abacavir and Chemical-and-Drug-Induced-Liver-Injury

Topics: Chemical and Drug Induced Liver Injury; Databases, Factual; Drug Labeling; Humans; Pharmaceutical Preparations; Risk

Rare but severe adverse drug reactions (ADRs) are an important issue in drug development and in the proper usage of drugs during the post-approval phase. The ability to predict patient susceptibility to severe ADRs would prevent drug administration to high-risk patients. This would save lives and ensure the quality of life for these patients, but occurrence of idiosyncratic severe ADRs had been very difficult to predict for a long time. However, in this decade, genetic markers have been found for several ADRs, especially for severe cutaneous adverse reactions (SCARs) and drug-induced liver injury (DILI). In this review, we summarize recent progress in identifying genetic markers for SCARS and DILI, and discuss issues that remain unresolved. As for SCARs, associations of HLA-B*15:02 or HLA-A*31:01 and HLA-B*58:01 have been revealed for carbamazepine- and allopurinol-related Stevens-Johnson syndrome and toxic epidermal neclolysis, respectively. HLA-B*57:01 is strongly associated with abacavir-induced hypersensitivity syndrome. Several HLA alleles also demonstrate drug-specific associations with DILI, such as HLA-A*33:03 for ticlopidine, HLA-B*57:01 for flucloxacillin and HLA-DQA1*02:01 for lapatinib. Efforts should be continued to find other genetic markers to achieve high predictability for ADRs, with the goal being development of genetic tests for use in clinical settings.

Topics: Alleles; Allopurinol; Amoxicillin-Potassium Clavulanate Combination; Azetidines; Benzylamines; Carbamazepine; Chemical and Drug Induced Liver Injury; Diclofenac; Dideoxynucleosides; Drug Hypersensitivity; Floxacillin; Genetic Markers; HLA Antigens; HLA-A Antigens; HLA-B Antigens; HLA-DQ alpha-Chains; Humans; Lapatinib; Pharmacogenetics; Quinazolines; Skin; Stevens-Johnson Syndrome; Ticlopidine

Combined antiretroviral therapy (cART) consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) and one non-nucleoside reverse transcriptase inhibitor (NNRTI), such as efavirenz, is still the first-line treatment in resource-limited settings. However, efavirenz has shown strong prominence of disadvantages with variance in plasma concentration and central nervous side effects. Our study presents HIV infected, drug naïve, female patient with relatively low BMI,

Topics: Adult; Alkynes; Benzoxazines; Body Mass Index; Chemical and Drug Induced Liver Injury; Cyclopropanes; Dideoxynucleosides; Drug Therapy, Combination; Female; HIV Infections; Humans; Lamivudine; Reverse Transcriptase Inhibitors

Genome-wide association studies indicate that several idiosyncratic adverse drug reactions are highly associated with specific human leukocyte antigen (HLA) alleles. For instance, abacavir, a human immunodeficiency virus reverse transcriptase inhibitor, induces multiorgan toxicity exclusively in patients carrying the HLA-B*57:01 allele. However, the underlying mechanism is unclear due to a lack of appropriate animal models. Previously, we developed HLA-B*57:01 transgenic mice and found that topical application of abacavir to the ears induced proliferation of CD8+ lymphocytes in local lymph nodes. Here, we attempted to reproduce abacavir-induced liver injury in these mice. However, oral administration of abacavir alone to HLA-B*57:01 transgenic mice did not increase levels of the liver injury marker alanine aminotransferase. Considering the importance of innate immune activation in mouse liver, we treated mice with CpG oligodeoxynucleotide, a toll-like receptor 9 agonist, plus abacavir. This resulted in a marked increase in alanine aminotransferase, pathological changes in liver, increased numbers of activated CD8+ T cells, and tissue infiltration by immune cells exclusively in HLA-B*57:01 transgenic mice. These results indicate that CpG oligodeoxynucleotide-induced inflammatory reactions and/or innate immune activation are necessary for abacavir-induced HLA-mediated liver injury characterized by infiltration of CD8+ T cells. Thus, we developed the first mouse model of HLA-mediated abacavir-induced idiosyncratic liver injury. Further investigation will show that the proposed HLA-mediated liver injury model can be applied to other combinations of drugs and HLA types, thereby improving drug development and contributing to the development of personalized medicine.

Topics: Alanine Transaminase; Animals; CD8-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Dideoxynucleosides; Disease Models, Animal; Hepatocytes; HLA-B Antigens; Immunity, Innate; Liver; Male; Mice, Inbred C57BL; Mice, Transgenic; Oligodeoxyribonucleotides; Reverse Transcriptase Inhibitors; Toll-Like Receptor 9

Topics: Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Chemical and Drug Induced Liver Injury; Cholestasis; Dideoxynucleosides; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Lamivudine; Male; Middle Aged; Oxazines; Piperazines; Pyridones

NRTIs are essential components of HIV therapy with well-documented, long-term mitochondrial toxicity in hepatic cells, but whose acute effects on mitochondria are unclear. As acetaminophen-induced hepatotoxicity also involves mitochondrial interference, we hypothesized that it would be exacerbated in the context of ART.. We evaluated the acute effects of clinically relevant concentrations of the most widely used NRTIs, alone or combined with acetaminophen, on mitochondrial function and cellular viability.. The purine analogues abacavir and didanosine produced an immediate and concentration-dependent inhibition of oxygen consumption and complex I and III activity. This inhibition was accompanied by an undermining of mitochondrial function, with increased production of reactive oxygen species and reduction of mitochondrial membrane potential and intracellular ATP levels. However, this interference did not compromise cell survival. Co-administration with concentrations of acetaminophen below those considered hepatotoxic exacerbated the deleterious effects of both compounds on mitochondrial function and compromised cellular viability, showing a clear correlation with diminished glutathione levels.. The simultaneous presence of purine analogues and low concentrations of acetaminophen significantly potentiates mitochondrial dysfunction, increasing the risk of liver injury. This new mechanism is relevant given the liver's susceptibility to mitochondrial dysfunction-related toxicity and the tendency of the HIV infection to increase oxidative stress.

Topics: Acetaminophen; Analgesics, Non-Narcotic; Anti-HIV Agents; Cell Line; Chemical and Drug Induced Liver Injury; Didanosine; Dideoxynucleosides; Electron Transport Chain Complex Proteins; Glutathione; Humans; Mitochondria, Liver; Mitochondrial Diseases; Oxygen Consumption; Reactive Nitrogen Species

Topics: Adult; Anti-HIV Agents; Chemical and Drug Induced Liver Injury; Dideoxynucleosides; HIV Infections; Humans; Liver; Liver Function Tests; Male

Drug hypersensitivity reactions are an immune-mediated reaction to otherwise innocuous antigens derived from drugs. These reactions can affect many different organs, with the skin being the commonest. Skin involvement can range in severity with hypersensitivity syndrome (or DRESS) and the blistering reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), also termed serious cutaneous adverse drug reactions, being the most severe and most feared. There is increasing evidence for the role of the immune system in the pathogenesis of these reactions, with drug-specific T cells having been identified in many patients. Until recently, very little was known about the predisposition to these reactions. However, the availability of more accurate molecular typing methods, and the ability to analyse the whole genome in an unbiased fashion, has led to some remarkable findings of the role of the HLA genes as genomic biomarkers of predisposition. The 'revolution' started with abacavir where the predisposition to hypersensitivity was linked to HLA-B*57:01, which was confirmed in a clinical trial, and where its implementation has shown to reduce the incidence of hypersensitivity in a cost-effective manner. Since then, associations have also been shown for allopurinol (HLA-B*58:01)- and carbamazepine (HLA-B*1502 and HLA-A*3101)-induced serious cutaneous adverse drug reactions. The latter is interesting since the association with HLA-B*1502 is present in certain South-Eastern Asian populations, and the predisposition is phenotype specific (only for SJS/TEN). The utility of this biomarker has been shown in a prospective cohort study performed in Taiwan. By contrast, the association with HLA-A*3101 is seen in more diverse ethnic groups, and predisposes to mild as well more severe cutaneous reactions associated with carbamazepine. It is important to note that strong HLA associations have also been shown with a number of drugs that cause liver injury including flucloxacillin, lumiracoxib, lapatinib and ximelagatran, indicating that the immune system is also important in the pathogenesis of other forms of drug-induced organ toxicity. The crucial question as to whether these HLA alleles are truly causative or acting as surrogate markers of predisposition, however, is still unclear, and will require further investigations in larger patient cohorts, through the use of bioinformatic techniques, fine mapping using next generation sequencing technologies and functional stud

Topics: Allopurinol; Anti-Bacterial Agents; Anti-HIV Agents; Anticonvulsants; Antimetabolites; Biomarkers; Carbamazepine; Chemical and Drug Induced Liver Injury; Dideoxynucleosides; Drug Hypersensitivity; Drug-Related Side Effects and Adverse Reactions; Genome-Wide Association Study; HLA Antigens; HLA-A Antigens; HLA-B Antigens; Humans; Immune System; Predictive Value of Tests; Stevens-Johnson Syndrome

Drug-induced liver injury (DILI) is a leading cause of drugs failing during clinical trials and being withdrawn from the market. Comparative analysis of drugs based on their DILI potential is an effective approach to discover key DILI mechanisms and risk factors. However, assessing the DILI potential of a drug is a challenge with no existing consensus methods. We proposed a systematic classification scheme using FDA-approved drug labeling to assess the DILI potential of drugs, which yielded a benchmark dataset with 287 drugs representing a wide range of therapeutic categories and daily dosage amounts. The method is transparent and reproducible with a potential to serve as a common practice to study the DILI of marketed drugs for supporting drug discovery and biomarker development.

Topics: Animals; Benchmarking; Biomarkers, Pharmacological; Chemical and Drug Induced Liver Injury; Drug Design; Drug Labeling; Drug-Related Side Effects and Adverse Reactions; Humans; Pharmaceutical Preparations; Reproducibility of Results; United States; United States Food and Drug Administration

Drug-induced liver injury (DILI) is a significant concern in drug development due to the poor concordance between preclinical and clinical findings of liver toxicity. We hypothesized that the DILI types (hepatotoxic side effects) seen in the clinic can be translated into the development of predictive in silico models for use in the drug discovery phase. We identified 13 hepatotoxic side effects with high accuracy for classifying marketed drugs for their DILI potential. We then developed in silico predictive models for each of these 13 side effects, which were further combined to construct a DILI prediction system (DILIps). The DILIps yielded 60-70% prediction accuracy for three independent validation sets. To enhance the confidence for identification of drugs that cause severe DILI in humans, the "Rule of Three" was developed in DILIps by using a consensus strategy based on 13 models. This gave high positive predictive value (91%) when applied to an external dataset containing 206 drugs from three independent literature datasets. Using the DILIps, we screened all the drugs in DrugBank and investigated their DILI potential in terms of protein targets and therapeutic categories through network modeling. We demonstrated that two therapeutic categories, anti-infectives for systemic use and musculoskeletal system drugs, were enriched for DILI, which is consistent with current knowledge. We also identified protein targets and pathways that are related to drugs that cause DILI by using pathway analysis and co-occurrence text mining. While marketed drugs were the focus of this study, the DILIps has a potential as an evaluation tool to screen and prioritize new drug candidates or chemicals, such as environmental chemicals, to avoid those that might cause liver toxicity. We expect that the methodology can be also applied to other drug safety endpoints, such as renal or cardiovascular toxicity.

Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Chemical and Drug Induced Liver Injury; Databases, Factual; Drug-Related Side Effects and Adverse Reactions; Humans; Liver; Models, Biological; Predictive Value of Tests

Drug-induced liver injury is a major issue of concern and has led to the withdrawal of a significant number of marketed drugs. An understanding of structure-activity relationships (SARs) of chemicals can make a significant contribution to the identification of potential toxic effects early in the drug development process and aid in avoiding such problems. This process can be supported by the use of existing toxicity data and mechanistic understanding of the biological processes for related compounds. In the published literature, this information is often spread across diverse sources and can be varied and unstructured in quality and content. The current work has explored whether it is feasible to collect and use such data for the development of new SARs for the hepatotoxicity endpoint and expand upon the limited information currently available in this area. Reviews of hepatotoxicity data were used to build a structure-searchable database, which was analyzed to identify chemical classes associated with an adverse effect on the liver. Searches of the published literature were then undertaken to identify additional supporting evidence, and the resulting information was incorporated into the database. This collated information was evaluated and used to determine the scope of the SARs for each class identified. Data for over 1266 chemicals were collected, and SARs for 38 classes were developed. The SARs have been implemented as structural alerts using Derek for Windows (DfW), a knowledge-based expert system, to allow clearly supported and transparent predictions. An evaluation exercise performed using a customized DfW version 10 knowledge base demonstrated an overall concordance of 56% and specificity and sensitivity values of 73% and 46%, respectively. The approach taken demonstrates that SARs for complex endpoints can be derived from the published data for use in the in silico toxicity assessment of new compounds.

Topics: Chemical and Drug Induced Liver Injury; Databases, Factual; Humans; Structure-Activity Relationship; Tetracyclines; Thiophenes

Drug-induced liver injury (DILI) is one of the most important reasons for drug development failure at both preapproval and postapproval stages. There has been increased interest in developing predictive in vivo, in vitro, and in silico models to identify compounds that cause idiosyncratic hepatotoxicity. In the current study, we applied machine learning, a Bayesian modeling method with extended connectivity fingerprints and other interpretable descriptors. The model that was developed and internally validated (using a training set of 295 compounds) was then applied to a large test set relative to the training set (237 compounds) for external validation. The resulting concordance of 60%, sensitivity of 56%, and specificity of 67% were comparable to results for internal validation. The Bayesian model with extended connectivity functional class fingerprints of maximum diameter 6 (ECFC_6) and interpretable descriptors suggested several substructures that are chemically reactive and may also be important for DILI-causing compounds, e.g., ketones, diols, and α-methyl styrene type structures. Using Smiles Arbitrary Target Specification (SMARTS) filters published by several pharmaceutical companies, we evaluated whether such reactive substructures could be readily detected by any of the published filters. It was apparent that the most stringent filters used in this study, such as the Abbott alerts, which captures thiol traps and other compounds, may be of use in identifying DILI-causing compounds (sensitivity 67%). A significant outcome of the present study is that we provide predictions for many compounds that cause DILI by using the knowledge we have available from previous studies. These computational models may represent cost-effective selection criteria before in vitro or in vivo experimental studies.

Topics: Bayes Theorem; Chemical and Drug Induced Liver Injury; Humans; Ligands

Topics: Adult; Chemical and Drug Induced Liver Injury; Dideoxynucleosides; Drug Administration Schedule; Drug Monitoring; Female; HIV Infections; Humans; Liver Function Tests; Reverse Transcriptase Inhibitors; Treatment Outcome

Syphilis remains a current infection in France, with an increase in cases associated with the increase in sexual practices at risk.. An HIV-seropositive homosexual male presented with a perturbed hepatic profile and roseola-like exanthema 15 days after starting treatment with Trizivir. Because of the combination of hepatitis and cutaneous eruption evoking hypersensitivity to abacavir, treatment was suspended, but no improvement was noted. The diagnosis of syphilitic hepatitis associated with roseola was made following a sero-conversion and improvement was obtained with benzathine-penicillin and the re-introduction of Trizivir without further problem.. This case report underlines the possibility of discovering syphilis when confronted with cholestatic and cytolytic hepatitis that regresses with penicillin and is isolated or associated with evocative cutaneous signs.

Topics: Adult; Anti-HIV Agents; Chemical and Drug Induced Liver Injury; Dideoxynucleosides; Drug Combinations; Drug Therapy, Combination; Ethylenediamines; HIV Seropositivity; Humans; Lamivudine; Male; Syphilis; Zidovudine