Worldwide Use of RUCAM for Causality Assessment in 81,856 Idiosyncratic DILI and 14,029 HILI Cases Published 1993-Mid 2020: A Comprehensive Analysis

Liver Injury in Immune Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Five New Classification Types

Liver injury in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) is a multifaceted disorder, lacking cohort homogeneity due to a variety of potential causes, including drugs, arsenic and other heavy metals, glyphosate, infections, and ultraviolet radiation. The goals of this review were (1) to analyze the role of diagnostic algorithms in assessing causality for potential culprits involved in the development of liver injury associated with immune-mediated SJS and TEN, which represent immune-based variant disorders within a continuous spectrum. Milder forms are classified as SJS or SJS/TEN overlap, while TEN is known as the most serious form; and (2) to interpret the findings that allow for the characterization of the different types of these disorders. The manuscript is based on an extensive literature search for single case reports, case cohorts, and review articles. Search terms included: Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, and specific diagnostic algorithms such as the Roussel Uclaf Causality Assessment Method (RUCAM) and the Algorithm of Drug Causality for Epidermal Necrolysis (ALDEN). For the purpose of basic feature description, the uniform term SJS/TEN is used in the current analysis. SJS/TEN presents with five different cohort types: SJS/TEN type (1), which refers to a cohort of SJS/TEN caused by drugs, as assessed by both ALDEN and RUCAM; type (2), representing SJS/TEN due to drugs and assessed by ALDEN only, but not by RUCAM; type (3), which includes a cohort of SJS/TEN caused by drugs, assessed by non-ALDEN and non-RUCAM tools; type (4), which focuses on a cohort of SJS/TEN caused by non-drug culprits, assessed by various tools; and type (5), which considers a cohort of SJS/TEN caused by unknown culprits. Using this new SJS/TEN typology will help better characterize individual features, personalize treatment, and clarify pathogenetic specifics for each of the five disease types. This new SJS/TEN typology provides clarity by replacing issues of inhomogeneity with cohort homogeneity.

Persistent hepatocyte secretory failure in lopinavir/ritonavir related to drug-induced liver injury: a case report

Lopinavir/ritonavir, an anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drug, may be associated with the development of liver injury. In this paper, we reported an elderly female patient with drug-induced liver injury secondary to lopinavir/ritonavir, which was evaluated for their causality using the updated Roussel Uclaf Causality Assessment Method (RUCAM) of 2016. She had a RUCAM score of 8 which was equivalent to a probable causality grading. Her clinical course was complicated by persistent hepatocyte secretion failure (PHSF), followed by septic shock and SARS-CoV-2 re-infection during her hospitalization. Her response to any medical intervention, including ursodeoxycholic acid, glutathione, methylprednisolone sodium succinate, rifampicin, artificial liver support, and endoscopic nasobiliary drainage (ENBD) was very poor, and her family members refused liver transplantation. Finally, she died. In summary, this case suggests the possibility that lopinavir/ritonavir can cause DILI and even PHSF in our clinical practice.

Liver Injury in People With HIV on Antituberculosis and/or Antiretroviral Therapy-Assessing Causality Using the Updated Roussel Uclaf Causality Assessment Method

PURPOSE

We compared performance of the Roussel Uclaf Causality Assessment Method (RUCAM) with multidisciplinary expert panel review in identifying a drug-induced liver injury (DILI) due to antituberculosis therapy (ATT) and/or antiretroviral therapy (ART).

METHODS

Cases were drawn from a prospective registry of hospitalised adults with suspected DILI due to ATT and/or ART in Cape Town, South Africa. Participants had to fulfil American Thoracic Society criteria for ATT interruption (alanine transaminase [ALT] ≥5 times upper limit of normal [ULN]/ALT ≥3 times [ULN] and symptomatic). Causality assessment by expert panel review served as reference standard. The panel ranked potentially implicated drugs as certain, probable, possible or unlikely causes guided by World Health Organization Uppsala Monitoring Centre criteria. The RUCAM was performed for each potentially implicated drug. We calculated sensitivity and specificity of the RUCAM in identifying a probable/certain drug cause for liver injury.

RESULTS

We included 48 participants. All were people with HIV (PWH). Twenty-seven were on concomitant ART and ATT, with a median of six potentially hepatotoxic drugs per case. Sensitivity and specificity of the RUCAM in identifying a probable/certain drug cause of liver injury compared with expert panel review was 7% and 100% respectively. Implicated drugs (times ranked probable/certain by panel) were isoniazid (18/0), pyrazinamide (17/0), rifampicin (15/1), efavirenz (6/4) and lopinavir/ritonavir (1/0).

CONCLUSIONS

PWH with liver injury received multiple potentially implicated drugs, which may increase liver injury risk and complicate causality assessment. Compared with expert panel review, the RUCAM had low sensitivity in detecting probable or certain drug causes of liver injury.

Copper, Iron, Cadmium, and Arsenic, All Generated in the Universe: Elucidating Their Environmental Impact Risk on Human Health Including Clinical Liver Injury

Humans are continuously exposed to various heavy metals including copper, iron, cadmium, and arsenic, which were specifically selected for the current analysis because they are among the most frequently encountered environmental mankind and industrial pollutants potentially causing human health hazards and liver injury. So far, these issues were poorly assessed and remained a matter of debate, also due to inconsistent results. The aim of the actual report is to thoroughly analyze the positive as well as negative effects of these four heavy metals on human health. Copper and iron are correctly viewed as pollutant elements essential for maintaining human health because they are part of important enzymes and metabolic pathways. Healthy individuals are prepared through various genetically based mechanisms to maintain cellular copper and iron homeostasis, thereby circumventing or reducing hazardous liver and organ injury due to excessive amounts of these metals continuously entering the human body. In a few humans with gene aberration, however, liver and organ injury may develop because excessively accumulated copper can lead to Wilson disease and substantial iron deposition to hemochromatosis. At the molecular level, toxicities of some heavy metals are traced back to the Haber Weiss and Fenton reactions involving reactive oxygen species formed in the course of oxidative stress. On the other hand, cellular homeostasis for cadmium and arsenic cannot be provided, causing their life-long excessive deposition in the liver and other organs. Consequently, cadmium and arsenic represent health hazards leading to higher disability-adjusted life years and increased mortality rates due to cancer and non-cancer diseases. For unknown reasons, however, liver injury in humans exposed to cadmium and arsenic is rarely observed. In sum, copper and iron are good for the human health of most individuals except for those with Wilson disease or hemochromatosis at risk of liver injury through radical formation, while cadmium and arsenic lack any beneficial effects but rather are potentially hazardous to human health with a focus on increased disability potential and risk for cancer. Primary efforts should focus on reducing the industrial emission of hazardous heavy metals.

Drug-induced liver injury secondary to tamoxifen

Tamoxifen is a non-steroidal selective oestrogen receptor modulator commonly used in the treatment of breast cancer. It is associated with the development of fatty liver and steatohepatitis however drug-induced liver injury is rare. We report a woman in her 50s who developed malaise with an acute moderate aminotransferase elevation without jaundice 6 months after starting tamoxifen. She was not commenced on any other recent drugs and extensive investigation including infective and autoimmune liver screen, cross-sectional imaging and FibroScan were unremarkable. Liver biopsy revealed moderate lobular hepatitis with hepatocyte drop-out. Tamoxifen was ceased and the liver enzymes showed resolution over the following 3 months and improvement of her symptoms.

Wilson Disease: Copper-Mediated Cuproptosis, Iron-Related Ferroptosis, and Clinical Highlights, with Comprehensive and Critical Analysis Update

Wilson disease is a genetic disorder of the liver characterized by excess accumulation of copper, which is found ubiquitously on earth and normally enters the human body in small amounts via the food chain. Many interesting disease details were published on the mechanistic steps, such as the generation of reactive oxygen species (ROS) and cuproptosis causing a copper dependent cell death. In the liver of patients with Wilson disease, also, increased iron deposits were found that may lead to iron-related ferroptosis responsible for phospholipid peroxidation within membranes of subcellular organelles. All topics are covered in this review article, in addition to the diagnostic and therapeutic issues of Wilson disease. Excess Cu2+ primarily leads to the generation of reactive oxygen species (ROS), as evidenced by early experimental studies exemplified with the detection of hydroxyl radical formation using the electron spin resonance (ESR) spin-trapping method. The generation of ROS products follows the principles of the Haber-Weiss reaction and the subsequent Fenton reaction leading to copper-related cuproptosis, and is thereby closely connected with ROS. Copper accumulation in the liver is due to impaired biliary excretion of copper caused by the inheritable malfunctioning or missing ATP7B protein. As a result, disturbed cellular homeostasis of copper prevails within the liver. Released from the liver cells due to limited storage capacity, the toxic copper enters the circulation and arrives at other organs, causing local accumulation and cell injury. This explains why copper injures not only the liver, but also the brain, kidneys, eyes, heart, muscles, and bones, explaining the multifaceted clinical features of Wilson disease. Among these are depression, psychosis, dysarthria, ataxia, writing problems, dysphagia, renal tubular dysfunction, Kayser-Fleischer corneal rings, cardiomyopathy, cardiac arrhythmias, rhabdomyolysis, osteoporosis, osteomalacia, arthritis, and arthralgia. In addition, Coombs-negative hemolytic anemia is a key feature of Wilson disease with undetectable serum haptoglobin. The modified Leipzig Scoring System helps diagnose Wilson disease. Patients with Wilson disease are well-treated first-line with copper chelators like D-penicillamine that facilitate the removal of circulating copper bound to albumin and increase in urinary copper excretion. Early chelation therapy improves prognosis. Liver transplantation is an option viewed as ultima ratio in end-stage liver disease with untreatable complications or acute liver failure. Liver transplantation finally may thus be a life-saving approach and curative treatment of the disease by replacing the hepatic gene mutation. In conclusion, Wilson disease is a multifaceted genetic disease representing a molecular and clinical challenge.

Human Leucocyte Antigen Genetics in Idiosyncratic Drug-Induced Liver Injury with Evidence Based on the Roussel Uclaf Causality Assessment Method

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.

Dietary Supplement-Induced Hepatotoxicity: A Clinical Perspective

The consumption of dietary supplements (DS) has resulted in a significant and escalating number of cases involving liver injury. It is crucial for clinicians and consumers to be well informed about the adverse effects of such products, leading to their discontinuation and timely reporting of any harmful cases. This article delves into the clinical perspective of DS-related hepatotoxicity, highlighting key concepts such as a systematic diagnostic approach. The discussion extends to notable examples of both currently popular and potential future dietary supplements, such as garcinia cambogia, turmeric, and ashwagandha, accompanied by an overview of recent findings. Causality assessment tools play a crucial role in establishing a connection between these products and instances of liver injury, with consideration of the advantages and disadvantages associated with their use. Fostering a comprehensive understanding of regulatory standards, coupled with a solid foundation of knowledge of DS, will prove instrumental in preventing DS-related hepatotoxicity. Achieving this goal requires collaborative efforts from both consumers and clinicians.

Diagnosis, toxicological mechanism, and detoxification for hepatotoxicity induced by pyrrolizidine alkaloids from herbal medicines or other plants

Pyrrolizidine alkaloids (PAs) are one type of phytotoxins distributed in various plants, including many medicinal herbs. Many organs might suffer injuries from the intake of PAs, and the liver is the most susceptible one. The diagnosis, toxicological mechanism, and detoxification of PAs-induced hepatotoxicity have been studied for several decades, which is of great significance for its prevention, diagnosis, and therapy. When the liver was exposed to PAs, liver sinusoidal endothelial cells (LSECs) loss, hemorrhage, liver parenchymal cells death, nodular regeneration, Kupffer cells activation, and fibrogenesis occurred. These pathological changes classified the PAs-induced liver injury as acute, sub-acute, and chronic type. PAs metabolic activation, mitochondria injury, glutathione (GSH) depletion, inflammation, and LSECs damage-induced activation of the coagulation system were well recognized to play critical roles in the pathological process of PAs-induced hepatotoxicity. A lot of natural compounds like glycyrrhizic acid, (-)-epicatechin, quercetin, baicalein, chlorogenic acid, and so on were demonstrated to be effective in alleviating PAs-induced liver injury, which rendered them huge potential to be developed into therapeutic drugs for PAs poisoning in clinics. This review presents updated information about the diagnosis, toxicological mechanism, and detoxification studies on PAs-induced hepatotoxicity.

Network Pharmacology Prediction and Experimental Validation of Ferulic Acid’s Protective Effects against Diclofenac‐Induced Liver Injury

Despite being one of the most consumed analgesics worldwide, liver injury is an adverse effect of diclofenac (DF). In pursuit of reliable hepatoprotective natural remedies, this study aimed to investigate the potential protective effect of ferulic acid (FA) and its mechanism against DF‐induced liver injury. Various network databases and datasets were used to collect targets corresponding to FA and DF‐induced liver injury. Enrichment analyses of common targets were performed, a protein‐protein interaction (PPI) network was constructed, the hub genes were identified, and the upstream miRNA interacting with the top hub gene was later predicted. A DF‐induced liver injury rat model was established to verify FA’s protective effects, and the selected hub gene expression level with its upstream regulatory miRNA and a downstream set of targets was examined to elucidate the underlying mechanism. A total of 18 genes were identified as potential targets of FA to protect against DF‐induced liver injury. Data from the enrichment and PPI analyses and the prediction of the upstream miRNAs indicated that the most worthwhile pair to study was miR‐296‐5p/Jun. In vivo findings showed that coadministration of FA significantly reduced the DF‐induced alterations in the liver function indices, oxidative stress, and liver histology. Mechanistically, FA downregulated the expression of Jun, Bim, Bax, Casp3, IL‐1β, IL‐6, and TNF‐α, whereas it upregulated the expression of rno‐miR‐296‐5p and Bcl2. In conclusion, combining network pharmacology and an in vivo study revealed that miR‐296‐5p/Jun axis could mediate the mitigative effect of FA against DF‐induced liver injury.

Industry Review of Best Practices for Risk Management of Drug-Induced Liver Injury from Development to Real-World Use

The relative treatment benefit of a drug for patients during development, marketing authorization review, or after approval includes an assessment of the risk of drug-induced liver injury (DILI). In this article, the Pharmacovigilance and Risk Mitigation Working Group of the IQ-DILI Initiative launched in June 2016 within the International Consortium for Innovation and Quality in Pharmaceutical Development presents and reviews three key topics for essential risk management activities to identify, characterize, monitor, mitigate, and communicate DILI risk associated with small molecules during drug development. The three topics are: (1) Current best practices for characterizing the DILI phenotype and the severity and incidence of DILI in the treatment population, including DILI identification, prediction and recovery. (2) Characterization of the relative treatment benefit for patients who will be exposed to a drug and the attendant risk of DILI in conjunction with existing global risk mitigation strategies. (3) Implementation of risk mitigation strategies during drug development highlighting patient factors, healthcare settings and site of product administration, and prescriber and healthcare provider factors. Industry guidance is provided for assessing whether the product labeling is sufficient to minimize the risk of DILI or whether a United States Food and Drug Administration (FDA) Risk Evaluation and Mitigation Strategy (REMS) or European Medicines Agency (EMA) Risk Management Plan (RMP) with additional Risk Minimization Measures (aRMM) is needed.

Drug induced liver injury - a 2023 update

Drug-Induced Liver Injury (DILI) constitutes hepatic damage attributed to drug exposure. DILI may be categorized as hepatocellular, cholestatic or mixed and might also involve immune responses. When DILI occurs in dose-dependent manner, it is referred to as intrinsic, while if the injury occurs spontaneously, it is termed as idiosyncratic. This review predominately focused on idiosyncratic liver injury. The established molecular mechanisms for DILI include (1) mitochondria dysfunction, (2) increased reactive oxygen species levels, (3) presence of elevated apoptosis and necrosis, (4) and bile duct injuries associated with immune mediated pathways. However, it should be emphasized that the underlying mechanisms responsible for DILI are still unknown. Prevention strategies are critical as incidences occur frequently, and treatment options are limited once the injury has developed. The aim of this review was to utilize retrospective cohort studies from across the globe to gain insight into epidemiological patterns. This review considers (1) what is currently known regarding the mechanisms underlying DILI, (2) discusses potential risk factors and (3) implications of the coronavirus pandemic on DILI presentation and research. Future perspectives are also considered and discussed and include potential new biomarkers, causality assessment and reporting methods.

Epidemiology and Management of Drug-induced Liver Injury: Importance of the Updated RUCAM

Drug-induced liver injury (DILI) is a major cause of acute liver injury, liver failure, and liver transplantation worldwide. In recent years, immune checkpoint inhibitors have become widely used. This has led to an increase in DILI, for which pathophysiology and management methods differ significantly from the past. As the number of cases of acute liver injury and liver transplantation due to DILI is expected to increase, information about a DILI is becoming more valuable. DILI is classified into two types according to its etiology: intrinsic DILI, in which the drug or its metabolites cause liver damage that is dose-dependent and predictable; and idiosyncratic DILI, in which liver damage is also dose-independent but unpredictable. In addition, depending on the course of the disease, chronic DILI or drug-induced autoimmune hepatitis may be present. The number of DILI cases caused by antimicrobial agents is decreasing, whereas that caused by drugs for malignant tumors and health foods is increasing. The Roussel Uclaf Causality Assessment Method is widely used to assess causality in DILI. Liver injury is a type of immune-related adverse event. The pattern of hepatic injury in immune-related adverse events is mostly hepatocellular, but mixed type and bile stasis have also been reported. Sclerosing cholangitis caused by immune checkpoint inhibitors has also been reported as a unique type of injury. Treatment mainly comprises withdrawal of immune checkpoint inhibitors and steroid administration; however, mycophenolate mofetil may be considered if the disease is refractory to steroids.

Certolizumab-induced liver injury: as assessed for causality by the updated RUCAM

We report a case of a woman in her 30s with a history of cholecystectomy, hypertension, type 2 diabetes and rheumatoid arthritis on methotrexate and certolizumab who presented with epigastric pain radiating to the right upper quadrant. Laboratory findings revealed significantly elevated liver enzymes consistent with hepatocellular liver injury. The hepatocellular pattern of liver injury, negative autoimmune serologies and improvement on cessation of certolizumab were consistent with drug-induced hepatotoxicity. We used Roussel Uclaf Causality Assessment Method to assess the likelihood of drug-induced liver injury that showed a score of 7, this was in line with a probable causality grading. Although the patient had a history of methotrexate use, the onset of symptoms and transaminitis coincided with the recent initiation of certolizumab, which was the trigger of hepatocellular injury. Liver enzymes also remained normal after the reinitiation of methotrexate on follow-up.

Drug-induced liver injury and COVID-19: Use of artificial intelligence and the updated Roussel Uclaf Causality Assessment Method in clinical practice

BACKGROUND

Liver injury is a relevant condition in coronavirus disease 2019 (COVID-19) inpatients. Pathophysiology varies from direct infection by virus, systemic inflammation or drug-induced adverse reaction (DILI). DILI detection and monitoring is clinically relevant, as it may contribute to poor prognosis, prolonged hospitalization and increase indirect healthcare costs. Artificial Intelligence (AI) applied in data mining of electronic medical records combining abnormal liver tests, keyword searching tools, and risk factors analysis is a relevant opportunity for early DILI detection by automated algorithms.

AIM

To describe DILI cases in COVID-19 inpatients detected from data mining in electronic medical records (EMR) using AI and the updated Roussel Uclaf Causality Assessment Method (RUCAM).

METHODS

The study was conducted in March 2021 in a hospital in southern Brazil. The NoHarm^© system uses AI to support decision making in clinical pharmacy. Hospital admissions were 100523 during this period, of which 478 met the inclusion criteria. From these, 290 inpatients were excluded due to alternative causes of liver injury and/or due to not having COVID-19. We manually reviewed the EMR of 188 patients for DILI investigation. Absence of clinical information excluded most eligible patients. The DILI assessment causality was possible via the updated RUCAM in 17 patients.

RESULTS

Mean patient age was 53 years (SD ± 18.37; range 22-83), most were male (70%), and admitted to the non-intensive care unit sector (65%). Liver injury pattern was mainly mixed, mean time to normalization of liver markers was 10 d, and mean length of hospitalization was 20.5 d (SD ± 16; range 7-70). Almost all patients recovered from DILI and one patient died of multiple organ failure. There were 31 suspected drugs with the following RUCAM score: Possible (n = 24), probable (n = 5), and unlikely (n = 2). DILI agents in our study were ivermectin, bicalutamide, linezolid, azithromycin, ceftriaxone, amoxicillin-clavulanate, tocilizumab, piperacillin-tazobactam, and albendazole. Lack of essential clinical information excluded most patients. Although rare, DILI is a relevant clinical condition in COVID-19 patients and may contribute to poor prognostics.

CONCLUSION

The incidence of DILI in COVID-19 inpatients is rare and the absence of relevant clinical information on EMR may underestimate DILI rates. Prospects involve creation and validation of alerts for risk factors in all DILI patients based on RUCAM assessment causality, alterations of liver biomarkers and AI and machine learning.

Meta-analysis of liver injury in patients with COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) is a major public health problem threatening human health. It can lead to multiple system complications, among which liver damage is also a common complication of COVID-19. The pathogenesis of liver injury is complex and involves the interaction of multiple factors. This study aims to investigate the incidence and risk factors of liver injury in COVID-19 patients and analyze the impact of liver injury on clinical prognosis of patients, so as to provide corresponding basis for clinical diagnosis and treatment.

METHODS

PubMed and Cochrane Library were searched in computer to collect original studies on liver injury cases, laboratory indicators and clinical outcomes in COVID-19 patients. Articles were screened according to inclusion and exclusion criteria, and data were meta-analyzed using Stata12.0 software.

RESULTS

A total of 49 studies, including 23,611 patients with COVID-19, had a prevalence of liver injury of 39.63%. Subgroup analysis found that patients in the Americas had the highest incidence of liver injury at 43.7% and lowest in Africa (25.99%). The vast majority of liver injury is manifested by aminotransferase or bilirubin levels greater than 1 times the upper limit of normal (49.16%). The older the age, the male, the associated chronic liver disease, and the higher the levels of white blood cells, neutrophils, and C-reactive protein, the higher the risk of liver injury. The use of hormones, hydroxychloroquine, and tocilizumab increases the risk of liver injury. Patients with concurrent liver injury have longer hospital stays, are more likely to progress to severe cases, and have a higher risk of death than patients without liver injury.

CONCLUSION

The incidence of liver injury in COVID-19 patients was high, affected by age, gender, chronic liver disease, inflammatory state and medication, and patients with liver injury were hospitalized longer and were more likely to have a poor prognosis. Therefore, clinical attention should be paid to early intervention.

Advances in Idiosyncratic Drug-Induced Liver Injury Issues: New Clinical and Mechanistic Analysis Due to Roussel Uclaf Causality Assessment Method Use

Clinical and mechanistic considerations in idiosyncratic drug-induced liver injury (iDILI) remain challenging topics when they are derived from mere case narratives or iDILI cases without valid diagnosis. To overcome these issues, attempts should be made on pathogenetic aspects based on published clinical iDILI cases firmly diagnosed by the original RUCAM (Roussel Uclaf Causality Assessment Method) or the RUCAM version updated in 2016. Analysis of RUCAM-based iDILI cases allowed for evaluating immune and genetic data obtained from the serum and the liver of affected patients. For instance, strong evidence for immune reactions in the liver of patients with RUCAM-based iDILI was provided by the detection of serum anti-CYP 2E1 due to drugs like volatile anesthetics sevoflurane and desflurane, partially associated with the formation of trifluoroacetyl (TFA) halide as toxic intermediates that form protein adducts and may generate reactive oxygen species (ROS). This is accompanied by production of anti-TFA antibodies detected in the serum of these patients. Other RUCAM-based studies on serum ANA (anti-nuclear antibodies) and SMA (anti-smooth muscle antibodies) associated with AIDILI (autoimmune DILI) syn DIAIH (drug-induced autoimmune hepatitis) provide additional evidence of immunological reactions with monocytes as one of several promoting immune cells. In addition, in the blood plasma of patients, mediators like the cytokines IL-22, IL-22 binding protein (IL-22BP), IL-6, IL-10, IL 12p70, IL-17A, IL-23, IP-10, or chemokines such as CD206 and sCD163 were found in DILI due to anti-tuberculosis drugs as ascertained by the prospective updated RUCAM, which scored a high causality. RUCAM-based analysis also provided compelling evidence of genetic factors such as HLA (human leucocyte antigen) alleles contributing to initiate iDILI by a few drugs. In conclusion, analysis of published RUCAM-based iDILI cases provided firm evidence of immune and genetic processes involved in iDILI caused by specific drugs.

Molecular Idiosyncratic Toxicology of Drugs in the Human Liver Compared with Animals: Basic Considerations

Drug induced liver injury (DILI) occurs in patients exposed to drugs at recommended doses that leads to idiosyncratic DILI and provides an excellent human model with well described clinical features, liver injury pattern, and diagnostic criteria, based on patients assessed for causality using RUCAM (Roussel Uclaf Causality Assessment Method) as original method of 1993 or its update of 2016. Overall, 81,856 RUCAM based DILI cases have been published until mid of 2020, allowing now for an analysis of mechanistic issues of the disease. From selected DILI cases with verified diagnosis by using RUCAM, direct evidence was provided for the involvement of the innate and adapted immune system as well as genetic HLA (Human Leucocyte Antigen) genotypes. Direct evidence for a role of hepatic immune systems was substantiated by (1) the detection of anti-CYP (Cytochrome P450) isoforms in the plasma of affected patients, in line with the observation that 65% of the drugs most implicated in DILI are metabolized by a range of CYP isoforms, (2) the DIAIH (drug induced autoimmune hepatitis), a subgroup of idiosyncratic DILI, which is characterized by high RUCAM causality gradings and the detection of plasma antibodies such as positive serum anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA), rarely also anti-mitochondrial antibodies (AMA), (3) the effective treatment with glucocorticoids in part of an unselected RUCAM based DILI group, and (4) its rare association with the immune-triggered Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) caused by a small group of drugs. Direct evidence of a genetic basis of idiosyncratic DILI was shown by the association of several HLA genotypes for DILI caused by selected drugs. Finally, animal models of idiosyncratic DILI mimicking human immune and genetic features are not available and further search likely will be unsuccessful. In essence and based on cases of DILI with verified diagnosis using RUCAM for causality evaluation, there is now substantial direct evidence that immune mechanisms and genetics can account for idiosyncratic DILI by many but not all implicated drugs, which may help understand the mechanistic background of the disease and contribute to new approaches of therapy and prevention.

Relationship between common telomere length-related genetic variations, telomere length, and risk of antituberculosis drug-induced hepatotoxicity in Chinese Han population: As assessed for causality using the updated Roussel Uclaf Causality Assessment Method

Antituberculosis drug-induced hepatotoxicity (ATDH) is a significant threat to tuberculosis control, and two recent studies indicated that leukocyte telomere length (LTL) might be a potential biomarker for ATDH. This study aimed to investigate the relationship between common telomere length-related genetic variations, LTL, and risk of ATDH in Eastern Chinese antituberculosis treatment patients. A 1:4 matched case-control study was conducted among 79 ATDH cases assessed for causality using the updated RUCAM and 316 controls. LTL was determined by quantitative real-time PCR, and nine SNPs involved in telomere biology reported by previous GWAS were assessed. Conditional logistic regression model was used to estimate the association between genotypes and risk of ATDH with odds ratios (ORs) and 95% confidence intervals (CIs). The average RUCAM score of cases was 7.1. The average LTL in cases was significantly shorter than that in controls (median = 1.239 vs. 1.481, P = 0.032). Differences in the distribution of LTL were statistically significant among three genotypes of SNP rs2736098 (CC vs. CT vs. TT, median = 1.544 vs. 1.356 vs. 1.337, P = 0.026) and rs2853677 (AA vs. AG vs. GG, median = 1.511 vs. 1.544 vs. 1.159, P = 0.005) in TERT. SNP rs7675998 in NAF1 was statistically associated with the risk of ATDH under the dominant model (adjusted OR = 1.725, 95% CI: 1.021-2.913, P = 0.042). This is the first study to investigate the relationship of LTL, common telomere length-related variations, and risk of ATDH. SNP rs2736098 and rs2853677 in TERT were significantly associated with LTL, and SNP rs7675998 in NAF1 may be associated with ATDH in Chinese population.

Molecular and Antioxidant Characterization of Opuntia robusta Fruit Extract and Its Protective Effect against Diclofenac-Induced Acute Liver Injury in an In Vivo Rat Model

A molecular characterization of the main phytochemicals and antioxidant activity of Opuntia robusta (OR) fruit extract was carried out, as well as an evaluation of its hepatoprotective effect against diclofenac (DF)-induced acute liver injury was evaluated. Phenols, flavonoids and betalains were quantified, and antioxidant characterization was performed by means of the ABTS^•+, DPPH and FRAP assays. UPLC-QTOF-MS/MS was used to identify the main biocompounds present in OR fruit extract was carried out via. In the in vivo model, groups of rats were treated prophylactically with the OR fruit extract, betanin and N-acteylcysteine followed by a single dose of DF. Biochemical markers of oxidative stress (MDA and GSH) and relative gene expression of the inducible antioxidant response (Nrf2, Sod2, Hmox1, Nqo1 and Gclc), cell death (Casp3) and DNA repair (Gadd45a) were analyzed. Western blot analysis was performed to measure protein levels of Nrf2 and immunohistochemical analysis was used to assess caspase-3 activity in the experimental groups. In our study, the OR fruit extract showed strong antioxidant and cytoprotective capacity due to the presence of bioactive compounds, such as betalain and phenols. We conclude that OR fruit extract or selected components can be used clinically to support patients with acute liver injury.

Treatment of Drug-Induced Liver Injury

Current pharmacotherapy options of drug-induced liver injury (DILI) remain under discussion and are now evaluated in this analysis. Needless to say, the use of the offending drug must be stopped as soon as DILI is suspected. Normal dosed drugs may cause idiosyncratic DILI, and drugs taken in overdose commonly lead to intrinsic DILI. Empirically used but not substantiated regarding efficiency by randomized controlled trials (RCTs) is the intravenous antidote treatment with N-acetylcysteine (NAC) in patients with intrinsic DILI by N-acetyl-p-aminophenol (APAP) overdose. Good data recommending pharmacotherapy in idiosyncratic DILI caused by hundreds of different drugs are lacking. Indeed, a recent analysis revealed that just eight RCTs have been published, and in only two out of eight trials were DILI cases evaluated for causality by the worldwide used Roussel Uclaf Causality Assessment Method (RUCAM), representing overall a significant methodology flaw, as results of DILI RCTs lacking RUCAM are misleading since many DILI cases are known to be attributable erroneously to nondrug alternative causes. In line with these major shortcomings and mostly based on anecdotal reports, glucocorticoids (GCs) and other immuno-suppressants may be given empirically in carefully selected patients with idiosyncratic DILI exhibiting autoimmune features or caused by immune checkpoint inhibitors (ICIs), while some patients with cholestatic DILI may benefit from ursodeoxycholic acid use; in other patients with drug-induced hepatic sinusoidal obstruction syndrome (HSOS) and coagulopathy risks, the indication for anticoagulants should be considered. In view of many other mechanistic factors such as the hepatic microsomal cytochrome P450 with a generation of reactive oxygen species (ROS), ferroptosis with toxicity of intracellular iron, and modification of the gut microbiome, additional therapy options may be available in the future. In summation, stopping the offending drug is still the first line of therapy for most instances of acute DILI, while various therapies are applied empirically and not based on good data from RCTs awaiting further trials using the updated RUCAM that asks for strict exclusion and inclusion details like liver injury criteria and provides valid causality rankings of probable and highly probable grades.

Urine metabolomics and microbiome analyses reveal the mechanism of anti-tuberculosis drug-induced liver injury, as assessed for causality using the updated RUCAM: A prospective study

Background

Anti-tuberculosis drug-induced liver injury (ATB-DILI) is one of the most common adverse reactions that brings great difficulties to the treatment of tuberculosis. Thus, early identification of individuals at risk for ATB-DILI is urgent. We conducted a prospective cohort study to analyze the urinary metabolic and microbial profiles of patients with ATB-DILI before drug administration. And machine learning method was used to perform prediction model for ATB-DILI based on metabolomics, microbiome and clinical data.

Methods

A total of 74 new TB patients treated with standard first-line anti-TB treatment regimens were enrolled from West China Hospital of Sichuan University. Only patients with an updated RUCAM score of 6 or more were accepted in this study. Nontargeted metabolomics and microbiome analyses were performed on urine samples prior to anti-tuberculosis drug ingestion to screen the differential metabolites and microbes between the ATB-DILI group and the non-ATB-DILI group. Integrating electronic medical records, metabolomics, and microbiome data, four machine learning methods was used, including random forest algorithm, artificial neural network, support vector machine with the linear kernel and radial basis function kernel.

Results

Of all included patients, 69 patients completed follow-up, with 16 (23.19%) patients developing ATB-DILI after antituberculosis treatment. Finally, 14 ATB-DILI patients and 30 age- and sex-matched non-ATB-DILI patients were subjected to urinary metabolomic and microbiome analysis. A total of 28 major differential metabolites were screened out, involving bile secretion, nicotinate and nicotinamide metabolism, tryptophan metabolism, ABC transporters, etc. Negativicoccus and Actinotignum were upregulated in the ATB-DILI group. Multivariate analysis also showed significant metabolic and microbial differences between the non-ATB-DILI and severe ATB-DILI groups. Finally, the four models showed high accuracy in predicting ATB-DILI, with the area under the curve of more than 0.85 for the training set and 1 for the validation set.

Conclusion

This study characterized the metabolic and microbial profile of ATB-DILI risk individuals before drug ingestion for the first time. Metabolomic and microbiome characteristics in patient urine before anti-tuberculosis drug ingestion may predict the risk of liver injury after ingesting anti-tuberculosis drugs. Machine learning algorithms provides a new way to predict the occurrence of ATB-DILI among tuberculosis patients.

Liver injury during durvalumab-based immunotherapy is associated with poorer patient survival: A retrospective analysis

Background

Durvalumab is approved for the treatment of lung cancer, advanced biliary tract cancers, and is also being evaluated in many other solid organ tumors. The aim of our study is to define the incidence, etiology, and outcomes of liver injury in consecutive patients receiving durvalumab-based immunotherapy.

Patients and methods

Durvalumab treated patients between 1/2016 - 7/2020 were identified from the electronic medical record. Liver injury was defined as serum AST or ALT ≥ 5x upper limit of normal (ULN), ALP ≥ 2x ULN, bilirubin ≥ 2.5 mg/dl, or INR ≥ 1.5. Potential drug induced liver injury (DILI) cases were adjudicated using expert opinion scoring and confirmed with Roussel Uclaf Causality Assessment Method (RUCAM).

Results

Amongst 112 patients, 58 (52%) had non-small cell lung cancer, the median age was 65 years, and 60% were male. The 21 (19%) liver injury patients were significantly more likely to harbor hepatic metastases (52% vs 17%, p=<0.001), experience tumor progression (67% vs 32%, p=0.01) or die (48% vs 11%, p<0.001) during follow-up compared to the 91 without liver injury. Using multivariate regression analysis, the development of liver injury during treatment as well as baseline hepatic metastases were independently associated with mortality during follow-up. Six of the 21 (29%) liver injury cases were adjudicated as probable DILI with four attributed to durvalumab and two due to other drugs (paclitaxel, pembrolizumab). Durvalumab was permanently discontinued in two DILI patients, three received corticosteroids, and one was successfully rechallenged. Only one patient with DILI developed jaundice, and none required hospitalization. Liver biochemistries normalized in all 6 DILI cases, while they only normalized in 27% of the 15 non-DILI cases (p=0.002). The 6 DILI patients also had a trend towards improved survival compared to those with other causes of liver injury.

Conclusion

Liver injury was observed in 19% of durvalumab-treated patients and is associated with a greater likelihood of tumor progression and death during follow-up. The four durvalumab DILI cases were mild and self-limited, highlighting the importance of causality assessment to determine the cause of liver injury in oncology patients receiving immunotherapy.

Plasma metabolomic and lipidomic alterations associated with anti-tuberculosis drug-induced liver injury

Background: Anti-tuberculosis drug-induced liver injury (ATB-DILI) is an adverse reaction with a high incidence and the greatest impact on tuberculosis treatment. However, there is a lack of effective biomarkers for the early prediction of ATB-DILI. Herein, this study uses UPLC‒MS/MS to reveal the plasma metabolic profile and lipid profile of ATB-DILI patients before drug administration and screen new biomarkers for predicting ATB-DILI. Methods: A total of 60 TB patients were enrolled, and plasma was collected before antituberculosis drug administration. The untargeted metabolomics and lipidomics analyses were performed using UPLC‒MS/MS, and the high-resolution mass spectrometer Q Exactive was used for data acquisition in both positive and negative ion modes. The random forest package of R software was used for data screening and model building. Results: A total of 60 TB patients, including 30 ATB-DILI patients and 30 non-ATB-DILI subjects, were enrolled. There were no significant differences between the ATB-DILI and control groups in age, sex, smoking, drinking or body mass index (p > 0.05). Twenty-two differential metabolites were selected. According to KEGG pathway analysis, 9 significantly enriched metabolic pathways were found, and both drug metabolism-other enzymes and niacin and nicotinamide metabolic pathways were found in both positive and negative ion models. A total of 7 differential lipid molecules were identified between the two groups. Ferroptosis and biosynthesis of unsaturated fatty acids were involved in the occurrence of ATB-DILI. Random forest analysis showed that the model built with the top 30 important variables had an area under the ROC curve of 0.79 (0.65-0.93) for the training set and 0.79 (0.55-1.00) for the validation set. Conclusion: This study demonstrated that potential markers for the early prediction of ATB-DILI can be found through plasma metabolomics and lipidomics. The random forest model showed good clinical predictive value for ATB-DILI.

The determination of causality of drug induced liver injury in patients with COVID-19 clinical syndrome

Background

Drug induced liver injury (DILI) is a rising morbidity amongst patients with COVID-19 clinical syndrome. The updated RUCAM causality assessment scale is validated for use in the general population, but its utility for causality determination in cohorts of patients with COVID-19 and DILI remains uncertain.

Methods

This retrospective study was comprised of COVID-19 patients presenting with suspected DILI to the emergency department of Weill Cornell medicine-affiliated Hamad General Hospital, Doha, Qatar. All cases that met the inclusion criteria were comparatively adjudicated by two independent rating pairs (2 clinical pharmacist and 2 physicians) utilizing the updated RUCAM scale to assess the likelihood of DILI.

Results

A total of 72 patients (mean age 48.96 (SD ± 10.21) years) were examined for the determination of DILI causality. The majority had probability likelihood of “possible” or “probable” by the updated RUCAM scale. Azithromycin was the most commonly reported drug as a cause of DILI. The median R-ratio was 4.74 which correspond to a mixed liver injury phenotype. The overall Krippendorf’s kappa was 0.52; with an intraclass correlation coefficient (ICC) of 0.79 (IQR 0.72–0.85). The proportion of exact pairwise agreement and disagreement between the rating pairs were 64.4%, kappa 0.269 (ICC 0.28 [0.18, 0.40]) and kappa 0.45 (ICC 0.43 [0.29–0.57]), respectively.

Conclusion

In a cohort of patients with COVID-19 clinical syndrome, we found the updated RUCAM scale to be useful in establishing “possible” or “probable” DILI likelihood as evident by the respective kappa values; this results if validated by larger sample sized studies will extend the clinical application of this universal tool for adjudication of DILI.

Nrf2-mediated liver protection by 18β-glycyrrhetinic acid against pyrrolizidine alkaloid-induced toxicity through PI3K/Akt/GSK3β pathway

BACKGROUND

Misusage of pyrrolizidine alkaloid (PA)-containing plants or unaware intake of PA-contaminated foodstuffs causes thousands of PA poisoning cases in humans. PA intoxication is accompanied by oxidative stress and subsequent extensive hepatocellular damage. Our previous study has demonstrated that 18β-glycyrrhetinic acid (GA), a bioactive constituent of liquorice, prevented PA-induced hepatotoxicity in rats, however the underlying mechanisms remain unclear.

OBJECTIVE

This study aims to explore the mechanisms underlying the hepato-protective effect of GA in combating retrorsine (RTS, a representative toxic PA)-induced liver injury.

METHODS

Histological and biochemical assessments were employed to evaluate the protective effect of GA on RTS-induced hepatotoxicity in rats. Sulforhodamine B assay, real-time PCR, western blotting, and immunostaining were used to explore the underlying mechanisms in human hepatocytes and rats.

RESULTS

Our findings demonstrated that GA alleviated RTS-induced elevation of serum ALT and bilirubin levels, as well as hepatocytes necrosis and sinusoidal endothelial cells (SECs) damage in rats. GA also enhanced the activities and expressions of several antioxidant enzymes through upregulating nuclear factor-erythroid 2-related factor2 (Nrf2). Moreover, inhibition of Nrf2 blocked the hepatoprotective effect of GA against RTS intoxication. Mechanistically, GA increased the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and enhanced glycogen synthase kinase 3 beta (GSK3β) inhibitory phosphorylation at serine 9, thus promoting the nuclear accumulation of Nrf2 and activating its downstream targets.

CONCLUSION

This study for the first time demonstrated that GA exerted protective effects against RTS-induced liver injury by potentiating the Nrf2-mediated antioxidant system through PI3K/Akt/GSK3β pathway. The findings indicated that GA may serve as a potential candidate drug for the treatment of PA intoxication.

BML-257, a Small Molecule that Protects against Drug-Induced Liver Injury in Zebrafish

The use of many essential drugs is restricted due to their deleterious effects on the liver. Molecules that can prevent or protect the liver from drug-induced liver injury (DILI) would be invaluable in such situations. We used a transgenic line in zebrafish with a hepatocyte-specific expression of bacterial nitroreductase to cause temporally controlled liver damage. A whole organism-based chemical screen using the transgenic line identified BML-257, a potent small molecule AKT inhibitor, that protected the liver against metronidazole-induced liver injury. BML-257 also showed potent prophylactic and pro-regenerative activity in this liver damage model. BML-257 was tested in two independent toxicological models of liver injury caused by acetaminophen and isoniazid and was found to be protective against damage. This suggests that BML-257 has the potential to protect against multiple kinds of DILI.

Using herbs medically without knowing their composition: are we playing Russian roulette?

Herbal medicine, a form of complementary and alternative medicine (CAM), is used throughout the world, in both developing and developed countries. The ingredients in herbal medicines are not standardized by any regulatory agency. Variability exists in the ingredients as well as in their concentrations. Plant products may become contaminated with bacteria and fungi during storage. Therefore, harm can occur to the kidney, liver, and blood components after ingestion. We encourage scientific studies to identify the active ingredients in herbs and to standardize their concentrations in all herbal preparations. Rigorous studies need to be performed in order to understand the effect of herbal ingredients on different organ systems as well as these substances' interaction with other medications.

Novel Clinical Biomarkers for Drug-Induced Liver Injury

Drug-induced liver injury (DILI) remains a critical clinical issue and has been a treatment challenge today as it was in the past. However, the traditional biomarkers or indicators are insufficient to predict the risks and outcome of patients with DILI due to its poor specificity and sensitivity. Recently, the development of high-throughput technologies, especially omics and multiomics has sparked growing interests in identification of novel clinical DILI biomarkers, many of which also provide a mechanistic insight. Accordingly, in this minireview, we summarize recent advances in novel clinical biomarkers for DILI prediction, diagnosis, and prognosis and highlight the limitations or challenges involved in biomarker discovery or its clinical translation. Although huge work has been done, most reported biomarkers lack comprehensive information and more specific DILI biomarkers are still needed to complement the traditional biomarkers such as alanine aminotransferase (ALT) or aspartate transaminase (AST) in clinical decision-making. SIGNIFICANCE STATEMENT: This current review outlines an overview of novel clinical biomarkers for drug-induced liver injury (DILI) identified in clinical retrospective or prospective clinical analysis. Many of these biomarkers provide a mechanistic insight and are promising to complement the traditional DILI biomarkers. This work also highlights the limitations or challenges involved in biomarker discovery or its clinical translation.

Liver Injury in COVID-19 Patients with Drugs as Causatives: A Systematic Review of 996 DILI Cases Published 2020/2021 Based on RUCAM as Causality Assessment Method

Patients with coronavirus disease 19 (COVID-19) commonly show abnormalities of liver tests (LTs) of undetermined cause. Considering drugs as tentative culprits, the current systematic review searched for published COVID-19 cases with suspected drug-induced liver injury (DILI) and established diagnosis using the diagnostic algorithm of RUCAM (Roussel Uclaf Causality Assessment Method). Data worldwide on DILI cases assessed by RUCAM in COVID-19 patients were sparse. A total of 6/200 reports with initially suspected 996 DILI cases in COVID-19 patients and using all RUCAM-based DILI cases allowed for a clear description of clinical features of RUCAM-based DILI cases among COVID-19 patients: (1) The updated RUCAM published in 2016 was equally often used as the original RUCAM of 1993, with both identifying DILI and other liver diseases as confounders; (2) RUCAM also worked well in patients treated with up to 18 drugs and provided for most DILI cases a probable or highly probable causality level for drugs; (3) DILI was preferentially caused by antiviral drugs given empirically due to their known therapeutic efficacy in other virus infections; (4) hepatocellular injury was more often reported than cholestatic or mixed injury; (5) maximum LT values were found for alanine aminotransferase (ALT) 1.541 U/L and aspartate aminotransferase (AST) 1.076 U/L; (6) the ALT/AST ratio was variable and ranged from 0.4 to 1.4; (7) the mean or median age of the COVID-19 patients with DILI ranged from 54.3 to 56 years; (8) the ratio of males to females was 1.8–3.4:1; (9) outcome was favorable for most patients, likely due to careful selection of the drugs and quick cessation of drug treatment with emerging DILI, but it was fatal in 19 patients; (10) countries reporting RUCAM-based DILI cases in COVID-19 patients included China, India, Japan, Montenegro, and Spain; (11) robust estimation of the percentage contribution of RUCAM-based DILI for the increased LTs in COVID-19 patients is outside of the current scope. In conclusion, RUCAM-based DILI with its clinical characteristics in COVID-19 patients and its classification as a confounding variable is now well defined, requiring a new correct description of COVID-19 features by removing DILI characteristics as confounders.

Study on the Characteristics of Small-Molecule Kinase Inhibitors-Related Drug-Induced Liver Injury

Background and Aim: More than half of the small-molecule kinase inhibitors (KIs) induced liver injury clinically. Meanwhile, studies have shown a close relationship between mitochondrial damage and drug-induced liver injury (DILI). We aimed to study KIs and the binding between drugs and mitochondrial proteins to find factors related to DILI occurrence.

Methods: A total of 1,223 oral FDA-approved drugs were collected and analyzed, including 44 KIs. Fisher’s exact test was used to analyze DILI potential and risk of different factors. A total of 187 human mitochondrial proteins were further collected, and high-throughput molecular docking was performed between human mitochondrial proteins and drugs in the data set. The molecular dynamics simulation was used to optimize and evaluate the dynamic binding behavior of the selected mitochondrial protein/KI complexes.

Results: The possibility of KIs to produce DILI is much higher than that of other types (OR = 46.89, p = 9.28E-13). A few DILI risk factors were identified, including molecular weight (MW) between 400 and 600, the defined daily dose (DDD) ≥ 100 mg/day, the octanol–water partition coefficient (LogP) ≥ 3, and the degree of liver metabolism (LM) more than 50%. Drugs that met this combination of rules were found to have a higher DILI risk than controls (OR = 8.28, p = 4.82E-05) and were more likely to cause severe DILI (OR = 8.26, p = 5.06E-04). The docking results showed that KIs had a significant higher affinity with human mitochondrial proteins (p = 4.19E-11) than other drug types. Furthermore, the five proteins with the lowest docking score were selected for molecular dynamics simulation, and the smallest fluctuation of the backbone RMSD curve was found in the protein 5FS8/KI complexes, which indicated the best stability of the protein 5FS8 bound to KIs.

Conclusions: KIs were found to have the highest odds ratio of causing DILI. MW was significantly related to the production of DILI, and the average docking scores of KI drugs were found to be significantly different from other classes. Further analysis identified the top binding mitochondrial proteins for KIs, and specific binding sites were analyzed. The optimization of molecular docking results by molecular dynamics simulation may contribute to further studying the mechanism of DILI.

Liquorice Extract and 18β-Glycyrrhetinic Acid Protect Against Experimental Pyrrolizidine Alkaloid-Induced Hepatotoxicity in Rats Through Inhibiting Cytochrome P450-Mediated Metabolic Activation

Misuse of pyrrolizidine alkaloid (PA)-containing plants or consumption of PA-contaminated foodstuffs causes numerous poisoning cases in humans yearly, while effective therapeutic strategies are still limited. PA-induced liver injury was initiated by cytochrome P450 (CYP)-mediated metabolic activation and subsequent formation of adducts with cellular proteins. Liquorice, a hepato-protective herbal medicine, is commonly used concurrently with PA-containing herbs in many compound traditional Chinese medicine formulas, and no PA-poisoning cases have been reported with this combination. The present study aimed to investigate hepato-protective effects of liquorice aqueous extract (EX) and 18β-glycyrrhetinic acid (GA, the primary bioactive constituent of liquorice) against PA-induced hepatotoxicity and the underlying mechanism. Histopathological and biochemical analysis demonstrated that both single- and multiple-treatment of EX (500 mg/kg) or GA (50 mg/kg) significantly attenuated liver damage caused by retrorsine (RTS, a representative hepatotoxic PA). The formation of pyrrole-protein adducts was significantly reduced by single- (30.3% reduction in liver; 50.8% reduction in plasma) and multiple- (32.5% reduction in liver; 56.5% reduction in plasma) treatment of GA in rats. Single- and multiple-treatment of EX also decreased the formation of pyrrole-protein adducts, with 30.2 and 31.1% reduction in rat liver and 51.8 and 53.1% reduction in rat plasma, respectively. In addition, in vitro metabolism assay with rat liver microsomes demonstrated that GA reduced the formation of metabolic activation-derived pyrrole-glutathione conjugate in a dose-dependent manner with the estimated IC50 value of 5.07 µM. Further mechanism study showed that GA inhibited activities of CYPs, especially CYP3A1, the major CYP isoform responsible for the metabolic activation of RTS in rats. Enzymatic kinetic study revealed a competitive inhibition of rat CYP3A1 by GA. In conclusion, our findings demonstrated that both EX and GA exhibited significant hepato-protective effects against RTS-induced hepatotoxicity, mainly through the competitive inhibition of CYP-mediated metabolic activation of RTS.

Causality imputation between herbal products and HILI: An algorithm evaluation in a systematic review

Algorithms can have several purposes in the clinical practice. There are different scales for causality imputation in DILI (Drug-Induced Liver Injury), but the applicability and validity of these for the HILI (Herb-Induced Liver Injury) evaluation is questionable for some scales. The purpose of the study was to determine the clinical and demographic profile of the patients with HILI, and the main algorithmic scales used in its causality assessment. The methodology was a systematic review of articles in English, Spanish, or Portuguese language, from 1979 to 2019, involving humans, with descriptors related to HILI. Qualitative and quantitative statistical analysis were performed. As a result, from a total of 60 articles, 203 HILI reports were selected: 59.9% were women, similar with other studies, and the average age was 45.8 years. Jaundice was the most frequent symptom and regarding the type of lesion, the hepatocellular was the most frequent. In regard to HILI severity, 3.0% were severe and 7.6% were fatal or required liver transplantation. In 72.3% of the cases, the most used algorithm was RUCAM (Roussel Uclaf Causality Assessment Method). The conclusion of the study is that RUCAM was the most used algorithm for causality assessment in HILI. The patients were predominantly female, jaundice was the main symptom, and HILI is reversible in the majority of cases.

Utility of Lymphocyte Transformation Test for Assisting Updated Roussel Uclaf Causality Assessment Method in Drug-Induced Liver Injury: A Case-Control Study

Background: The Roussel Uclaf Causality Assessment Method (RUCAM) is a validated tool for assessing causality in cases of suspected drug-induced liver injury (DILI). However, RUCAM cannot discriminate between concomitant hepatotoxic drugs with the same temporal sequence.

Objective: To analyse the utility of the lymphocyte transformation test (LTT) for assisting updated RUCAM in 45 patients and 40 controls with a clinical diagnosis of DILI.

Methods: Suspected DILI cases were detected through the Prospective Pharmacovigilance Program from Laboratory Signals in Hospital (PPLSH) or by consultations. The controls completed the drug therapy with no adverse reactions during the study period. A receiver operating characteristics (ROC) curve analysis was performed to calculate the optimal cut-off value for the stimulation index (SI), corresponding to the largest sum for the specificity and sensitivity values of LTT for true DILI cases.

Results: Out of 45 patients diagnosed with DILI, 42 cases were detected by the PPLSH, two cases by consultation and one case by both methods. Most DILI cases (64.4%) arose during hospitalization. According to the biochemical parameters, 24 cases (53.3%) had the hepatocellular phenotype, 14 (31.1%) had the cholestatic phenotype, and 7 cases (15.6%) had the mixed phenotype. Considering the severity criteria, 7 (15.5%) cases were classified as moderate DILI, and 4 (8.9%) were severe DILI; there were no fatal cases. A total of 149 drugs (median/case, 3; IQR, 2–5) were suspected to be involved in the DILI cases (RUCAM score ≥3). In 8 cases, only one drug was suspected, and polypharmacy (≥5 drugs) was identified in 29% of the cases. Of all DILI cases, 46 (30.9%) of the 149 suspected drugs produced positive LTT results, and the LTT was positive in 34 (75.5%) of the 45 patients. No exposed controls produced positive LTT results. The optimal cut-off of 1.95 for the SI was obtained with a sensitivity of 77% and specificity of 100% (area under the curve, 0.91; 95% asymptotic confidence interval 0.84–0.97; p < 0.001). The sensitivity of the hepatocellular phenotype was 92%.

Conclusion: Our results demonstrate that LTT is an add on strengthening causality in cases of suspected idiosyncratic DILI, especially for patients with several suspected drugs and a hepatocellular phenotype.

What might have happened: the impact of interrupting entry of innovative drugs on disease outcomes in the United States

INTRODUCTION

This study estimated the extent to which drug innovations over the past 30 years may have improved outcomes for six diseases.

AREAS COVERED

We analyzed six diseases (ischemic heart disease, lung cancer, breast cancer, human immunodeficiency virus [HIV] infection, type 2 diabetes mellitus, and rheumatoid arthritis [RA]) with significant mortality or morbidity for which there have been major drug innovations over the past 30 years. We used US data from the Global Burden of Disease (GBD) database and a patient registry to perform counterfactual time series analyses predicting the improved health outcomes that may have been associated with major drug innovations.

For 5 conditions using data from the GBD study, years of life lost per individual with the condition could have been higher by 17.1% (breast cancer) to 660.6% (HIV infection) in 2017 had the major drug innovations not been introduced. For RA, using patient registry data, patients' functional status could have been 11.5% worse had biological therapies not been introduced.

EXPERT OPINION

Over the next 5 years, policies targeting drug prices should be broadened to include all health care services. In addition, the value of the pharmaceutical industry for generating rapid responses to new diseases should be recognized.

Herb-Induced Liver Injury—A Challenging Diagnosis

Herb-induced liver injury (HILI) can be caused by supplements containing herbs, natural products, and products used in traditional medicine. Herbal products’ most common adverse reaction is hepatotoxicity. Almost every plant part can be used to make herbal products, and these products can come in many different forms, such as teas, powders, oils, creams, capsules, and injectables. HILI incidence and prevalence are hard to estimate and vary from study to study because of insufficient large-scale prospective studies. The diagnosis of HILI is a challenging process that requires not only insight but also a high degree of suspicion by the clinician. HILI presents with unspecific symptoms and is a diagnosis of exclusion. For diagnosis, it is necessary to make a causality assessment; the Council for International Organizations of Medical Sciences assessment is the preferred method worldwide. The most effective treatment is the suspension of the use of the suspected herbal product and close monitoring of liver function. The objective of this review is to highlight the necessary steps for the clinician to follow to reach a correct diagnosis of herb-induced liver injury. Further studies of HILI are needed to better understand its complexity and prevent increased morbidity and mortality.

Toxic Hepatitis Associated With the Use of Contraceptives: A Diagnosis to Bear in Mind

Drug-induced liver injury (DILI) is a rare condition with a high burden of morbidity and risk of severe complications that may even require liver transplantation to survive. There are no pathognomonic diagnostic tests for this condition, thus being a challenge it is considered a diagnosis of exclusion. We present the case of a patient who, after starting intramuscular contraceptives, presented with acute alteration of liver function that requires the ruling out of multiple pathologies that could be the cause of the biochemical findings. With the pharmacological suspension and initiation of support measures, full recovery was achieved.

Incidence, predictors and outcome of sepsis-associated liver injury in children: a prospective observational study

Sepsis-associated liver injury (SALI) occurs as a result of the systemic and microcirculatory changes that happen because of sepsis. Its prognostic significance in the paediatric population is unclear. We enrolled all children < 19 years, admitted between July, 2020 and July, 2021 to the paediatric unit (ward or intensive care unit) with a diagnosis of sepsis for this study. Clinical and biochemical parameters of children with sepsis who developed SALI were compared with those without SALI to determine the risk factors of SALI and its impact on in-hospital mortality. A total of 127 children, median age 72 (1-204) months, 74 males were included. SALI developed in 45 (31.3%) at a median 1 (1-13) days after the diagnosis of sepsis. The SALI pattern was cholestatic in 18 (40%), hepatocellular in 17 (37.7%) and hypoxic hepatitis in 10 (22.3%). Paediatric sequential organ failure assessment (pSOFA) was an independent predictor of SALI - OR 1.17 (95% CI 1.067-1.302), p = 0.001. A pSOFA score of > 9.5 predicted the development of SALI with 66.7% sensitivity and 77.1% specificity. SALI was an independent predictor of mortality in children with sepsis - OR 1.9 (95% CI 1.3-3.4), p = 0.01.   Conclusions: SALI develops in 45 (31.3%) with sepsis. A higher pSOFA score is associated with SALI. Children who develop SALI have a ~ twofold higher risk of mortality than those without SALI. What is Known: • During the process of sepsis, the liver plays a role by scavenging bacteria and producing inflammatory mediators. However, at times the liver itself becomes a target of the dysregulated inflammatory response. This is known as sepsis-associated liver injury (SALI). • The incidence of sepsis-associated liver injury and its prognostic significance in children is not known.. What is New: • SALI develops in one-third children with sepsis and is associated with a higher pSOFA score. • Children who develop SALI have a higher risk of mortality.

Evaluation of Adverse Drug Reactions in Paediatric Patients: A Retrospective Study in Turkish Hospital

Drug safety in paediatric patients is a serious public health concern around the world. The paediatric patients are more prone to adverse drug reactions (ADRs) than adults. Moreover, there is a scarcity of information about ADRs in paediatric patients. This study was conducted to determine the frequency, causality, severity, preventability of paediatric patients’ ADRs reported in a tertiary care hospital in Adana, Turkey. A retrospective study was conducted on all spontaneously reported ADRs between January 01, 2020, to July 30, 2021, in paediatric patients. The ADRs reports were evaluated in terms of gender, age, ADR characteristics, suspected drugs and reporting source. All included ADRs reports were characterized according to the Naranjo Algorithm/World Health Organization (WHO) causality scales, Hartwig/Siegel and Common Terminology Criteria for Adverse Events (CTCAE) severity scales, the modified Schoumock and Thornton preventability scale and hospital pharmacovigilance center criteria for seriousness. Therapeutic groups were also coded using the WHO-Anatomical Therapeutic and Chemical (ATC) classification. During the study period, 8,912 paediatric patients who were admitted had 16 ADRs with 1.7 ADRs/1,000 admissions. The majority of ADRs were found in infants (31.2%) and children (56.2%) as compared to adolescents (12.5%). ADRs were observed more in females (81.2%) than males. Skin (62.5%) was the most affected organ due to the ADRs, and maculopapular rash and erythema multiforme were the most commonly reported symptoms. Most ADRs were probable/likely (93.7%), severe (50%), preventable or probably preventable (43.7%) and serious (37.5%). Antibiotics (93.7%) were found to be the most common cause of ADRs in paediatric patients. The majority of ADRs were associated with vancomycin (68.7%). Most of the ADRs were reported by a medical doctor in this study. This small sample size study highlights significant problems of ADRs in paediatric patients, mainly caused by antibiotics and with a majority of ADRs manifest as skin reactions. Furthermore, a high proportion of the identified ADRs were found to be preventable. More focused efforts are needed at the national level to avoid preventable ADRs in hospitals. Monitoring and management of ADRs and future studies would be beneficial for better patient care and safety.

Curcuma longa Hepatotoxicity: A Baseless Accusation. Cases Assessed for Causality Using RUCAM Method

Curcuma longa is a perennial herb that belongs to the Zingiberaceae family. To date, literature includes more than 11.000 scientific articles describing all its beneficial properties. In the last 3 decades various surveys by the U.S. Food and Drug Administration (FDA) concluded that curcumin, the most active ingredient of the drug, is a "generally safe" compound with strong anti-oxidant effects. Curcuma longa was introduced in the daily diet by ayurvedic teachers due to its beneficial effects on health. Nonetheless, recently several reports, from the various global surveillance systems on the safety of plant products, pointed out cases of hepatotoxicity linked to consumption of food supplements containing powdered extract and preparations of Curcuma longa. The latest trend is the use of Curcuma longa as a weight-loss product in combination with piperine, which is used to increase its very low systemic bioavailability. Indeed, only 20 mg piperine, one of the alkaloids found in black pepper (Piper nigrum), assumed at the same time with 2 g curcumin increased 20-fold serum curcumin bioavailability. This combination of natural products is now present in several weight loss supplements containing Curcuma longa. The enhanced drug bioavailability caused by piperine is due to its potent inhibition of drug metabolism, being able to inhibit human P-glycoprotein and CYP3A4, while it interferes with UDP-glucose dehydrogenase and glucuronidation activities in liver. While only few cases of hepatotoxicity, assessed using Roussel Uclaf Causality Assessment Method (RUCAM) method, from prolonged intake of piperine and curcumin have been reported, it would be reasonable to speculate that the suspected toxicity of Curcuma longa could be due to the concomitant presence of piperine itself. Hence, not only there is the need of more basic research to understand the etiopathology of curcumin-related hepatotoxicity and of the combination curcumin-piperine, but human trials will be necessary to settle this dispute.

Pyrrolizidine Alkaloid-Induced Hepatotoxicity Associated with the Formation of Reactive Metabolite-Derived Pyrrole-Protein Adducts

Pyrrolizidine alkaloids (PAs) with 1,2-unsaturated necine base are hepatotoxic phytotoxins. Acute PA intoxication is initiated by the formation of adducts between PA-derived reactive pyrrolic metabolites with cellular proteins. The present study aimed to investigate the correlation between the formation of hepatic pyrrole-protein adducts and occurrence of PA-induced liver injury (PA-ILI), and to further explore the use of such adducts for rapidly screening the hepatotoxic potency of natural products which contain PAs. Aqueous extracts of Crotalaria sessiliflora (containing one PA: monocrotaline) and Gynura japonica (containing two PAs: senecionine and seneciphylline) were orally administered to rats at different doses for 24 h to investigate PA-ILI. Serum alanine aminotransferase (ALT) activity, hepatic glutathione (GSH) level, and liver histological changes of the treated rats were evaluated to assess the severity of PA-ILI. The levels of pyrrole-protein adducts formed in the rats' livers were determined by a well-established spectrophotometric method. The biological and histological results showed a dose-dependent hepatotoxicity with significantly different toxic severity among groups of rats treated with herbal extracts containing different PAs. Both serum ALT activity and the amount of hepatic pyrrole-protein adducts increased in a dose-dependent manner. Moreover, the elevation of ALT activity correlated well with the formation of hepatic pyrrole-protein adducts, regardless of the structures of different PAs. The findings revealed that the formation of hepatic pyrrole-protein adducts-which directly correlated with the elevation of serum ALT activity-was a common insult leading to PA-ILI, suggesting a potential for using pyrrole-protein adducts to screen hepatotoxicity and rank PA-containing natural products, which generally contain multiple PAs with different structures.

Metabolic Toxification of 1,2-Unsaturated Pyrrolizidine Alkaloids Causes Human Hepatic Sinusoidal Obstruction Syndrome: The Update

Saturated and unsaturated pyrrolizidine alkaloids (PAs) are present in more than 6000 plant species growing in countries all over the world. They have a typical heterocyclic structure in common, but differ in their potential toxicity, depending on the presence or absence of a double bond between C1 and C2. Fortunately, most plants contain saturated PAs without this double bond and are therefore not toxic for consumption by humans or animals. In a minority of plants, however, PAs with this double bond between C1 and C2 exhibit strong hepatotoxic, genotoxic, cytotoxic, neurotoxic, and tumorigenic potentials. If consumed in error and in large emouns, plants with 1,2-unsaturated PAs induce metabolic breaking-off of the double bonds of the unsaturated PAs, generating PA radicals that may trigger severe liver injury through a process involving microsomal P450 (CYP), with preference of its isoforms CYP 2A6, CYP 3A4, and CYP 3A5. This toxifying CYP-dependent conversion occurs primarily in the endoplasmic reticulum of the hepatocytes equivalent to the microsomal fraction. Toxified PAs injure the protein membranes of hepatocytes, and after passing their plasma membranes, more so the liver sinusoidal endothelial cells (LSECs), leading to life-threatening hepatic sinusoidal obstruction syndrome (HSOS). This injury is easily diagnosed by blood pyrrolizidine protein adducts, which are perfect diagnostic biomarkers, supporting causality evaluation using the updated RUCAM (Roussel Uclaf Causality Assessment Method). HSOS is clinically characterized by weight gain due to fluid accumulation (ascites, pleural effusion, and edema), and may lead to acute liver failure, liver transplantation, or death. In conclusion, plant-derived PAs with a double bond between C1 and C2 are potentially hepatotoxic after metabolic removal of the double bond, and may cause PA-HSOS with a potential lethal outcome, even if PA consumption is stopped.

Herbal and dietary supplement induced liver injury: Highlights from the recent literature

Herbal-induced liver injury (HILI) is an important and increasingly concerning cause of liver toxicity, and this study presents recent updates to the literature. An extensive literature review was conducted encompassing September 2019 through March 2021. Studies with clinically significant findings were analyzed and included in this review. We emphasized those studies that provided a causality assessment methodology, such as Roussel Uclaf Causality Assessment Method scores. Our review includes reports of individual herbals, including Garcinia cambogia, green tea extract, kratom as well as classes such as performance enhancing supplements, Traditional Chinese medicine, Ayurvedic medicine and herbal contamination. Newly described herbals include ashwagandha, boldo, skyfruit, and 'Thermo gun'. Several studies discussing data from national registries, including the United States Drug-Induced Liver Injury (DILI) Network, Spanish DILI Registry, and Latin American DILI Network were incorporated. There has also been a continued interest in hepatoprotection, with promising use of herbals to counter hepatotoxicity from anti-tubercular medications. We also elucidated the current legal conversation surrounding use of herbals by presenting updates from the Federal Drug Administration. The highlights of the literature over the past year indicate interest in HILI that will continue as the supplement industry in the United States grows.

Research Progress of Pharmacogenomics in Drug-Induced Liver Injury

Background: Drug-induced liver injury (DILI) is a common and serious adverse drug reaction with insufficient clinical diagnostic strategies and treatment methods. The only clinically well-received method is the Roussel UCLAF Causality Assessment Method scale, which can be applied to both individuals and prospective or retrospective studies. However, in severe cases, patients with DILI still would develop acute liver failure or even death. Pharmacogenomics, a powerful tool to achieve precision medicine, has been used to study the polymorphism of DILI related genes.

Summary: We summarized the pathogenesis of DILI and findings on associated genes and variations with DILI, including but not limited to HLA genes, drug metabolizing enzymes, and transporters genes, and pointed out further fields for DILI related pharmacogenomics study to provide references for DILI clinical diagnosis and treatment.

Key Messages: At present, most of the studies are mainly limited to CGS and GWAS, and there is still a long way to achieve clinical transformation. DNA methylation could be a new consideration, and ethnic differences and special populations also deserve attention.

The LiverTox Paradox-Gaps between Promised Data and Reality Check

The LiverTox database compiles cases of idiosyncratic drug-induced liver injury (iDILI) with the promised aims to help identify hepatotoxicants and provide evidence-based information on iDILI. Weaknesses of this approach include case selection merely based on published case number and not on a strong causality assessment method such as the Roussel Uclaf Causality Assessment Method (RUCAM). The aim of this analysis was to find out whether the promised aims have been achieved by comparison of current iDILI case data with those promised in 2012 in LiverTox. First, the LiverTox criteria of likelihood categories applied to iDILI cases were analyzed regarding robustness. Second, the quality was analyzed in LiverTox cases caused by 46 selected drugs implicated in iDILI. LiverTox included iDILI cases of insufficient quality because most promised details were not fulfilled: (1) Standard liver injury definition; (2) incomplete narratives or inaccurate for alternative causes; and (3) not a single case was assessed for causality with RUCAM, as promised. Instead, causality was arbitrarily judged on the iDILI case number presented in published reports with the same drug. All of these issues characterize the paradox of LiverTox, requiring changes in the method to improve data quality and database reliability. In conclusion, establishing LiverTox is recognized as a valuable effort, but the paradox due to weaknesses between promised data quality and actual data must be settled by substantial improvements, including, for instance, clear definition and identification of iDILI cases after evaluation with RUCAM to establish a robust causality grading.