Histopathological challenges in suspected drug-induced liver injury

Procyanidin B2 mitigates methotrexate-induced hepatic pyroptosis by suppressing TLR4/NF-κB and caspase-3/GSDME pathways

Methotrexate (MTX), a potent chemotherapeutic and immunosuppressive agent, is widely used for cancer and autoimmune diseases. MTX-induced hepatotoxicity is a well-recognized adverse response, even at relatively low doses. This study investigates the possible protective effects of procyanidin B2 (PCB2) on MTX-induced hepatotoxicity. Rats were orally treated with PCB2 (40 mg/kg) for 10 days, followed by a single intraperitoneal MTX injection (20 mg/kg) on day 8. The study also included a positive control group treated with quercetin (20 mg/kg), a known antioxidant, alongside MTX. The results revealed that MTX-induced hepatic injury was evidenced by elevation in serum transaminases. This elevation was accompanied by hepatic oxidative stress due to an imbalance in oxidative/antioxidant markers, specifically elevated malondialdehyde (MDA) and decreased glutathione (GSH) levels and superoxide dismutase (SOD) activity. The inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), were markedly upregulated in the liver of MTX-intoxicated rats. Additionally, the expressions of nuclear factor kappa B (NF-κB), toll-like receptor 4 (TLR4), caspase-3 and gasdermin E (GSDME) were significantly increased in MTX rats. The use of PCB2 significantly ameliorated the deleterious effect of MTX on previous parameters by restoring oxidant/antioxidant balance, decreasing the inflammatory markers, and normalizing the expression of NF-κB, TLR4, caspase-3 and GSDME. In conclusion, this study uncovered the potential role of PCB2 on MTX-induced hepatotoxicity, confirming its antioxidant, anti-inflammatory, and anti-pyroptosis effects yet, further studies are needed to support its use as a protective therapy against such toxicity.

Rare Liver Diseases With Near-Normal Histology: A Review Focusing on Metabolic, Storage, and Inclusion Disorders

Despite the growing availability of noninvasive and faster diagnostic modalities, biopsy remains an important tool in the diagnosis and management of liver diseases. However, it is not uncommon that liver biopsies reveal normal or near normal histologic findings in patients with abnormal liver biochemistries, elevated autoantibodies, clinical findings suggestive of portal hypertension, systemic autoimmune or inflammatory diseases, hepatomegaly, cirrhosis by imaging, or other indications. These scenarios present significant diagnostic challenges and are rarely discussed in detail in the literature or textbooks. This article aims to provide a comprehensive review of a group of selected rare liver diseases, with a focus on metabolic, storage and inclusion disorders, that may exhibit a near-normal histology on biopsy. By recognizing subtle histologic features and correlating with clinical history, laboratory results and imaging findings, it is often possible to narrow down the differential diagnosis. In many cases, this integrative approach can yield a definitive diagnosis, allowing for tailored treatment and better patient outcomes.

[Drug-induced autoimmune-like liver injury]

Drug-induced liver injury (DILI) is a rare yet potentially life-threatening disease. Besides intrinsic DILI, which is mainly caused by paracetamol overdosing and which is dose-dependent and predictable, there is idiosyncratic DILI-an unpredictable and dose-independent injury of the liver caused by certain medications that only occurs in a minority of patients taking this drug. The reason why some patients react with DILI towards a specific drug is still unknown. However, the immune system plays a central role, which is underlined by the association of certain human leukocyte antigen (HLA) polymorphisms and DILI caused by specific drug classes. Due to the immunological processes that lead to the liver injury in DILI, there are great overlaps regarding laboratory and histological parameters between DILI and autoimmune hepatitis (AIH). Differentiating DILI and AIH can therefore be challenging, especially at the time of presentation. In addition, there are other immunologically mediated DILI phenotypes, in particular the newly defined drug-induced autoimmune-like hepatitis (DI-ALH) and liver injuries caused by checkpoint inhibitors (CPI). DI-ALH is characterized by autoimmune features and good responses towards corticosteroids, with the difference that DI-ALH mostly does not relapse after discontinuation of corticosteroids. CPI-induced liver injury has become more frequent with the rising use of those drugs and is characterized by a distinct histopathological pattern with granulomatous hepatitis and infiltration dominated by cytotoxic T cells. Similarly, the recently recognized liver injury following vaccinations also shows an autoimmune phenotype; however, in contrast to AIH, cytotoxic T cells seem to dominate the inflammatory infiltrates in the liver.

Validation of the revised electronic version of RUCAM for diagnosis of DILI in Chinese patients

BACKGROUND AIMS

The Revised Electronic Causality Assessment Method (RECAM), a computerized update of the Roussel Uclaf Causality Assessment Methodology (RUCAM), was recently proposed. In this study, we validated and compared the utility of the RECAM and RUCAM in Chinese patients with a single conventional or herbal agent-induced liver injury.

METHODS

In this retrospective multicenter cohort of well-established DILI and non-DILI patients from 5 centers in China, the diagnostic performance of the RUCAM and RECAM was compared by AUC analysis. The consistency was evaluated by weighted kappa. The major causes of discrepancy were explored.

RESULTS

A total of 481 DILI and 100 non-DILI patients were included. In total, 62.6% of the DILI cases were induced by conventional agents, and 37.4% were induced by herbs. The RECAM had relatively higher AUC than RUCAM for overall [0.947 (0.926-0.964) vs. 0.867 (0.836-0.893), p=0.0016], conventional agents [0.923 (0.890-0.949) vs. 0.819 (0.775-0.858), p=0.0185], and herbs [0.972 (0.941-0.989) vs.0.911 (0.866-0.944), p=0.0199]. Latency, scores associated with hepatitis B, and hepatotoxicity information of the insulting drugs were the 3 main causes for the inconsistency between RECAM and RUCAM scores.

CONCLUSIONS

The RECAM had relatively better diagnostic performance than RUCAM, with a higher AUC for Chinese DILI patients. Timely updates of the LiverTox category and refinement of serum markers to exclude hepatitis B activity would further improve the applicability of RECAM in areas where the use of herbs and resolution of past HBV infections are common.

Pterostilbene-Loaded Soluplus/Poloxamer 188 Mixed Micelles for Protection against Acetaminophen-Induced Acute Liver Injury

Excessive acetaminophen (APAP) induces excess reactive oxygen species (ROS), leading to liver damage. Pterostilbene (PTE) has excellent antioxidant and anti-inflammatory activities, but poor solubility limits its biological activity. In this study, we prepared PTE-loaded Soluplus/poloxamer 188 mixed micelles (PTE-MMs), and the protective mechanism against APAP-induced liver injury was investigated. In vitro results showed that PTE-MMs protected H₂O₂-induced HepG2 cell proliferation inhibition, ROS accumulation, and mitochondrial membrane potential destruction. Immunofluorescence results indicated that PTE-MMs significantly inhibited H₂O₂-induced DNA damage and cGAS-STING pathway activation. For in vivo protection studies, PTE-MMs (25 and 50 mg/kg) were administered orally for 5 days, followed by APAP (300 mg/kg). The results showed that APAP significantly induced injury in liver histopathology as well as an increase in serum aspartate aminotransferase and alanine aminotransferase levels. Moreover, the above characteristics of APAP-induced acute liver injury were inhibited by PTE-MMs. In addition, APAP-induced changes in the activities of antioxidant enzymes such as SOD and GSH in liver tissue were also inhibited by PTE-MMs. Immunohistochemical results showed that PTE-MMs inhibited APAP-induced DNA damage and cGAS-STING pathway activation in liver tissues. For in vivo therapeutic effect study, mice were first given APAP (300 mg/kg), followed by oral administration of PTE-MMs (50 mg/kg) for 3 days. The results showed that PTE-MMs exhibited promising therapeutic effects on APAP-induced acute liver injury. In conclusion, our study shows that the Soluplus/poloxamer 188 MM system has the potential to enhance the biological activity of PTE in the protection and therapeutic of liver injury.

Osimertinib-related liver injury with successful osimertinib rechallenge: A case report

Osimertinib is approved as the first‐line treatment for advanced non‐small cell lung cancer patients with epidermal growth factor (EGFR) mutation and for patients who develop EGFR T790M mutation during EGFR tyrosine kinase inhibitor (TKI) treatment and disease progression. Asymptomatic elevation of aminotransferase levels is commonly observed during TKI treatment; however, significant hepatotoxicity is infrequent. Here, we report a patient with osimertinib‐related drug‐induced liver injury who was successfully managed with osimertinib rechallenge.

Alanine Aminotransferase and Bilirubin Dynamic Evolution Pattern as a Novel Model for the Prediction of Acute Liver Failure in Drug-Induced Liver Injury

Aims: To develop, optimize, and validate a novel model using alanine aminotransferase (ALT) and total bilirubin (TB) dynamic evolution patterns in predicting acute liver failure (ALF) in drug-induced liver injury (DILI) patients.

Methods: The demographics, clinical data, liver biopsy, and outcomes of DILI patients were collected from two hospitals. According to the dynamic evolution of ALT and TB after DILI onset, the enrolled patients were divided into ALT-mono-peak, TB-mono-peak, double-overlap-peak, and double-separate-peak (DSP) patterns and compared. Logistic regression was used to develop this predictive model in both discovery and validation cohorts.

Results: The proportion of ALF was significantly higher in patients with the DSP pattern than in the ALT-mono-peak pattern and DOP pattern (10.0 vs. 0.0% vs. 1.8%,p < 0.05). The area under receiver operating characteristic curve (AUROC) of the DSP pattern model was 0.720 (95% CI: 0.682–0.756) in the discovery cohort and 0.828 (95% CI: 0.788–0.864) in the validation cohort in predicting ALF, being further improved by combining with international normalized ratio (INR) and alkaline phosphatase (ALP) (AUROC in the discovery cohort: 0.899; validation cohort: 0.958). Histopathologically, patients with the DSP pattern exhibited a predominantly cholestatic hepatitis pattern (75.0%, p < 0.05) with a higher degree of necrosis (29.2%, p = 0.084).

Conclusion: DILI patients with the DSP pattern are more likely to progress to ALF. The predictive potency of the model for ALF can be improved by incorporating INR and ALP. This novel model allows for better identification of high-risk DILI patients, enabling timely measures to be instituted for better outcome.

Challenges and Future of Drug-Induced Liver Injury Research-Laboratory Tests

Drug-induced liver injury (DILI) is a rare but potentially severe adverse drug event, which is also a major cause of study cessation and market withdrawal during drug development. Since no acknowledged diagnostic tests are available, DILI diagnosis poses a major challenge both in clinical practice as well as in pharmacovigilance. Differentiation from other liver diseases and the identification of the causative agent in the case of polymedication are the main issues that clinicians and drug developers face in this regard. Thus, efforts have been made to establish diagnostic testing methods and biomarkers in order to safely diagnose DILI and ensure a distinguishment from alternative liver pathologies. This review provides an overview of the diagnostic methods used in differential diagnosis, especially with regards to autoimmune hepatitis (AIH) and drug-induced autoimmune hepatitis (DI-AIH), in vitro causality methods using individual blood samples, biomarkers for diagnosis and severity prediction, as well as experimental predictive models utilized in pre-clinical settings during drug development regimes.

The anti-inflammatory effects of Akkermansia muciniphila and its derivates in HFD/CCL4-induced murine model of liver injury

Inflammation plays a critical role in the promotion of hepatocyte damage and liver fibrosis. In recent years the protective role of Akkermansia muciniphila, a next-generation beneficial microbe, has been suggested for metabolic and inflammatory disorders. In this study, we aimed to evaluate the effects of live and pasteurized A. muciniphila and its extra cellular vesicles (EVs) on inflammatory markers involved in liver fibrosis in a mouse model of a high-fat diet (HFD)/carbon tetrachloride (CCl₄)-induced liver injury. Firstly, the responses of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs were examined in the quiescent and LPS-activated LX-2 cells. Next, the anti-inflammatory effects of different forms of A. muciniphila were examined in the mouse model of HFD/CCl₄-induced liver injury. The gene expression of various inflammatory markers was evaluated in liver, colon, and white adipose tissues. The cytokine secretion in the liver and white adipose tissues was also measured by ELISA. The results showed that administration of live and pasteurized A. muciniphila and its EVs leads to amelioration in HSCs activation. Based on data obtained from the histopathological analysis, an improvement in gut health was observed through enhancing the epithelium and mucosal layer thickness and strengthening the intestinal integrity in all treatments. Moreover, live A. muciniphila and its EVs had inhibitory effects on liver inflammation and hepatocytes damage. In addition, the tissue cytokine production and inflammatory gene expression levels revealed that live A. muciniphila and its EVs had more pronounced anti-inflammatory effects on liver and adipose tissues. Furthermore, EVs had better effects on the modulation of gene expression related to TLRs, PPARs, and immune response in the liver. In conclusion, the present results showed that oral administration of A. muciniphila and its derivatives for four weeks could enhance the intestinal integrity and anti-inflammatory responses of the colon, adipose, and liver tissues and subsequently prevent liver injury in HFD/CCL₄ mice.

Detailed Molecular Mechanisms Involved in Drug-Induced Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis: An Update

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are some of the biggest public health challenges due to their spread and increasing incidence around the world. NAFLD is characterized by intrahepatic lipid deposition, accompanied by dyslipidemia, hypertension, and insulin resistance, leading to more serious complications. Among the various causes, drug administration for the treatment of numerous kinds of diseases, such as antiarrhythmic and antihypertensive drugs, promotes the onset and progression of steatosis, causing drug-induced hepatic steatosis (DIHS). Here, we reviewed in detail the major classes of drugs that cause DIHS and the specific molecular mechanisms involved in these processes. Eight classes of drugs, among the most used for the treatment of common pathologies, were considered. The most diffused mechanism whereby drugs can induce NAFLD/NASH is interfering with mitochondrial activity, inhibiting fatty acid oxidation, but other pathways involved in lipid homeostasis are also affected. PubMed research was performed to obtain significant papers published up to November 2021. The key words included the class of drugs, or the specific compound, combined with steatosis, nonalcoholic steatohepatitis, fibrosis, fatty liver and hepatic lipid deposition. Additional information was found in the citations listed in other papers, when they were not displayed in the original search.

Hepatoprotective Activity of Pirdot Leaves (Saurauia vulcani Korth) Ethanol Extract in Laboratory Rats (Rattus norvegicus) and Characterization of Bioactive Compounds Using a Molecular Docking Approach

AIM: The hepatoprotective activities of  bioactive compounds Pirdot were investigated in vivo and in silico. METHODS: In this study, the completely randomized design non-factorial was experimentally to assess the value of SGPT and SGOT and twenty four adult male rats were divided into four groups : group G0, control group; group G1, a treated group received 0.1 ml sheep red blood cell; group G2, a treated group received 500 mg ethanol extract Pirdot; group G3, a group treated received 500 mg ethanol extract Pirdot and 0,1 ml sheep red blood cell. On thirty one days of treatment, the blood of all rats group were taken to value SGPT and SGOT using DiaLab kit. Furthermore, the molecular docking study was done to analyse molecular interaction that COX-2 and  TNF-α were the primary target protein of bioactive compounds of Pirdot associated with hepatoprotective activities. In addition, it tends to be the target of non-steroidal anti-inflammatory drugs such as Ibuprofen. RESULTS: The results show SGOT and SGPT value significantly [p<0.05] decreased on Group G2 and G3. Moreover, the bioactive compounds of Pirdot, such as Pomolic acid and Ursolic acid tend to be the potential compound on liver protection. Moreover, Pomolic acid has a good binding affinity -14.6 kcal mol-1 with COX-2 Protein and the binding affinity of cis-3-O-p-hydroxycinnamoyl Ursolic acid was -15.1 kcal mol-1 associated with TNF-α Protein. CONLUSION:  Pirdot Leaves (Saurauia vulcani Korth.)  Ethanol Extract showed Hepatoprotective activity in rats (Rattus norvegicus). Molecular docking approach showed that pomolic acid has a good binding affinity with COX-2 Protein and TNF-α Protein.

Pathology of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a relatively rare non-resolving chronic liver disease, which mainly affects women. It is characterized by hypergammaglobulinemia, circulating autoantibodies, interface hepatitis on liver histology and a favourable response to immunosuppression. The putative mechanism for the development of autoimmune hepatitis is thought to be the interaction between genetic predisposition, environmental triggers and failure of the native immune system.

AIH still remains a major diagnostic and therapeutic challenge, mainly because it is a very heterogeneous disease. Prompt and timely diagnosis is crucial since, if left untreated, AIH has a high mortality rate. Histological demonstration of hepatitis is required for the diagnosis of AIH and, therefore, liver biopsy is mandatory in the initial diagnostic work-up, before treatment. In this review, we summarize the histological features of AIH with the main aim of highlighting the most important clinical-pathological hallmarks useful in the routine diagnostic practice.

Hepatic manifestations of drug reaction with eosinophilia and systemic symptoms syndrome

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life-threatening drug reaction, which can affect multiple organs. Patients with DRESS syndrome and hepatic manifestations may present alterations ranging from mild hepatitis to acute liver failure. The diagnosis might be difficult, and the management of these patients is challenging. This report analyzes a series of five cases reporting the clinical presentation, which ranged from acute hepatitis to liver failure, and discussed their treatment.

Dual-Colored Fluorescence Imaging of Mitochondrial HNO and Golgi-HNO in Mice with DILI

Drug-induced liver injury (DILI) is the most common reason for the post-marketing withdrawal of drugs. Poor understanding of the mechanisms of DILI presents a large challenge in clinical diagnosis. Previous evidences indicate a potential relationship between reactive nitrogen species (RNS) and DILI. Hence, we developed two specific probes, Golgi-HNO and Mito-HNO, for the multicolored and simultaneous in situ imaging of nitroxyl (HNO) in the Golgi apparatus and mitochondria, respectively. We discovered a significant rise in HNO levels in the livers of mice with DILI, which means that for the first time, we revealed a positive correlation between HNO levels and DILI. Based on changes in the HNO level, we also successfully explored the extent of liver damage induced by an anticarcinogen, bleomycin. In addition, we uncovered catalase was involved in HNO synthesis, which is the unprecedented function of catalase. These findings demonstrate that HNO is an ideal biomarker for DILI diagnosis, and Golgi-HNO and Mito-HNO are ideal fluorescent probes to study in situ HNO changes in various physiological and biochemical processes.

Chronic Drug-Induced Liver Injury: Updates and Future Challenges

Chronic drug-induced liver injury (DILI), defined as DILI with persistent liver injury more than one year after the first onset by the latest European guidelines, is a notable challenge globally with big issues of defining causality and establishing effective treatment. About 20% of patients with DILI develop into chronic DILI. Chronic DILI manifests as persistent or repeated inflammatory or diminishing bile ducts, even progresses to cirrhosis and needs liver transplantation eventually. However, research on chronic DILI over the last decades is still lacking, and the incidence, phenotypes, mechanisms, risk factors, and treatment have not been fully understood. In this paper, we reviewed the definition of chronic DILI, updated clinical studies in terms of incidence, special manifestations, and promising risk factors of chronic DILI, along with the recent progress and challenges in glucocorticoid therapy.

Immune-mediated drug-induced liver injury secondary to Omeprazole: A case report

Omeprazole is a rare cause of DILI with autoimmune hepatitis features and should be considered when seeing patients with acute liver injury. The causative drug should be promptly identified and discontinued to avoid any permanent liver damage.

Comparison of diagnostic accuracy of 3 diagnostic criteria combined with refined pathological scoring system for drug-induced liver injury

Drug-induced liver injury (DILI) is difficult in diagnose, criteria used now are mostly based on history review. We tried to evaluate the value of these criteria and histopathology features in DILI to perform a method diagnosing DILI more definitely.We enrolled 458 consecutive hospitalized DILI patients from January 1, 2012 to December 31, 2018, using Roussel-Uclaf Causality Assessment Method (RUCAM), Maria & Victorino scale (M&V), and Digestive Disease Week-Japan criterion (DDW-J) combined with refined pathological scoring system respectively to perform the evaluation.A total of 458 DILI patients were enrolled, the area under receiver operating characteristics (AUROC) of the 3 clinical diagnostic criteria were 0.730 (95% confidence interval [CI]: 0.667-0.793), 0.793 (95% CI: 0.740-0.847), and 0.764 (95% CI: 0.702-0.826) respectively. Three hundred two DILI patients' liver biopsies were included: steatosis in 204 cases (67.5%), cholestasis in 151 cases (50%), cell apoptosis in 139 cases (46%), eosinophil granulocyte infiltration in 131 cases (43.4%), central and/or portal phlebitis in 103 cases (34.1%), iron deposition in 90 cases (29.8%), and pigmented macrophages in 92 cases (30.5%). The AUROC of refined pathological scale combined with 3 criteria were 0.843 (95% CI: 0.747-0.914), 0.907 (95% CI: 0.822-0.960), and 0.881 (95% CI: 0.790-0.942) respectively. In hepatocellular type, the AUROCs were 0.894 (95% CI: 0.787-0.959), 0.960 (95% CI: 0.857-0.994), and 0.940 (95% CI: 0.847-0.985); in cholestatic type, the AUROCs were 0.750 (95% CI: 0.466-0.931), 0.500 (95% CI: 0.239-0.761), and 0.500 (95% CI: 0.239-0.761); in mixed type, the AUROCs were 0.786 (95% CI: 0.524-0.943), 0.869 (95% CI: 0.619-0.981), and 0.762 (95% CI: 0.498 to -0.930).Combined with pathological scale can significantly improve the accuracy of clinical diagnostic criteria, no matter in alone or combined condition, M&V might be more accurate in diagnosing DILI from suspected patients.

Drug induced liver injury: an update

Drug induced liver injury (DILI) is a relatively rare hepatic condition in response to the use of medications, illegal drugs, herbal products or dietary supplements. It occurs in susceptible individuals through a combination of genetic and environmental risk factors believed to modify drug metabolism and/or excretion leading to a cascade of cellular events, including oxidative stress formation, apoptosis/necrosis, haptenization, immune response activation and a failure to adapt. The resultant liver damage can present with an array of phenotypes, which mimic almost every other liver disorder, and varies in severity from asymptomatic elevation of liver tests to fulminant hepatic failure. Despite recent research efforts specific biomarkers are not still available for routine use in clinical practice, which makes the diagnosis of DILI uncertain and relying on a high degree of awareness of this condition and the exclusion of other causes of liver disease. Diagnostic scales such as the CIOMS/RUCAM can support the causality assessment of a DILI suspicion, but need refinement as some criteria are not evidence-based. Prospective collection of well-vetted DILI cases in established DILI registries has allowed the identification and validation of a number of clinical variables, and to predict a more severe DILI outcome. DILI is also in need of properly designed clinical trials to evaluate the efficacy of new DILI treatments as well as older drugs such as ursodeoxycholic acid traditionally used to ameliorate cholestasis or corticosteroids now widely tried in the oncology field to manage the emergent type of hepatotoxicity related to immune checkpoint inhibitors.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

Drug-Induced Liver Injury in GI Practice

Although drug-induced liver injury (DILI) is a rare clinical event, it carries significant morbidity and mortality, leaving it as the leading cause of acute liver failure in the United States. It is one of the most challenging diagnoses encountered by gastroenterologists. The development of various drug injury networks has played a vital role in expanding our knowledge regarding drug-related and herbal and dietary supplement-related liver injury. In this review, we discuss what defines liver injury, epidemiology of DILI, its biochemical and pathologic patterns, and management.

Clinicopathological features of Bu Gu Zhi-induced liver injury, a long-term follow-up cohort study

BACKGROUND & AIMS

Bu Gu Zhi (BGZ) is a Chinese herb consumed mainly for osteoporosis treatment. Only small case series of BGZ-induced liver injury (BGZILI) have been reported. We describe the clinicopathological features and clinical course of BGZILI.

METHODS

Patients diagnosed with drug-induced liver injury (DILI) at Beijing Friendship Hospital from 2005 to 2017 were reviewed. Clinical and follow-up data were analysed.

RESULTS

Of the 547 DILI patients, 40 cases (7.3%) were attributed to BGZILI. About 34/40 (85.0%) patients were females with a median age of 63 (range, 54-70) years. The median latency period was 45 (range, 29-90) days. Patients commonly presented with loss of appetite (57.5%), dark urine (57.5%) and fatigue (55.0%). The median level of alanine aminotransferase and aspartate aminotransferase at BGZILI onset was 673.5 and 423.0 U/L respectively. Total bilirubin (TB) and direct bilirubin (DB) were 59.0 and 39.4 µmol/L respectively. The biochemical liver injury pattern was hepatocellular (92.5%), cholestatic (5.0%) and mixed (2.5%). They were categorized into 'mild' (N = 23, 57.5%), 'moderate' (6, 15.0%) or 'severe' (11, 27.5%) according to severity assessment by DILI network. The main histological injury pattern in 9/40 patients with liver biopsy was acute hepatitis with/without cholestasis. Median duration of follow-up was 26.3 months with recovery in 37 patients within 6 months. No patients died or required transplantation.

CONCLUSIONS

BGZ-induced liver injury manifested more often as a hepatocellular injury pattern with mild to moderate hepatocellular damage. Most patients recovered after cessation of BGZ within 6 months, and none developed end-stage liver disease or died.

Diagnostic and prognostic assessment of suspected drug-induced liver injury in clinical practice

Idiosyncratic drug-induced liver injury (DILI) is a challenging liver disorder because it can present with a range of phenotypes, mimicking almost every other hepatic disease, and lacks specific biomarkers for its diagnosis. Hence, a confident DILI diagnosis is seldom possible as it relies on the precise establishment of a temporal sequence between the exposure to a given prescription drug or sometimes hidden herbal product/over the counter medication as well as the exclusion of other aetiologies of liver disease. However, an accurate diagnosis is of most importance, as prompt withdrawal of the causative agent is essential in DILI management. Indeed, DILI can be severe and even fatal or in a fraction of cases evolve to chronic damage, but specific biomarkers for predicting mortality/liver transplantation or a chronic outcome in the very early phases of DILI are not yet available. In this article, we discuss the best diagnostic and prognostic approach of a DILI suspicion by judiciously choosing and interpreting the standard tests currently used in clinical practice.

Histologic pattern is better correlated with clinical outcomes than biochemical classification in patients with drug-induced liver injury

Histologically, drug-induced liver injury could be classified into acute hepatitis, chronic hepatitis, acute cholestasis, chronic cholestasis, and cholestatic hepatitis. The correlation between these histologic patterns and long-term clinical outcomes has not been well established. Therefore, we conducted a retrospective cohort study to investigate the association of histologic patterns and long-term clinical outcomes defined as biochemical normalization, persistent abnormal liver biochemistry or death at designated time points. In this study, biochemical classification was determined by R-values; histologic injury pattern was determined by morphological features. Predictive ability of clinical outcomes by these two classifications was assessed using Receiver Operating Characteristic Curves. Logistic regression was performed to identify histologic factors associated with outcomes. Totally, 88 patients with drug-induced liver injury were included for final analysis. Biochemical and histologic classification were consistent in 50 (57%) cases. 53 (60%) cases showed biochemical normalization within 6 months, and a further 11 (13%), 16 (18%), and 6 (7%) cases within 1, 2, and 3 years, respectively. Compared with biochemical classification, histologic injury pattern had better predictive ability for abnormal biochemistry at 6 months (Areas under Receiver Operating Characteristic Curves 0.92 versus 0.60, P < 0.001) and 1 year (Areas under Receiver Operating Characteristic Curves 0.94 versus 0.69, P < 0.001). Interlobular bile duct loss in >25% portal areas was independently associated with abnormal biochemistry at 6 months, 1 year, and 2 years. In conclusion, histologic injury pattern is better correlated with clinical outcome at 6 months and 1 year than biochemical classification. Moderate bile duct loss is an important histologic feature associated with persistent biochemical abnormality at 6 months, 1 year, and 2 years.

Translating new knowledge on drug-induced liver injury into clinical practice

Drug-induced liver injury (DILI) is one of the main reasons for drug withdrawal from the market, and a cause of worldwide morbidity. Although several issues on DILI are still unsolved, there have been significant advances in new definitions and diagnosis tools. DILI is the result of a complex interaction between genetic and environmental factors, and constitutes an expanding area of investigation. DILI can mimic virtually all known hepatopathies, including vascular disorders and liver tumours. As part of this broad spectrum of clinical presentations, DILI severity ranges from asymptomatic elevations of aminotransferases to acute liver failure. Although biomarkers are emerging as valuable diagnostic tools, they are not available in clinical practice. Accurate DILI diagnosis is a challenging issue, particularly the establishing of causal relationships with the culprit agent and the exclusion of competing causes of liver injury. Given that the understanding of the mechanisms inducing DILI is growing, and both DILI causality assessment scales and the performance of international DILI networks have been improved, hepatotoxicity may be recognised earlier in clinical practice. In this review, advances and results obtained by DILI registries around the world, case characterisations, particularly those relevant to newer definitions in DILI, and the behaviour of chronic liver disease induced by drugs will be updated. In addition, recently published data on herbal and dietary supplements and new predictive scores for acute liver failure assessment will also be discussed.

Drug-induced liver injury: a safety review

INTRODUCTION

Idiosyncratic drug-induced liver injury (DILI) remains one of the most important causes of drug attrition both in the early phases of clinical drug development and in the postmarketing scenario. This is because, in spite of emerging data on genetic susceptibility variants associated to the risk of hepatotoxicity, the precise identification of the individual who will develop DILI when exposed to a given drug remains elusive.

AREAS COVERED

In this review, we have addressed recent progress made and initiatives taken in the field of DILI from a safety perspective through a comprehensive search of the literature.

EXPERT OPINION

Despite the substantial progress made over this century, new approaches using big data analysis to characterize the true incidence of DILI are needed and to categorize the drugs' hepatotoxic potential. Genetic studies have highlighted the role of the adaptive immune system yet the mechanisms leading adaptation versus progression remain to be elucidated. There is a compelling need for development and qualification of sensitive, specific, and affordable biomarkers in DILI to foster drug development, patient treatment stratification and, improvement of causality assessment methods. Gaining mechanistic insights in DILI is essential to uncover therapeutic targets and design prospective clinical trials with appropriate endpoints.