Search Results (43)

Drug-induced liver injury (DILI) remains one of the most challenging adverse drug reactions in clinical practice, particularly in its idiosyncratic form, which is not dose-dependent and is largely driven by host-specific immune and genetic factors. Recent genomic studies have revealed strong associations between certain human leukocyte antigen (HLA) alleles and susceptibility to DILI, supporting an immunogenetic mechanism in which drug or metabolite–protein adducts act as neoantigens, triggering aberrant T-cell activation and hepatocellular injury. This review summarizes current evidence on the contribution of HLA polymorphisms to the pathogenesis of idiosyncratic DILI, highlighting allele-specific risk patterns, such as HLA-B*57:01 associated with flucloxacillin, HLA-DRB1*15:01–DQB1*06:02 in amoxicillin–clavulanate, and HLA-B*35:02 in minocycline-induced liver injury. Furthermore, ethnic variability and allele-haplotype interactions are discussed as potential modulators of susceptibility and clinical phenotype. By integrating genetic and immunological insights, the identification of HLA signatures offers promising tools for precision medicine, enabling earlier identification of at-risk individuals and improved prevention of severe hepatotoxic reactions. Full article

Trastuzumab deruxtecan (T-DXd) has demonstrated efficacy in HER2-positive and HER2-low breast cancer. Its main safety concern is interstitial lung disease, while clinically relevant hepatotoxicity is rarely reported. In our case report we describe a 49-year-old woman with HER2-positive advanced breast cancer that developed persistent grade 3 transaminase elevations after 2 cycles of T-DXd, refractory to corticosteroid treatment and requiring treatment discontinuation. This case underlines the unpredictable and idiosyncratic nature of T-DXd associated hepatotoxicity and the importance of liver function monitoring. Clinicians should consider DILI in patients with unexplained liver enzyme elevations during therapy. Further studies are needed to clarify mechanisms and risk factors. Full article

Drug-induced autoimmune hepatitis (DIAIH) is a rare and complex disorder caused by drugs that are commonly metabolized by hepatic microsomal cytochrome P450 (CYP) pathways. Whereas DIAIH presents generally with a single clinical flare, in rare cases its clinical course shows two different, consecutively emerging flares. The aim of this report was to analyze details of this rare but interesting phenomenon and to help improve appropriate causality evaluation in patients with suspected iDILI or DIAIH to provide better insight into the pathomechanistic steps leading the diseases. A clinical course with two flares was found in a DIAIH patient treated with varenicline, a smoking cessation drug, and in another patient experiencing DIAIH following intravenous application of infliximab used to treat ankylosing spondylitis. In both patients, the first flare was determined as a typical liver injury with increased serum activities of alanine aminotransferase (ALT) and normal titers of serum autoimmune parameters, classified as an acute liver injury analogous to idiosyncratic DILI (iDILI), with verified causality using a modified version of RUCAM (Roussel Uclaf Causality Assessment Method). After an interval of around two months from the cessation of varenicline use, the second flare emerged, as evidenced by increased serum ALT values now associated with newly increased serum autoimmune titers of antinuclear antibodies (ANAs), classifying this flare as hepatic autoimmune injury with verified causality for varenicline using the simplified autoimmune hepatitis (AIH) score. A similar clinical DIAIH course of a continuous disease with two flares was described for the second patient, who received infliximab and experienced an interval of one month between the first and second flare. Interestingly to note, neither varenicline nor infliximab is degraded via a CYP pathway, and the metabolic disposition of both drugs is low. In sum, DIAIH can develop with two consecutive flares caused by two drugs not metabolized by CYPs and with slow drug disposition, raising the question of whether this phenomenon of two flares can occur in additional cases of DIAIH due to other drugs metabolized by CYPs or non-CYPs, a question to be resolved by DILI experts in future cases of iDILI and DIAIH. Full article

Drug-induced autoimmune hepatitis (DIAIH) is a relatively new subtype of idiosyncratic drug-induced liver injury (iDILI), but the features of DIAIH have been variably described due to the inhomogeneity of assessed study cohorts. The aim of this analysis is to harmonize DIAIH cohorts by unifying causality assessments, which may help characterize the features of DIAIH. Methods: Published reports of DIAIH cases were evaluated for the causality assessment methods used to verify the diagnosis of DIAIH. This disorder consists of two parts, i.e., the iDILI part and the autoimmune (AIH) part, whereby each part needs a specific diagnostic algorithm. The validated and scoring Roussel Uclaf Causality Assessment (RUCAM) is privileged for assessing the iDILI part, and the validated, simplified AIH score is the perfect choice for evaluating the AIH part. The analysis of DIAIH publications revealed that 12/20 reports (60%) presented cases assessed by both the RUCAM and the simplified AIH score, providing 49 drugs and drug combinations as causative drugs in up to 25 cases of DIAIH. Serum alanine aminotransferase activities of up to 3489 UL and high titers of autoimmune parameters such as anti-nuclear antibodies, anti-smooth-muscle antibodies, and soluble liver antigen antibodies supported DIAIH diagnosis. In contrast, 4/20 reports (20%) applied only RUCAM, and 2/20 reports (10%) used only the simplified AIH score; these 6 reports therefore provided insufficient criteria for a valid DIAIH diagnosis. Moreover, 2/20 reports (10%) did not use any causality algorithm, providing elusive features of DIAIH. While DIAIH is clearly restricted to drugs as responsible agents, this term is erroneously used to refer to disease induced by non-drugs such as herbs, green tea, dimethoate (an organophosphate insecticide), dietary supplements, biologics, herbal remedies, different viruses, and bacteria, as well as vaccines. For diseases induced by these agents, a better term could be, for instance, non-drug-induced autoimmune hepatitis. Drug cessation and immunotherapy with corticosteroids and azathioprine comprise the treatment of choice. The characteristics of DIAIH can best be described if both the RUCAM and the simplified AIH score are used concomitantly. Full article

Drug-induced liver injury (DILI) is one of the main causes of acute liver failure in children. Its incidence is probably underestimated, as specific diagnostic tools are currently lacking. Over 1000 known drugs cause DILI, and the list is expanding. The aim of this review is to describe DILI pathogenesis and emphasize the drugs accountable for child DILI in order to aid its recognition. Intrinsic DILI is well described in terms of mechanism, incriminated drugs, and toxic dose. Conversely, idiosyncratic DILI (iDILI) is unpredictable, occurring as a result of a particular response to drug administration, and its occurrence cannot be foreseen in clinical studies. Half of pediatric iDILI cases are linked to antibiotics, mostly amoxicillin–clavulanate, in the immune-allergic group, while autoimmune DILI is the hallmark of minocycline and nitrofurantoin. Secondly, antiepileptics are responsible for 20% of pediatric iDILI cases, children being more prone to iDILI caused by these agents than adults. A similar tendency was observed in anti-tuberculosis drugs, higher incidences being reported in children below three years old. Current data show growing cases of iDILI related to antineoplastic agents, atomoxetine, and albendazole, so that it is advisable for clinicians to maintain a high index of suspicion regarding iDILI. Full article

Conventionally, drug-induced liver injury (DILI) exists in two types: idiosyncratic and intrinsic. Both types are classified as non-immune disorders, thereby ignoring that some iDILI cases may have an immune or autoimmune background that requires a different therapeutic approach because steroids may be helpful. The purpose of this analysis was to analyze and classify the subtypes of iDILI which, indeed, show autoimmune or immune features among four cohorts, namely idiosyncratic DILI type 1: idiosyncratic drug-induced autoimmune hepatitis (DIAIH), to be differentiated from the classic drug-unrelated idiosyncratic autoimmune hepatitis (AIH); idiosyncratic DILI type 2: human leucocyte antigen-based idiosyncratic drug-induced autoimmune hepatitis; idiosyncratic DILI type 3: anti-cytochrome P450-based idiosyncratic drug-induced autoimmune hepatitis; and idiosyncratic DILI type 4: immune-based idiosyncratic drug-induced liver injury associated with Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). In conclusion, the traditional non-immune and non-autoimmune iDILI, as well as the four immune or autoimmune iDILI subtypes, are now well classified and clinically characterized by the broadly applied Roussel Uclaf Causality Assessment Method (RUCAM), facilitating additional immunology and therapy studies for the four subtypes, all of which could benefit from steroid treatment. Full article

Background and objective: Iliopsoas abscess (IPA) is a rare condition with varied symptomology and etiology. Less than one-third of patients with IPA present in the emergency department (ED) with the traditional triad of fever, back pain, and restricted hip motion (or limp), leading to delays in diagnosis and management. Acute liver failure is also a rare clinical presentation in the ED, being associated with high morbidity and mortality. It occurs most often in young patients without pre-existing liver disease, presenting unique challenges in clinical management. Most cases currently happen because of drug-induced liver injury (DILI), mainly from acetaminophen or idiosyncratic drug reactions. This case report aims to raise awareness among healthcare professionals regarding the two atypical presentations in ED and introduce a potential differential diagnosis when evaluating patients with fever and back pain or liver enzyme elevations with or without nonspecific symptoms associated with the development of jaundice. The intention is to provide insights into the signs and symptoms that may indicate the presence of an iliopsoas abscess and prompt additional investigations. Case report: Here, we describe a case of primary iliopsoas abscess associated with drug-induced liver injury in our ED. The patient complained of pain in the left lumbar region and fatigue that started two weeks before this presentation, claiming that, during the previous night, the pain suddenly worsened. At the first clinical examination in the ED, the patient presented pain at palpation in the right hypochondriac and left lumbar regions, accompanied by fever, vomiting, and jaundice. On abdominal ultrasonography, the diagnosis of acute cholangitis was suspected. The laboratory test shows leukocytosis with neutrophilia, thrombocytosis, elevated liver enzymes, and hyperbilirubinemia with the predominance of indirect bilirubin. After analyzing the laboratory test results, we repeated and performed a more detailed anamnesis and medical history of the patient. Because of her increasing pain and persistent fever, she recognized excessive consumption in the last five days of drug-induced hepatotoxicity. We performed abdominal and pelvic computed tomography, which confirmed the diagnosis of cholelithiasis observed with the diameter of the bile duct within normal limits but also showed an abscess collection fused to the interfibrillar level of the left iliopsoas muscle, a diagnosis we most likely would have missed. The patient was hospitalized in the General Surgery Department, and surgical abscess drainage was performed. The patient’s evolution was excellent; she was discharged after 11 days. Conclusions: The case presented here exemplifies how iliopsoas abscess, a rare cause of back pain, can quickly go unrecognized, especially in the emergency department. Our experiences will raise awareness among doctors in emergency departments about this uncommon but essential diagnosis. With advancements in diagnostic tools and techniques, we hope that more cases of iliopsoas abscess will be accurately diagnosed. Moreover, no case report from the literature has presented IPA associated with DILI. This case is unique because our patient did not exhibit classic features of either pathology. This case also emphasizes the importance of a medical history that includes thorough evaluations of potential high utilization of drug-induced hepatotoxicity. Full article

Idiosyncratic drug-induced liver injury (iDILI) by flucloxacillin presents as both cholestatic and hepatocellular injury. Its mechanistic steps are explored in the present analysis as limited data exist on the cascade of events leading to iDILI in patients with an established diagnosis assessed for causality by the Roussel Uclaf Causality Assessment Method (RUCAM). Studies with human liver microsomes showed that flucloxacillin is a substrate of cytochrome P450 (CYP) with ist preferred isoforms CYP 3A4/3A7 that toxified flucloxacillin toward 5′-hydroxymethylflucloxacillin, which was cytotoxic to human biliary epithelial cell cultures, simulating human cholestatic injury. This provided evidence for a restricted role of the metabolic CYP-dependent hypothesis. In contrast, 5′-hydroxymethylflucloxacillin generated metabolically via CYP 3A4/3A7 was not cytotoxic to human hepatocytes due to missing genetic host features and a lack of non-parenchymal cells, including immune cells, which commonly surround the hepatocytes in the intact liver in abundance. This indicated a mechanistic gap regarding the clinical hepatocellular iDILI, now closed by additional studies and clinical evidence based on HLA B*57:01-positive patients with iDILI by flucloxacillin and a verified diagnosis by the RUCAM. Naïve T-cells from volunteers expressing HLA B*57:01 activated by flucloxacillin when the drug antigen was presented by dendritic cells provided the immunological basis for hepatocellular iDILI caused by flucloxacillin. HLA B*57:01-restricted activation of drug-specific T-cells caused covalent binding of flucloxacillin to albumin acting as a hapten. Following drug stimulation, T-cell clones expressing CCR4 and CCR9 migrated toward CCL17 and CCL25 and secreted interferon-γ and cytokines. In conclusion, cholestatic injury can be explained metabolically, while hepatocellular injury requires both metabolic and immune activation. Full article

Several hepatic disorders are influenced by gut microbiota, but its role in idiosyncratic drug-induced liver injury (iDILI), whose main causative agent is amoxicillin–clavulanate, remains unknown. This pioneering study aims to unravel particular patterns of gut microbiota composition and associated metabolites in iDILI and iDILI patients by amoxicillin–clavulanate (iDILI-AC). Thus, serum and fecal samples from 46 patients were divided into three study groups: healthy controls (n = 10), non-iDILI acute hepatitis (n = 12) and iDILI patients (n = 24). To evaluate the amoxicillin–clavulanate effect, iDILI patients were separated into two subgroups: iDILI non-caused by amoxicillin–clavulanate (iDILI-nonAC) (n = 18) and iDILI-AC patients (n = 6). Gut microbiota composition and fecal metabolome plus serum and fecal bile acid (BA) analyses were performed, along with correlation analyses. iDILI patients presented a particular microbiome profile associated with reduced fecal secondary BAs and fecal metabolites linked to lower inflammation, such as dodecanedioic acid and pyridoxamine. Moreover, certain taxa like Barnesiella, Clostridia UCG-014 and Eubacterium spp. correlated with significant metabolites and BAs. Additionally, comparisons between iDILI-nonAC and iDILI-AC groups unraveled unique features associated with iDILI when caused by amoxicillin–clavulanate. In conclusion, specific gut microbiota profiles in iDILI and iDILI-AC patients were associated with particular metabolic and BA status, which could affect disease onset and progression. Full article

Idiosyncratic drug-induced liver injury (DILI) is a complex multifactorial disease in which the toxic potential of the drug, together with genetic and acquired factors and deficiencies in adaptive processes, which limit the extent of damage, may determine susceptibility and make individuals unique in their development of hepatotoxicity. In our study, we sequenced the exomes of 43 pediatric patients diagnosed with DILI to identify important gene variations associated with this pathology. The result showed the presence of two variations in the NAT2 gene: c.590G>A (p.Arg197Gln) and c.341T>C (p.Ile114Thr). These variations could be found separately or together in 41 of the 43 patients studied. The presence of these variations as a risk factor for DILI could confirm the importance of the acetylation pathway in drug metabolism. Full article

Predicting whether a compound can cause drug-induced liver injury (DILI) is difficult due to the complexity of drug mechanism. The cysteine trapping assay is a method for detecting reactive metabolites that bind to microsomes covalently. However, it is cumbersome to use 35S isotope-labeled cysteine for this assay. Therefore, we constructed an in silico classification model for predicting a positive/negative outcome in the cysteine trapping assay. We collected 475 compounds (436 in-house compounds and 39 publicly available drugs) based on experimental data performed in this study, and the composition of the results showed 248 positives and 227 negatives. Using a Message Passing Neural Network (MPNN) and Random Forest (RF) with extended connectivity fingerprint (ECFP) 4, we built machine learning models to predict the covalent binding risk of compounds. In the time-split dataset, AUC-ROC of MPNN and RF were 0.625 and 0.559 in the hold-out test, restrictively. This result suggests that the MPNN model has a higher predictivity than RF in the time-split dataset. Hence, we conclude that the in silico MPNN classification model for the cysteine trapping assay has a better predictive power. Furthermore, most of the substructures that contributed positively to the cysteine trapping assay were consistent with previous results. Full article

The incidence and prevalence of drug-induced liver injury appear to be increasing globally, for example, with the introduction of checkpoint inhibitors. Several reviews have been published in the last decade on the epidemiology of DILI, both among hospitalized patients and in the general population, as well as from retrospective and prospective studies on DILI. Most of these reviews have not focused on newly recognized agents that have recently changed the landscape of DILI. Apart from liver injury associated with antibiotics, oncological agents, particularly checkpoint inhibitors, are increasingly being recognized as causing liver injury. The type of liver injury associated with these agents is not idiosyncratic but rather an indirect type of injury. Furthermore, recently, COVID-19 vaccines and green tea extract have been found to lead to liver injury. Checkpoint inhibitors have revolutionized the treatment of many malignancies, such as malignant melanoma, lung cancer, and renal cancer. Via the activation of T cells, they can increase immune activity against malignant cells, but at the same time, they can decrease immune tolerance and therefore lead to immune-related adverse effects in many organs. The most common adverse effect in clinical practice is liver injury. A recent prospective study demonstrated an 8% frequency of DILI due to the use of checkpoint inhibitors among patients with malignant melanoma and renal cancer. This rate is much higher than observed with drugs, leading to idiosyncratic liver injury. Shortly after the implementation of the worldwide vaccination program against COVID-19, several case reports were published on suspected vaccination-induced autoimmune-like hepatitis occurring shortly after the vaccination. At first, these reports were met with skepticism, but currently, around 100 reports have been published, and cases of positive recurrence have been reported. The clinical, biochemical, immunological, and histological features are indistinguishable from classic autoimmune hepatitis (AIH). These reactions are very similar to drug-induced autoimmune-like hepatitis (DI-ALH) due to drugs such as nitrofurantoin, minocycline, and infliximab, which do not relapse after a short course of corticosteroids, which is the general rule in classic autoimmune hepatitis (AIH). Green tea extract has been found to be a well-documented cause of acute hepatocellular liver injury with jaundice. A strong HLA association has been reported, showing a high prevalence of HLA-B*35:01 among patients suffering from green tea-induced liver injury. Overall, 3% of patients recruited in the DILIN study were supplemented with green tea extract as one of the ingredients. In a prospective population-based study from Iceland, green tea was implicated in approximately 8% of patients with DILI. Full article

The human leucocyte antigen (HLA) allele variability was studied in cohorts of patients with idiosyncratic drug-induced liver injury (iDILI). Some reports showed an association between HLA genetics and iDILI, proposing HLA alleles as a potential risk factor for the liver injury. However, the strength of such assumptions heavily depends on the quality of the iDILI diagnosis, calling for a thorough analysis. Using the PubMed database and Google Science, a total of 25 reports of case series or single cases were retrieved using the terms HLA genes and iDILI. It turned out that in 10/25 reports (40%), HLA genetics were determined in iDILI cases, for which no causality assessment method (CAM) was used or a non-validated tool was applied, meaning the findings were based on subjective opinion, providing disputable results and hence not scoring individual key elements. By contrast, in most iDILI reports (60%), the Roussel Uclaf Causality Assessment Method (RUCAM) was applied, which is the diagnostic algorithm preferred worldwide to assess causality in iDILI cases and represents a quantitative, objective tool that has been well validated by both internal and external DILI experts. The RUCAM provided evidence-based results concerning liver injury by 1 drug class (antituberculotics + antiretrovirals) and 19 different drugs, comprising 900 iDILI cases. Among the top-ranking drugs were amoxicillin–clavulanate (290 cases, HLA A*02:01 or HLA A*30:02), followed by flucloxacillin (255 cases, HLA B*57:01), trimethoprim–sulfamethoxazole (86 cases, HLA B*14:01 or HLA B*14:02), methimazole (40 cases, HLA C*03:02), carbamazepine (29 cases, HLA A*31:01), and nitrofurantoin (26 cases, HLA A*33:01). In conclusion, the HLA genetics in 900 idiosyncratic drug-induced liver injury cases with evidence based on the RUCAM are available for studying the mechanistic steps leading to the injury, including metabolic factors through cytochrome P450 isoforms and processes that activate the innate immune system to the adaptive immune system. Full article

Drug-induced liver injury (DILI) is a serious adverse hepatic event presenting diagnostic and prognostic challenges. The clinical categorization of DILI into hepatocellular, cholestatic, or mixed phenotype is based on serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) values; however, this classification may not capture the full spectrum of DILI subtypes. With this aim, we explored the utility of assessing changes in the plasma metabolomic profiles of 79 DILI patients assessed by the RUCAM (Roussel Uclaf Causality Assessment Method) score to better characterize this condition and compare results obtained with the standard clinical characterization. Through the identification of various metabolites in the plasma (including free and conjugated bile acids and glycerophospholipids), and the integration of this information into predictive models, we were able to evaluate the extent of the hepatocellular or cholestatic phenotype and to assign a numeric value with the contribution of each specific DILI sub-phenotype into the patient’s general condition. Additionally, our results showed that metabolomic analysis enabled the monitoring of DILI variability responses to the same drug, the transitions between sub-phenotypes during disease progression, and identified a spectrum of residual DILI metabolic features, which can be overlooked using standard clinical diagnosis during patient follow-up. Full article

Idiosyncratic drug-induced liver injury (DILI) is an unpredictable reaction of individuals exposed to a certain drug, and drug-induced autoimmune hepatitis (DIAIH) presents a DILI phenotype that mimics idiopathic autoimmune hepatitis (AIH) when considering the clinical, biochemical, serological and histological parameters. We present a case report of a 48-year-old male who was hospitalized due to severe hepatocellular liver injury two months after self-treatment with a muscle-building dietary supplement based on arginine-alpha-ketoglutarate, L-citrulline, L tyrosine, creatine malate and beet extract. His immunology panel was positive with increased IgG levels, and radiologic methods showed no signs of chronic liver disease. He underwent corticosteroid treatment with adequate response. After therapy withdrawal, a clinical relapse occurred. Seven months after the initial presentation, liver MR suggested initial cirrhotic changes in the right liver lobe. A liver biopsy revealed abundant lymphoplasmacytic infiltrate with piecemeal necrosis and grade 2 fibrosis. He responded well to the corticosteroid treatment again, and was further treated with low-dose prednisone without additional relapses. Several years later, further management confirmed the presence of liver cirrhosis with no histological or biochemical signs of disease activity. DIAIH is a DILI phenotype that is difficult to distinguish from idiopathic AIH despite a wide armamentarium of diagnostic methods. It should always be considered among the differential diagnoses in patients presenting with hepatocellular liver injury. Full article