1
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Christen U. Breakdown of tolerance in autoimmune hepatitis: This time toxin beats virus. Immunol Lett 2020; 218:51-53. [DOI: 10.1016/j.imlet.2019.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 10/25/2022]
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Czaja AJ. Examining pathogenic concepts of autoimmune hepatitis for cues to future investigations and interventions. World J Gastroenterol 2019; 25:6579-6606. [PMID: 31832000 PMCID: PMC6906207 DOI: 10.3748/wjg.v25.i45.6579] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Multiple pathogenic mechanisms have been implicated in autoimmune hepatitis, but they have not fully explained susceptibility, triggering events, and maintenance or escalation of the disease. Furthermore, they have not identified a critical defect that can be targeted. The goals of this review are to examine the diverse pathogenic mechanisms that have been considered in autoimmune hepatitis, indicate investigational opportunities to validate their contribution, and suggest interventions that might evolve to modify their impact. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Genetic and epigenetic factors can affect susceptibility by influencing the expression of immune regulatory genes. Thymic dysfunction, possibly related to deficient production of programmed cell death protein-1, can allow autoreactive T cells to escape deletion, and alterations in the intestinal microbiome may help overcome immune tolerance and affect gender bias. Environmental factors may trigger the disease or induce epigenetic changes in gene function. Molecular mimicry, epitope spread, bystander activation, neo-antigen production, lymphocytic polyspecificity, and disturbances in immune inhibitory mechanisms may maintain or escalate the disease. Interventions that modify epigenetic effects on gene expression, alter intestinal dysbiosis, eliminate deleterious environmental factors, and target critical pathogenic mechanisms are therapeutic possibilities that might reduce risk, individualize management, and improve outcome. In conclusion, diverse pathogenic mechanisms have been implicated in autoimmune hepatitis, and they may identify a critical factor or sequence that can be validated and used to direct future management and preventive strategies.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, United States
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Choe HJ, Ahn S, Jung K, Kim JW. Acute liver failure caused by occupational exposure to HCFC-123: Two case reports. Medicine (Baltimore) 2019; 98:e14522. [PMID: 30817569 PMCID: PMC6831264 DOI: 10.1097/md.0000000000014522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Hydrochlorofluorocarbon 123 (HCFC-123, Freon123; 2,2-dichloro-1,1,1-trifluoroethane) has been widely used in refrigeration and heat-transfer applications as a substitute for chlorofluorocarbons due to its lower ozone-depleting potentials. Occupational exposure to HCFC-123 may cause mild reversible hepatoxicity, but no fatal cases have been reported yet. PATIENT CONCERNS In this report, we present cases of severe hepatitis with fatal outcome by HCFC-123. Two industrial workers from a manufacturing factory of fire extinguishers which use HCFC-123 were presented with diarrhea, fever, myalgia, and jaundice. Patients had been repeatedly exposed to the liquid form of HCFC-123 for the past three weeks before flare of symptoms. DIAGNOSIS The blood biochemistry tests showed acute cholestatic hepatitis and liver biopsy findings indicated inflammatory hepatocellular injury. The diagnosis of HCFC-123 induced hepatitis was made. INTERVENTIONS The treatment for both patients were generally supportive. The second patient went through hemodialysis, ventilatory care, and artificial liver support therapy (molecular adsorbent recirculating system) at intensive care unit. OUTCOMES One patient recovered uneventfully, whereas the other patient showed rapid deterioration leading to acute liver failure complicated with cerebral edema, subdural hemorrhage, and death on hospital day 10. LESSONS The HCFC-123-induced hepatitis showed similarities with halothane hepatitis, both of which may share pathophysiologic mechanisms. Exposure to HCFC-123 needs to be listed as a potential cause of acute liver failure, and to be considered in patients with acute hepatitis of uncertain etiology and negative viral serology.
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Affiliation(s)
| | - Soomin Ahn
- Department of Pathology, Seoul National University Bundang Hospital, Seongnam
| | | | - Jin-Wook Kim
- Department of Medicine
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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Bessone F, Dirchwolf M, Rodil MA, Razori MV, Roma MG. Review article: drug-induced liver injury in the context of nonalcoholic fatty liver disease - a physiopathological and clinical integrated view. Aliment Pharmacol Ther 2018; 48:892-913. [PMID: 30194708 DOI: 10.1111/apt.14952] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 03/25/2018] [Accepted: 07/30/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND Nonalcoholic fatty disease (NAFLD) is the most common liver disease, since it is strongly associated with obesity and metabolic syndrome pandemics. NAFLD may affect drug disposal and has common pathophysiological mechanisms with drug-induced liver injury (DILI); this may predispose to hepatoxicity induced by certain drugs that share these pathophysiological mechanisms. In addition, drugs may trigger fatty liver and inflammation per se by mimicking NAFLD pathophysiological mechanisms. AIMS To provide a comprehensive update on (a) potential mechanisms whereby certain drugs can be more hepatotoxic in NAFLD patients, (b) the steatogenic effects of drugs, and (c) the mechanism involved in drug-induced steatohepatitis (DISH). METHODS A language- and date-unrestricted Medline literature search was conducted to identify pertinent basic and clinical studies on the topic. RESULTS Drugs can induce macrovesicular steatosis by mimicking NAFLD pathogenic factors, including insulin resistance and imbalance between fat gain and loss. Other forms of hepatic fat accumulation exist, such as microvesicular steatosis and phospholipidosis, and are mostly associated with acute mitochondrial dysfunction and defective lipophagy, respectively. Drug-induced mitochondrial dysfunction is also commonly involved in DISH. Patients with pre-existing NAFLD may be at higher risk of DILI induced by certain drugs, and polypharmacy in obese individuals to treat their comorbidities may be a contributing factor. CONCLUSIONS The relationship between DILI and NAFLD may be reciprocal: drugs can cause NAFLD by acting as steatogenic factors, and pre-existing NAFLD could be a predisposing condition for certain drugs to cause DILI. Polypharmacy associated with obesity might potentiate the association between this condition and DILI.
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Affiliation(s)
- Fernando Bessone
- Hospital Provincial del Centenario, Facultad de Ciencias Médicas, Servicio de Gastroenterología y Hepatología, Universidad Nacional de Rosario, Rosario, Argentina
| | - Melisa Dirchwolf
- Unidad de Transplante Hepático, Servicio de Hepatología, Hospital Privado de Rosario, Rosario, Argentina
| | - María Agustina Rodil
- Hospital Provincial del Centenario, Facultad de Ciencias Médicas, Servicio de Gastroenterología y Hepatología, Universidad Nacional de Rosario, Rosario, Argentina
| | - María Valeria Razori
- Instituto de Fisiología Experimental (IFISE-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Marcelo G Roma
- Instituto de Fisiología Experimental (IFISE-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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5
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Christen U. Animal models of autoimmune hepatitis. Biochim Biophys Acta Mol Basis Dis 2018; 1865:970-981. [PMID: 29857050 DOI: 10.1016/j.bbadis.2018.05.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/14/2018] [Accepted: 05/22/2018] [Indexed: 02/06/2023]
Abstract
Many animal models for autoimmune hepatitis (AIH) have been described in the past. Most models had to deal with the relative immunosuppressive environment of the liver. Therefore, some models used a combination of several triggering factors often on a susceptible background to generate an aggressive immune response that targets the liver. In addition, in order to be able to track the immune response the models used specific model autoantigens as targets that are either not present or have not been identified as a natural autoantigen in AIH patients. Thereby the feasibility of such models is somewhat questionable. Although many historic approaches included challenges of experimental animals with liver homogenates it was only in the last decade that natural occurring liver autoantigens have been used in animal models. This article reflects on the requirements for breaking liver tolerance and on how an ideal experimental model for AIH would look like. In addition, it discusses historic as well as recent animal models in the context of feasibility of induction, similarity of the clinical outcome to human AIH, and gain of knowledge for possible future therapies.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Frankfurt am Main, Germany.
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Christen U, Hintermann E. Autoantibodies in Autoimmune Hepatitis: Can Epitopes Tell Us about the Etiology of the Disease? Front Immunol 2018; 9:163. [PMID: 29503645 PMCID: PMC5820307 DOI: 10.3389/fimmu.2018.00163] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/18/2018] [Indexed: 12/12/2022] Open
Abstract
Autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are serious autoimmune liver diseases that are characterized by a progressive destruction of the liver parenchyma and/or the hepatic bile ducts and the development of chronic fibrosis. Left untreated autoimmune liver diseases are often life-threatening, and patients require a liver transplantation to survive. Thus, an early and reliable diagnosis is paramount for the initiation of a proper therapy with immunosuppressive and/or anticholelithic drugs. Besides the analysis of liver biopsies and serum markers indicating liver damage, the screening for specific autoantibodies is an indispensable tool for the diagnosis of autoimmune liver diseases. Such liver autoantigen-specific antibodies might be involved in the disease pathogenesis, and their epitope specificity may give some insight into the etiology of the disease. Here, we will mainly focus on the generation and specificity of autoantibodies in AIH patients. In addition, we will review data from animal models that aim toward a better understanding of the origins and pathogenicity of such autoantibodies.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
| | - Edith Hintermann
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
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Massart J, Begriche K, Moreau C, Fromenty B. Role of nonalcoholic fatty liver disease as risk factor for drug-induced hepatotoxicity. J Clin Transl Res 2017; 3:212-232. [PMID: 28691103 PMCID: PMC5500243 DOI: 10.18053/jctres.03.2017s1.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Obesity is often associated with nonalcoholic fatty liver disease (NAFLD), which refers to a large spectrum of hepatic lesions including fatty liver, nonalcoholic steatohepatitis (NASH) and cirrhosis. Different investigations showed or suggested that obesity and NAFLD are able to increase the risk of hepatotoxicity of different drugs. Some of these drugs could induce more frequently an acute hepatitis in obese individuals whereas others could worsen pre-existing NAFLD. AIM The main objective of the present review was to collect the available information regarding the role of NAFLD as risk factor for drug-induced hepatotoxicity. For this purpose, we performed a data-mining analysis using different queries including drug-induced liver injury (or DILI), drug-induced hepatotoxicity, fatty liver, nonalcoholic fatty liver disease (or NAFLD), steatosis and obesity. The main data from the collected articles are reported in this review and when available, some pathophysiological hypotheses are put forward. RELEVANCE FOR PATIENTS Drugs that could pose a potential risk in obese patients include compounds belonging to different pharmacological classes such as acetaminophen, halothane, methotrexate, rosiglitazone, stavudine and tamoxifen. For some of these drugs, experimental investigations in obese rodents confirmed the clinical observations and unveiled different pathophysiological mechanisms which could explain why these pharmaceuticals are particularly hepatotoxic in obesity and NAFLD. Other drugs such as pentoxifylline, phenobarbital and omeprazole might also pose a risk but more investigations are required to determine whether this risk is significant or not. Because obese people often take several drugs for the treatment of different obesity-related diseases such as type 2 diabetes, hyperlipidemia and coronary heart disease, it is urgent to identify the main pharmaceuticals that can cause acute hepatitis on a fatty liver background or induce NAFLD worsening.
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Affiliation(s)
- Julie Massart
- Department of Molecular Medicine and Surgery, Karolinska University Hospital, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | | | - Caroline Moreau
- INSERM, U991, Université de Rennes 1, Rennes, France.,Service de Biochimie et Toxicologie, CHU Pontchaillou, Rennes, France
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Safari S, Motavaf M, Seyed Siamdoust SA, Alavian SM. Hepatotoxicity of halogenated inhalational anesthetics. IRANIAN RED CRESCENT MEDICAL JOURNAL 2014; 16:e20153. [PMID: 25593732 PMCID: PMC4270648 DOI: 10.5812/ircmj.20153] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 08/18/2014] [Accepted: 07/31/2014] [Indexed: 12/17/2022]
Abstract
Context: Halogenated inhalational anesthetics are currently the most common drugs used for the induction and maintenance of general anesthesia. Postoperative hepatic injury has been reported after exposure to these agents. Based on much evidence, mechanism of liver toxicity is more likely to be immunoallergic. The objective of this review study was to assess available studies on hepatotoxicity of these anesthetics. Evidence Acquisition: We searched PubMed, Google Scholar, Scopus, Index Copernicus, EBSCO and the Cochrane Database using the following keywords: “inhalational Anesthetics” and “liver injury”; “inhalational anesthetics” and “hepatotoxicity”; “volatile anesthetics” and “liver injury”; “volatile anesthetics” and hepatotoxicity for the period of 1966 to 2013. Fifty two studies were included in this work. Results: All halogenated inhalational anesthetics are associated with liver injury. Halothane, enflurane, isoflurane and desflurane are metabolized through the metabolic pathway involving cytochrome P-450 2E1 (CYP2E1) and produce trifluoroacetylated components; some of which may be immunogenic. The severity of hepatotoxicity is associated with the degree by which they undergo hepatic metabolism by this cytochrome. However, liver toxicity is highly unlikely from sevoflurane as is not metabolized to trifluoroacetyl compounds. Conclusions: Hepatotoxicity of halogenated inhalational anesthetics has been well documented in available literature. Halothane-induced liver injury was extensively acknowledged; however, the next generation halogenated anesthetics have different molecular structures and associated with less hepatotoxicity. Although anesthesia-induced hepatitis is not a common occurrence, we must consider the association between this disorder and the use of halogenated anesthetics.
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Affiliation(s)
- Saeid Safari
- Department of Anesthesiology and Pain Medicine, Iran University of Medical Sciences, Tehran, IR Iran
| | - Mahsa Motavaf
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, IR Iran
- Department of Molecular Hepatology, Middle East Liver Disease Center, Tehran, IR Iran
| | | | - Seyed Moayed Alavian
- Department of Molecular Hepatology, Middle East Liver Disease Center, Tehran, IR Iran
- Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
- Corresponding Author: Seyed Moayed Alavian, Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallah University of Medical Sciences and Tehran Hepatitis Center, Tehran, IR Iran. Tel: +98-2188945186, Fax: +98-2188945188, E-mail:
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Abstract
Autoimmune disorders afflicting the liver comprise the bona fide autoimmune diseases, primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis as well as drug-induced autoimmune-like diseases, such as halothane hepatitis. Whereas drug-induced forms of acute or chronic hepatitis often have a clear triggering factor, the etiology of classical autoimmune liver diseases is only poorly understood. Besides a genetic component present in disease susceptible individuals, environmental triggering factors are likely to play a role in the initiation and/or propagation of the disease. In this article, we will review on current evidence obtained from epidemiological associations, case studies, and findings in animal models for pathogens, to be involved in the etiology of autoimmune liver disease with a special focus on autoimmune hepatitis.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital , Frankfurt am Main , Germany
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10
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Endo S, Yano A, Fukami T, Nakajima M, Yokoi T. Involvement of miRNAs in the early phase of halothane-induced liver injury. Toxicology 2014; 319:75-84. [PMID: 24598351 DOI: 10.1016/j.tox.2014.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 12/25/2013] [Accepted: 02/13/2014] [Indexed: 12/12/2022]
Abstract
MicroRNAs (miRNA) form a class of small non-coding RNA molecules that negatively regulate gene expression. Most cellular pathways are modulated by miRNAs. However, the pathophysiological role of miRNAs during drug-induced liver injury (DILI) remains largely unknown. In this study, the possible involvement of miRNAs in DILI caused by the hepatotoxic drug halothane (HAL) was investigated. Toward this purpose, miRNA microarray studies of HAL-induced liver injury were performed in mice at five different time points up to 24h after dosing. To exclude any pharmacological effects on miRNA expression, isoflurane was used as a low hepatotoxic drug because it is structurally similar to HAL. Approximately 30-50% of the miRNA expression levels changed more than two-fold at every time point. In silico biological pathway analysis was performed to predict the targeted genes. Consequently, the miRNA gene down-regulation that occurred 1h after HAL administration was primarily related to inflammation, immune systems and liver injury. Based on additional in silico analyses, we identified miR-106b. Subsequently target of miR-106b was investigated using liver samples from mice with HAL-induced liver injury. Among the predicted targets, we discovered that a signal transducer and activator of transcription 3 (STAT3) was particularly up-regulated beginning during the early phase of HAL-induced liver injury. Collectively, the suppressed miR-106b expression, as well as the subsequent up-regulation of STAT3, was critical for the pathogenesis of HAL-induced liver injury.
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Affiliation(s)
- Shinya Endo
- Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Azusa Yano
- Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Tatsuki Fukami
- Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Miki Nakajima
- Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Tsuyoshi Yokoi
- Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan; Department of Drug Safety Sciences, Nagoya University School of Medicine, Nagoya 466-8550, Japan.
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12
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Abstract
Trichloroethylene is commonly used as an industrial solvent and degreasing agent. The clinical features of acute and chronic intoxication with trichloroethylene are well-known and have been described in many reports, but hypersensitivity syndrome caused by trichloroethylene is rarely encountered. For managing patients with trichloroethylene hypersensitivity syndrome, avoiding trichloroethylene and initiating glucocorticoid have been generally accepted. Generally, glucocorticoid had been tapered as trichloroethylene hypersensitivity syndrome had ameliorated. However, we encountered a typical case of trichloroethylene hypersensitivity syndrome refractory to high dose glucocorticoid treatment. A 54-year-old Korean man developed jaundice, fever, red sore eyes, and generalized erythematous maculopapular rashes. A detailed history revealed occupational exposure to trichloroethylene. After starting intravenous methylprednisolone, his clinical condition improved remarkably, but we could not reduce prednisolone because his liver enzyme and total bilirubin began to rise within 2 days after reducing prednisolone under 60 mg/day. We recommended an extended admission for complete recovery, but the patient decided to leave the hospital against medical advice. The patient visited the emergency department due to pneumonia and developed asystole, which did not respond to resuscitation.
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Affiliation(s)
- Hyun Gul Jung
- Department of Internal Medicine, Inje University College of Medicine, Seoul Paik Hospital, Seoul, Korea
| | - Hyung Hun Kim
- Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
| | - Bong Gun Song
- Department of Internal Medicine, Inje University College of Medicine, Seoul Paik Hospital, Seoul, Korea
| | - Eun Jin Kim
- Department of Internal Medicine, Inje University College of Medicine, Seoul Paik Hospital, Seoul, Korea
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13
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Toyoda Y, Miyashita T, Endo S, Tsuneyama K, Fukami T, Nakajima M, Yokoi T. Estradiol and progesterone modulate halothane-induced liver injury in mice. Toxicol Lett 2011; 204:17-24. [DOI: 10.1016/j.toxlet.2011.03.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/29/2011] [Accepted: 03/30/2011] [Indexed: 12/22/2022]
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Mohutsky MA, Romeike A, Meador V, Lee WM, Fowler J, Francke-Carroll S. Hepatic Drug-Metabolizing Enzyme Induction and Implications for Preclinical and Clinical Risk Assessment. Toxicol Pathol 2010; 38:799-809. [DOI: 10.1177/0192623310375099] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Hepatic drug metabolizing enzyme (DME) induction complicates the development of new drugs owing to altered efficacy of concomitant treatments, reduction in exposure resulting from autoinduction, and potential generation of toxic metabolites. Risk assessment of DME induction during clinical evaluation is confounded by several uncertainties pertaining to hazard identification and dose response analysis. Hepatic DME induction rarely leads to clinical evidence of altered metabolism and toxicity in the patient, which typically occur only if the DME induction is relatively severe. High drug doses are associated with a greater likelihood of hepatic DME induction and downstream effects; therefore, drugs of low potency requiring higher dosing tend to lead to a greater risk of drug–drug interactions. Vigilance in clinical trials for increased or diminished drug effect and, specifically, pharmacokinetic studies in the presence of other drugs and concomitant diseases are necessary for a drug risk assessment profile. Efforts to remove hepatic DME-inducing drugs from development can be facilitated with current in vitro and in vivo assessments and will improve with the development of newer technologies. A carefully tailored case-by-case approach will lead to the development of efficacious drugs with an acceptable risk/benefit profile available to patients.
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Affiliation(s)
| | | | | | - William M. Lee
- Department of Internal Medicine, UT Southwestern Medical Center at Dallas, Dallas, TX, USA
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Abstract
Troglitazone was the first thiazolidinedione antidiabetic agent approved for clinical use in 1997, but it was withdrawn from the market in 2000 due to serious idiosyncratic hepatotoxicity. Troglitazone contains the structure of a unique chroman ring of vitamin E, and this structure has the potential to undergo metabolic biotransformation to form quinone metabolites, phenoxy radical intermediate, and epoxide species. Although troglitazone has been shown to induce apoptosis in various hepatic and nonhepatic cells, the involvement of reactive metabolites in the troglitazone cytotoxicity is controversial. Numerous toxicological tests, both in vivo and in vitro, have been used to try to predict the toxicity, but no direct mechanism has been demonstrated that can explain the hepatotoxicity that occurred in some individuals. This chapter summarizes the proposed mechanisms of troglitazone hepatotoxicity based in vivo and in vitro studies. Many factors have been proposed to contribute to the mechanism underlying this idiosyncratic toxicity.
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Affiliation(s)
- Tsuyoshi Yokoi
- Drug Metabolism and Toxicology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
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16
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Muilenburg DJ, Singh A, Torzilli G, Khatri VP. Surgery in the patient with liver disease. Anesthesiol Clin 2009; 27:721-37. [PMID: 19942176 DOI: 10.1016/j.anclin.2009.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Liver dysfunction is a prominent entity in Western medicine that has historically affected patients suffering from chronic viral or alcoholic hepatitis. The incidence of these conditions has not changed dramatically in recent years but the overall number of patients with liver dysfunction has increased considerably with the emergence of the obesity epidemic. Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of chronic liver disease in the United States. Although the rate of progression of NAFLD to overt cirrhosis is low, the high prevalence of this condition, combined with the moderate degree of liver dysfunction it engenders, has resulted in a significant increase in the number of patients with liver disease that can be encountered by a surgical practice. Any degree of clinically evident liver disease in a prospective surgical patient should raise concern for the entire surgical team. This particularly applies to intraabdominal surgery whereby the presence of hepatomegaly, portal hypertension, variceal bleeding, and ascites can turn even the most routine operation into a morbid and life-threatening procedure. Nonabdominal surgery avoids some of the technical challenges presented by liver disease but the anesthetic management of a cirrhotic patient still makes any operation potentially more dangerous. In this article, approaches to minimize the risk when surgery becomes necessary in the presence of liver disease are discussed.
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Affiliation(s)
- Diego J Muilenburg
- Department of Surgery, University of California-Davis, 2315 Stockton Boulevard, Sacramento, CA 95817, USA
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Grattagliano I, Bonfrate L, Diogo CV, Wang HH, Wang DQH, Portincasa P. Biochemical mechanisms in drug-induced liver injury: Certainties and doubts. World J Gastroenterol 2009; 15:4865-76. [PMID: 19842215 PMCID: PMC2764962 DOI: 10.3748/wjg.15.4865] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Drug-induced liver injury is a significant and still unresolved clinical problem. Limitations to knowledge about the mechanisms of toxicity render incomplete the detection of hepatotoxic potential during preclinical development. Several xenobiotics are lipophilic substances and their transformation into hydrophilic compounds by the cytochrome P-450 system results in production of toxic metabolites. Aging, preexisting liver disease, enzyme induction or inhibition, genetic variances, local O2 supply and, above all, the intrinsic molecular properties of the drug may affect this process. Necrotic death follows antioxidant consumption and oxidation of intracellular proteins, which determine increased permeability of mitochondrial membranes, loss of potential, decreased ATP synthesis, inhibition of Ca2+-dependent ATPase, reduced capability to sequester Ca2+ within mitochondria, and membrane bleb formation. Conversely, activation of nucleases and energetic participation of mitochondria are the main intracellular mechanisms that lead to apoptosis. Non-parenchymal hepatic cells are inducers of hepatocellular injury and targets for damage. Activation of the immune system promotes idiosyncratic reactions that result in hepatic necrosis or cholestasis, in which different HLA genotypes might play a major role. This review focuses on current knowledge of the mechanisms of drug-induced liver injury and recent advances on newly discovered mechanisms of liver damage. Future perspectives including new frontiers for research are discussed.
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Abstract
Liver dysfunction is a prominent entity in Western medicine that has historically affected patients suffering from chronic viral or alcoholic hepatitis. The incidence of these conditions has not changed dramatically in recent years but the overall number of patients with liver dysfunction has increased considerably with the emergence of the obesity epidemic. Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of chronic liver disease in the United States. Although the rate of progression of NAFLD to overt cirrhosis is low, the high prevalence of this condition, combined with the moderate degree of liver dysfunction it engenders, has resulted in a significant increase in the number of patients with liver disease that can be encountered by a surgical practice. Any degree of clinically evident liver disease in a prospective surgical patient should raise concern for the entire surgical team. This particularly applies to intraabdominal surgery whereby the presence of hepatomegaly, portal hypertension, variceal bleeding, and ascites can turn even the most routine operation into a morbid and life-threatening procedure. Nonabdominal surgery avoids some of the technical challenges presented by liver disease but the anesthetic management of a cirrhotic patient still makes any operation potentially more dangerous. In this article, approaches to minimize the risk when surgery becomes necessary in the presence of liver disease are discussed.
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Affiliation(s)
- Diego J Muilenburg
- Department of Surgery, University of California-Davis, Sacramento, CA 95817, USA
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19
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Affiliation(s)
- B P Sweeney
- Poole and Royal Bournemouth Hospitals, Bournemouth, BH7 7DW, UK.
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Cribb AE, Peyrou M, Muruganandan S, Schneider L. The Endoplasmic Reticulum in Xenobiotic Toxicity. Drug Metab Rev 2008; 37:405-42. [PMID: 16257829 DOI: 10.1080/03602530500205135] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The endoplasmic reticulum (ER) is involved in an array of cellular functions that play important roles in xenobiotic toxicity. The ER contains the majority of cytochrome P450 enzymes involved in xenobiotic metabolism, as well as a number of conjugating enzymes. In addition to its role in drug bioactivation and detoxification, the ER can be a target for damage by reactive intermediates leading to cell death or immune-mediated toxicity. The ER contains a set of luminal proteins referred to as ER stress proteins (including GRP78, GRP94, protein disulfide isomerase, and calreticulin). These proteins help regulate protein processing and folding of membrane and secretory proteins in the ER, calcium homeostasis, and ER-associated apoptotic pathways. They are induced in response to ER stress. This review discusses the importance of the ER in molecular events leading to cell death following xenobiotic exposure. Data showing that the ER is important in both renal and hepatic toxicity will be discussed.
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Affiliation(s)
- Alastair E Cribb
- Laboratory of Comparative Pharmacogenetics, Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada.
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21
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Holdener M, Hintermann E, Bayer M, Rhode A, Rodrigo E, Hintereder G, Johnson EF, Gonzalez FJ, Pfeilschifter J, Manns MP, Herrath MVG, Christen U. Breaking tolerance to the natural human liver autoantigen cytochrome P450 2D6 by virus infection. ACTA ACUST UNITED AC 2008; 205:1409-22. [PMID: 18474629 PMCID: PMC2413037 DOI: 10.1084/jem.20071859] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Autoimmune liver diseases, such as autoimmune hepatitis (AIH) and primary biliary cirrhosis, often have severe consequences for the patient. Because of a lack of appropriate animal models, not much is known about their potential viral etiology. Infection by liver-tropic viruses is one possibility for the breakdown of self-tolerance. Therefore, we infected mice with adenovirus Ad5 expressing human cytochrome P450 2D6 (Ad-2D6). Ad-2D6–infected mice developed persistent autoimmune liver disease, apparent by cellular infiltration, hepatic fibrosis, “fused” liver lobules, and necrosis. Similar to type 2 AIH patients, Ad-2D6–infected mice generated type 1 liver kidney microsomal–like antibodies recognizing the immunodominant epitope WDPAQPPRD of cytochrome P450 2D6 (CYP2D6). Interestingly, Ad-2D6–infected wild-type FVB/N mice displayed exacerbated liver damage when compared with transgenic mice expressing the identical human CYP2D6 protein in the liver, indicating the presence of a stronger immunological tolerance in CYP2D6 mice. We demonstrate for the first time that infection with a virus expressing a natural human autoantigen breaks tolerance, resulting in a chronic form of severe, autoimmune liver damage. Our novel model system should be instrumental for studying mechanisms involved in the initiation, propagation, and precipitation of virus-induced autoimmune liver diseases.
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Affiliation(s)
- Martin Holdener
- Pharmazentrum Frankfurt/Zentrum für Arzneimittelforschung, Entwicklung und Sicherheit, Johann Wolfgang Goethe University, 60590 Frankfurt am Main, Germany
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22
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Testa B, Krämer SD. The biochemistry of drug metabolism--an introduction: Part 2. Redox reactions and their enzymes. Chem Biodivers 2007; 4:257-405. [PMID: 17372942 DOI: 10.1002/cbdv.200790032] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review continues a general presentation of the metabolism of drugs and other xenobiotics started in a recent issue of Chemistry & Biodiversity. This Part 2 presents the numerous oxidoreductases involved, their nomenclature, relevant biochemical properties, catalytic mechanisms, and the very diverse reactions they catalyze. Many medicinally, environmentally, and toxicologically relevant examples are presented and discussed. Cytochromes P450 occupy a majority of the pages of Part 2, but a large number of relevant oxidoreductases are also considered, e.g., flavin-containing monooxygenases, amine oxidases, molybdenum hydroxylases, peroxidases, and the innumerable dehydrogenases/reductases.
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Affiliation(s)
- Bernard Testa
- Department of Pharmacy, University Hospital Centre (CHUV), Rue du Bugnon, CH-1011 Lausanne.
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23
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Erve JC. Chemical toxicology: reactive intermediates and their role in pharmacology and toxicology. Expert Opin Drug Metab Toxicol 2007; 2:923-46. [PMID: 17125409 DOI: 10.1517/17425255.2.6.923] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Reactive intermediates formed during the metabolism of drugs have been investigated extensively over the past decades. Today, interest in reactive intermediates in drug discovery is focused on minimising bioactivation in hopes of reducing the risk of causing so-called idiosyncratic toxicity. These efforts are justified based on the 'hapten hypothesis', namely, that on binding to protein, reactive intermediates may elicit an immune response to the modified protein, leading to a cascade of events that ultimately manifests as a toxic outcome. However, the pharmacological action of certain drugs depends on reactive intermediates that modify critical amino acid residues of proteins, typically enzymes, thereby altering their activity. Thus, the notion that reactive intermediates are inherently dangerous is unjustified. When a reactive intermediate is necessary for the desired pharmacological effect of a drug, the selectivity it displays towards the target protein is crucial, as off-target binding may produce unwanted toxicities. On the other hand, reactive intermediates may play no role in toxicity. This review provides a balanced perspective, primarily focusing on the proposed role of reactive intermediates in drug toxicity, while also highlighting examples in which they are involved in causing the desired pharmacology. It is hoped that this knowledge can help scientists involved in drug discovery and development in their challenging task of producing safe and effective drugs.
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Affiliation(s)
- John Cl Erve
- Wyeth Research, Drug Safety and Metabolism, Collegeville, PA 19426, USA.
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24
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Nakajima T. Cytochrome P450 Isoforms and the Metabolism of Volatile Hydrocarbons of Low Relative Molecular Mass. J Occup Health 2006. [DOI: 10.1539/joh.39.83] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Tamie Nakajima
- Department of HygieneShinshu University School of Medicine
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Sanderson JP, Naisbitt DJ, Park BK. Role of bioactivation in drug-induced hypersensitivity reactions. AAPS JOURNAL 2006; 8:E55-64. [PMID: 16584134 PMCID: PMC2751424 DOI: 10.1208/aapsj080107] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Drug-induced hypersensitivity reactions are a major problem in both clinical treatment and drug development. This review covers recent developments in our understanding of the pathogenic mechanisms involved, with special focus on the potential role of metabolism and bioactivation in generating a chemical signal for activation of the immune system. The possible role of haptenation and neoantigen formation is discussed, alongside recent findings that challenge this paradigm. Additionally, the essential role of costimulation is examined, as are the potential points whereby costimulation may be driven by reactive metabolites. The relevance of local generation of metabolites in determining the location and character of a reaction is also covered.
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Affiliation(s)
- Joseph P. Sanderson
- Department of Pharmacology and Therapeutics, University of Liverpool, Sherrington Buildings, Ashton Street, L69 3GE Liverpool, England
| | - Dean J. Naisbitt
- Department of Pharmacology and Therapeutics, University of Liverpool, Sherrington Buildings, Ashton Street, L69 3GE Liverpool, England
| | - B. Kevin Park
- Department of Pharmacology and Therapeutics, University of Liverpool, Sherrington Buildings, Ashton Street, L69 3GE Liverpool, England
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26
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Maniratanachote R, Shibata A, Kaneko S, Yamamori I, Wakasugi T, Sawazaki T, Katoh K, Tokudome S, Nakajima M, Yokoi T. Detection of autoantibody to aldolase B in sera from patients with troglitazone-induced liver dysfunction. Toxicology 2005; 216:15-23. [PMID: 16115720 DOI: 10.1016/j.tox.2005.07.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Revised: 07/13/2005] [Accepted: 07/13/2005] [Indexed: 10/25/2022]
Abstract
Troglitazone is a thiazolidinedione antidiabetic agent with insulin-sensitizing activities that was withdrawn from the market in 2000 due to its association with idiosyncratic hepatotoxicity. To address the suspected autoantibody production associated with troglitazone, we investigated autoantibodies in sera from patients with type II diabetes mellitus with troglitazone-induced liver dysfunction. Two female patients (47- and 70-year-old) ceased taking troglitazone (400 mg/day) after 23.5 and 16 weeks, respectively, due to increased serum ALT. Using two-dimensional electrophoresis and amino acid sequence analyses, aldolase B was identified as an autoantigen that reacted with antibodies in sera from both patients. The titer of anti-aldolase B remained high for several weeks after stopping troglitazone administration. The mean reactivity of autoantibodies to aldolase B determined by ELISA with sera of patients with chronic hepatitis (n = 40) and liver cirrhosis (n = 40) was significantly higher (p < 0.05 and p < 0.001, respectively) than with sera of healthy subjects (n = 80). These findings suggest that liver injury may cause the appearance of autoantibodies to aldolase B which may then aggravate the hepatitis. In addition, the anti-aldolase B titer might indicate the severity of liver dysfunction.
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Affiliation(s)
- Rawiwan Maniratanachote
- Division of Drug Metabolism, Faculty of Pharmaceutical Sciences, Kanazawa University, Kanazawa 920-1192, Japan
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Ferreira V, Molina MC, Valck C, Rojas A, Aguilar L, Ramírez G, Schwaeble W, Ferreira A. Role of calreticulin from parasites in its interaction with vertebrate hosts. Mol Immunol 2004; 40:1279-91. [PMID: 15128045 DOI: 10.1016/j.molimm.2003.11.018] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although parasites range from protozoan to complex, evolutionary advanced arthropods, in general, a hallmark of parasite life cycles is their ability to adapt to changes in temperature, pH and host defense strategies. Calreticulin, a calcium-binding protein, highly conserved and multifunctional, is present in every cell of higher organisms, except erythrocytes. The surprising array of calreticulin-associated functions include lectin-like chaperoning, calcium storage and signaling, modulation of gene expression, cell adhesion, enhancement of phagocytosis of C1q or collectin opsonized apoptotic cells, inhibition of angiogenesis and tumoral growth, inhibition of perforin pore formation in T and NK cells, and inhibition of C1q-dependent complement activation. Likewise, calreticulin is present in a wide spectrum of sub cellular compartments. Parasite calreticulin shows a surprisingly high degree of conservation within the framework of its functional domains. Its role within the parasite/host relationship needs to be assessed further, in particular with regard to its impact on parasite infectivity, by helping to evade from its hosts' immune response. With special emphasis on calreticulin from Trypanosoma cruzi, the intracellular protozoan agent of American trypanosomiasis (Chagas' disease), we wish to exemplify and highlight the various implications of parasite calreticulin, within the pathophysiology of parasite-mediated human and animal disease.
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Affiliation(s)
- Viviana Ferreira
- Programa de Immunología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Bruggraber SFA, Leung PSC, Amano K, Quan C, Kurth MJ, Nantz MH, Benson GD, Van de Water J, Luketic V, Roche TE, Ansari AA, Coppel RL, Gershwin ME. Autoreactivity to lipoate and a conjugated form of lipoate in primary biliary cirrhosis. Gastroenterology 2003; 125:1705-13. [PMID: 14724823 DOI: 10.1053/j.gastro.2003.09.034] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Although considerable effort has been directed toward the mapping of peptide epitopes by autoantibodies, the role of nonprotein molecules has been less well studied. The immunodominant autoantigen in primary biliary cirrhosis (PBC), E2 components of pyruvate dehydrogenase complexes (PDC-E2), has a lipoate molecule bonded to the domain to which autoantibodies are directed. METHODS We examined sera from patients with PBC (n = 105), primary sclerosing cholangitis (n = 70), and rheumatoid arthritis (n = 28) as well as healthy volunteers (n = 43) for reactivity against lipoic acid. The lipoic acid hapten specificity of the reactive antibodies in PBC sera was determined following incubation of aliquots of the sera with human serum albumin (HSA), lipoylated HSA (HSA-LA), PDC-E2, lipoylated PDC-E2, polyethylene glycol (PEG), lipoylated PEG, free lipoic acid, and synthetic molecular mimics of lipoic acid. RESULTS Anti-lipoic acid specific antibodies were detected in 81% (79 of 97) of antimitochondrial antibody (AMA)-positive patients with PBC but not in controls. Two previously unreported specificities in AMA-positive sera that recognize free lipoic acid and a carrier-conjugated form of lipoic acid were also identified. CONCLUSIONS We hypothesize that conjugated form(s) of native or xenobiotic lipoic acid mimics contribute to the initiation and perpetuation of autoimmunity by at first breaking self-tolerance and participating in subsequent determinant spreading. The variability in the immunoreactive carrier/lipoate conjugates provides an experimental framework on which potential mechanisms for the breakdown of self-tolerance following exposure to xenobiotics can be investigated. The data have implications for patients taking lipoic acid as a dietary supplement.
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Affiliation(s)
- Sylvaine F A Bruggraber
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis Medical School, 95616, USA
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29
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Staikou EV, Routsias JG, Makri AA, Terzoglou A, Sakarellos-Daitsiotis M, Sakarellos C, Panayotou G, Moutsopoulos HM, Tzioufas AG. Calreticulin binds preferentially with B cell linear epitopes of Ro60 kD autoantigen, enhancing recognition by anti-Ro60 kD autoantibodies. Clin Exp Immunol 2003; 134:143-50. [PMID: 12974767 PMCID: PMC1808837 DOI: 10.1046/j.1365-2249.2003.02246.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2003] [Indexed: 11/20/2022] Open
Abstract
Calreticulin is a molecular chaperone to newly synthesized polypeptides. Previous studies suggested that calreticulin is probably a protein member of the Ro/La RNP complex. The aims of this study were (a) to investigate whether linear B cell epitopes of the Ro/La RNP complex are bound to calreticulin and (b) if the complex peptide-calreticulin is recognized specifically by anti-Ro autoantibodies. Calreticulin was isolated from either human or pig spleen using a multi-step purification method and found to interact preferentially with biotinylated peptides derived from the sequence of the Ro60 kD 175-184aa(10p) and 216-232aa(17p). The interaction of the peptide-calreticulin complex was favoured by the combination of heat treatment, divalent cations and ATP. La/SSB epitopes did not react with calreticulin. Peptides corresponding to La/SSB epitopes as well as the common epitope of Sm did not interact with calreticulin. Thirty-eight anti-Ro60 KD positive and 23 anti-Ro60 kD negative sera of patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) were tested. All anti-Ro60 kD positive sera bound the complex calreticulin-17p, while 95% of the same sera had activity against the complex calreticulin - 10p. Tested individually, calreticulin, pep10p and pep17p presented very low reactivity (8%, 11% and 29%, respectively) against anti-Ro60 kD positive sera. Anti-Ro60 KD negative sera did not exhibit significant reactivity either with calreticulin, 10rho and 17rho or with the complexes calreticulin - 10p and calreticulin-17p (<5%). These results suggest that calreticulin can induce conformation-dependent recognition of the Ro60 kD epitopes, leading eventually to their recognition by autoantibodies. This is the first time that such a relationship is shown between a chaperone protein and fragments of an intracellular autoantigen. This work also provides insights into the understanding of mechanisms for autoantibody production. Furthermore, this association can be proved useful for the development of new sensitive assays for autoantibody detection.
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Affiliation(s)
- E V Staikou
- Department of Pathophysiology, School of Medicine, National University of Athens, 11527 Athens, Greece
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Abstract
Toxicology has matured since it was defined as the 'science of poisons'. Modern toxicology is no longer anthropocentric but takes on different views at various biological systems, including ecosystems. Each will interact specifically when exposed to defined chemical agents, including drugs. Adverse effects during drug therapy or after (accidental) poisoning are the result of some negative interactions between the agent and the exposed biological system. Toxicity is no longer a specific property of drugs and chemicals but an operative term to describe the adverse outcome of a specific drugs-host interaction. Newer developments in toxicology have focused on the host. Toxicogenetics continues to provide answers to variations of host response to xenobiotics, including drugs. Clinically relevant genetic polymorphisms and gene defects have been detected, and their number is rapidly growing. The key to understanding is in the host proteins that interact with the drug and mediate the cellular response. Hence, the proteom, i.e. the complete set of proteins of a cell, an individual or a species, determines how an exposed biological system may interact with the manifold of different xenobiotics. Structure-activity studies try to find out useful predictive parameters for risk and toxicity assessment.
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Affiliation(s)
- Harald Mückter
- Walther-Straub-Institute for Pharmacology and Toxicology, Nussbaumstrasse 26, München D-80336, Germany.
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31
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Naisbitt DJ, Pirmohamed M, Park BK. Immunopharmacology of hypersensitivity reactions to drugs. Curr Allergy Asthma Rep 2003; 3:22-9. [PMID: 12542989 DOI: 10.1007/s11882-003-0006-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Drug hypersensitivity reactions are characterized by their unpredictability, lack of simple dose-dependency, host sensitivity, and potentially serious clinical outcome. They occur in a small proportion of patients, and usually the predisposing factors are unknown, although there is increasing evidence for genetic predisposition and disease being significant risk factors. The current understanding of the chemical basis of immune-mediated reactions is based on the hapten hypothesis, which requires drug bioactivation, covalent binding to proteins, followed by uptake, antigen processing, and a polyclonal immune response. The recently proposed "danger hypothesis" can be considered to be an essential addition to the hapten hypothesis. According to the danger hypothesis, the immune response to a drug-derived antigen requires the presence of co-stimulatory signals and cytokines, which propagate and determine the type of immune response. The "danger signal" might result from chemical, physical, or viral stress.
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Affiliation(s)
- Dean J Naisbitt
- Department of Pharmacology and Therapeutics, The University of Liverpool, Ashton Street, Liverpool, L69 3GE, UK.
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Pirmohamed M, Naisbitt DJ, Gordon F, Park BK. The danger hypothesis--potential role in idiosyncratic drug reactions. Toxicology 2002; 181-182:55-63. [PMID: 12505285 DOI: 10.1016/s0300-483x(02)00255-x] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Idiosyncratic or type B reactions are characterised by their unpredictability and lack of simple dose-dependency. They occur in a small proportion of patients, and usually the predisposing factors are unknown. A proportion of, but not all, idiosyncratic reactions are immune-mediated. Our understanding of immune-mediated reactions is based on the hapten hypothesis, which requires drug bioactivation, covalent binding to proteins, followed by uptake, antigen processing and a polyclonal immune response. The recently proposed 'danger hypothesis' can be considered to be additive to the hapten hypothesis. The hypothesis states that the immune system only responds when it detects danger. If no danger is detected, tolerance results. Thus, stimulation of an immune response to a drug-protein conjugate (signal 1) requires the presence of co-stimulatory signals and cytokines (signals 2 and 3), which propagate and determine the type of immune response. The nature of the danger signal is poorly defined, and has been proposed to include different forms of stress including chemical, physical and viral. Indeed, there are several examples where the frequency of drug hypersensitivity is increased in the presence of a viral infection, most notably in HIV disease. Nevertheless, this clinical evidence has to be regarded as being circumstantial and more direct experimental evidence is required to understand the role of 'danger' in the overall pathogenesis of drug hypersensitivity reactions.
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Affiliation(s)
- Munir Pirmohamed
- Department of Pharmacology and Therapeutics, The University of Liverpool, Ashton Street, Liverpool L69 3GE, UK.
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Wiklund CU, Lindsten U, Lim S, Lindahl SGE. Interactions of volatile anesthetics with cholinergic, tachykinin, and leukotriene mechanisms in isolated Guinea pig bronchial smooth muscle. Anesth Analg 2002; 95:1650-5, table of contents. [PMID: 12456432 DOI: 10.1097/00000539-200212000-00032] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED We studied relaxation of airway smooth muscle by sevoflurane, desflurane, and halothane in isolated guinea pig bronchi. Ring preparations were mounted in tissue baths filled with physiological salt solution and continuously aerated with 5% CO(2) in oxygen. Electrical field stimulation induced contractions sensitive to tetrodotoxin, indicating nerve-mediated responses. These consisted of an atropine-sensitive cholinergic phase and a nonadrenergic noncholinergic (NANC) phase sensitive to SR48968, a neurokinin-2 receptor antagonist. Anesthetics were added to the gas aerating the tissue baths. Sevoflurane and desflurane at 1.0 minimum alveolar anesthetic concentration and halothane at 1.0-2.0 minimum alveolar anesthetic concentrations inhibited both cholinergic and NANC contractions to electrical field stimulation. None of the anesthetics affected responses to exogenously applied neurokinin A, a likely mediator of NANC contractions, suggesting prejunctional inhibition of NANC neurotransmission. The anesthetics did not affect the initiation of contractile responses to leukotriene C(4) (LTC(4)), a mediator of asthmatic bronchoconstriction. However, sevoflurane and desflurane both relaxed bronchi in a steady-state contraction achieved by LTC(4). Surprisingly, halothane did not relax LTC(4) contractions. Concerning LTC(4)-elicited bronchoconstriction, sevoflurane and desflurane were more potent airway smooth muscle relaxants in vitro. IMPLICATIONS Halothane, sevoflurane, and desflurane attenuated airway smooth muscle tone via inhibition of cholinergic and nonadrenergic noncholinergic neurotransmission. Sevoflurane and desflurane reduced leukotriene C(4)-induced bronchoconstriction, whereas halothane did not. This indicates a beneficial role for sevoflurane and desflurane in asthmatics.
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Affiliation(s)
- C U Wiklund
- Department of Anesthesiology and Intensive Care Medicine, Karolinska Hospital and Institute, Stockholm, Sweden.
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Marini S, Longo V, Zaccaro C, De Matteis F, Gervasi PG. Selective inactivation of rat and bovine olfactory cytochrome P450 by three haloethanes. Toxicol Lett 2001; 124:83-90. [PMID: 11684360 DOI: 10.1016/s0378-4274(01)00323-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The effects of halothane, 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1,1-dichloro-1-fluoroethane (HCFC-141b) on the P450 system in olfactory and hepatic microsomes of bovine and rat have been investigated. In the in vitro experiments, all three compounds decreased olfactory CYP-dependent activities in microsomes from both species, especially under anaerobic conditions, halothane showing the greatest effect. Hepatic activities were not affected. A selective olfactory CYP depletion was also observed in vivo after treatment with halothane, but not with HCFC-123 or HCFC-141b. A loss of olfactory ethoxycoumarin-O-deethylase activity was also found both in vitro and in vivo experiments, suggesting that a CYP2A isoform may be the main target of inactivation. The present results therefore suggest that CYP2A, the major isoform expressed in the olfactory tissue of mammals, may be particularly prone to catalyze the reductive metabolism of halothane both in anaerobic and aerobic conditions.
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Affiliation(s)
- S Marini
- Istituto di Mutagenesi e Differenziamento, CNR, Area della Ricerca-Via Moruzzi, via Svezia 10, 56124 Pisa, Italy
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Long SA, Quan C, Van de Water J, Nantz MH, Kurth MJ, Barsky D, Colvin ME, Lam KS, Coppel RL, Ansari A, Gershwin ME. Immunoreactivity of organic mimeotopes of the E2 component of pyruvate dehydrogenase: connecting xenobiotics with primary biliary cirrhosis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2956-63. [PMID: 11509645 DOI: 10.4049/jimmunol.167.5.2956] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In primary biliary cirrhosis (PBC), the major autoepitope recognized by both T and B cells is the inner lipoyl domain of the E2 component of pyruvate dehydrogenase. To address the hypothesis that PBC is induced by xenobiotic exposure, we took advantage of ab initio quantum chemistry and synthesized the inner lipoyl domain of E2 component of pyruvate dehydrogenase, replacing the lipoic acid moiety with synthetic structures designed to mimic a xenobiotically modified lipoyl hapten, and we quantitated the reactivity of these structures with sera from PBC patients. Interestingly, antimitochondrial Abs from all seropositive patients with PBC, but no controls, reacted against 3 of the 18 organic modified autoepitopes significantly better than to the native domain. By structural analysis, the features that correlated with autoantibody binding included synthetic domain peptides with a halide or methyl halide in the meta or para position containing no strong hydrogen bond accepting groups on the phenyl ring of the lysine substituents, and synthetic domain peptides with a relatively low rotation barrier about the linkage bond. Many chemicals including pharmaceuticals and household detergents have the potential to form such halogenated derivatives as metabolites. These data reflect the first time that an organic compound has been shown to serve as a mimeotope for an autoantigen and further provide evidence for a potential mechanism by which environmental organic compounds may cause PBC.
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Affiliation(s)
- S A Long
- Division of Rheumatology, University of California School of Medicine, Davis, CA 95616, USA
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Gotts JE, Press C, Leasure JL, Schallert T. Focal brain injury, FGF-2 and the adverse effects of excessive motor demand on cortical and nigral degeneration: marked protection by delayed intermittent exposure to halothane. J Neurotrauma 2000; 17:1067-77. [PMID: 11101209 DOI: 10.1089/neu.2000.17.1067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The neuroprotective potential of halothane anesthesia was investigated following unilateral electrolytic lesions to the forelimb representation area of the sensorimotor cortex (FL-SMC). Previously, it was found that the FL-SMC lesion increases substantially in size when the intact forelimb is immobilized with a plaster of paris cast for the first 7 days postlesion, which forces extreme overuse of the impaired forelimb during a time when nonlethally damaged tissue is vulnerable to behavioral demand. Initially, the purpose of this study was to investigate whether intracisternal infusion of basic fibroblast growth factor (bFGF or FGF-2), a potent neurotrophic factor that has been shown to have neuroprotective and plasticity promoting properties in focal stroke and other injury models, could prevent this use-dependent exaggeration of injury. Although intracisternal bFGF (starting 24 h after surgery, twice per week) was not found to produce significant neuroprotective or behavioral effects, the brief exposure to halothane anesthesia (15-20 min) during bFGF or vehicle administration was found to prevent expansion of the lesion size, and to reduce delayed loss of neurons in the substantia nigra pars reticulata (SNr). The data have implications for investigations of the effects of neurotrophic factor in vivo, and other investigations requiring brief, intermittent halothane anesthesia.
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Affiliation(s)
- J E Gotts
- Department of Psychology and Institute for Neuroscience, University of Texas at Austin, USA
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Mealey KA, Matthews NS. Drug interactions during anesthesia. General principles. Vet Clin North Am Small Anim Pract 1999; 29:629-43, v. [PMID: 10332814 DOI: 10.1016/s0195-5616(99)50052-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Anesthesia for most procedures in small animal practice involves administration of more than one drug. In addition, many patients concurrently receive a number of other drugs related to their surgical condition or disease. The probability of a drug interaction increases exponentially with the number of drugs a patient receives; therefore, the potential for drug interactions may be greater in anesthesia than for any other area of medicine. This article describes potentially harmful drug interactions that may occur in the anesthetic setting.
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Affiliation(s)
- K A Mealey
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, USA
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Kitteringham NR, Pirmohamed M, Park BK. 3 The pharmacology of the cytochrome P450 enzyme system. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0950-3501(98)80028-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Hess DA, Rieder MJ. The role of reactive drug metabolites in immune-mediated adverse drug reactions. Ann Pharmacother 1997; 31:1378-87. [PMID: 9391694 DOI: 10.1177/106002809703101116] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To highlight recent advances in the understanding of adverse drug reactions (ADRs), with a focus on models outlining interactions between drug metabolism, disease processes, and immunity. Specific mechanisms that identify the metabolic pathways responsible for drug bioactivation to reactive drug metabolites (RDMs) involved in the initiation and propagation of specific immune-mediated hypersensitivity reactions are discussed. Drug classes well known to be associated with immune-mediated ADRs are reviewed and the clinical implications of current research are discussed. DATA SOURCES Original experimental research and immunologic review articles relevant to ADR diagnosis and etiology. DATA EXTRACTION Results of relevant in vitro experiments and clinical reactions to drug therapy were compiled and reviewed. Critical discoveries concerning the identification of RDMs involved in ADRs were highlighted, with respect to RDM involvement in the production of an immune response to drug haptens. DATA SYNTHESIS Drug adverse effects are classified according to clinical characteristics, immune interactions, and mechanistic similarities. Cytochrome P450 bioactivation of drug molecules to RDMs is a prerequisite to many ADRs. An electrophilic metabolite may react with cellular macromolecules (i.e., lipids, proteins, nucleic acids), resulting in direct cellular damage and organ toxicity. Covalent binding of an RDM to cellular macromolecules may also result in the formation of a hapten that is capable of eliciting a cellular or humoral immune response against drug or protein epitopes, culminating in the characteristic symptoms of hypersensitivity reactions. Mechanistic details concerning the identification of stable protein-metabolite conjugates and their interaction with the immune system remain unclear. Genetic imbalance between bioactivation and detoxification pathways, as well as reduced cellular defense against RDMs due to disease or concomitant drug therapy, act as risk factors to the onset and severity of ADRs. CONCLUSIONS Adverse reactions to drug therapy cause significant morbidity and mortality. Identification of the pathways involved in drug bioactivation and detoxification may elucidate the potential of chemical agents to induce immune-mediated ADRs. Understanding the mechanisms of ADRs to current xenobiotics is helpful in the prevention and management of ADRs, and may prove useful in the design of novel therapeutic agents with reduced incidence of severe adverse events.
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Affiliation(s)
- D A Hess
- Department of Pharmacology and Toxicology, University of Western Ontario, London, Canada
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Durak I, Kurtipek O, Oztürk HS, Birey M, Güven T, Kavutcu M, Kaçmaz M, Dikmen B, Yel M, Canbolat O. Impaired antioxidant defence in guinea pig heart tissues treated with halothane. Can J Anaesth 1997; 44:1014-20. [PMID: 9305567 DOI: 10.1007/bf03011975] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To investigate the effects of halothane and halothane plus vitamin E treatment on myocardial free radical metabolism in guinea pigs. METHODS Four groups of seven animals were studied: control, halothane, halothane plus vitamin E and vitamin E groups. In the halothane group, halothane 1.5% in oxygen was given for 90 min over three days. In the halothane plus vitamin E group, 300 mg.kg-1.day-1 vitamin E im was started three days before the first halothane treatment and continued for three days. Following sacrifice, the hearts were assayed for superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and malondialdehyde (MDA) level was determined. Electron spin resonance (ESR) analysis and electron microscopy (EM) were also performed. RESULTS In the halothane group, SOD activities and MDA concentrations were increased compared with control and GSH-Px and CAT activities were decreased. In the halothane plus vitamin E group, there were no differences in enzyme activity compared with halothane alone but the MDA level was decreased. In the vitamin E group, enzyme activities were increased compared with control. Mainly the CF3CHCl radical was identified by ESR analysis in heart tissues exposed to halothane and the concentration of this radical was reduced by vitamin E. Electron microscopy showed cytoplasmic vacuolisation and dilation in sarcoplasmic reticulum in the heart tissues exposed to halothane: both were prevented by vitamin E. CONCLUSION Although halothane causes impairment in enzymatic antioxidant defence potential, due to lowered GSH-Px and CAT activity, and accelerates peroxidative reactions in the tissues affected, no subcellular damage occurred. Vitamin E may protect tissues against free radical attack by scavenging toxic free radicals formed in heart tissue during halothane anaesthesia.
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Affiliation(s)
- I Durak
- Department of Biochemistry, Ankara University Medical Faculty, Turkey
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Sturgill MG, Lambert GH. Xenobiotic-induced hepatotoxicity: mechanisms of liver injury and methods of monitoring hepatic function. Clin Chem 1997. [DOI: 10.1093/clinchem/43.8.1512] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
AbstractXenobiotic-induced liver injury is a clinically important etiology of hepatic disease that, if not recognized, can lead to hepatic failure. In this article we discuss the mechanisms of xenobiotic-induced liver injury, various factors that can alter the risk and severity of injury, the clinical and laboratory manifestations of injury, and the methods used to detect the presence of injury and (or) functioning liver mass.
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Affiliation(s)
- Marc G Sturgill
- Department of Pharmacy Practice and Administration, Rutgers University College of Pharmacy, PO Box 789 William Levine Hall, Piscataway, NJ 08855-0789
- Division of Pediatric Pharmacology and Toxicology, University of Medicine and Dentistry of New Jersey–Robert Wood Johnson Medical School, 681 Frelinghuysen Rd., PO Box 1179, Piscataway, NJ 08855-1179
| | - George H Lambert
- Division of Pediatric Pharmacology and Toxicology, University of Medicine and Dentistry of New Jersey–Robert Wood Johnson Medical School, 681 Frelinghuysen Rd., PO Box 1179, Piscataway, NJ 08855-1179
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Chen M, Gandolfi J. Characterization of the humoral immune response and hepatotoxicity after multiple halothane exposures in guinea pigs. Drug Metab Rev 1997; 29:103-22. [PMID: 9187513 DOI: 10.3109/03602539709037575] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- M Chen
- Department of Anesthesiology, College of Medicine, University of Arizona, Tucson 85724-5114, USA
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Pirmohamed M, Park K. Mechanism of clozapine-induced agranulocytosis : current status of research and implications for drug development. CNS Drugs 1997; 7:139-58. [PMID: 23338132 DOI: 10.2165/00023210-199707020-00005] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Clozapine is an atypical antipsychotic agent that has several advantages over conventional antipsychotics, not least of which is its superior efficacy. However, the high risk of agranulocytosis (0.8% of patients) associated with clozapine therapy has resulted in restricted indications for its use.The mechanism of clozapine-induced agranulocytosis is not clear. The target cells affected are the myeloid precursors, although the mature neutrophil may also be targeted simultaneously. There is no convincing evidence of direct toxicity of the parent compound or its stable metabolites (demethyl-clozapine and clozapine N-oxide). Clozapine is also metabolised by liver microsomes, peripheral blood neutrophils and their bone marrow precursors to a chemically reactive intermediate that has been postulated to be a nitrenium ion. This toxic metabolite has been shown to covalently bind to neutrophil proteins, suggesting that it may be involved in the pathogenesis of the toxicity. However, it is not clear how toxicity is mediated. The nitrenium ion may bind to essential cellular proteins and disrupt neutrophil function or, alternatively, it may act as a hapten and initiate an immune reaction resulting in immune-mediated destruction of the neutrophil. Indirect evidence exists to support both mechanisms, although clear direct evidence is still lacking. The role of cytokines and apoptosis in the pathogenesis of the agranulocytosis is unclear.The reason why only approximately 1% of individuals who are treated with clozapine are affected by agranulocytosis has not been elucidated. Evidence exists to implicate both the major histocompatibility complex antigens and heat shock protein variants in determining individual susceptibility, although more patients of different ethnic backgrounds need to be studied.The ultimate aim of research into clozapine-induced agranulocytosis should be to either prospectively predict which individuals are going to develop agranulocytosis and/or to develop analogues that retain efficacy but are not toxic. The former is complicated by the fact that predisposition may be multifactorial, and thus prediction may require multiple tests that may be of statistical but not absolute validity. The latter depends on identifying the mechanism of toxicity and the chemical characteristics of clozapine that are responsible for the toxicity. This knowledge may allow rational design of new analogues that do not cause agranulocytosis.
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Affiliation(s)
- M Pirmohamed
- Department of Pharmacology and Therapeutics, The University of Liverpool, Liverpool, L69 3BX, UK,
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Robin MA, Le Roy M, Descatoire V, Pessayre D. Plasma membrane cytochromes P450 as neoantigens and autoimmune targets in drug-induced hepatitis. J Hepatol 1997; 26 Suppl 1:23-30. [PMID: 9138125 DOI: 10.1016/s0168-8278(97)82329-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- M A Robin
- INSERM U-24, Hôpital Beaujon, Clichy, France
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Njoku D, Laster MJ, Gong DH, Eger EI, Reed GF, Martin JL. Biotransformation of Halothane, Enflurane, Isoflurane, and Desflurane to Trifluoroacetylated Liver Proteins. Anesth Analg 1997. [DOI: 10.1213/00000539-199701000-00031] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Njoku D, Laster MJ, Gong DH, Eger EI, Reed GF, Martin JL. Biotransformation of halothane, enflurane, isoflurane, and desflurane to trifluoroacetylated liver proteins: association between protein acylation and hepatic injury. Anesth Analg 1997; 84:173-8. [PMID: 8989020 DOI: 10.1097/00000539-199701000-00031] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In susceptible patients, halothane, enflurane, isoflurane, and desflurane can produce severe hepatic injury by an immune response directed against reactive anesthetic metabolites covalently bound to hepatic proteins. The incidence of hepatotoxicity appears to directly correlate with anesthetic metabolism catalyzed by cytochrome P450 2E1 to trifluoroacetylated hepatic proteins. In the present study, we examined whether the extent of acylation of hepatic proteins in rats by halothane, enflurane, isoflurane, and desflurane correlated with reported relative rates of metabolism. After pretreatment with the P450 2E1 inducer isoniazid, five groups of 10 rats breathed 1.25 minimum alveolar anesthetic concentration (MAC) of halothane, enflurane, isoflurane, or desflurane in oxygen, or oxygen alone, each for 8 h. Immunochemical analysis of livers harvested 18 h after anesthetic exposure showed tissue acylation (greatest to least) after exposure to halothane, enflurane, or isoflurane. Reactivity was not different between isoflurane as compared to desflurane or oxygen alone. An enzyme-linked immunosorbent assay showed halothane reactivity was significantly greater than that of enflurane, isoflurane, desflurane, or oxygen, and that enflurane reactivity was significantly greater than desflurane or oxygen. Sera from patients with a clinical diagnosis of halothane hepatitis showed antibody reactivity against hepatic proteins from rats exposed to halothane or enflurane. No reactivity was detected in rats exposed to isoflurane, desflurane, or oxygen alone. These results indicate that production of acylated proteins may be an important mediator of anesthetic-induced hepatotoxicity.
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Affiliation(s)
- D Njoku
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
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