Drug- and chemical-induced cholestasis

Network pharmacology-based mechanism prediction and pharmacological validation of Xiaoyan Lidan formula on attenuating alpha-naphthylisothiocyanate induced cholestatic hepatic injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The well-known Chinese prescription, Xiaoyan Lidan Formula (XYLDF), possesses efficiency of heat-clearing, dampness-eliminating and jaundice-removing. It has long been used clinically for the treatment of hepatobiliary diseases due to intrahepatic cholestasis (IHC). However, the mechanism of XYLDF for its therapeutic effects remains elusive.

AIM OF THE STUDY

The study aimed to explore the potential targets for liver protective mechanism of XYLDF based on network pharmacology and experimental assays in ANIT-induced cholestatic hepatic injury (CHI) in rats.

MATERIALS AND METHODS

On the basis of the 29 serum migrant compounds of XYLDF elucidated by UPLC-TOF-MS/MS, a network pharmacology approach was applied for the mechanism prediction. Systematic networks were constructed to identify potential molecular targets, biological processes, and signaling pathways. And the interactions between significantly potential targets and active compounds were simulated by molecular docking. For the mechanism validation, an ANIT-induced rat model was used to evaluate the effects of XYLDF on CHI according to serum biochemistry, bile flow rates, histopathological examination, and the gene and protein expression including enzymes related to synthesis, export, and import of bile acid in liver and ileum, and those of inflammatory cytokines, analyzed by RT-qPCR and WB.

RESULTS

The results of network pharmacology research indicated TNF (TNF-α), RELA (NF-κB), NR1H4 (FXR), and ICAM1 (ICAM-1) to be the important potential targets of XYLDF for cholestatic liver injury, which are related to bile metabolism and NF-κB-mediated inflammatory signaling. And the molecular docking had pre-validated the prediction of network pharmacology, as the core active compounds of XYLDF had shown strong simulation binding affinity with FXR, followed by NF-κB, TNF-α, and ICAM-1. Meanwhile, the effects of XYLDF after oral administration on ANIT-induced CHI in rats exhibited the decreased levels of transaminases (ALT and AST), TBA, and TBIL in serum, raised bile flow rates, and markedly improved hepatic histopathology. Furthermore, consistent to the above targets prediction and molecular docking, XYLDF significantly up-regulated the expression of FXR, SHP, BSEP, and MRP2, and down-regulated CYP7A1 and NTCP in liver, and promoted expression of IBABP and OSTα/β in ileum, suggesting the activation of FXR-mediated pathway referring to bile acid synthesis, transportation, and reabsorption. Moreover, the lower levels of TNF-α in plasma and liver, as well as the reduced hepatic gene and protein expression of NF-κB, TNF-α, and ICAM-1 after XYLDF treatment revealed the suppression of NF-κB-mediated inflammatory signaling pathway, as evidenced by the inhibition of nuclear translocation of NF-κB.

CONCLUSIONS

XYLDF exhibited an ameliorative liver protective effect on ANIT-induced cholestatic hepatic injury. The present study has confirmed its mechanism as activating the FXR-regulated bile acid pathway and inhibiting inflammation via the NF-κB signaling pathway.

Oral ibuprofen promoted cholestatic liver disease in very low birth weight infants with patent ductus arteriosus

OBJECTIVES

Hemodynamically significant patent ductus arteriosus (hsPDA) in very low birth weight (VLBW) infants is routinely treated in many countries with oral ibuprofen. This study retrospectively assessed whether the risk of cholestatic liver disease (CLD) increased due to oral ibuprofen administration in VLBW infants.

METHODS

A total of 122 VLBW preterm infants (26∼32 weeks, birth weight<1500g) diagnosed with patent ductus arteriosus (PDA) admitted to our neonatal intensive care unit (NICU) between September 2016 to August 2018 were included. Sixty-four infants were diagnosed with hs-PDA and received ibuprofen treatment. VLBW infants with PDA untreated with ibuprofen served as controls. Soybean oil and fat emulsions were routinely added to parenteral nutrition (PN). Once CLD was diagnosed, the fat emulsions were immediately replaced with multi-oil fat emulsion injections. To assess the independent association of treatment and duration of ibuprofen with CLD and duration of fasting and PN, binary logistic regression or multivariate linear regression analyses were conducted, adjusting for major confounders (birth weight, gestational age, Clinical Risk Index for Babies, and cholestasis-associated risk factors).

RESULTS

The duration of PN increased due to ibuprofen treatment for 6.559 days (95% CI: 1.769, 11.349; P=0.008), and the risk of prolonged fasting (cutoff>5 days) might have increased due to ibuprofen treatment (OR: 3.043, 95% CI: 0.965, 9.594; P=0.057). Furthermore, CLD was influenced by ibuprofen treatment (OR: 6.730; 95% CI: 1.279, 35.41; P=0.024), early thrombocytopenia 7 days postnatal (OR: 6.996; 95% CI: 1.769, 27.658; P=0.004), and late onset sepsis (OR: 6.976; 95% CI: 1.561, 31.169; P=0.011). Further analysis adjusting for cholestasis-associated risk factors revealed that CLD was influenced by the duration of ibuprofen treatment (OR: 2.864; 95% CI: 1.104, 7.422; P=0.030), Platlets counts 7 days postnatal (OR: 0.971; 95% CI: 0.950, 0.994; P=0.013), and duration of antibiotics (OR: 1.134; 95% CI: 1.002, 1.282; P=0.046).

CONCLUSIONS

This retrospective study indicated oral ibuprofen duration-dependently increased the risk of CLD in VLBW infants with PDA, and early thrombocytopenia served as the critical risk factor.

Amoxicillin-clavulanate-induced Granulomatous Hepatitis: Case Report and Review of the Literature

Amoxicillin-clavulanate (AC) is a common cause of drug-induced liver injury, either cholestatic or mixed with hepatitis pattern. Rarely, AC causes granulomatous hepatitis. We report a new case of AC-induced granulomatous hepatitis documented by liver biopsy, with complete resolution of any histological sequelae on a follow-up liver biopsy after AC was withdrawn.

Advances in drug-induced cholestasis: Clinical perspectives, potential mechanisms and in vitro systems

Despite growing research, drug-induced liver injury (DILI) remains a serious issue of increasing importance to the medical community that challenges health systems, pharmaceutical industries and drug regulatory agencies. Drug-induced cholestasis (DIC) represents a frequent manifestation of DILI in humans, which is characterised by an impaired canalicular bile flow resulting in a detrimental accumulation of bile constituents in blood and tissues. From a clinical point of view, cholestatic DILI generates a wide spectrum of presentations and can be a diagnostic challenge. The drug classes mostly associated with DIC are anti-infectious, anti-diabetic, anti-inflammatory, psychotropic and cardiovascular agents, steroids, and other miscellaneous drugs. The molecular mechanisms of DIC have been investigated since the 1980s but they remain debatable. It is recognised that altered expression and/or function of hepatobiliary membrane transporters underlies some forms of cholestasis, and this and other concomitant mechanisms are very likely in DIC. Deciphering these processes may pave the ways for diagnosis, prognosis and prevention, for which currently major gaps and caveats exist. In this review, we summarise recent advances in the field of DIC, including clinical aspects, the potential mechanisms postulated so far and the in vitro systems that can be useful to investigate and identify new cholestatic drugs.

Side effects of anabolic steroids used by athletes at Unaizah Gyms, Saudi Arabia: a pilot study

BACKGROUND

A large number of Saudi athletes are recently shown to use androgenic anabolic steroid (AAS) products to achieve rapid muscle growth without realizing the serious health risks of these drugs. Aim of this study was to elucidate the side effects encountered with prolonged use of AAS products by Saudi athletes.

METHODS

A cross-sectional study was conducted, in which 16 regular gym members, 12 of them used AAS, were asked to answer a questionnaire and provide blood samples following current AAS course completion. Hemoglobin, serum proteins, lipid profile and hematological parameters were measured. Meanwhile, the parameters of kidneys, liver, heart, and immune system function were monitored.

RESULTS

The subjects reported taking a 3-month course of an AAS comprising three compounds (testosterone enanthate, nandrolone decanoate and methandienone). A two-week gap separated every two courses, during which tamoxifen citrate (40 mg per day) and clomiphene citrate (10 mg per day) were taken to control serum testosterone levels. The intake of AAS one course had remarkable effects on some parameters related to kidney function. However, AAS three courses or more treatments showed abnormal liver and heart enzymes. Moreover, endogenous testosterone levels decreased dramatically with prolonged use of AAS (more than 10 courses). Alpha 2 protein increased by taking more than 10 courses, which might cause acute phase reactant of liver infection or inflammation.

CONCLUSIONS

AAS products must be controlled by Saudi ministry of health and should not be taken randomly without the supervision of the healthcare professional.

Drug-induced liver injury: Do we know everything?

Interest in drug-induced liver injury (DILI) has dramatically increased over the past decade, and it has become a hot topic for clinicians, academics, pharmaceutical companies and regulatory bodies. By investigating the current state of the art, the latest scientific findings, controversies, and guidelines, this review will attempt to answer the question: Do we know everything? Since the first descriptions of hepatotoxicity over 70 years ago, more than 1000 drugs have been identified to date, however, much of our knowledge of diagnostic and pathophysiologic principles remains unchanged. Clinically ranging from asymptomatic transaminitis and acute or chronic hepatitis, to acute liver failure, DILI remains a leading causes of emergent liver transplant. The consumption of unregulated herbal and dietary supplements has introduced new challenges in epidemiological assessment and clinician management. As such, numerous registries have been created, including the United States Drug-Induced Liver Injury Network, to further our understanding of all aspects of DILI. The launch of LiverTox and other online hepatotoxicity resources has increased our awareness of DILI. In 2013, the first guidelines for the diagnosis and management of DILI, were offered by the Practice Parameters Committee of the American College of Gastroenterology, and along with the identification of risk factors and predictors of injury, novel mechanisms of injury, refined causality assessment tools, and targeted treatment options have come to define the current state of the art, however, gaps in our knowledge still undoubtedly remain.

Risperidone- and Quetiapine-Induced Cholestasis

Objective:

To describe a case of a patient who developed drug-induced cholestasis after being on risperidone maintenance therapy for 8 years.

Case Summary:

A 30-year-old male with schizoaffective disorder, bipolar type, and insulin-dependent diabetes mellitus had been stable on risperidone 6 mg at night for 8 years. His other medications included lithium 900 mg twice daily and enalapril 5 mg daily, as well as regular insulin and NPH insulin as needed. The patient developed cholestasis that resolved once risperidone was discontinued. Over the next 11 months, he tolerated trials of ziprasidone and olanzapine. When quetiapine was initiated, the patient developed signs and symptoms of cholestasis within 3 weeks after starting this medication. The signs and symptoms of cholestasis resolved with removal of quetiapine. The Naranjo probability scale indicated that these atypical antipsychotics (risperidone and quetiapine) were the probable cause of cholestasis in this patient.

Discussion:

It is well known that atypical antipsychotics can cause isolated asymptomatic increases in aminotransferase levels. Liver injury, both the hepatic and cholestatic type, has been described previously, although the incidence with atypical antipsychotics is rare.

Conclusions:

To our knowledge, this is the first case of cholestasis that developed after years of treatment and reappeared with another antipsychotic agent. Given that liver failure, of either the hepatic or cholestatic type, is a relatively rare phenomenon with atypical antipsychotics, it seems that the most reasonable approach to manage this risk is through education. By educating patients on early warning signs of hepatotoxicity, this rare but potentially fatal consequence could be detected early to allow appropriate intervention.

Early Alterations of Bile Canaliculi Dynamics and the Rho Kinase/Myosin Light Chain Kinase Pathway Are Characteristics of Drug-Induced Intrahepatic Cholestasis

Intrahepatic cholestasis represents 20%-40% of drug-induced injuries from which a large proportion remains unpredictable. We aimed to investigate mechanisms underlying drug-induced cholestasis and improve its early detection using human HepaRG cells and a set of 12 cholestatic drugs and six noncholestatic drugs. In this study, we analyzed bile canaliculi dynamics, Rho kinase (ROCK)/myosin light chain kinase (MLCK) pathway implication, efflux inhibition of taurocholate [a predominant bile salt export pump (BSEP) substrate], and expression of the major canalicular and basolateral bile acid transporters. We demonstrated that 12 cholestatic drugs classified on the basis of reported clinical findings caused disturbances of both bile canaliculi dynamics, characterized by either dilatation or constriction, and alteration of the ROCK/MLCK signaling pathway, whereas noncholestatic compounds, by contrast, had no effect. Cotreatment with ROCK inhibitor Y-27632 [4-(1-aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride] and MLCK activator calmodulin reduced bile canaliculi constriction and dilatation, respectively, confirming the role of these pathways in drug-induced intrahepatic cholestasis. By contrast, inhibition of taurocholate efflux and/or human BSEP overexpressed in membrane vesicles was not observed with all cholestatic drugs; moreover, examples of noncholestatic compounds were reportedly found to inhibit BSEP. Transcripts levels of major bile acid transporters were determined after 24-hour treatment. BSEP, Na+-taurocholate cotransporting polypeptide, and organic anion transporting polypeptide B were downregulated with most cholestatic and some noncholestatic drugs, whereas deregulation of multidrug resistance-associated proteins was more variable, probably mainly reflecting secondary effects. Together, our results show that cholestatic drugs consistently cause an early alteration of bile canaliculi dynamics associated with modulation of ROCK/MLCK and these changes are more specific than efflux inhibition measurements alone as predictive nonclinical markers of drug-induced cholestasis.

The pathogenesis of drug-induced liver injury

Drugs can induce liver injury when taken as an over-dose, or even at therapeutic doses in susceptible individuals. Although severe drug-induced liver injury (DILI) is a relatively uncommon clinical event, it is a potentially life threatening adverse drug reaction and is the most common indication for the drug withdrawal. Areas covered: However, the diagnosis of DILI remains a significant challenge, because the establishment of causality is very difficult, and the histopathologic findings of DILI may be indistinguishable from those of other hepatic disorders, such as viral and alcoholic hepatitis. In this review, we provide an overview of recent advances in identification of serologic markers of diagnosis and prognosis, etiologic factors for susceptibility and diagnostic evaluation of DILI, with a focus on its pathogenic mechanisms and the role of liver biopsy. Expert commentary: Further studies of divergent research platforms, using a systems biology approach such as genomics and transcriptomics, may provide a deeper understanding of human drug metabolism and the causes, risk factors, and pathogenesis of DILI.

Amoxicillin-Clavulanate-Induced Liver Injury

BACKGROUND AND AIMS

Amoxicillin-clavulanate (AC) is the most frequent cause of idiosyncratic drug-induced injury (DILI) in the US DILI Network (DILIN) registry. Here, we examined a large cohort of AC-DILI cases and compared features of AC-DILI to those of other drugs.

METHODS

Subjects with suspected DILI were enrolled prospectively, and cases were adjudicated as previously described. Clinical variables and outcomes of patients with AC-DILI were compared to the overall DILIN cohort and to DILI caused by other antimicrobials.

RESULTS

One hundred and seventeen subjects with AC-DILI were identified from the cohort (n = 1038) representing 11 % of all cases and 24 % of those due to antimicrobial agents (n = 479). Those with AC-DILI were older (60 vs. 48 years, P < 0.001). AC-DILI was more frequent in men than women (62 vs. 39 %) compared to the overall cohort (40 vs. 60 %, P < 0.001). The mean time to symptom onset was 31 days. The Tb, ALT, and ALP were 7 mg/dL, 478, and 325 U/L at onset. Nearly all liver biopsies showed prominent cholestatic features. Resolution of AC-DILI, defined by return of Tb to <2.5 mg/dL, occurred on average 55 days after the peak value. Three female subjects required liver transplantation, and none died due to DILI.

CONCLUSION

AC-DILI causes a moderately severe, mixed hepatocellular-cholestatic injury, particularly in older men, unlike DILI in general, which predominates in women. Although often protracted, eventual apparent recovery is typical, particularly for men and usually in women, but three women required liver transplantation.

The fungicide thiabendazole causes apoptosis in rat hepatocytes

Many pharmaceutical drugs cause hepatotoxicity in humans leading to severe liver diseases, representing a serious public health issue. This study investigates the ability of the anthelmintic and antifungal drug thiabendazole to cause cell death by apoptosis and metabolic changes in primary cultures of rat hepatocytes. Thiabendazole (200-500 μM) induced apoptosis in hepatocytes after 1 to 24h, causing loss of mitochondrial membrane potential, cytochrome c release from mitochondria, Fas-associated death domain (FADD) translocation from the cytosol to membranes, and activation of caspases-3, -8 and -9. Thus, thiabendazole activated both the mitochondrial and death receptor pathways of apoptosis. Under these conditions, cell death by necrosis was not detected following exposure to thiabendazole (100-500 μM) for 24-48 h, measured by lactate dehydrogenase release and propidium iodide uptake. Furthermore, thiabendazole increased activities of cytochrome P450 (CYP) isoenzymes CYP1A and CYP2B after 24 and 48 h, determined by 7-ethoxyresorufin-O-deethylase (EROD) and 7-pentoxyresorufin-O-dealkylase (PROD) activities, respectively. An important finding is that thiabendazole can eliminate hepatocytes by apoptosis, which could be a sensitive marker for hepatic damage and cell death. This study improves understanding of the mode of cell death induced by thiabendazole, which is important given that humans and animals are exposed to this compound as a pharmaceutical agent and in an environmental context.

Current and future directions in the treatment and prevention of drug-induced liver injury: a systematic review

While the pace of discovery of new agents, mechanisms and risk factors involved in drug-induced liver injury (DILI) remains brisk, advances in the treatment of acute DILI seems slow by comparison. In general, the key to treating suspected DILI is to stop using the drug prior to developing irreversible liver failure. However, predicting when to stop is an inexact science, and commonly used ALT monitoring is an ineffective strategy outside of clinical trials. The only specific antidote for acute DILI remains N-acetylcysteine (NAC) for acetaminophen poisoning, although NAC is proving to be beneficial in some cases of non-acetaminophen DILI in adults. Corticosteroids can be effective for DILI associated with autoimmune or systemic hypersensitivity features. Ursodeoxycholic acid, silymarin and glycyrrhizin have been used to treat DILI for decades, but success remains anecdotal. Bile acid washout regimens using cholestyramine appear to be more evidenced based, in particular for leflunomide toxicity. For drug-induced acute liver failure, the use of liver support systems is still investigational in the United States and emergency liver transplant remains limited by its availability. Primary prevention appears to be the key to avoiding DILI and the need for acute treatment. Pharmacogenomics, including human leukocyte antigen genotyping and the discovery of specific DILI biomarkers offers significant promise for the future. This article describes and summarizes the numerous and diverse treatment and prevention modalities that are currently available to manage DILI.

Histological and Clinicopathological Evaluation of Liver Allograft Biopsy: An Initial Experience of Fifty Six Biopsies

INTRODUCTION

Liver biopsy is gold standard for diagnosis of allograft dysfunction.

AIM

The aim of study was to evaluate liver allograft biopsies performed for graft dysfunction, study the pattern of injury and intensity, and timeline of occurrence of graft dysfunction.

MATERIALS AND METHODS

Retrospective study was carried out of 56 liver allograft biopsies and their histological findings with clinical presentation were correlated. Totally 56 needle liver allograft biopsies from January 1210 to July 2014, obtained from 35 patients were studied for histological and clinicopathological evaluation.

RESULTS

The mean age was 53.2±5.48 years. The most common original disease was alcoholic cirrhosis. The most common histological lesion was acute cellular rejection (ACR) in 31 (55.36%) biopsies followed by preservation-reperfusion injury (PRI) in 10 (17.86%) biopsies and drug toxicity in 8 (14.29%) biopsies. Chronic rejection was reported in 2 (3.57%) and recurrence of HCV in 3 (5.36%). Ischemic coagulative necrosis and acute cholangitis were seen in 1 (1.79 %) case each.

CONCLUSION

Alcoholic cirrhosis was the most common etiology for end stage liver disease. ACR and PRI were the major complications in liver allograft biopsies at our centre.

The Art and Science of Diagnosing and Managing Drug-induced Liver Injury in 2015 and Beyond

Drug-induced liver injury (DILI) remains a leading reason why new compounds are dropped from further study or are the subject of product warnings and regulatory actions. Hy's Law of drug-induced hepatocellular jaundice causing a case-fatality rate or need for transplant of 10% or higher has been validated in several large national registries, including the ongoing, prospective U.S. Drug-Induced Liver Injury Network. It serves as the basis for stopping rules in clinical trials and in clinical practice. Because DILI can mimic all known causes of acute and chronic liver disease, establishing causality can be difficult. Histopathologic findings are often nonspecific and rarely, if ever, considered pathognomonic. A daily drug dose >50-100 mg is more likely to be hepatotoxic than does <10 mg, especially if the compound is highly lipophilic or undergoes extensive hepatic metabolism. The quest for a predictive biomarker to replace alanine aminotransferase is ongoing. Markers of necrosis and apoptosis such as microRNA-122 and keratin 18 may prove useful in identifying patients at risk for severe injury when they initially present with a suspected acetaminophen overdose. Although a number of drugs causing idiosyncratic DILI have HLA associations that may allow for pre-prescription testing to prevent hepatotoxicity, the cost and relatively low frequency of injury among affected patients limit the current usefulness of such genome-wide association studies. Alanine aminotransferase monitoring is often recommended but has rarely been shown to be an effective method to prevent serious DILI. Guidelines on the diagnosis and management of DILI have recently been published, although specific therapies remain limited. The LiverTox Web site has been introduced as an interactive online virtual textbook that makes the latest information on more than 650 agents available to clinicians, regulators, and drug developers alike.

Hepatotoxicity of antibiotics: a review and update for the clinician

Collectively, the various classes of antibiotics are a leading cause of drug-induced liver injury (DILI). However, acute antibiotic-associated DILI can be difficult to diagnose, as the course of therapy is usually brief, and other confounding factors are often present. In addition to the broad clinicopathologic spectrum of hepatotoxicity associated with the antimicrobials, the underlying infectious disease being treated may itself be associated with hepatic dysfunction and jaundice. This review provides summarized information on several classes of antimicrobial agents, highlighting new agents causing DILI and updating information on older agents.

Intrahepatic cholestasis in common chronic liver diseases

BACKGROUND AND OBJECTIVE

Cholestasis represents the consequence of impaired bile formation and decrease in bile flow, generally classified as extra- and intrahepatic. Cholestasis is the pivotal hallmark of the so-called primary cholestatic liver diseases but may also emerge in other forms of chronic liver injury. The aim now was to summarise the current state of knowledge on intrahepatic cholestasis related to chronic liver diseases.

METHODS

For this overview on intrahepatic cholestasis in chronic liver disorders other than the 'classic' cholestatic liver diseases, selected references were retrieved by literature search in MEDLINE and textbooks were reviewed. All articles were selected that discussed pathophysiological and clinical aspects of intrahepatic cholestasis in the context of alcoholic liver disease, nonalcoholic fatty liver disease, chronic hepatitis B and C virus infections as well as drug-induced and granulomatous liver diseases. Titles referring to primary biliary cirrhosis and sclerosing cholangitis were excluded.

RESULTS AND CONCLUSIONS

Dependent on the aetiology, intrahepatic cholestasis is present at variable frequencies and in different disease stages in chronic liver diseases. Cholestasis secondary to chronic liver injury may denote a severe disease course and development of end-stage liver disease or specific disease variants. These findings indicate that 'secondary intrahepatic cholestasis' (SIC) can occur in the natural course of chronic liver diseases other than the primary cholestatic diseases, in particular in the setting of advanced disease progression.

An updated review on drug-induced cholestasis: mechanisms and investigation of physicochemical properties and pharmacokinetic parameters

Drug-induced cholestasis is an important form of acquired liver disease and is associated with significant morbidity and mortality. Bile acids are key signaling molecules, but they can exert toxic responses when they accumulate in hepatocytes. This review focuses on the physiological mechanisms of drug-induced cholestasis associated with altered bile acid homeostasis due to direct (e.g., bile acid transporter inhibition) or indirect (e.g., activation of nuclear receptors, altered function/expression of bile acid transporters) processes. Mechanistic information about the effects of a drug on bile acid homeostasis is important when evaluating the cholestatic potential of a compound, but experimental data often are not available. The relationship between physicochemical properties, pharmacokinetic parameters, and inhibition of the bile salt export pump among 77 cholestatic drugs with different pathophysiological mechanisms of cholestasis (i.e., impaired formation of bile vs. physical obstruction of bile flow) was investigated. The utility of in silico models to obtain mechanistic information about the impact of compounds on bile acid homeostasis to aid in predicting the cholestatic potential of drugs is highlighted.

Histopathology of post-transplant liver biopsies, the first report from iran

BACKGROUND

Evaluation of a transplanted liver by Imaging techniques and enzyme changes is sensitive to hepatocellular or biliary problems, but in most instances liver allograft biopsies are performed in order to find out the final reason for these changes.

OBJECTIVES

It's been about 17 years (with more than 1326 cases) since the first liver transplantation in the Namazi Hospital of Shiraz University of Medical Sciences while during the last five years the number of post liver transplant biopsies have increased. Until now there has been no report of the pathological results of post liver transplant needle biopsies from Iran.

MATERIALS AND METHODS

During the last 5 years, there have been 382 post liver transplant biopsies. We studied the clinical charts and pathological results of all needle biopsies.

RESULTS

A total of 382 needle biopsies were performed on 287 patients aged between 1 and 64 years old. The earliest specimen was obtained within the first few hours following transplantation, and the last was gathered 3209 days (261 ± 523) post-transplantation. Acute rejection was the most common diagnosis, which occurred in 180 (47%) of specimens. Among other complications were vascular problems (8.6%), preservation/reperfusion (I/R) injury (7%), chronic rejection (5.2%), biliary injury/obstruction (3.4%), recurrence of primary disease (2.6%), drug-induced hepatic injury (1.8%), cirrhosis (1.6%), sepsis (1.4%), cytomegalovirus hepatitis (1.4%), post-transplantation lymphoproliferative disease (1%) and Venous outflow obstruction (0.5%).

CONCLUSIONS

The most common pathological diagnosis of post-transplant liver needle biopsies has been acute rejection, followed by ischemia due to hepatic artery thrombosis, preservation/reperfusion injury, and chronic rejection.

Drug-induced liver injury in the elderly

Historically, the elderly have been considered to be at increased risk for drug-induced liver injury (DILI). Animal studies have demonstrated changes in hepatic physiology that affect drug metabolism in the aging liver; however, there is no evidence that this leads to any appreciable deterioration of liver function in healthy older humans. Updated data from international DILI registries give us pause to consider whether the elderly are truly at increased risk to develop hepatic injury. Instead, hepatotoxicity in the elderly appears to be more a function of drug exposure, polypharmacy and drug-drug interactions. Isoniazid and benoxaprofen are the only two agents with a well-studied correlation between increasing age and risk of DILI. Nevertheless, given the increasing proportion of patients over age 65 in the U.S. and abroad, the influence of age on the risk of DILI is the focus of this review.

Changes of serum biochemical parameters and liver pathology in 18 patients with 1,1,2,2-tetrachloroethane-induced hepatotoxicity

OBJECTIVE

To evaluate the changes of serum biochemical parameters and liver pathology in patients with 1,1,2,2-tetrachloroethane (TTCE)-induced hepatotoxicity.

METHODS

A total of 18 patients were diagnosed as TTCE-induced hepatotoxicity with an incubation period of 11-56 days. Blood samples were obtained from all patients and liver biopsy was performed in 16.

RESULTS

All patients had fatigue, poor appetite and dark urine, 15 of whom suffered nausea, vomiting, abdominal distension and other gastrointestinal disorders. All patients had various degrees of liver function damage, and one died from liver failure. The prothrombin time was significantly prolonged in 6 patients. Histological findings showed varying degrees of necrosis, fatty degeneration and fibrosis in portal areas without cirrhosis. Patients with more severe jaundice had more severe pathologic changes, including piecemeal and bridge necrosis, and cholestasis.

CONCLUSIONS

TTCE-induced hepatotoxicity may cause the changes in serum biochemical parameters and liver pathology. Most patients might recover with regular treatment. Prevention and early diagnosis of TTCE-induced hepatotoxicity are necessary.

Valproic acid-associated vanishing bile duct syndrome

Hepatotoxicity as a result of valproic acid therapy is well documented. Elevation in aminotransferase activities is rarely associated with symptoms. It sometimes manifests as acute liver failure. Here, we report a 8-year-old girl who was referred for unresolving jaundice and itching for 3 months. Past history revealed afebrile convulsion 5 months previously and beginning of valproic acid treatment. Valproic acid was discontinued after the development of jaundice. Physical examination revealed ichterus, xanthomas on extensor surfaces of extremities, and hepatomegaly without any sign of chronic liver disease. Total and direct bilirubin levels were 20.2 and 12.9 mg/dL, respectively. Enzyme activities indicating cholestasis were increased together with blood cholesterol. Tests for infectious and autoimmune, metabolic, and genetic disorders were not informative. Liver biopsy revealed portal inflammation, severe bile duct loss, and cholestasis. The patient was considered to have valproic acid-associated vanishing bile duct syndrome, which has not been reported previously.

Atazanavir-Associated Choledocholithiasis Leading to Acute Hepatitis in an HIV-infected Adult

OBJECTIVE

To report a case of atazanavir-associated choledocholithiasis in an HIV-infected individual.

CASE SUMMARY

A 47-year-old treatment-naïve HIV-positive African female presented to the emergency department with a 3-day history of right epigastric pain. Six weeks prior to this episode, she began antiretroviral therapy with a regimen consisting of atazanavir 400 mg and abacavir/lamivudine 600/300 mg once daily. Alanine aminotransferase (766 U/L), aspartate aminotransferase (876 U/L), γ-glutamyltransferase (588 U/L), alkaline phosphatase (348 U/L), and total bilirubin (3.9 mg/dL) levels were elevated. Abdominal ultrasound revealed obstructive choledocholithiasis as well as intra- and extrahepatic biliary dilatation. She underwent a laparoscopic cholecystectomy, which revealed approximately 50 small calculi present in the gallbladder. Since previous ultrasounds had also shown gallstones, an analysis of the extracted calculi was performed to determine the possible association with atazanavir use; low amounts of atazanavir were detected.

DISCUSSION

Atazanavir is an inhibitor of the bilirubin-conjugating enzyme UGT1A1 and has been frequently linked to the occurrence of hyperbilirubinemia without complications. This individual experienced hyperbilirubinemia that peaked at hospital presentation after she developed choledocholithiasis and secondary acute hepatitis. Analysis of the extracted gallstones revealed that smaller stones contained a higher content of atazanavir than larger stones, which suggests that atazanavir precipitation may play a role in cholelithiasis, although the mechanism remains unknown. The low yield of atazanavir may be explained by the short, 6-week duration of drug exposure as well as the lack of assay for metabolites. The Naranjo probability scale implicated choledocholithiasis as a possible atazanavir-associated adverse event. This report provides the first published evidence that even short-term use of atazanavir may lead to hyperbilirubinemia with choledocholithiasis and secondary acute hepatitis in HIV-infected adults.

CONCLUSIONS

Atazanavir should be considered a possible contributor in the development of cholelithiasis or choledocholithiasis, and people with HIV should receive adequate counseling in the recognition of symptoms associated with gallstones. The exact incidence and mechanism still need to be elucidated.

Vanishing bile duct syndrome associated with azithromycin in a 62-year-old man

Vanishing bile duct syndrome is a severe cholestatic disease associated with toxic effects of medications. Stevens-Johnson syndrome is a hypersensitivity disorder that may also be caused by medications. We present a case of a 62-year-old male patient who developed vanishing bile duct syndrome a month after Stevens-Johnson syndrome. These adverse drug reactions were associated with the use of azithromycin (500 mg daily for 3 days). The patient was initially treated for Stevens-Johnson syndrome with steroids, antihistamines and proton pump inhibitors and fully recovered. However, a month after the beginning of Stevens-Johnson syndrome, he developed vanishing bile duct syndrome and was treated with steroids, ursodeoxycholic acid, antihistamines and tacrolimus. Unfortunately, the treatment was unsuccessful and he was listed for liver transplantation which was performed 7 months after the beginning of jaundice. This is the first case of vanishing bile duct syndrome associated with the use of azithromycin and one of few that reports vanishing bile duct syndrome and Stevens-Johnson syndrome co-occurrence.

Altered integrity and decreased expression of hepatocyte tight junctions in rifampicin-induced cholestasis in mice

Rifampicin is a well-known hepatotoxicant, but little is known about the mechanism of rifampicin-induced hepatotoxicity. The aim of this study was to characterize the expression and localization of hepatocyte tight junctions in rifampicin-induced cholestasis in mice. Cholestasis was induced by administration of rifampicin (200 mg/kg) for 7 consecutive days or treatment with a single dose of rifampicin (200 mg/kg) by gastric intubation. The expression of mRNA for hepatic zonula occludens (ZO)-1, ZO-2, ZO-3, occludin and claudin-1 was determined using RT-PCR. Localization of ZO-1 and occludin was detected using immunofluorescence. Results showed that there was an 82-fold increase in the conjugated bilirubin in serum in rifampicin-treated mice. In addition, an 8-fold increase in total bile acid in serum was observed after a seven-day administration of rifampicin. The integrity of hepatocyte ZO-1 and occludin was altered by a seven-day administration of rifampicin. Importantly, the integrity and intensity of hepatocyte tight junctions were altered as early as 30 min after a single dose of rifampicin. The expression of hepatic ZO-1 and ZO-2 mRNA was significantly decreased, beginning as early as 30 min and remaining a lower level 12 h after a single dose of rifampicin. Taken together, these results suggest that the altered integrity and internalization of hepatocyte tight junctions are associated with rifampicin-induced cholestasis.

Intrahepatic cholestasis in subclinical and overt hyperthyroidism: two case reports

Introduction

Non-specific abnormalities in liver function tests might accompany the clinical course of hyperthyroidism. Hyperthyroidism can cause the elevation of hepatic enzymes and bilirubin. Jaundice is rare in overt hyperthyroidism, especially in subclinical hyperthyroidism. On the other hand, the use of anti-thyroid drugs has rarely been associated with toxic hepatitis and cholestatic jaundice.

Case presentation

Here we present two cases of cholestasis that accompanied two distinct forms of clinical hyperthyroidism. The first patient had a clinical presentation of severe cholestasis in the absence of congestive failure related to hyperthyroidism. The second case had developed intrahepatic cholestasis in the presence of subclinical hyperthyroidism, and improved with rifampicin treatment.

Conclusion

Hyperthyroidism should be a consideration in non-specific liver dysfunction.

Medications for Extensively Drug-Resistant Tuberculosis: Back to the Future?

Objective:

To reexamine the existing medications for the potential treatment of extensively drug-resistant tuberculosis (XDR-TB), based on susceptibility data, and to identify potential future medications from the literature.

Data Sources:

Relevant information was identified through a search of MEDLINE (1966–November 2007), PubMed (1955–November 2007), American Search Premier (1975–November 2007), International Pharmaceutical Abstracts (1960–November 2007), Science Citation Index Expanded (1996–November 2007), Cochrane Databases (publications archived until November 2007), and various tertiary sources as listed in the references, using the terms extensively drug-resistant tuberculosis (XDR-TB), ethambutol, pyrazinamide, para-aminosalicylic acid, cycloserine, linezolid, diarylquinoline, nitroimidazopyran, fluoroquinolones, β-lactams, new treatments, and ethionamide alone or in combination regimens.

Study Selection and Data Extraction:

After identification of the relevant information, the data presented in this article were selected based on clinical relevance and value of information.

Data Synthesis:

Based on susceptibility data, pyrazinamide, ethambutol, para-aminosalicylic acid, cycloserine, and ethionamide may be used for the treatment of tuberculosis. However, due to the emergence of XDR-TB, many of these agents are no longer successful treatment regimens. We have found limited data supporting potential future use of β-lactams, clarithromycin, and linezolid in resistant TB infections. TMC207, nitroimidazopyran, and SQ109 compounds may also prove to be viable options in the near future for treatment of tuberculosis, especially in cases with resistance to mainstay medications.

Conclusions:

Extensively resistant tuberculosis appears to be a potentially catastrophic disease if allowed to spread. Due to its resistance profile, very few potentially effective agents are available, calling attention to this growing problem.

Anabolic-androgenic steroids and liver injury

Athletes and nonathletes have been using anabolic-androgenic steroids (AAS) for a long time, in an inadequate and unsurveilled manner, with the aim of improving sports performance or for cosmetic purposes. AAS consumption is becoming more widespread and involving younger people, and there is a trend for self-administration of higher doses and for combining AAS with other potentially harmful drugs. Almost any subject abusing AAS will experience adverse effects. Therefore, adverse effects from these exposures, including liver toxicity, are expected to increase in the years to come. The present manuscript describes a representative case of intrahepatic cholestasis with the intention to discuss AAS-related liver toxicity (including the potential therapeutic role of ursodeoxycholic acid) and to comment on several aspects of the clinical scenario the gastroenterologist should be aware of.

Non invasive high resolution in vivo imaging of alpha-naphthylisothiocyanate (ANIT) induced hepatobiliary toxicity in STII medaka

A novel transparent stock of medaka (Oryzias latipes; STII), homozygous recessive for all four pigments (iridophores, xanthophores, leucophores, melanophores), permits transcutaneous, high resolution (<1 microm) imaging of internal organs and tissues in living individuals. We applied this model to in vivo investigation of alpha -naphthylisothiocyanate (ANIT) induced hepatobiliary toxicity. Distinct phenotypic responses to ANIT involving all aspects of intrahepatic biliary passageways (IHBPs), particularly bile preductular epithelial cells (BPDECs), associated with transitional passageways between canaliculi and bile ductules, were observed. Alterations included: attenuation/dilation of bile canaliculi, bile preductular lesions, hydropic vacuolation of hepatocytes and BPDECs, mild BPDEC hypertrophy, and biliary epithelial cell (BEC) hyperplasia. Ex vivo histological, immunohistochemical, and ultrastructural studies were employed to aid in interpretation of, and verify, in vivo findings. 3D reconstructions from in vivo investigations provided quantitative morphometric and volumetric evaluation of ANIT exposed and untreated livers. The findings presented show for the first time in vivo evaluation of toxicity in the STII medaka hepatobiliary system, and, in conjunction with prior in vivo work characterizing normalcy, advance our comparative understanding of this lower vertebrate hepatobiliary system and its response to toxic insult.

Causality assessment of drug-induced hepatotoxicity: promises and pitfalls

Drug-induced liver injury is the leading cause of acute liver failure in the United States, but the ability to ascribe hepatic injury confidently to a specific drug remains a challenging and often difficult pursuit. This article explores the ongoing challenges inherent in what is currently a clinical process of elimination made in the attempt of assigning causality in drug-induced liver injury. In particular, it points out the shortcomings and pitfalls that often limit the applicability of the causality-assessment methodologies currently in use.

Parenteral nutrition-associated liver disease in adult and pediatric patients

There are essentially 3 types of hepatobiliary disorders associated with parenteral nutrition (PN) therapy: steatosis, cholestasis, and gallbladder sludge/stones. Reported prevalence rates of PN-associated liver disease (PNALD) vary greatly, and there are distinct differences between adult and pediatric patients. Various etiologic factors have been evaluated for significance in contributing to PNALD, including enteral feeding history, septic events, bacterial overgrowth, length of intestinal resection, and prematurity/low birth weight. Etiologic factors specifically related to the PN formulation or nutrient intake have also been evaluated, including excessive calorie intake, dextrose-to-lipid ratio, amino acid dose, taurine deficiency, IV fat emulsion (IVFE) dose, carnitine deficiency, choline deficiency, and continuous vs cyclic infusion. Minor increases in serum aminotransferase concentrations are relatively common in patients receiving PN therapy and generally require no intervention. The primary indicator of cholestasis is a serum conjugated bilirubin >2 mg/dL. When a patient receiving PN develops liver complications, it is necessary to rule out all treatable causes and minimize other risk factors. All potential hepatotoxic medications and herbal supplements should be eliminated. Modifications to the PN regimen that may be helpful include reduction of calories, reduction of IVFE dose to <1 g/kg/d, supplementation of taurine in the infant, and use of cyclic infusion. Initiation of even small amounts of enteral nutrition and use of ursodiol may be beneficial in stimulating bile flow. In the long-term PN patient with severe and progressive liver disease, intestinal or liver transplantation may be the only remaining treatment option.

Inhibition of bile acid transport across Na+/taurocholate cotransporting polypeptide (SLC10A1) and bile salt export pump (ABCB 11)-coexpressing LLC-PK1 cells by cholestasis-inducing drugs

Vectorial transport of bile acids across hepatocytes is a major driving force for bile flow, and bile acid retention in the liver causes hepatotoxicity. The basolateral and apical transporters for bile acids are thought to be targets of drugs that induce cholestasis. Previously, we constructed polarized LLC-PK1 cells that express both a major bile acid uptake transporter human Na+/taurocholate cotransporting polypeptide (SLC10A1) (NTCP) and the bile acid efflux transporter human bile salt export pump (ABCB 11) (BSEP) and showed that monolayers of such cells can be used to characterize vectorial transcellular transport of bile acids. In the present study, we investigated whether cholestasis-inducing drugs could inhibit bile acid transport in such cells. Because fluorescent substrates allow the development of a high-throughput screening method, we examined the transport by NTCP and BSEP of fluorescent bile acids as well as taurocholate. The aminofluorescein-tagged bile acids, chenodeoxycholylglycylamidofluorescein and cholylglycylamidofluorescein, were substrates of both NTCP and BSEP, and their basal-to-apical transport rates across coexpressing cell monolayers were 4.3 to 4.5 times those of the vector control, although smaller than for taurocholate. The well known cholestatic drugs, rifampicin, rifamycin SV, glibenclamide, and cyclosporin A, reduced the basal-to-apical transport and the apical efflux clearance of taurocholate across NTCP- and BSEP-coexpressing cell monolayers. Further analysis indicated that the drugs inhibited both NTCP and BSEP. Our study suggests that such coexpressing cells can provide a useful system for the identification of inhibitors of these two transport systems, including potential drug candidates.

Hepatic Findings in Long-Term Clinical Trials of Ximelagatran

OBJECTIVE

In clinical trials, the efficacy and safety of the oral direct thrombin inhibitor ximelagatran have been evaluated in the prevention or treatment of thromboembolic conditions known to have high morbidity and mortality. In these studies, raised aminotransferase levels were observed during long-term use (>35 days). The aim of this analysis is to review the data regarding these hepatic findings in the long-term trials of ximelagatran.

PATIENTS AND METHODS

The prospective analysis included 6948 patients randomised to ximelagatran and 6230 patients randomised to comparator (warfarin, low-molecular weight heparin followed by warfarin or placebo). Of these, 6931 patients received ximelagatran for a mean of 357 days and 6216 patients received comparator for a mean of 389 days. An algorithm was developed for frequent testing of hepatic enzyme levels. A panel of four hepatologists analysed all cases of potential concern with regard to causal relation to ximelagatran treatment using an established evaluation tool (Roussel Uclaf Causality Assessment Method [RUCAM]).

RESULTS

An elevated alanine aminotransferase (ALT) level of >3 x the upper limit of normal (ULN) was found in 7.9% of patients in the ximelagatran group versus 1.2% in the comparator group. The increase in ALT level occurred 1-6 months after initiation of therapy and data were available to confirm recovery of the ALT level to <2 x ULN in 96% of patients, whether they continued to receive ximelagatran or not. There was some variability in the incidence of ALT level elevation between indications, those with simultaneous acute illnesses (acute myocardial infarction or venous thromboembolism) having higher incidences. Combined elevations of ALT level of >3 x ULN and total bilirubin level of >2 x ULN (within 1 month of the ALT elevation), regardless of aetiology, were infrequent, occurring in 37 patients (0.5%) treated with ximelagatran, of whom one sustained a severe hepatic illness that appeared to be resolving when the patient died from a gastrointestinal haemorrhage. No death was observed directly related to hepatic failure caused by ximelagatran.

CONCLUSION

Treatment with ximelagatran has been associated with mainly asymptomatic elevation of ALT levels in a mean of 7.9% of patients in the long-term clinical trial programme and nearly all of the cases occurred within the first 6 months of therapy. Rare symptomatic cases have been observed. An algorithm has been developed for testing ALT to ensure appropriate management of patients with elevated ALT levels. Regular ALT testing should allow the clinical benefits of ximelagatran to reach the widest population of patients while minimising the risk of hepatic adverse effects.