Immunoallergic drug-induced hepatitis: lessons from halothane

Scavenger receptor a is a major homeostatic regulator that restrains drug-induced liver injury

BACKGROUND AND AIM

Drug-induced liver injury occurs frequently and can be life threatening. Although drug-induced liver injury is mainly caused by the direct drug cytotoxicity, increasing evidence suggests that the interplay between hepatocytes and immune cells can define this pathogenic process. Here, we interrogate the role of the pattern recognition scavenger receptor A (SRA) for regulating hepatic inflammation and drug-induced liver injury.

APPROACH AND RESULTS

Using acetaminophen (APAP) or halothane-induced liver injury models, we showed that SRA loss renders mice highly susceptible to drug hepatotoxicity, indicated by the increased mortality and liver pathology. Mechanistic studies revealed that APAP-induced liver injury exaggerated in the absence of SRA was associated with the decreased anti-inflammatory and prosurvival cytokine IL-10 concomitant with excessive hepatic inflammation. The similar correlation between SRA and IL-10 expression was also seen in human following APAP uptake. Bone marrow reconstitution and liposomal clodronate depletion studies established that the hepatoprotective activity of SRA mostly resized in the immune sentinel KCs. Furthermore, SRA-facilitated IL-10 production by KCs in response to injured hepatocytes mitigated activation of the Jun N-terminal kinase-mediated signaling pathway in hepatocytes. In addition, supplemental use of IL-10 with N -acetylcysteine, only approved treatment of APAP overdose, conferred mice improved protection from APAP-induced liver injury.

CONCLUSION

We identify a novel hepatocyte-extrinsic pathway governed by the immune receptor SRA that maintains liver homeostasis upon drug insult. Giving that drug (ie, APAP) overdose is the leading cause of acute liver failure, targeting this hepatoprotective SRA-IL-10 axis may provide new opportunities to optimize the current management of drug-induced liver injury.

Clinical and biochemical understanding of Zinc interaction during liver diseases: A paradigm shift

Zinc (Zn) is an essential and the second most abundant trace element after Iron. It can apply antioxidant, anti-inflammatory, and anti-apoptotic activity. It is assumed to be indispensable for cell division, cellular differentiation and cell signalling. Zinc is essential for proper liver function which is also the site of its metabolism. Depleted Zn concentrations have been observed in both acute and chronic hepatic diseases. It is reported that Zn deficiency or abnormal Zn metabolism during majority of liver diseases is attributed to deficient dietary intake of Zn, augmented disposal of Zn in the urine, activation of certain Zn transporters, and expression of hepatic metallothionein. Undoubtedly, Zn is involved in generating many diseases but how and whether it plays role from acute to fulminant stage of all chronic liver diseases remains to be cleared. Here, we will discuss the role of Zn in development of different diseases specifically the involvement of Zn to understand the aetiology and intricate mechanism of dynamic liver diseases.

Impact of Prior Drug Allergies on the Risk, Clinical Features, and Outcomes of Idiosyncratic Drug-Induced Liver Injury in Adults

BACKGROUND

Prior drug allergies are common and may increase susceptibility to adverse medication effects. The aim of this study was to compare the frequency, clinical features, and outcomes of DILI among patients with and without a history of prior drug allergy.

METHODS

The EMR at a large liver referral center was searched for all DILI encounters using ICD-10 T-codes for drug poisoning/toxicity and K-71 codes for toxic liver injury between 10/1/2015 and 9/30/2019. Clinically significant liver injury was identified using predefined laboratory criteria, and cases were adjudicated using a 5-point expert opinion scale: 1/2/3 = probable DILI and 4/5 = non-DILI. Drug allergy was defined as a history of anaphylaxis, hives, rash, or pruritus after drug exposure.

RESULTS

Among 766,930 patient encounters, 127 unique patients met inclusion criteria with 72 (56.7%) cases adjudicated as probable DILI and 55 (43.3%) as non-DILI. In the probable DILI group, the most frequent suspect drug classes were: antimicrobials (41.9%), herbal and dietary supplements (9.5%), and antineoplastics (8.1%). Twenty-three of the 72 DILI patients (31.9%) had a history of drug allergy before the DILI episode compared to 16 (29.1%) of the 55 non-DILI cases (p = 0.89). However, none of the allergy drugs and suspect DILI drugs were the same although many were in the same drug class. DILI patients with a prior drug allergy were more likely to be female (73.9% vs. 44.9%, p = 0.04) and have lower serum bilirubin (4.0 vs. 7.8, p = 0.08) and INR (1.1 vs. 1.6, p = 0.043) levels at presentation. The likelihood of death or liver transplantation among probable DILI cases with prior drug allergy was lower than those without prior drug allergy (0% vs. 8.2%, p = 0.35). The suspect drug was subsequently documented in the "Drug Allergy" section of the EMR in only 23 (31.9%) of the 72 probable DILI patients, and these patients were more likely to present with a rash (7% vs. 2%, p = 0.006) and higher serum bilirubin levels (10.5 vs. 4.7, p = 0.008) compared to those in whom the suspect drug was not listed as "drug allergy."

CONCLUSION

A prior drug allergy history was not associated with a greater likelihood of developing DILI compared to other causes of acute liver injury. However, the probable DILI patients with a history of prior drug allergy tended to have less severe liver injury and clinical outcomes. The low rate of suspect drug documentation in the "Drug Allergy" section of EMR after a DILI episode is of concern and could lead to avoidable harm from inadvertent suspect drug re-challenge.

[Recent findings regarding the mechanism of idiosyncratic drug toxicity]

Animal experiments cannot predict the probability of idiosyncratic drug toxicity; consequently, an important goal of the pharmaceutical industry is to develop a new methodology for preventing this form of drug reaction. Although the mechanism remains unclear, immune reactions are likely involved in the toxic processes underlying idiosyncratic drug toxicity: the drug is first activated into a chemically reactive metabolite that binds covalently to proteins and then acts as an immunogen. Therefore, screening tests to detect chemically reactive metabolites are conducted early during drug development and typically involve trapping with glutathione. More quantitative methods are then used in a later stage of drug development and frequently employ (14)Cor (3)H-labeled compounds. It has recently been demonstrated that a zone classification system can be used to separate risky drugs from likely safe drugs: by plotting the amount of each protein-bound reactive metabolite in vitro against the dose levels in vivo, the risk associated with each drug candidate can be assessed. A mechanism for idiosyncratic drug-induced hepatotoxicity was proposed by analogy to virus-induced hepatitis, in which cytotoxic T lymphocytes play an important role. This mechanism suggests that polymorphism in human leukocyte antigens is involved in idiosyncrasy, and a strong correlation with a specific genotype of human leukocyte antigens has been found in many cases of idiosyncratic drug toxicity. Therefore, gene biomarkers hold promise for reducing the clinical risk and prolonging the life cycle of otherwise useful drugs.

Mind the Gap! A Journey towards Computational Toxicology

Computational methods have advanced toxicology towards the development of target-specific models based on a clear cause-effect rationale. However, the predictive potential of these models presents strengths and weaknesses. On the good side, in silico models are valuable cheap alternatives to in vitro and in vivo experiments. On the other, the unconscious use of in silico methods can mislead end-users with elusive results. The focus of this review is on the basic scientific and regulatory recommendations in the derivation and application of computational models. Attention is paid to examine the interplay between computational toxicology and drug discovery and development. Avoiding the easy temptation of an overoptimistic future, we report our view on what can, or cannot, realistically be done. Indeed, studies of safety/toxicity represent a key element of chemical prioritization programs carried out by chemical industries, and primarily by pharmaceutical companies.

Hypersensitivity syndrome due to trichloroethylene exposure: a severe generalized skin reaction resembling drug-induced hypersensitivity syndrome

The number of patients suffering from trichloroethylene (TCE)-related severe skin disorders with liver dysfunction has been increasing in developing countries in Asia, especially since the mid-1990s. In Japan, five cases of this disease have been reported, but none since the 1990s. However, two additional cases were recently observed in Tokyo. The published work and our investigation indicated that oxidative metabolites of TCE, which might include trichloroacetylated-protein adducts, could induce a generalized skin eruption. Furthermore, human leukocyte antigen (HLA)-B*1301 and HLA-B*44 were identified as markers of individual susceptibility to TCE-induced hypersensitivity syndrome (HS). Moreover, polymorphism of aldehyde dehydrogenase (ALDH), the major enzyme in TCE metabolism, appeared to be associated with TCE-induced HS. Interestingly, this disorder is quite similar to drug-induced hypersensitivity syndrome (DIHS), also referred to as drug rash with eosinophilia and systemic symptoms (DRESS), from the perspective of the onset of the reaction after exposure to TCE/drugs, clinical manifestations, blood examination and period of virus reactivation. This article reviews the similarity between TCE-related HS and DIHS/DRESS.

Preoperative risk assessment for patients with liver disease

Patients with underlying liver disease often present for non-liver-related surgery and are at risk for postoperative decompensation. Several predictive models exist to determine the risk of morbidity and mortality after surgery in such patients, but the risk depends on the severity of liver disease and also the type and urgency of the surgery. Clinicians should be cognizant of the various risk assessment tools and incorporate them into their practice when encountering patients with liver disease undergoing surgery.

Understanding the role of reactive metabolites in drug-induced hepatotoxicity: state of the science

Drug-induced liver injury (DILI) represents a major impediment to the development of new drugs and is a leading cause of drug withdrawal. The occurrence of hepatotoxicity has been closely associated with the formation of chemically reactive metabolites. Huge investment has focused on the screening of chemically reactive metabolites to offer a pragmatic approach to produce safer drugs and also reduce drug attrition and prevent market place withdrawal. However, questions surrounding the importance of chemically reactive metabolites still remain. Increasing evidence now exists for the multi-factorial nature of DILI, in particular the role played by the host immune system or disease state in the pathogenesis of DILI. This review aims to evaluate the current measures for the prediction and diagnosis of DILI and to highlight investigations being made to understand the multidimensional nature. Some of the steps being made to generate improved physiological systems to identify more sensitive, reflective mechanism-based biomarkers to aid the earlier identification of DILI and develop safer medicines are also discussed.

Toxicological Significance of Mechanism-Based Inactivation of Cytochrome P450 Enzymes by Drugs

Cytochrome P450 (P450) enzymes oxidize xenobiotics into chemically reactive metabolites or intermediates as well as into stable metabolites. If the reactivity of the product is very high, it binds to a catalytic site or sites of the enzyme itself and inactivates it. This phenomenon is referred to as mechanism-based inactivation. Many clinically important drugs are mechanism-based inactivators that include macrolide antibiotics, calcium channel blockers, and selective serotonin uptake inhibitors, but are not always structurally and pharmacologically related. The inactivation of P450s during drug therapy results in serious drug interactions, since irreversibility of the binding allows enzyme inhibition to be prolonged after elimination of the causal drug. The inhibition of the metabolism of drugs with narrow therapeutic indexes, such as terfenadine and astemizole, leads to toxicities. On the other hand, the fate of P450s after the inactivation and the toxicological consequences remains to be elucidated, while it has been suggested that P450s modified and degraded are involved in some forms of tissue toxicity. Porphyrinogenic drugs, such as griseofulvin, cause mechanism-based heme inactivation, leading to formation of ferrochelatase-inhibitory N-alkylated protoporphyrins and resulting in porphyria. Involvement of P450-derived free heme in halothane-induced hepatotoxicity and catalytic iron in cisplatin-induced nephrotoxicity has also been suggested. Autoantibodies against P450s have been found in hepatitis following administration of tienilic acid and dihydralazine. Tienilic acid is activated by and covalently bound to CYP2C9, and the neoantigens thus formed activate immune systems, resulting in the formation of an autoantibodydirected against CYP2C9, named anti-liver/kidney microsomal autoantibody type 2, whereas the pathological role of the autoantibodies in drug-induced hepatitis remains largely unknown.

Model for end-stage liver disease score versus Child score in predicting the outcome of surgical procedures in patients with cirrhosis

AIM: To determine factors affecting the outcome of patients with cirrhosis undergoing surgery and to compare the capacities of the Child-Turcotte-Pugh (CTP) and model for end-stage liver disease (MELD) score to predict that outcome.

METHODS: We reviewed the charts of 195 patients with cirrhosis who underwent surgery at two teaching hospitals over a five-year period. The combined endpoint of death or hepatic decompensation was considered to be the primary endpoint.

RESULTS: Patients who reached the endpoint had a higher MELD score, a higher CTP score and were more likely to have undergone an urgent procedure. Among patients undergoing elective surgical procedures, no statistically significant difference was noted in the mean MELD (12.8 ± 3.9 vs 12.6 ± 4.7, P = 0.9) or in the mean CTP (7.6 ± 1.2 vs 7.7 ± 1.7, P = 0.8) between patients who reached the endpoint and those who did not. Both mean scores were higher in the patients reaching the endpoint in the case of urgent procedures (MELD: 22.4 ± 8.7 vs 15.2 ± 6.4, P = 0.0007; CTP: 9.9 ± 1.8 vs 8.5 ± 1.8, P = 0.008). The performances of the MELD and CTP scores in predicting the outcome of urgent surgery were only fair, without a significant difference between them (AUC = 0.755 ± 0.066 for MELD vs AUC = 0.696 ± 0.070 for CTP, P = 0.3).

CONCLUSION: The CTP and MELD scores performed equally, but only fairly in predicting the outcome of urgent surgical procedures. Larger studies are needed to better define the factors capable of predicting the outcome of elective surgical procedures in patients with cirrhosis.

Preoperative evaluation of patients with liver disease

Patients with end-stage liver disease often undergo surgery for indications other than liver transplantation. These patients have an increased risk of morbidity and mortality that is related to their underlying liver disease. Assessments of surgical risk provide a basis for discussion of risks and benefits, treatment decision making, and for optimal management of patients for whom surgery is planned. The most useful indicators of surgical risk are indices that predict advanced disease, such as the Child-Turcotte-Pugh score, or those that predict prognosis, such as the Model for End-stage Liver Disease score. Careful preoperative risk assessment, patient selection, and management of various manifestations of advanced disease might decrease morbidity and mortality from nontransplant surgery in patients with liver disease.

Selection of new chemical entities with decreased potential for adverse drug reactions

Adverse drug reactions, such as hepatotoxicity, blood dyscrasias and hypersensitivity are a major obstacle for the use and the development of new medicines. Many forms of organ-directed toxicity can arise from the bioactivation of drugs to so-called chemically reactive metabolites, which can modify tissue macromolecules. It is well established that the toxicities of model hepatotoxins, such as acetaminophen, furosemide, bromobenzene and methapyrilene can be correlated with the generation of chemically reactive metabolites, which can be detected by measurement of the irreversible binding of radiolabelled material to hepatic protein and/or the detection of stable phase II metabolites such as glutathione conjugates. The basic chemistry of the reaction of such metabolites with model nucleophiles is relatively well understood. A major challenge is to define how certain reactive intermediates may chemically modify critical proteins and how modification of specific amino acids may alter protein function which in turn may affect cell signalling, regulation, defence, function and viability. This in turn will determine whether or not bioactivation will result in a particular form of drug-induced injury. It is now clear that even relatively simple reactive intermediates can react in a discriminative manner with particular cellular proteins and even with specific amino acids within those proteins. Therefore both non-covalent, as well as covalent bonds will be important determinants of the target protein for a particular reactive metabolite. Mammalian cells have evolved numerous defence systems against reactive intermediates. Sensitive redox proteins such as Nrf-2 recognize oxidative stress and electrophilic agents. This is achieved by chemical modification of cysteine groups within keap-1, which normally forms an inactive heterodimer with Nrf-2. Modification of keap-1 releases Nrf-2 that translocates to the nucleus and effects gene transcription of a number of genes involved in the detoxication of chemically reactive metabolites. Diminution of protein function can occur by either covalent modification of nucleophilic amino acids (e.g. cysteine, lysine, histidine etc.) or oxidation of thiols, which can be reversible or irreversible. In the case of acetaminophen, more than 30 target proteins have been identified and for several of them, corresponding alterations in protein function have been defined in the context of tissue necrosis. Alternatively, protein modification may induce signalling systems which initiate cell death, an immune response or to an altered tissue genotype.

The role of metabolic activation in drug-induced hepatotoxicity

The importance of reactive metabolites in the pathogenesis of drug-induced toxicity has been a focus of research interest since pioneering investigations in the 1950s revealed the link between toxic metabolites and chemical carcinogenesis. There is now a great deal of evidence that shows that reactive metabolites are formed from drugs known to cause hepatotoxicity, but how these toxic species initiate and propagate tissue damage is still poorly understood. This review summarizes the evidence for reactive metabolite formation from hepatotoxic drugs, such as acetaminophen, tamoxifen, diclofenac, and troglitazone, and the current hypotheses of how this leads to liver injury. Several hepatic proteins can be modified by reactive metabolites, but this in general equates poorly with the extent of toxicity. Much more important may be the identification of the critical proteins modified by these toxic species and how this alters their function. It is also important to note that the toxicity of reactive metabolites may be mediated by noncovalent binding mechanisms, which may also have profound effects on normal liver physiology. Technological developments in the wake of the genomic revolution now provide unprecedented power to characterize and quantify covalent modification of individual target proteins and their functional consequences; such information should dramatically improve our understanding of drug-induced hepatotoxic reactions.

Autoimmunity and environmental factors in the pathogenesis of primary biliary cirrhosis

It is generally believed that autoimmune processes are initiated when tolerance to self-proteins is broken. Primary biliary cirrhosis (PBC) is an autoimmune liver disease of unknown etiology. Autoimmune attack in PBC is predominantly organ-specific, despite the presence of mitochondrial autoantigens, the major targets of autoimmunity in PBC, in all nucleated cells. Although the events that provoke initial activation remain unknown, the hypothesis of molecular mimicry implies that foreign pathogens with homology to self-protein or modified self-protein can break tolerance. Several reports have suggested the association of autoimmune diseases with drugs, chemicals, and other environmental factors. Specifically, many xenobiotics are metabolized in the liver. Liver autoantigens exposed to these chemicals could be modified and become immunogenic. We propose that exposure to the environmental xenobiotics is one of the initiating factors that leads to the loss of tolerance to self-proteins in genetically susceptible hosts, resulting in development of PBC.

Concordance between trifluoroacetic acid and hepatic protein trifluoroacetylation after disulfiram inhibition of halothane metabolism in rats

BACKGROUND

Cytochrome P4502E1(CYP2E1)-mediated oxidation of halothane to a reactive intermediate (trifluoroacyl chloride) that covalently binds to hepatic proteins forming trifluoroacetylated neoantigens is believed to be the initiating event in a complex immunologic cascade culminating in antibody formation and severe hepatic necrosis ('halothane hepatitis') in susceptible patients. Trifluoroacyl chloride may also hydrolyze to the stable metabolite trifluoroacetic acid (TFA). CYP2E1 inactivation by disulfiram or its primary metabolite, diethyldithiocarbamate, inhibits human halothane oxidation to TFA in vitro and in vivo. Nevertheless, disulfiram effects on hepatic protein trifluoroacetylation by halothane in vivo are unknown. This investigation tested the hypotheses that disulfiram prevents halothane-dependent protein trifluoroacetylation in vivo, and that TFA represents a biomarker for hepatic protein trifluoroacetylation.

METHODS

Rats were pretreated with isoniazid (CYP2E1 induction), isoniazid followed by disulfiram (CYP2E1 inhibition), or nothing (controls), then anesthetized with halothane or nothing (controls). Plasma and urine TFA were quantified by ion HPLC; hepatic microsomal TFA-proteins were analyzed by Western blot.

RESULTS

CYP2E1 induction increased both TFA and TFA-protein formation compared with uninduced halothane-treated rats. Disulfiram, even after CYP2E1 induction, nearly abolished both TFA and TFA-protein formation. Pretreatments similarly affected both TFA and TFA-protein formation across all groups.

CONCLUSIONS

Disulfiram inhibition of CYP2E1-mediated halothane oxidation prevents hepatic protein trifluoroacetylation. Based on the concordance between TFA and TFA-protein formation, TFA appears to be a valid biomarker for TFA-protein formation. Disulfiram inhibition of human halothane oxidation in vivo, previously assessed by diminished TFA formation, probably also confers inhibition of hepatic TFA-protein formation.

Fulminant liver disease

Fulminant liver disease, acute liver failure (ALF), is one of the most intriguing and challenging conditions in the entire field of internal medicine. ALF is defined as the onset of hepatic encephalopathy and coagulopathy in patients with no known underlying liver disease within 8 to 26 weeks of onset of illness. Many cases develop within a few days, dramatically transforming an otherwise healthy individual to a patient with a high risk for developing multi-organ failure and death.

Immune-mediated drug-induced liver disease

Drug-induced immune-mediated hepatic injury is an adverse immune response against the liver that results in a disease with hepatitic, cholestatic, or mixed clinical features. Drugs such as halothane, tienilic acid, dihydralazine, and anticonvulsants trigger a hepatitic reaction, and drugs such as chlorpromazine, erythromycins, amoxicillin-calvulanic acid, sulfonamides and sulindac trigger a cholestatic or mixed reaction. Unstable metabolites derived from the metabolism of the drug may bind to cellular proteins or macromolecules, leading to a direct toxic effect on hepatocytes. Protein adducts formed in the metabolism of the drug may be recognized by the immune system as neoantigens. Immunocyte activation may then generate autoantibodies and cell-mediated immune responses, which in turn damage the hepatocytes. Cytochromes 450 are the major oxidative catalysts in drug metabolism, and they can form a neoantigen by covalently binding with the drug metabolite that they produce. Autoantibodies that develop are selectively directed against the particular cytochrome isoenzyme that metabolized the parent drug. The hapten hypothesis proposes that the drug metabolite can act as a hapten and can modify the self of the individual by covalently binding to proteins. The danger hypothesis proposes that the immune system only responds to a foreign antigen if the antigen is associated with a danger signal, such as cell stress or cell death. Most clinically overt adverse hepatic events associated with drugs are unpredictable, and they have intermediate (1 to 8 weeks) or long latency (up to 12 months) periods characteristic of hypersensitivity reactions. Immune-mediated drug-induced liver disease nearly always disappears or becomes quiescent when the drug is removed. Methyldopa, minocycline, and nitrofurantoin can produce a chronic hepatitis resembling AIH if the drug is continued.

Bioactivation and toxicity in vitro of HCFC-123 and HCFC-141b: role of cytochrome P450

The bioactivation and cytotoxicity in vitro of 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1,1-dichloro-1-fluoroethane (HCFC-141b), two replacements for some ozone-depleting chlorofluorocarbons (CFC), were investigated in rat liver microsomes and isolated rat hepatocytes. Both compounds were activated by cytochrome P450 to reactive metabolites, as indicated by: (i) the depletion of exogenous and cellular glutathione, (ii) the increased LDH release from hepatocytes, (iii) the loss of microsomal P450 content and activities, and (iv) the formation of free radical species observed in the presence of the two compounds. Moreover, the formation of two stable metabolites and an increased production of conjugated dienes, a marker of lipid peroxidation, were observed for both HCFC-123 and HCFC-141b. The biotransformation of both compounds by pyridine- and phenobarbital-induced rat liver microsomes and the inhibition of LDH release by 4-methylpyrazole and troleandomycin indicate that P450 2E1, 2B and, possibly, also 3A are the isoforms involved in the bioactivation and toxicity of HCFC-123 and HCFC-141b in the rat.

Anti-malondialdehyde antibodies in MRL+/+ mice treated with trichloroethene and dichloroacetyl chloride: possible role of lipid peroxidation in autoimmunity

Trichloroethene (TCE) and one of its metabolites dichloroacetyl chloride (DCAC) are known to induce/accelerate autoimmune (AI) response in MRL+/+ mice as evident from anti-nuclear, anti-ssDNA, anti-cardiolipin, and DCAC-specific antibodies in the serum (Khan et al., Toxicol. Appl. Pharmacol. 134, 155-160, 1995). In the present study, we measured anti-malondialdehyde antibodies (AMDA) in the serum of TCE- or DCAC-treated mice in order to understand the contribution of lipid peroxidation to this AI response. Female MRL+/+ mice (5 weeks old) received ip injections of 10 mmol/kg TCE or 0.2 mmol/kg of DCAC in corn oil (100 microl) every 4(th) day for 6 weeks, while controls received an equal volume of vehicle only, and AMDA was measured in the sera of these animals by an ELISA established in our laboratory. While TCE treatment caused only marginal induction of AMDA, DCAC treatment elicited a significant AMDA response. Furthermore, a time-response study of DCAC (0.2 mmol/kg, every 4(th) day, for 2, 4, 6, or 8 weeks) showed an induction of AMDA (3/4) after 4 weeks of treatment, which was even greater at both 6 and 8 weeks of DCAC treatment (5/5). These findings were further substantiated by the presence of AMDA in systemic lupus erythematosus-prone MRL-lpr/lpr mice as early as 6 weeks of age. Presence of AMDA, as observed in this study, not only indicates increased lipid peroxidation (oxidative stress), but also suggests a putative role of oxidative stress in inflammatory autoimmune diseases.

Drug-induced liver disease

The incidence of drug-induced liver disease appears to be increasing, reflecting the increasing number of new agents that have been introduced into clinical use over the past several decades. Among the topics covered, the author discusses incidence, diagnosis, risk factors, clinical presentations, hepatitis, and vascular injury. The author also reviews the hepatic injury seen with commonly prescribed drugs, emphasizing newer developments in the field and recent publications and reports.

Gallstones and isoflurane hepatitis

This report is of a case of a previously fit 65-year-old woman who developed postoperative liver dysfunction following an anaesthetic involving isoflurane. Biliary ultrasound demonstrated gallstones. However, serum antibodies to trifluoroacetylated proteins were detected, suggesting that immune sensitisation to the anaesthetic could have contributed to the impaired liver function.