Drug-induced steatohepatitis

Beta vulgaris L. var cicla Decreases Liver Injury Induced by Antiarrhytmic Agent, Amiodarone

Amiodarone (AMD) is an effective antiarrhythmic drug, but its long-term usage strongly forms liver toxicity due to its accumulation tendency. The chard (Beta vulgaris L. var. cicla) is a unique plant which has a blood sugar-lowering effect and powerful antioxidant activity. The aim of the current study was to investigate the possible protective effects of chard on AMD-induced liver injury. Male Sprague-Dawley rats were divided into four groups. Control group, aqueous chard extract given group 500 mg/kg/day for one week, AMD given group 100 mg/kg/day for one week, AMD+Chard given group (at the same doses and times). They were sacrificed on the 8th day. The blood and liver samples were taken. The serum and liver biochemical parameters were found to be changed in AMD treated group. Chard administration reversed these parameters in serum and liver. In histological experiments, necrotic areas, mononuclear cell infiltration, the endothelial rupture in central vein, sinusoidal dilatation, hyperemia, dark eosinophilic cells and picnotic nucleus were observed in liver tissues of AMD treated group. Chard treatment reduced liver tissue damage. Considering results, we can suggest that chard prevented AMD induced liver injury biochemically and histologically.

Drug-Induced Fatty Liver Disease (DIFLD): A Comprehensive Analysis of Clinical, Biochemical, and Histopathological Data for Mechanisms Identification and Consistency with Current Adverse Outcome Pathways

Drug induced fatty liver disease (DIFLD) is a form of drug-induced liver injury (DILI), which can also be included in the more general metabolic dysfunction-associated steatotic liver disease (MASLD), which specifically refers to the accumulation of fat in the liver unrelated to alcohol intake. A bi-directional relationship between DILI and MASLD is likely to exist: while certain drugs can cause MASLD by acting as pro-steatogenic factors, MASLD may make hepatocytes more vulnerable to drugs. Having a pre-existing MASLD significantly heightens the likelihood of experiencing DILI from certain medications. Thus, the prevalence of steatosis within DILI may be biased by pre-existing MASLD, and it can be concluded that the genuine true incidence of DIFLD in the general population remains unknown. In certain individuals, drug-induced steatosis is often accompanied by concomitant injury mechanisms such as oxidative stress, cell death, and inflammation, which leads to the development of drug-induced steatohepatitis (DISH). DISH is much more severe from the clinical point of view, has worse prognosis and outcome, and resembles MASH (metabolic-associated steatohepatitis), as it is associated with inflammation and sometimes with fibrosis. A literature review of clinical case reports allowed us to examine and evaluate the clinical features of DIFLD and their association with specific drugs, enabling us to propose a classification of DIFLD drugs based on clinical outcomes and pathological severity: Group 1, drugs with low intrinsic toxicity (e.g., ibuprofen, naproxen, acetaminophen, irinotecan, methotrexate, and tamoxifen), but expected to promote/aggravate steatosis in patients with pre-existing MASLD; Group 2, drugs associated with steatosis and only occasionally with steatohepatitis (e.g., amiodarone, valproic acid, and tetracycline); and Group 3, drugs with a great tendency to transit to steatohepatitis and further to fibrosis. Different mechanisms may be in play when identifying drug mode of action: (1) inhibition of mitochondrial fatty acid β-oxidation; (2) inhibition of fatty acid transport across mitochondrial membranes; (3) increased de novo lipid synthesis; (4) reduction in lipid export by the inhibition of microsomal triglyceride transfer protein; (5) induction of mitochondrial permeability transition pore opening; (6) dissipation of the mitochondrial transmembrane potential; (7) impairment of the mitochondrial respiratory chain/oxidative phosphorylation; (8) mitochondrial DNA damage, degradation and depletion; and (9) nuclear receptors (NRs)/transcriptomic alterations. Currently, the majority of, if not all, adverse outcome pathways (AOPs) for steatosis in AOP-Wiki highlight the interaction with NRs or transcription factors as the key molecular initiating event (MIE). This perspective suggests that chemical-induced steatosis typically results from the interplay between a chemical and a NR or transcription factors, implying that this interaction represents the primary and pivotal MIE. However, upon conducting this exhaustive literature review, it became evident that the current AOPs tend to overly emphasize this interaction as the sole MIE. Some studies indeed support the involvement of NRs in steatosis, but others demonstrate that such NR interactions alone do not necessarily lead to steatosis. This view, ignoring other mitochondrial-related injury mechanisms, falls short in encapsulating the intricate biological mechanisms involved in chemically induced liver steatosis, necessitating their consideration as part of the AOP's map road as well.

The Possibility of Acute Drug-Induced Liver Injury Associated With Prednisolone

A female patient was referred to our hospital with complaints of liver injury. She had been treated for immunoglobulin (Ig)A nephropathy using prednisolone and other medications. Drug-induced liver injury (DILI) was suspected, as no evidence of viral infection or autoimmune liver disease was apparent. All medications except for prednisolone were discontinued, but liver enzyme levels remained elevated. Percutaneous liver biopsy showed the characteristics of DILI and drug lymphocyte stimulation testing yielded positive results for prednisolone. After stopping administration of prednisolone, liver enzyme levels recovered to near-normal. Prednisolone has immunosuppressive effects and is sometimes used to treat DILI. Some reports have revealed that high-dose corticosteroids can induce liver injury, but liver injuries associated with low-dose corticosteroid therapy have not been described. Prednisolone-induced liver injury is a rare phenomenon. When low-dose corticosteroids are used for treatment, care should be taken regarding the possibility of liver injury.

Comparison of Multimaterial Decomposition Fat Fraction with DECT and Proton Density Fat Fraction with IDEAL IQ MRI for Quantification of Liver Steatosis in a Population Exposed to Chemotherapy

Introduction:

Oncologic patients who develop chemotherapy-associated liver injury (CALI) secondary to chemotherapy treatment tend to have worse outcomes. Biopsy remains the gold standard for the diagnosis of hepatic steatosis. The purpose of this article is to compare 2 alternatives: Proton-Density-Fat-Fraction (PDFF) MRI and MultiMaterial-Decomposition (MMD) DECT.

Materials and Methods:

49 consecutive oncologic patients treated with Chemotherapy underwent abdominal DECT and abdominal MRI within 2 weeks of each other. Two radiologists tracked Regions of Interest independently both in the PDFF fat maps and in the MMD DECT fat maps. Non-parametric exact Wilcoxon signed rank test and Cohen’s K were used to compare the 2 sequences and to evaluate the agreement.

Results:

There was no statistically significant difference in the fat fraction measured as a continuous value between PDFF and DECT between 2 readers. Within the same imaging method (PDFF) the degree of agreement based on the k coefficient between reader 1 and reader 2 is 0.88 (p-value < 0.05). Similarly, for single-source DECT(ssDECT) the degree of agreement based on the k coefficient between reader 1 and reader 2 is 0.97 (p-value < 0.05).

Conclusions:

The results of this study demonstrate that the hepatic fat fraction of ssDECT with MMD are not significantly different from PDFF. This could be an advantage in an oncological population that undergoes serial CT scans for follow up of chemotherapy response.

Zucker Lean Rats With Hepatic Steatosis Recapitulate Asymptomatic Metabolic Syndrome and Exhibit Greater Sensitivity to Drug-Induced Liver Injury Compared With Standard Nonclinical Sprague-Dawley Rat Model

Fatty liver disease is a potential risk factor for drug-induced liver injury (DILI). Despite advances in nonclinical in vitro and in vivo models to assess liver injury during drug development, the pharmaceutical industry is still plagued by idiosyncratic DILI. Here, we tested the hypothesis that certain features of asymptomatic metabolic syndrome (namely hepatic steatosis) increase the risk for DILI in certain phenotypes of the human population. Comparison of the Zucker Lean (ZL) and Zucker Fatty rats fed a high fat diet (HFD) revealed that HFD-fed ZL rats developed mild hepatic steatosis with compensatory hyperinsulinemia without increases in liver enzymes. We then challenged steatotic HFD-fed ZL rats and Sprague-Dawley (SD) rats fed normal chow, a nonclinical model widely used in the pharmaceutical industry, with acetaminophen overdose to induce liver injury. Observations in HFD-fed ZL rats included increased liver injury enzymes and greater incidence and severity of hepatic necrosis compared with similarly treated SD rats. The HFD-fed ZL rats also had disproportionately higher hepatic drug accumulation, which was linked with abnormal hepatocellular efflux transporter distribution. Here, we identify ZL rats with HFD-induced hepatic steatosis as a more sensitive nonclinical in vivo test system for modeling DILI compared with SD rats fed normal chow.

One-year chronic toxicity evaluation of single dose intravenously administered silica nanoparticles in mice and their Ex vivo human hemocompatibility

Chronic toxicity evaluations of nanotechnology-based drugs are essential to support initiation of clinical trials. Ideally such evaluations should address the dosing strategy in human applications and provide sufficient information for long-term usage. Herein, we investigated one-year toxicity of non-surface modified silica nanoparticles (SNPs) with variations in size and porosity (Stöber SNPs 46 ± 4.9 and 432.0 ± 18.7 nm and mesoporous SNPs 466.0 ± 86.0 nm) upon single dose intravenous administration to female and male BALB/c mice (10 animal/sex/group) along with their human blood compatibility. Our evidence of clinical observation and blood parameters showed no significant changes in body weight, cell blood count, nor plasma biomarker indices. No significant changes were noted in post necropsy examination of internal organs and organ-to-body weight ratio. However, microscopic examination revealed significant amount of liver inflammation and aggregates of histocytes with neutrophils within the spleen suggesting an ongoing or resolving injury. The fast accumulation of these plain SNPs in the liver and spleen upon IV administration and the duration needed for their clearance caused these injuries. There were also subtle changes which were attributed to prior infarctions or resolved intravascular thrombosis and included calcifications in pulmonary vessels, focal cardiac fibrosis with calcifications, and focal renal injury. Most of the pathologic lesions were observed when large, non-porous SNPs were administered. Statistically significant chronic toxicity was not observed for the small non-porous particles and for the mesoporous particles. This one-year post-exposure evaluation indicate that female and male BALB/c mice need up to one year to recover from acute tissue toxic effects of silica nanoparticles upon single dose intravenous administration at their 10-day maximum tolerated dose. Further, ex vivo testing with human blood and plasma revealed no hemolysis or complement activation following incubation with these silica nanoparticles. These results can inform the potential utility of silica nanoparticles in biomedical applications such as controlled drug delivery where intravenous injection of the particles is intended.

Iodine accumulation of the liver in patients treated with amiodarone can be unmasked using material decomposition from multiphase spectral-detector CT

Amiodarone accumulates in the liver, where it increases x-ray attenuation due to its iodine content. We evaluated liver attenuation in patients treated and not treated with amiodarone using true-non-contrast (TNC) and virtual-non-contrast (VNC) images acquired with spectral-detector-CT (SDCT). 142 patients, of which 21 have been treated with amiodarone, receiving SDCT-examinations (unenhanced-chest CT [TNC], CT-angiography of chest and abdomen [CTA-Chest, CTA-Abdomen]) were included. TNC, CTA-Chest, CTA-Abdomen, and corresponding VNC-images (VNC-Chest, VNC-Abdomen) were reconstructed. Liver-attenuation-index (LAI) was calculated as difference between liver- and spleen-attenuation. Liver-attenuation and LAI derived from TNC-images of patients receiving amiodarone were higher. Contrary to TNC, liver-attenuation and LAI were not higher in amiodarone patients in VNC-Chest and in VNC-Abdomen. To verify these initial results, a phantom scan was performed and an additional patient cohort included, both confirming that VNC is viable of accurately subtracting iodine of hepatic amiodarone-deposits. This might help to monitor liver-attenuation more accurately and thereby detect liver steatosis as a sign of liver damage earlier as well as to verify amiodarone accumulation in the liver.

Anastrozole-induced liver injury after a prolonged latency: a very rare complication of a commonly prescribed medication

Anastrozole is an aromatase inhibitor that has been used more frequently over the last decade especially for oestrogen receptor-positive breast cancer. It has a relatively safe side effect profile. However, occasionally it has been associated with serious adverse events. Here, we present the case of a 58-year-old woman who presented with significantly elevated liver enzymes 4 years after starting anastrozole. She was not taking any other medications and an extensive workup did not reveal any other cause for her liver injury. The patient's liver enzymes normalised after discounting the anastrozole. She scored 4 on the updated Roussel Uclaf Causality Assessment Method grading system which was possible for drug-induced liver injury. A review of the literature revealed six prior cases of anastrozole-related liver injury. Anastrozole should be considered as a possible culprit in patients who develop an unexplained acute liver injury.

MRI liver fat quantification in an oncologic population: the added value of complex chemical shift-encoded MRI

INTRODUCTION

Chemotherapy prolongs the survival of patients with advanced and metastatic tumors. Since the liver plays an active role in the metabolism of chemotherapy agents, hepatic injury is a common adverse effect. The purpose of this study is to compare a novel quantitative chemical shift encoded magnetic resonance imaging (CSE-MRI) method with conventional T1-weighted In and Out of phase (T1 IOP) MR for evaluating the reproducibility of the methods in an oncologic population exposed to chemotherapy.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board with a waiver for informed consent. The study included patients who underwent chemotherapy, no suspected liver iron overload, and underwent upper abdomen MRI. Two radiologists independently draw circular ROIsin the liver parenchyma. The fat fraction was calculated from IOP imaging and measured from IDEAL-IQ fat fraction maps. Two different equations were used to estimate fat with IOP sequences. Intra-class correlation coefficient and repeatability coefficient were estimated to evaluate agreement between two readers on iron level and fat fraction measurement.

RESULTS

CSE-MRI showed a higher reliability in fat quantification compared with both IOP methods, with a substantially higher inter-reader agreement (0.961 vs 0.372). This has important clinical implications.

CONCLUSION

The novel CSE-MRI method described here provides increased reproducibility and confidence in diagnosing hepatic steatosis in a oncologic clinical setting. IDEAL-IQ has been proved to be more reproducible than conventional IOP imaging.

Analysis of computed tomography density of liver before and after amiodarone administration

PURPOSE

To evaluate CT density of liver changes between before and after amiodarone administration.

MATERIALS AND METHODS

Twenty-five patients underwent non-enhanced CT including the liver before and after amiodarone administration. We set regions of interest (ROIs) at liver S8, spleen, paraspinal muscle, and calculated average CT density in these ROIs, then compared CT density between liver and other organs. Statistical differences between CT density of liver and various ratios before and after administration were determined, along with correlations between cumulative dose of amiodarone and liver density after administration, density change of liver, and various ratios after administration.

RESULTS

Liver density, liver-to-spleen ratio, and liver-to-paraspinal muscle ratio differed significantly between before and after amiodarone administration. No significant correlations were found between cumulative doses of amiodarone and any of liver density after administration, density change of liver, or various ratios after administration.

CONCLUSION

CT density of liver after amiodarone administration was significantly higher than that before administration. No correlations were identified between cumulative dose of amiodarone and either liver density after administration or density change of liver. Amiodarone usage should be checked when radiologists identify high density of the liver on CT.

Evidence-based selection of training compounds for use in the mechanism-based integrated prediction of drug-induced liver injury in man

The current test systems employed by pharmaceutical industry are poorly predictive for drug-induced liver injury (DILI). The ‘MIP-DILI’ project addresses this situation by the development of innovative preclinical test systems which are both mechanism-based and of physiological, pharmacological and pathological relevance to DILI in humans. An iterative, tiered approach with respect to test compounds, test systems, bioanalysis and systems analysis is adopted to evaluate existing models and develop new models that can provide validated test systems with respect to the prediction of specific forms of DILI and further elucidation of mechanisms. An essential component of this effort is the choice of compound training set that will be used to inform refinement and/or development of new model systems that allow prediction based on knowledge of mechanisms, in a tiered fashion. In this review, we focus on the selection of MIP-DILI training compounds for mechanism-based evaluation of non-clinical prediction of DILI. The selected compounds address both hepatocellular and cholestatic DILI patterns in man, covering a broad range of pharmacologies and chemistries, and taking into account available data on potential DILI mechanisms (e.g. mitochondrial injury, reactive metabolites, biliary transport inhibition, and immune responses). Known mechanisms by which these compounds are believed to cause liver injury have been described, where many if not all drugs in this review appear to exhibit multiple toxicological mechanisms. Thus, the training compounds selection offered a valuable tool to profile DILI mechanisms and to interrogate existing and novel in vitro systems for the prediction of human DILI.

The Pathology of Alcoholic Liver Disease

The term "alcoholic liver disease" encompasses a spectrum of pathologic conditions ranging from isolated steatosis to established cirrhosis. Within this spectrum, varying degrees of inflammation, hepatocellular ballooning degeneration, hepatocyte necrosis, cholestasis, and fibrosis may be encountered. This article reviews the characteristic histologic features of the many forms of alcoholic liver disease. Histologic scoring systems are described, and diseases with overlapping morphologic features and comorbid conditions are also discussed.

Drug-induced fatty liver disease: An overview of pathogenesis and management

Over the past decades, many drugs have been identified, that can potentially induce steatohepatitis in the predisposed individual. Classically this has been incriminated to amiodarone, perhexiline, and 4,4'-diethylaminoethoxyhexestrol (DH), all of which have been found to independently induce the histologic picture of non-alcoholic steatohepatitis (NASH). Pathogenetic mechanisms of hepatotoxicity although still evolving, demonstrate that mitochondrial dysfunction, deranged ATP production and fatty acid catabolism likely play an important role. Drugs like steroid hormones can exacerbate the pathogenetic mechanisms that lead to NASH, and other drugs like tamoxifen, cisplatin and irenotecan have been shown to precipitate latent fatty liver as well. Further research aiming to elucidate the pathogenesis of drug-induced steatosis and steatohepatitis is needed in order to better design therapeutic targets.

Non-alcoholic fatty liver disease (NAFLD) in different populations: A clinical and epidemiological study – sample of São José do Rio Preto

SUMMARY Introduction: NAFLD is an heterogeneous condition that includes steatosis and non-alcoholic steatohepatitis (NASH), in the absence of significant alcohol consumption, reaching 30% of the population. The most common risk factors are: age, gender, ethnicity, diabetes mellitus (DM), obesity, predisposition, metabolic syndrome (MS), insulin resistance (IR), drugs, and polycystic ovary syndrome. Objective: To describe the profile of patients with NAFLD seen at Hospital de Base of Rio Preto, in the state of São Paulo. Method: Patients with NAFLD were assessed, with medical and epidemiological data collected after informed consent. Results: Of the 62 patients evaluated, 76% were women, 73% Caucasians, and 71% were aged between 50 and 69 years and had no symptoms. Ultrasonography results showed steatosis in 84%. NASH was diagnosed in 61% of the sample. 21 patients underwent liver biopsy, of which 36% had cirrhosis, 1 had liver cancer, and 1 pure steatosis (5% each). Risk factors were found in 70% of patients with metabolic syndrome, 87% with increased waist circumference, 63% with dyslipidemia, 61% (n=38) with high blood pressure (HBP), 28% with DM, 52% physically inactive, and 44% with insulin resistance (IR) (HOMA> 3.5). There was an association between IR and NASH (p=0.013), IR and obesity (p=0.027), IR and MS (p=0.006), and MS and steatosis on medical ultrasound (USG) (p=0.014). Conclusion: The most frequent risk factors were MS and its variables: increased waist circumference, dyslipidemia and HBP. This underscores the importance of metabolic control in NAFLD and confirms its role as the hepatic component of metabolic syndrome.

Clinical Presentation and Patient Evaluation in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a diagnosis of exclusion. Most patients are asymptomatic and diagnosed incidentally. Most patients remain undiagnosed. A high index of suspicion and serologic work-up to rule out alternative causes of liver disease is required. In NALFD, fibrosis correlates with outcomes, including mortality. To diagnose, assess severity, and monitor fibrosis, 2 noninvasive methods can be used. However, noninvasive tests are more helpful at extremes of fibrosis: excluding it or diagnosing advanced fibrosis. Liver biopsy is usually reserved for cases whereby noninvasive tests fail to accurately determine the degree of fibrosis or the diagnosis is unclear.

Diagnosis and classification of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis: Current concepts and remaining challenges

The high prevalence of non-alcoholic fatty liver disease (NAFLD) has made the condition an important public health issue. Two clinical entities are manifestations of NAFLD, namely, non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH). The former tends to be benign and non-progressive while the latter can progress to cirrhosis, which in rare cases gives rise to hepatocellular carcinoma. The diagnosis of NAFLD is based on: (i) a history of no or limited daily alcohol intake (<20 g for women and <30 g for men); (ii) presence of hepatic steatosis by imaging or by histology; and (iii) exclusion of other liver diseases. NAFL is defined histologically by the presence of bland, primarily macrovesicular, hepatocellular fatty change, while NASH features fatty change with inflammation and evidence of hepatocyte injury, such as ballooning degeneration. Presence of fibrosis is a sign of chronicity. Thus, the diagnosis of NAFL/NASH rests on clinicopathological criteria; it always requires both clinical and biopsy-based information. NAFLD could be both the result and the cause of metabolic syndrome, with a vicious cycle operating between these conditions. Remaining challenges are: (i) the lack of a clear threshold alcohol intake for defining "non-alcoholic"; (ii) a lacking consensus for the classification of fatty liver disease; and (iii) absence of a histological definition of NASH, which currently remains the gold standard for the diagnosis. Further challenges include the overlap of the criteria for NAFLD and alcoholic liver disease as many obese individuals also consume considerable volumes of alcohol.

An unusual cause of jaundice in a patient with breast cancer

A 48-year old woman with metastatic breast cancer and extensive bone marrow infiltration was admitted with extreme lethargy, jaundice and deranged liver function tests. She had been started on anastrozole in May 2013 for bony metastases, detected on a bone scan. A CT scan performed at that time had shown no evidence of metastatic or nodal disease elsewhere. Over the subsequent 2 months, the patient had become progressively jaundiced. Outpatient abdominal ultrasound and CT liver had shown a fatty liver with no focal lesions. She was admitted in August 2013 with bilirubin 567, alkaline phosphatase 385, alanine aminotransferase 98, albumin 25 and international normalised ratio 1.9. The patient ultimately had a liver biopsy, which demonstrated features of drug-induced steatohepatitis, and anastrozole was found to have been the probable cause. This case explores the differentials of jaundice in a patient with cancer and describes a rare cause of drug-induced liver injury.

Proteomic profile of carbonylated proteins in rat liver: discovering possible mechanisms for tetracycline-induced steatosis

To investigate biochemical mechanisms for the tetracycline-induced steatosis in rats, targeted proteins of oxidative modification were profiled. The results showed that tetracycline induced lipid accumulation, oxidative stress, and cell viability decline in HepG2 cells only under the circumstances of palmitic acid overload. Tetracycline administration in rats led to significant decrement in blood lipids, while resulted in more than four times increment in intrahepatic triacylglycerol and typical microvesicular steatosis in the livers. The triacylglycerol levels were positively correlated with oxidative stress. Proteomic profiles of carbonylated proteins revealed 26 targeted proteins susceptible to oxidative modification and most of them located in mitochondria. Among them, the long-chain specific acyl-CoA dehydrogenase was one of the key enzymes regulating fatty acid β-oxidation. Oxidative modification of the enzyme in the tetracycline group depressed its enzymatic activity. In conclusion, the increased influx of lipid into the livers is the first hit of tetracycline-induced microvesicular steatosis. Oxidative stress is an essential part of the second hit, which may arise from the lipid overload and attack a series of functional proteins, aggravating the development of steatosis. The 26 targeted proteins revealed here provide a potential direct link between oxidative stress and tetracycline-induced steatosis.

Circulating microRNA 122 in the methionine and choline-deficient mouse model of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD) and is a major cause of liver cirrhosis and hepatic failure. The methionine choline-deficient diet (MCD) is a frequently used hepatotoxicity animal model of NASH that induces hepatic transaminase (ALT, AST) elevations and hepatobiliary histological changes similar to those observed in human NASH. Liver-specific microRNA-122 (miR-122) has been shown as a key regulator of cholesterol and fatty acid metabolism in adult liver, and has recently been proposed as a sensitive and specific circulating biomarker of hepatic injury. The purpose of this study was to assess miR-122 serum levels in mice receiving an MCD diet for 0, 3, 7, 14, 28 and 56 days and compare the performance vs. routine clinical chemistry when benchmarked against the histopathological liver findings. MiR-122 levels were quantified in serum using RT-qPCR. Both miR-122 and ALT/AST levels were significantly elevated in serum at all timepoints. MiR-122 levels increased on average by 40-fold after 3 days of initiating the MCD diet, whereas ALT and AST changes were 4.8- and 3.3-fold, respectively. In general, miR-122 levels remained elevated across all time points, whereas the ALT/AST increases were less robust but correlated with the progressive severity of NASH as assessed by histopathology. In conclusion, serum levels of miR-122 can potentially be used as a sensitive biomarker for the early detection of hepatotoxicity and can aid in monitoring the extent of NAFLD-associated liver injury in mouse efficacy models.

Drug-induced steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease in the United States. The term NALFD was first used by Ludwig in 1980 to describe the presence of hepatic steatosis and steatohepatitis in a series of patients with no identifiable cause. Since then, our insight into the pathogenesis of NAFLD has expanded significantly. We now know that NAFLD is closely related to metabolic syndrome and chronic low-grade inflammation. In the following review, the authors summarize the current evidence about drugs that lead to hepatic steatosis and steatohepatitis and pathogenic mechanisms thereof.

Amiodarone hepatotoxicity with absent phospholipidosis and steatosis: a case report and review of amiodarone toxicity in various organs

We present the first description of amiodarone toxicity in the liver without phospholipidosis or steatosis. In doing so, we will review the various effects of amiodarone toxicity in various organs. The patient is a young adult who had cardiac reconstruction as a child for transposition of the great vessels. A needle biopsy was taken due to elevated liver enzymes. Her ALT was 188 U/L (5-50) and AST 162 U/L (5-50). Alkaline phosphatase, total bilirubin, protein, and albumin were within normal limits. A serologic panel for viral hepatitis was negative. Antinuclear antibodies were positive at 260; however, anti-smooth muscle antibody and anti-mitochondrial antibody were negative. A protein electrophoresis showed a slightly elevated beta globulin 2 level of 0.5. Quantitative immunoglobulin levels were within normal limits except for a slightly elevated IgA 409 mg/dL (60-350). Liver ultrasound was unremarkable. The clinical differential was broad and included hepatic congestion along with autoimmune hepatitis. Sections showed only ballooned hepatocytes with Mallory-Denk bodies and perisinusoidal fibrosis. Arrival to the diagnosis was possible only after careful review of the patient's medications. After discontinuation of amiodarone, the patient's liver enzymes returned to normal levels.

Nonalcoholic Steatohepatitis: Diagnostic Challenges

This article reviews diagnostic criteria for nonalcoholic steatohepatitis (NASH), current grading and staging methodology, and diagnostic challenges and pitfalls in routine practice. Current practice guidelines and prognostic and treatment considerations are discussed. The clinical diagnosis of nonalcoholic fatty liver disease may represent stable disease without progressive liver damage, in the form of nonalcoholic fatty liver (NAFL), or aggressive disease that will progress to advanced fibrosis, in the form of NASH. NASH is diagnosed from a liver biopsy after assessment by a pathologist to distinguish NASH from NAFL (and other histologic mimics of NASH); this distinction is critical for patient management.

α-Terpineol induces fatty liver in mice mediated by the AMP-activated kinase and sterol response element binding protein pathway

The use of herbal medicines in disease prevention and treatment is growing rapidly worldwide, without careful consideration of safety issues. α-Terpineol is a monoterpene alcoholic component of Melaleuca alternifolia, Salvia officinalis and Carthamus tinctorius that is used widely as a flavor and essential oil in food. The present study showed that α-terpineol induces fatty liver via the AMP-activated protein kinase (AMPK)-mTOR-sterol regulatory element-binding protein-1 (SREBP-1) pathway. α-Terpineol-treated hepatocytes had significantly increased neutral lipid accumulation. α-Terpineol suppressed AMPK phosphorylation, and increased p70S6 kinase (p70S6K) phosphorylation and SREBP-1 activation. It also increased luciferase activity in cells transfected with LXRE-tk-Luc and SRE-tk-Luc. Inhibition of mTOR signaling by co-treatment with rapamycin or co-transfection with dominant negative p70S6K blocked completely the effects of α-terpineol. α-Terpineol oral administration to mice for 2weeks led to decreased AMPK phosphorylation and increased SREBP-1 activation in the liver, followed by hepatic lipid accumulation. Conversely, rapamycin co-treatment reversed α-terpineol-induced SREBP-1 activation and fatty liver in mice. These data provide evidence that α-terpineol causes fatty liver, an effect mediated by the AMPK/mTOR/SREBP-1 pathway.

Managing atrial fibrillation in the elderly: critical appraisal of dronedarone

Atrial fibrillation is the most commonly seen arrhythmia in the geriatric population and is associated with increased cardiovascular morbidity and mortality. Treatment of the elderly with atrial fibrillation remains challenging for physicians, because this unique subpopulation is characterized by multiple comorbidities requiring chronic use of numerous medications, which can potentially lead to severe drug interactions. Furthermore, age-related changes in the cardiovascular system as well as other physiological changes result in altered drug pharmacokinetics. Dronedarone is a new drug recently approved for the treatment of arrhythmias, such as atrial fibrillation and/or atrial flutter. Dronedarone is a benzofuran amiodarone analog which lacks the iodine moiety and contains a methane sulfonyl group that decreases its lipophilicity. These differences in chemical structure are responsible for making dronedarone less toxic than amiodarone which, in turn, results in fewer side effects. Adverse events for dronedarone include gastrointestinal side effects and rash. No dosage adjustments are required for patients with renal impairment. However, the use of dronedarone is contraindicated in the presence of severe hepatic dysfunction.

Strategies for the early detection of drug-induced hepatic steatosis in preclinical drug safety evaluation studies

Hepatic steatosis is characterized by the accumulation of lipid droplets in the liver. Although relatively benign, simple steatosis can eventually lead to the development of steatohepatitis, a more serious condition characterized by fibrosis, cirrhosis, and eventual liver failure if the underlying cause is not eliminated. According to the "two hit" theory of steatohepatitis, the initial hit involves fat accumulation in the liver, and a second hit leads to inflammation and subsequent tissue injury. Because some xenobiotics target liver fatty acid metabolism, especially mitochondrial β-oxidation, it is important to avoid potential drug candidates that can contribute to either the initiation of liver steatosis or progression to the more injurious steatohepatitis. The gold standard for the detection of these types of hepatic effects is histopathological examination of liver tissue. In animal studies, these examinations are slow, restricted to a single sampling time, and limited tissue sections. Recent literature suggests that rapid in vitro screening methods can be used early in the drug R&D process to identify compounds with steatotic potential. Further, progress in the identification of potential serum or plasma protein biomarkers for these liver changes may provide additional in vivo tools to the preclinical study toxicologist. This review summarizes recent developments for in vitro screening and in vivo biomarker detection for steatotic drug candidates.

Screening for the drug-phospholipid interaction: correlation to phospholipidosis

Phospholipid bilayers represent a complex, anisotropic environment fundamentally different from bulk oil or octanol, for instance. Even "simple" drug association to phospholipid bilayers can only be fully understood if the slab-of-hydrocarbon approach is abandoned and the complex, anisotropic properties of lipid bilayers reflecting the chemical structures and organization of the constituent phospholipids are considered. The interactions of drugs with phospholipids are important in various processes, such as drug absorption, tissue distribution, and subcellular distribution. In addition, drug-lipid interactions may lead to changes in lipid-dependent protein activities, and further, to functional and morphological changes in cells, a prominent example being the phospholipidosis (PLD) induced by cationic amphiphilic drugs. Herein we briefly review drug-lipid interactions in general and the significance of these interactions in PLD in particular. We also focus on a potential causal connection between drug-induced PLD and steatohepatitis, which is induced by some cationic amphiphilic drugs.

Ground-glass-like hepatocellular inclusions in the course of adult-onset Still's disease

Ground-glass hepatocytes are the cardinal biopsy feature of chronic hepatitis B virus (HBV) infection and may also be present in other specific conditions, including Lafora's disease, cyanamide aversion therapy for alcohol use, patients with transplantation, uremia, and metabolic disorders. In this report, we present the case of a patient with adult-onset Still's disease who underwent percutaneous liver biopsy, which revealed ground-glass-like cytoplasmic inclusions and which is a very unusual finding.

Marked elevation of serum mitochondrion-derived markers in mild models of non-alcoholic steatohepatitis in rats

BACKGROUND AND AIM

In order to find sensitive serum markers in non-alcoholic steatohepatitis, liver-specific injury markers were thoroughly examined in mild models of NASH in rats.

METHODS

Wistar and Sprague-Dawley rats were fed a choline-deficient diet for 4 weeks, and serum activities of liver-specific enzyme markers were examined. In the drug-induced steatohepatitis model, tetracycline (0.4 mmol/kg) was given i.p. to rats and the course of hepatotoxicity was evaluated with serum markers, together with the accumulation of total lipid and thiobarbituric acid-reactive substances in the liver.

RESULTS

In Wistar rats, serum activities of most enzymes tested were significantly increased. In Sprague-Dawley rats, in contrast, the serum level of ornithine carbamyltransferase and glutamate dehydrogenase were markedly elevated in the choline-deficient diet group compared with the control diet groups, whereas other markers were not significantly increased. In the tetracycline-induced steatohepatitis model, the extent of the increase was much higher in mitochondrial markers and the peak of the increase in these markers corresponded with the increase of hepatic total lipid and thiobarbituric acid-reactive substance.

CONCLUSIONS

These observations show that serum mitochondrial enzyme markers are potent markers for non-alcoholic steatohepatitis in rats and are possibly applicable to humans.

The effects of tibolone in older postmenopausal women

BACKGROUND

Tibolone has estrogenic, progestogenic, and androgenic effects. Although tibolone prevents bone loss, its effects on fractures, breast cancer, and cardiovascular disease are uncertain.

METHODS

In this randomized study, we assigned 4538 women, who were between the ages of 60 and 85 years and had a bone mineral density T score of -2.5 or less at the hip or spine or a T score of -2.0 or less and radiologic evidence of a vertebral fracture, to receive once-daily tibolone (at a dose of 1.25 mg) or placebo. Annual spine radiographs were used to assess for vertebral fracture. Rates of cardiovascular events and breast cancer were adjudicated by expert panels.

RESULTS

During a median of 34 months of treatment, the tibolone group, as compared with the placebo group, had a decreased risk of vertebral fracture, with 70 cases versus 126 cases per 1000 person-years (relative hazard, 0.55; 95% confidence interval [CI], 0.41 to 0.74; P<0.001), and a decreased risk of nonvertebral fracture, with 122 cases versus 166 cases per 1000 person-years (relative hazard, 0.74; 95% CI, 0.58 to 0.93; P=0.01). The tibolone group also had a decreased risk of invasive breast cancer (relative hazard, 0.32; 95% CI, 0.13 to 0.80; P=0.02) and colon cancer (relative hazard, 0.31; 95% CI, 0.10 to 0.96; P=0.04). However, the tibolone group had an increased risk of stroke (relative hazard, 2.19; 95% CI, 1.14 to 4.23; P=0.02), for which the study was stopped in February 2006 at the recommendation of the data and safety monitoring board. There were no significant differences in the risk of either coronary heart disease or venous thromboembolism between the two groups.

CONCLUSIONS

Tibolone reduced the risk of fracture and breast cancer and possibly colon cancer but increased the risk of stroke in older women with osteoporosis. (ClinicalTrials.gov number, NCT00519857.)

Fidelity of gamma-glutamyl transferase (GGT) in differentiating skeletal muscle from liver damage

This study tested the hypothesis that gamma-glutamyl transferase (GGT) can be used as a reliable biomarker to distinguish skeletal muscle from liver damage. Twenty-eight Duchenne muscular dystrophy subjects with proven dystrophin gene mutations were enrolled. Included were 14 ambulatory and 14 nonambulatory patients with approximately half of each cohort taking corticosteroids. Twenty normal males served as controls. Initial blood samples for serum GGT and creatine kinase were taken between 8AM and 9AM and redrawn 8 hours later to test for variability. Between blood draws, subjects resumed normal activities in a play environment or could leave the clinic. Not a single duchenne muscular dystrophy patient showed a GGT outside the control range at any time point, while creatine kinase levels were 14 to 200 times normal. Validation of this finding is essential for management of patients with muscle disorders exposed to potentially hepatotoxic drugs for clinical management or monitoring subjects participating in clinical trials.

Evolving trends in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common etiologies of chronic liver disease worldwide. NALFD encompasses a continuum of histological findings ranging from steatosis alone, to nonalcoholic steatohepatitis (NASH) with steatosis, inflammation, hepatocyte ballooning, fibrosis and eventually liver cirrhosis. The pathogenesis of NAFLD might be related to a deregulated cross-talk between liver and visceral adipose tissue, originating an impairment of normal insulin signaling. A better comprehension of the immunologic and metabolic roles of adipose tissue in modulating inflammatory pathways will enhance our understanding of the molecular mechanisms leading to progression of fatty liver disease. These insights, moreover, will suggest new strategies to improve insulin sensitivity and reduce obesity-associated morbidities and mortality.

Therapeutic potential of curcumin in non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) may be associated with a number of clinical conditions, but it occurs most commonly in patients with insulin resistance. There is as yet no established disease-modifying treatment, and a safe and broadly available agent that targets hepatic steatosis, insulin resistance, inflammation and fibrosis is necessary. The polyphenolic compound curcumin exhibits antioxidant and anti-inflammatory properties, inhibits NF-κB and activates PPAR-γ. In rodents, curcumin prevents dietary-induced hepatic steatosis, hepatic stellate cell activation and production of fibrotic proteins, and ameliorates steatohepatitis induced by the intake of alcohol or a methionine–choline-deficient diet. Indirect evidence suggests that curcumin may improve insulin sensitivity in diabetes and inflammatory states. The present paper reviews the numerous cellular and animal studies indicating that curcumin attenuates many of the pathophysiological processes involved in the development and progression of NASH. It is suggested that basic and clinical studies on curcumin in the development and progression of NASH are indicated.

Chemotherapy for colorectal cancer prior to liver resection for colorectal cancer hepatic metastases does not adversely affect peri-operative outcomes

BACKGROUND

Systemic chemotherapy is being used increasingly in patients with colorectal cancer. The effects of prior systemic adjuvant or palliative chemotherapy on morbidity following hepatic resection for metastases are not well defined.

OBJECTIVES

To assess the peri-operative impact of systemic chemotherapy on liver resection for colorectal cancer hepatic metastases.

METHODS

Ninety-six resections for colorectal cancer hepatic metastases performed from July 2001 to July 2003 (93% > or =2 segments) were reviewed. Pre-operative demographics, peri-operative features, and post-operative outcomes were collected prospectively. Type of chemotherapy and the temporal relationship of chemotherapy to the liver resection were analyzed.

RESULTS

Fifty-three of 96 patients (55%) received a mean of 5.7 cycles (6.1 months) of systemic chemotherapy prior to hepatic resection, with a median interval of 12 months from end of chemotherapy to liver resection (range 1-75 months). Thirty-five received 5-fluorouracil/leucovorin (5-FU/LV) alone, nine had irinotecan (CPT-11) in addition to 5-FU/LV, and nine were not specified. Pre-operative age, sex, co-morbidities, ASA score, biochemical and liver enzyme profiles, tumor number, and extent and technique of hepatic resection were the same in the chemotherapy and non-chemotherapy cohorts. Mean tumor size was smaller (4.5 cm vs. 5.8 cm) and synchronous metastases were half as common (25% vs. 49%) in the chemotherapy group. Liver resection operative time was equivalent (270 min) in the two groups. Higher estimated blood loss (EBL) (1,000 ml vs. 850 ml), but fewer transfusions (23% vs. 15%) were associated with the chemotherapy group. Although not statistically significant, post-operative liver enzyme peaks were higher in the chemotherapy group (AST = 402 U/L vs. 302 U/L, P = 0.09 and ALT = 433 U/L vs. 312 U/L, P = 0.1). Peak changes in INR and serum bilirubin did not differ. Complications and length of stay (LOS) did not differ between the groups. The only post-operative death was in the non-chemotherapy group. Interestingly, hepatic steatosis was present in 28% of the non-chemotherapy cases and 57% of the chemotherapy resection specimens (P = 0.005) and was marked (>30%) in 7% and 10%, respectively. Further analysis of the chemotherapy group based on the interval between completion of chemotherapy and the hepatic resection (<6 months, 7-12 months, 1-2 years, and >2 years) revealed a trend towards worse outcomes in most categories for those in the >2 years cohort. When comparing the 5-FU/LV alone, to the CPT-11 group there were no significant differences except higher intra-operative blood loss in the group receiving 5-FU/LV alone (1,295 ml vs. 756 ml, P = 0.01).

CONCLUSION

Despite variations in biochemical function and hepatic steatosis, short-term clinical outcomes are not affected by the administration of chemotherapy prior to hepatic resection. Furthermore, there is no detrimental effect of close timing of chemotherapy prior to resection, and there are no appreciable differences between irinotecan containing regimes and more traditional 5-FU-only based therapies, although the subset sample sizes were small in this study.

Drug-induced phospholipidosis: issues and future directions

Numerous drugs containing a cationic amphiphilic structure are capable of inducing phospholipidosis in cells under conditions of in vivo administration or ex vivo incubation. The principal characteristics of this condition include the reversible accumulation of polar phospholipids in association with the development of unicentric or multicentric lamellated bodies within cells. There is an abundance of data providing an understanding of potential mechanisms for the induction of phospholipidosis; however, the process is likely to be complex and may differ from one drug to another. The functional consequences of the presence of this condition on cellular or tissue function are not well understood. The general consensus is that the condition is an adaptive response rather than a toxicological manifestation; however, additional studies to examine this question are needed. Until this issue is resolved, concerns about phospholipidosis will continue to exist at regulatory agencies. Procedures for the screening of potential phospholipogenic candidate compounds are available. In contrast, a clear need exists for the identification of valid biomarkers to assess the development of phospholipidosis in preclinical and clinical studies.

Autoimmune hepatitis during intravenous glucocorticoid pulse therapy for Graves' ophthalmopathy treated successfully with glucocorticoids themselves

We report a case of acute hepatitis of autoimmune origin which occurred in a 43-yr-old woman during iv glucocorticoid (GC) pulse therapy for Graves' ophthalmopathy (GO). Prior to therapy, liver function tests were normal with no previous history of liver disorders or conditions predisposing to GC-associated liver damage. After the administration of a 4.7-g cumulative dose of methylprednisolone acetate, there was a marked increase of liver enzymes, prompting immediate discontinuation of iv GC. Nevertheless, liver enzymes increased further, reaching a peak 45 days later, with values 30- to 50-fold greater than those prior to therapy, associated with evidence of impaired liver function. Liver biopsy showed a marked lymphocytic infiltration, likely indicating an autoimmune hepatitis. Based on the assumption that following GC-induced immune suppression, autoimmune hepatitis might have been precipitated by sudden re-activation of the immune system during interpulse periods, we treated the patient with im and then oral GC, in order to re-induce immune suppression. Within three days from re-institution of GC therapy, there was a marked reduction of liver enzymes and amelioration of liver function. Complete normalization was achieved two months later, while the patient was still receiving a low maintenance dose of oral prednisone.

Stress- (and diet-) related regulation of hepatic nuclear receptors and its relevance for ABC-transporter functions

Nuclear receptors (NRs) play an important role in maintaining cellular homeostasis. With clearly established roles in fatty acid metabolism and inflammation, peroxisome proliferator activated receptors (PPARs) and other nuclear receptors are essential in liver functioning. However, much less is known about the regulation of NRs themselves during inflammatory processes in the liver. Interestingly PPARs and other NRs are negative acute phase proteins because they become rapidly downregulated during the acute phase response. However, PPARs have important roles in modulating inflammatory responses. One of the mechanisms by which dietary or inflammatory stress is relieved involves the hepatic adenosine triphosphate-binding cassette (ABC) transporter proteins, which import and export a wide variety of substrates. These ABC transporters are under close control of several NRs. Because NRs play important roles in fatty acid metabolism and inflammation as well as in the regulation of bile production, they are reviewed here with respect to their role in dietary and stress-related responses of the liver and their impact on the regulation and function of hepatic ABC transporters.

Disruption of hepatic lipid homeostasis in mice after amiodarone treatment is associated with peroxisome proliferator-activated receptor-alpha target gene activation

Amiodarone, an efficacious and widely used antiarrhythmic agent, has been reported to cause hepatotoxicity in some patients. To gain insight into the mechanism of this unwanted effect, mice were administered various doses of amiodarone and examined for changes in hepatic histology and gene regulation. Amiodarone induced hepatomegaly, hepatocyte microvesicular lipid accumulation, and a significant decrease in serum triglycerides and glucose. Northern blot analysis of hepatic RNA revealed a dose-dependent increase in the expression of a number of genes critical for fatty acid oxidation, lipoprotein assembly, and lipid transport. Many of these genes are regulated by the peroxisome proliferator-activated receptor-alpha (PPARalpha), a ligand-activated nuclear hormone receptor transcription factor. The absence of induction of these genes as well as hepatomegaly in PPARalpha knockout [PPARalpha-/-] mice indicated that the effects of amiodarone were dependent upon the presence of a functional PPARalpha gene. Compared to wild-type mice, treatment of PPARalpha-/- mice with amiodarone resulted in an increased rate and extent of total body weight loss. The inability of amiodarone to directly activate either human or mouse PPARalpha transiently expressed in human HepG2 hepatoma cells indicates that the effects of amiodarone on the function of this receptor were indirect. Based upon these results, we conclude that amiodarone disrupts hepatic lipid homeostasis and that the increased expression of PPARalpha target genes is secondary to this toxic effect. These results provide important new mechanistic information regarding the hepatotoxic effects of amiodarone and indicate that PPARalpha protects against amiodarone-induced hepatotoxicity.