This was combined with the multicenter prospective DILI Network (DILIN) cohort and the US population-based Medical Expenditure Panel Survey (MEPS). From 2005 to 2019, prescription drugs with at least five bona fide DILIN cases and data from at least 10 of the 15years from MEPS during that timeframe were included. The EI for 'drug A' was calculated as follows: RESULTS: In total, 30 drugs met the inclusion criteria, of which 11 were antibiotics, 4 were antiepileptic drugs (AEDs), 4 were statins, and 11 were other drug types. The highest EI was seen with azathioprine and older AEDs, with one DILI case per 349-2329 new prescriptions. The EI of antibiotics ranged greatly, with the highest risk seen for minocycline, amoxicillin/clavulanate, and nitrofurantoin (approximately 1:1000-2400 new prescriptions), and lowest risk for clindamycin, doxycycline, azithromycin, and amoxicillin (approximately 1:40,000-170,000 new prescriptions). The EI for commonly prescribed statins was approximately 1:10,000-50,000. Important medication classes with > 5 million new prescriptions from 2005 to 2019 but fewer than five DILIN cases included β-blockers, thiazide diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, selective serotonin reuptake inhibitors, and metformin, which presumably have very low DILI incidence. The highest EI was found for azathioprine, older antiepileptics, and minocycline. In contrast, many widely used drugs are rare causes of DILI. These findings may help clinicians better weigh potential benefits of medications against hepatotoxicity risk.

Genetic variants associated with immune-mediated liver injury from checkpoint inhibitors.

The clinical features, liver histology, and genetic variants in 57 patients with moderate to severe immune-mediated liver injury from checkpoint inhibitors (ILICI) are presented. Between 2010 and 2022, 57 high-causality ILICI cases were enrolled in the Drug-Induced Liver Injury Network. HLA and selected candidate gene variants were tested for association with ILICI risk compared to the general population and other DILI controls. The 57 high-causality cases were attributed to pembrolizumab (16), ipilimumab (15), ipilimumab and nivolumab (13), and other immune checkpoint inhibitors (13) and occurred at a median of 72 days after the first infusion. Median age was 57.8 years, 66% male, and 89% were non-Hispanic Whites. At DILI onset, 53% had hepatocellular, 35% mixed, and 15% cholestatic, with younger patients more likely to have hepatocellular injury. The incidence of ANA, smooth muscle antibody, and elevated IgG levels was low (17%, 23%, and 0%), but corticosteroids were given to 86%. Microgranulomas and hepatic steatosis were seen in 54% and 46% of the 26 liver biopsies, respectively. The HLA alleles associated with autoimmune hepatitis were not over-represented, but 2 host immune response genes (EDIL3 and SAMA5A) and 3 other genes (GABRP, SMAD3, and SLCO1B1) were associated with ILICI (OR: 2.08-2.4, p<0.01). ILICI typically arises within 12 weeks of initiating immunotherapy and is self-limited in most cases. Genetic variants involved in host T-cell regulation and drug disposition were identified, implicating these pathways in the pathogenesis of ILICI. If validated, these findings could lead to improved diagnostic instruments and possible treatments for ILICI.

Challenges in herbal-induced liver injury identification and prevention.

Herbal and dietary supplements (HDS) are being used worldwide at an increasing rate. Mirroring this trend, HDS-induced liver injury, also known as HDS-induced liver injury (HILI), has increased significantly over the past three decades in the Drug-Induced Liver Injury Network (DILIN), now accounting for 20% of cases of drug-induced liver injury (DILI). There are significant challenges in the identification and prevention of HILI due to varying presentations, ability to make clear diagnosis, identification of the responsible ingredient, lack of treatment, and lack of regulatory oversight of HDS products to confirm their ingredients and ensure safety. The major implicated agents include anabolic steroids, green tea extract, garcinia cambogia, kratom, ashwagandha, turmeric and multi-ingredient nutritional supplements. Fortunately, with the formation of major DILI consortiums across the world, the last decade has seen advances in the identification of at-risk genetic phenotypes, the use of chemical analysis on multi-ingredient nutritional supplements, and the publication of data/injury patterns of potentially risky HDS.

Clinical characteristics and HLA associations of azithromycin-induced liver injury.

Azithromycin (AZ) is a widely used antibiotic. The aim of this study was to characterise the clinical features, outcomes, and HLA association in patients with drug-induced liver injury (DILI) due to AZ. The clinical characteristics of individuals with definite, highly likely, or probable AZ-DILI enrolled in the US Drug-Induced Liver Injury Network (DILIN) were reviewed. HLA typing was performed using an Illumina MiSeq platform. The allele frequency (AF) of AZ-DILI cases was compared to population controls, other DILI cases, and other antibiotic-associated DILI cases. Thirty cases (4 definite, 14 highly likely, 12 probable) of AZ-DILI were enrolled between 2004 and 2022 with a median age of 46 years, 83% white, and 60% female. Median duration of AZ treatment was 5 days. Latency was 18.5 days. 73% were jaundiced at presentation. The injury pattern was hepatocellular in 60%, cholestatic in 27%, and mixed in 3%. Ten cases (33%) were severe or fatal; 90% of these were hepatocellular. Two patients required liver transplantation. One patient with chronic liver disease died of hepatic failure. Chronic liver injury developed in 17%, of which 80% had hepatocellular injury at onset. HLA-DQA1*03:01 was significantly more common in AZ-DILI versus population controls and amoxicillin-clavulanate DILI cases (AF: 0.29 vs. 0.11, p = 0.001 and 0.002, respectively). Azithromycin therapy can lead to rapid onset of severe hepatic morbidity and mortality in adult and paediatric populations. Hepatocellular injury and younger age were associated with worse outcomes. HLA-DQA1*03:01 was significantly more common in AZ cases compared to controls.

Turmeric-Induced Liver Injury in a Patient with Concurrent Semaglutide Use

Turmeric has surged in popularity as one of the most widely used dietary supplements in the United States. Recognized for its antiinflammatory and antioxidant properties, it has traditionally been regarded as safe. Recent literature and reports in LiverTox have documented over a dozen cases of acute liver injury associated with the use of turmeric supplements. However, potential drug interactions with turmeric have been described but not well-documented. Thus, we present a case of drug-induced liver injury (DILI) correlated with turmeric supplement use and the concurrent use of semaglutide. INTRODUCTION Drug-induced liver injury (DILI) from herbal and dietary supplements (HDS) in the United States has increased as the usage of HDS has become more popular. According to the United States Drug-Induced Liver Injury Network (DILIN), approximately 20% of cases of DILI can be attributed to HDS, an increase from 7% in 2004.1 Turmeric supplements have become one of the top selling HDS in the United States. It is promoted for arthritis, pain, and digestive disorders. Common side effects include dermatitis and gastrointestinal upset, while instances of hepatotoxicity are rare. Different formulations that increase the bioavailability of curcumin, the active ingredient in turmeric, have been linked to cases of liver injury and acute hepatitis outbreaks outside of the United States.2 Possible interactions between turmeric and other drugs, such as anticoagulants, antiplatelets, antidiabetics, and chemotherapeutic agents, have been described in in vitro and animal studies, but have not been well studied in humans.3 In this report, we describe a possible drug interaction in a patient who had been using turmeric supplements and semaglutide injections and presented with elevated liver transaminases and bilirubin, with improvement upon cessation of the supplement.

Drug-induced Liver Injury in Latin America: 10-year Experience of the Latin American DILI (LATINDILI) Network

Background and aimsLatin America is a region of great interest for studying the clinical presentation of idiosyncratic drug-induced liver injury (DILI). A comprehensive analysis of patients enrolled into the LATINDILI Network over a decade is presented. MethodsDemographics, clinical presentation, histological findings and outcome of prospectively recruited DILI cases in the LATINDILI Network were analyzed. Suspected culprit drugs were classified according to the Anatomical Therapeutic Chemical classification. Causality was assessed using the Roussel Uclaf Causality Assessment Method (RUCAM) scale. ResultsOverall, 468 idiosyncratic DILI cases were analyzed (62% women, mean age 49 years). Hepatocellular injury predominated (62%), jaundice was present in 60% of patients and 42% were hospitalized. 4.1% of the cases had a fatal outcome, and 24 (12%) patients developed chronic DILI. The most common drug classes were systemic anti-infectives (31%), musculoskeletal agents (12%), antineoplastic and immunomodulating agents (11%), and herbal and dietary supplements (HDS, 9%). Notably, none of the patients with DILI due to antibacterials or immunosuppressants had a fatal outcome. In fact, Hy's law showed to have drug-specific predictive value, with anti-tuberculosis drugs, nimesulide and HDS associated with the worst outcome, whereas DILI caused by amoxicillin-clavulanate, nitrofurantoin and diclofenac that fulfilled Hy's law did not have a fatal outcome. ConclusionFeatures of DILI in Latin America are comparable to other prospective registries. However, the pattern of drugs responsible for DILI differs. An increasing incidence of HDS, with high mortality rate, and likewise nimesulide and nitrofurantoin was noted. Thus, public health policies should raise awareness of the potential adverse effects of these compounds.

Characterisation of an outbreak of acute liver injury after ingestion of plant-based food supplement.

In April 2022, French Lentil and Leek Crumble (FLLC), a new frozen food preparation manufactured by Daily Harvest™ (containing Tara flour) was offered as a natural high-protein meal product. Soon thereafter, widespread anecdotal reports of acute gastrointestinal symptoms with liver injury were reported, leading to its voluntary withdrawal in June 2022, after shipment of 28,000 preparations. To summarise the clinical and laboratory features of 17 patients with FLLC associated liver injury from the Drug Induced Liver Injury Network (DILIN). Patients with FLLC-associated liver injury were enrolled into a prospective protocol and followed for 6 months. Cases were adjudicated by expert opinion causality assessment with summary statistics for data analysis. Enrolled subjects had a mean age of 41 years, 82% were female with mean BMI of 24 kg/m2. All were Caucasian without underlying liver disease. In most cases, abdominal pain and nausea arose within hours of FLLC ingestion. Mean days from ingestion to identification of liver injury was 3.1 days (±2.8). On enrolment, 53% had jaundice, 47% nausea, 24% fever, 59% abdominal pain, 41% itching and 12% rash. The mean initial serum ALT was 475 U/L (±302), AST 315 U/L (±315), alkaline phosphatase 190 U/L (±76), with a total bilirubin of 2.6 mg/dL (±2). In this study, 63% presented with a hepatocellular pattern of liver injury, 6% cholestatic and 31% mixed as determined by the R value. In addition, 24% of patients were hospitalised, and there were no fatalities or liver transplants. Liver biopsy in one subject revealed acute hepatitis with mild ductular reaction, mild lymphocytic and eosinophilic portal inflammation, mild lobular inflammation, preserved bile ducts and absence of interface hepatitis, steatosis, granulomatous reaction or cholestasis. Phylogenetic analysis confirmed the presence of Tara spinosa, the source of Tara flour. Natural food products are increasingly ubiquitous and may unexpectedly cause significant illness. All clinicians should inquire whether patients are consuming natural food products or herbal supplements and consider them as a potential cause of liver injury.

Drug-Induced Liver Injury in Pregnancy: The U.S. Drug-Induced Liver Injury Network Experience.

There are limited data on the causative agents and characteristics of drug-induced liver injury in pregnant individuals. Data from patients with drug-induced liver injury enrolled in the ongoing multicenter Drug-Induced Liver Injury Network between 2004 and 2022 and occurring during pregnancy or 6 months postpartum were reviewed and compared with cases of drug-induced liver injury in nonpregnant women of childbearing age. Among 325 individuals of childbearing age in the Drug-Induced Liver Injury Network, 16 cases of drug-induced liver injury (5%) occurred during pregnancy or postpartum. Compared with drug-induced liver injury in nonpregnant women, pregnancy-related drug-induced liver injury was more severe ( P <.05). One elective termination and three miscarriages were documented; there were no maternal deaths. We recommend that isoniazid for latent tuberculosis be deferred to the postpartum period whenever feasible and that β-blockers or calcium channel blockers rather than methyldopa be used for hypertension management during pregnancy.

Amiodarone and Dronedarone Causes Liver Injury with Distinctly Different Clinical Presentations

ObjectiveTo describe hepatotoxicity due to amiodarone and dronedarone from the DILIN and the US FDA’s surveillance database.MethodsHepatotoxicity due to amiodarone and dronedarone enrolled in the U.S. Drug Induced Liver Injury Network (DILIN) from 2004 to 2020 are described. Dronedarone hepatotoxicity cases associated with liver biopsy results were obtained from the FDA Adverse Event Reporting System (FAERS) from 2009 to 2020.ResultsAmong DILIN’s 10 amiodarone and 3 dronedarone DILIN cases, the latency for amiodarone was longer than with dronedarone (388 vs 119 days, p = 0.50) and the median ALT at DILI onset was significantly lower with amiodarone (118 vs 1191 U/L, p = 0.05). Liver biopsies in five amiodarone cases showed fibrosis, steatosis, and numerous Mallory-Denk bodies. Five patients died although only one from liver failure. One patient with dronedarone induced liver injury died of a non-liver related cause.Nine additional cases of DILI due to dronedarone requiring hospitalization were identified in the FAERS database. Three patients developed liver injury within a month of starting the medication. Two developed acute liver failure and underwent urgent liver transplant, one was evaluated for liver transplant but then recovered spontaneously, while one patient with cirrhosis died of liver related causes.ConclusionAmiodarone hepatotoxicity resembles that seen in alcohol related liver injury, with fatty infiltration and inflammation. Dronedarone is less predictable, typically without fat and with a shorter latency of use before presentation. These differences may be explained, in part, by the differing pharmacokinetics of the two drugs leading to different mechanisms of hepatotoxicity.

The ABC of Immune-Mediated Hepatitis during Immunotherapy in Patients with Cancer: From Pathogenesis to Multidisciplinary Management.

Immune-mediated hepatotoxicity (IMH) is not-so-rare complication during treatment with immune checkpoint inhibitors (ICIs). This narrative review aims to report the current knowledge on hepatic immune-related adverse events (irAEs) during immunotherapy from pathogenesis to multidisciplinary management. The majority of cases of IMH are asymptomatic and only a few patients may have clinical conditions. The severity of IMH is usually stratified according to Common Terminology for Clinical Adverse Events (CTCAE) criteria, but these scores may overestimate the clinical severity of IMH compared to the Drug-Induced Liver Injury Network (DILIN) scale. The differential diagnosis of IMH is challenging because the elevated liver enzymes can be due to a number of etiologies such as viral infection, autoimmune and metabolic diseases, liver metastases, biliary diseases, and other drugs. The cornerstones of IMH management are represented by withholding or delaying ICI administration and starting immunosuppressive therapy. A multidisciplinary team, including oncologists, hepatologists, internists, and emergency medicine physicians, is essential for the management of IMH.

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

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. 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. 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). 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.

A study of the effect of antitubercular drugs on liver functions in newly diagnosed cases of tuberculosis during intensive phase of therapy in tertiary care hospital

Background: Antitubercular drugs are commonly associated with drug-induced liver injury (DILI), which can present as asymptomatic alterations in liver function test (LFT) to symptomatic hepatic injury and failure. Regular and frequent monitoring of LFT during intensive phase of therapy helps to identify early DILI and its complication. Aims and Objectives: The main objective was to evaluate the effects of antitubercular drugs on liver functions by early monitoring. Materials and Methods: A prospective observational study was conducted for 1 year among 97 newly diagnosed tuberculosis patients in tertiary care hospital. LFT was performed during baseline, at the end of 2nd week, and at end of intensive phase of treatment. Diagnosis of liver injury was based on DILI criteria and assessment of the clinical pattern of liver damage was done using “R value”. Results: Among 97 patients, 16 had experienced DILI and incidence was higher during the first visit. Aspartate aminotransferase (AST) and alanine aminotransferase were significantly altered during the first visit while AST and total bilirubin during the second visit. The number of parameters deranged was higher at the end of intensive phase than during the end of 2nd week. Cholestatic pattern (81.25 %) of liver injury was the most common type as per “R value”. According to DILI network severity index, the majority were categorized as “moderately-severe” and “moderate” during the first and second follow-up, respectively. Conclusion: The incidence of antitubercular drugs-induced liver injury was higher during the initial 2 weeks of treatment, but the derangement was more evident at the end of the intensive phase. Frequent and regular monitoring during the initial phase of treatment helps to detect early DILI which prevents the impending liver failure.

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

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

Vancomycin-Induced Liver Injury, DRESS, and HLA-A∗32:01

Intravenous vancomycin therapy can cause liver injury as well as "drug reaction with eosinophilia and systemic symptoms" (DRESS) syndrome. This study aimed to better define the clinical features and HLA associations of vancomycin-induced liver injury. To describe clinical, biochemical, and temporal characteristics of vancomycin-induced liver injury. Cases of liver injury with recent exposure to vancomycin who were enrolled in the US Drug-induced Liver Injury Network between 2004 and 2020 were assessed. Sequencing of HLA alleles was performed on stored blood samples. Among 1697 cases of drug-induced liver injury identified between 2004 and 2021, 9 (0.5%) were attributed to intravenous vancomycin. The 9 cases included 6 men, median age 60 years (range, 23-85 days), and treatment for 26 days (range, 1-34 days). The clinical presentation was DRESS syndrome in 8 patients, of whom 6 received corticosteroids. Liver injury varied from hepatocellular to cholestatic and from mild (n= 5) to fatal (n= 1). In survivors, liver injury and DRESS syndrome ultimately resolved. HLA typing demonstrated the HLA-A∗32:01 allele in 7 vancomycin cases (78%, all with DRESS syndrome), versus 1 of 81 cases (1.2%) exposed but not attributed to vancomycin, and 113 of 1708 cases (6.6%) without vancomycin exposure. The allele frequency in vancomycin cases was 0.44 compared with less than 0.04 in US populations. Vancomycin-induced liver injury is commonly associated with DRESS syndrome and linked to HLA-A∗32:01. HLA-A∗32:01 testing could be considered early to risk-stratify patients using long-term intravenous vancomycin therapy.

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

Idiosyncratic drug-induced liver injury (DILI) with autoimmune features is a liver condition with laboratory and histological characteristics similar to those of idiopathic autoimmune hepatitis (AIH), which despite being increasingly reported, remains largely undefined. We aimed to describe in-depth the features of this entity in a large series of patients from two prospective DILI registries. DILI cases with autoimmune features collected in the Spanish DILI Registry and the Latin American DILI Network were compared with DILI patients without autoimmune features and with an independent cohort of patients with AIH. Out of 1,426 patients with DILI, 33 cases with autoimmune features were identified. Female sex was more frequent in AIH patients than in the other groups (p = .001). DILI cases with autoimmune features had significantly longer time to onset (p < .001) and resolution time (p = .004) than those without autoimmune features. Interestingly, DILI patients with autoimmune features who relapsed exhibited significantly higher total bilirubin and transaminases at onset and absence of peripheral eosinophilia than those who did not relapse. The likelihood of relapse increased over time, from 17% at 6 months to 50% 4 years after biochemical normalization. Statins, nitrofurantoin and minocycline were the drugs most frequently associated with this phenotype. DILI with autoimmune features shows different clinical features than DILI patients lacking characteristics of autoimmunity. Higher transaminases and total bilirubin values with no eosinophilia at presentation increase the likelihood of relapse in DILI with autoimmune features. As the tendency to relapse increases over time, these patients will require long-term follow-up.

Immunophenotyping to improve the mechanistic understanding of idiosyncratic drug-induced liver injury: clinical implications and future directions

The late event onset of a fraction of idiosyncratic drug-induced liver injury (DILI) cases and the link observed by genome-wide association studies (GWASs) of certain human leucocyte antigen (HLA) alleles with DILI due to specific drugs support the crucial role of the immune system (both innate and adaptive) in the pathogenesis of DILI. Recent advances in both flow and mass cytometry have allowed the profiling of all major immune cell types in a given sample. Therefore, determining the lymphocyte populations in samples from patients with DILI would facilitate the development of specific biomarkers for DILI diagnosis and prognosis. To date, a few studies have explored the immune landscape in DILI. In a recent study of leukocyte immunophenotyping using flow cytometry from the Spanish DILI Registry, an important role of adaptive immune response in DILI is suggested. DILI patients had significantly higher levels of T helper 1 (Th1) cells and activated helper and cytotoxic T cells than healthy controls. Furthermore, the increased expression of negative immune checkpoints and ligands in DILI patients could reflect a restoration of the immune homeostasis. Differences in the profile of cytokines in DILI patients from the Drug-Induced Liver Injury Network (DILIN) also suggest an involvement of both innate and adaptive immune systems in DILI development and prognosis. Moreover, several studies based on immunophenotyping of liver infiltrates showed a distinctive pattern of cellular infiltrates in patients with immune checkpoint inhibitors (ICIs)-DILI, with lower levels of plasma cells, CD20+ B cells and CD4+ T cells than in autoimmune hepatitis (AIH) patients. These pioneering studies highlight the importance of immunophenotyping for the mechanistic understanding of DILI. In this review, available data on immunophenotyping in DILI are gathered, and the potential clinical applications of cutting-edge, novel immunophenotyping techniques are discussed.

From the Editor’s Desk...

From the Editor’s Desk...