AGA technical review on the evaluation of liver chemistry tests

Acute hepatic injury associated with varenicline in a patient with underlying liver disease

OBJECTIVE

To report a case of acute hepatic injury associated with varenicline.

CASE SUMMARY

A 53-year-old white male with underlying alcoholic liver disease and history of hepatitis C virus infection experienced elevated aminotransferase and alkaline phosphatase levels consistent with acute hepatic injury after initiation of varenicline for smoking cessation. The hepatic injury manifested 4 weeks after initiation of varenicline therapy at 0.5 mg once daily for 3 days, 0.5 mg twice daily for 4 days, and then 1 mg twice daily. Following discontinuation of varenicline, the patient's aminotransferase levels continued to rise for 2 days before steadily decreasing and returning to baseline levels in approximately 4 months. Alkaline phosphatase continued to rise for 8 days after discontinuation of varenicline before returning to baseline within 1 month. Rechallenge was not attempted.

DISCUSSION

Varenicline is a novel, first-line agent for smoking cessation. The presentation of this patient is most consistent with an acute hepatic injury related to drug toxicity. The pattern of the patient's elevated hepatic enzyme levels is not consistent with his underlying alcoholic liver disease or hepatitis C. Using the Naranjo probability scale, as well as the Counsel for International Organizations of Medical Science/Roussel Uclaf Causality Assessment Method algorithm for drug-induced liver toxicity, we determined that varenicline was the probable cause of the acute hepatic injury. Varenicline was a possible cause of the acute hepatic injury using the algorithm for drug-induced liver toxicity developed by Maria and Victorino. To our knowledge, this is the first report of acute hepatic injury associated with varenicline.

CONCLUSIONS

While the benefits of smoking cessation are likely greater than the risk of hepatic injury, clinicians should be cognizant of this reaction associated with varenicline.

Hyperamylasaemia and/or hyperlipasaemia: incidence and underlying causes in hospitalized patients with non-pancreatic diseases

OBJECTIVE

There are no recommendations on how to proceed in patients with increased pancreatic enzyme activities but non-pancreatic diseases. The objective of this study was to investigate prospectively in a general medical hospital the incidence, causes and clinical impact of hyperamylasaemia and/or hyperlipasaemia in these patients.

MATERIAL AND METHODS

During a 4-month period in 2004, amylase and lipase activities were measured in all patients (n, 1765) admitted to the Department of Internal Medicine of the Municipal Clinic of Lüneburg, Germany. Patients with increased enzyme activities underwent abdominal ultrasonography and, if inconclusive, other imaging procedures.

RESULTS

Amylase and/or lipase activities were increased in 140 (8%) patients with non-pancreatic diseases: amylase in 29 cases (21%) and 1 case (1%)<3 and>3 times the upper limit of normal, respectively, lipase in 120 cases (86%) and 6 cases (4%)<3 and>3 times, respectively. In 53 (38%) patients no further imaging studies could be performed. In the remaining 87 patients amylase was increased in 18 patients (21%) and lipase in 3 patients (3%). The pancreas was normal on imaging procedures in 77 (89%) patients and abnormal in 10 (11%) (chronic pancreatitis: 4, small cystic lesions: 6). The cystic lesions were mostly located in the pancreas head, probably corresponding to branch-duct intraductal papillary mucinous neoplasm.

CONCLUSIONS

Increased pancreatic enzyme activities occur in 8% of hospitalized patients with non-pancreatic diseases, but pancreatic abnormalities will be found in only a few (11%), which are unlikely to need further investigation or therapy. Therefore, routine analysis of amylase or lipase activities in patients with non-pancreatic diseases is not indicated.

Pharmacokinetics of acetaminophen-protein adducts in adults with acetaminophen overdose and acute liver failure

Acetaminophen (APAP)-induced liver toxicity occurs with formation of APAP-protein adducts. These adducts are formed by hepatic metabolism of APAP to N-acetyl-p-benzoquinone imine, which covalently binds to hepatic proteins as 3-(cystein-S-yl)-APAP adducts. Adducts are released into blood during hepatocyte lysis. We previously showed that adducts could be quantified by high-performance liquid chromatography with electrochemical detection following proteolytic hydrolysis, and that the concentration of adducts in serum of overdose patients correlated with toxicity. The following study examined the pharmacokinetic profile and clinical associations of adducts in 53 adults with acute APAP overdose resulting in acute liver failure. A population pharmacokinetic analysis using nonlinear mixed effects (statistical regression type) models was conducted; individual empiric Bayesian estimates were determined for the elimination rate constant and elimination half-life. Correlations between clinical and laboratory data were examined relative to adduct concentrations using nonparametric statistical approaches. Peak concentrations of APAP-protein adducts correlated with peak aminotransferase concentrations (r = 0.779) in adults with APAP-related acute liver failure. Adducts did not correlate with bilirubin, creatinine, and APAP concentration at admission, international normalized ratio for prothrombin time, or reported APAP dose. After N-acetylcysteine therapy, adducts exhibited first-order disappearance. The mean elimination rate constant and elimination half-life were 0.42 +/- 0.09 days(-1) and 1.72 +/- 0.34 days, respectively, and estimates from the population model were in strong agreement with these data. Adducts were detected in some patient samples 12 days post-ingestion. The persistence and specificity of APAP-protein adducts as correlates of toxicity support their use as specific biomarkers of APAP toxicity in patients with acute liver injury.

Addison's disease and hypertransaminasemia

Endocrine diseases, such as diabetes mellitus and thyroid dysfunction, have been rarely associated with increased serum transaminase activity. The association of Addison's disease with abnormal liver function tests has received less attention. Addison's disease as a part of autoimmune polyglandular syndrome-1 may be associated with autoimmune hepatitis. Addison's disease may also coexist with celiac disease, an autoimmune disorder commonly associated with hypertransaminasemia. On the other hand, a number of case reports have suggested hypertransaminasemia to be one of the few diagnostic clues to the underlying adrenal insufficiency, allowing the introduction of steroid replacement and obviation of a potential adrenal crisis. We performed a thorough literature review on the prevalence and pathogenesis of hypertransaminasemia as a feature of Addison's disease in an attempt to highlight an as yet under-recognized association.

The asymptomatic outpatient with abnormal liver function tests

Traditionally, the constellation of biochemistry tests including liver enzymes, total bilirubin, and hepatic synthetic measures (prothrombin time (PT) and serum albumin level) are referred to as liver function tests (LFTs). Abnormal LFTs can be encountered during primary health care visits, routine blood donation, and insurance screening. A reported 1% to 4% of asymptomatic patients exhibit abnormal LFTs, leading to a sizeable number of annual consultations to a gastroenterology and/or hepatology practice. A cost-effective and systematic approach is essential to the interpretation of abnormal LFTs. A review of pattern of abnormal LFTs, detailed medical history, and a comprehensive physical examination help establish a foundation for further individualized testing. Further investigation often involves biochemical testing for disease-specific markers, radiographic imaging, and even consideration of a liver biopsy. In the following account, markers of hepatic injury are reviewed followed by a discussion on an approach to various patterns of abnormal LFTs in an asymptomatic patient.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery medical guidelines for clinical practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist health-care professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Increased hepatic expression is a major determinant of serum alanine aminotransferase elevation in mice with nonalcoholic steatohepatitis

BACKGROUND

Serum alanine aminotransferase (ALT) is a biomarker for hepatitis of various aetiologies including fatty liver disease. Increased serum ALT is thought to be related to its increased release from dying hepatocytes.

AIM

We sought to understand the mechanisms by which serum ALT is elevated in a mouse model of experimental fatty liver disease where hepatocyte death is minimal.

METHODS

To induce fatty liver disease, female A/J mice were fed a methionine-choline deficient (MCD) diet for up to 12 weeks. Serum and liver ALT expression and hepatic inflammation, necrosis and apoptosis were assessed and expressed relative to their expressions in control-diet-fed mice.

RESULTS

Feeding mice the MCD diet produced hepatic steatosis with minimal hepatic inflammation or necrosis. Liver cell apoptosis was not significantly increased by MCD diet treatment. Conversely, serum ALT activity was approximately four-fold increased at 12 weeks of diet treatment, and ALT protein expressions in serum were correspondingly increased: ALT1 1.7-fold and ALT2 1.9-fold at 12 weeks. The expressions of ALT1 and ALT2 protein in liver increased over 2-12 weeks of MCD treatment. At 12 weeks, liver ALT1 protein was 2.27+/-0.31-fold increased and ALT2 protein 4.72+/-0.48-fold increased relative to their expressions in the mice fed a diet replete with methionine and choline. Liver ALT mRNA expressions were correspondingly increased: ALT1 mRNA 2.58-fold and ALT2 mRNA 4.97-fold at 12 weeks. Linear regression analysis showed a strong correlation between serum and liver tissue expressions for both ALT1 and ALT2.

CONCLUSIONS

These findings suggest that induction of hepatic expression significantly contributes to increased serum ALT in this model of experimental fatty liver disease, whereas cell death appears not to.

Serum aminotransferase level and the risk of hepatocellular carcinoma: a population-based cohort study in Japan

Aminotransferase level is presumed to be a marker of hepatic inflammation, but uncertainty remains whether elevated aminotransferase levels are associated with an increased risk of hepatocellular carcinoma (HCC). We evaluated the incidence of HCC by aminotransferase level in 19 812 middle-aged and older individuals with and without hepatitis virus infection from a large-scale population-based cohort study (JPHC Study cohort II) in Japan. Hepatitis virus infection was identified at baseline in 1236 participants, namely 737 (3.7%) with hepatitis C virus, 479 (2.4%) with hepatitis B virus, and 20 (0.1%) with both. By the end of follow-up, a total of 109 newly arising HCC cases were diagnosed (71 men, 38 women), of which 87 (79.8%) had evidence of viral etiology. Alanine aminotransferase (ALT) was concentration-dependently associated with an increased risk of HCC in both virus-positive and virus-negative participants. Compared with virus-negative participants with ALT levels of less than 30 IU/l, a significant increase in the risk of HCC was observed in virus-negative participants with an ALT level greater than 30 IU/l, and in virus-positive participants with an ALT less than 30 IU/l, 30-69 IU/l, and > or =70 IU/l [Hazard ratio (95% confidence interval): 9.4 (3.9-22.3), 15.2 (6.1-37.6), 180.5 (89.4-364.2), 454.2 (221.5-931.2), respectively; P for trend <0.001]. In conclusion, our findings suggest that elevated ALT levels are strongly associated with the incidence of HCC regardless of hepatitis virus positivity. This finding indicates that ALT level is a good independent determinant of the need for intervention. Clinical application of these findings may help decrease HCC-associated mortality in hepatitis virus-endemic regions.

Aminotransferase levels and 20-year risk of metabolic syndrome, diabetes, and cardiovascular disease

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of obesity and metabolic syndrome (MetS). Alanine aminotransferase (ALT) levels are used to detect NAFLD and have also been associated with increased risk for MetS, diabetes mellitus, and cardiovascular disease (CVD). We studied the relationship between ALT levels and these disorders in a long-term follow-up study.

METHODS

Framingham Offspring Heart Study participants (n = 2812; mean age, 44 years; 56% women) were followed for the development of MetS, diabetes, CVD, and all-cause mortality using logistic regression (MetS, diabetes) or Cox proportional hazards models (CVD, all-cause mortality).

RESULTS

Among individuals at baseline, per 1 standard deviation increase in log ALT level, there were increased odds of the development of MetS (odds ratio [OR] 1.21, P < .001) and diabetes (OR, 1.48; P < .0001) over 20 years of follow-up. These findings also applied to participants with ALT levels within the normal range (MetS OR, 1.17; P = .006; diabetes OR, 1.34; P =.002). There was an increased risk of CVD in age/gender-adjusted models (hazard ratio, 1.23; P < .0001), but this was attenuated in multivariable-adjusted models (hazard ratio 1.05; P = .27); no association was observed for all-cause mortality. Aspartate aminotransferase levels were found to be associated with an increased risk of only diabetes.

CONCLUSIONS

Both normal and increased levels of ALT are associated with long-term development of multiple metabolic disorders. These results indicate the potential for ALT values as biomarkers for the risk of metabolic disease.

Anti-HCV reactive blood donors: clinical and epidemiological factors associated with false-reactive results

BACKGROUND

In certain clinical settings, false-reactive anti-hepatitis C virus (HCV) results are rare because the majority of persons being tested have evidence of liver disease and the specificity of the screening assays is high. However, among healthy populations, such as blood donors, mainly in regions with a low prevalence of HCV infection, this situation does occur. In this study, we sought to assess clinical, epidemiological, and laboratory characteristics of blood donors with false-reactive anti-HCV screening tests.

METHODS

This retrospective cross-sectional study included 537 anti-HCV reactive blood donors referred to a tertiary care centre for liver diseases.

RESULTS

The mean age was 36.5+/-11.2 years and 71.8% were men. Blood donors of older age (P=0.010), history of alcohol abuse (P=0.039), past transfusion (P<0.001), intravenous drug use (P<0.001), and with antibody against core antigen of hepatitis B virus reactivity (P=0.003) were less likely to have a false-reactive anti-HCV result. By multivariate analysis, only the absence of parenteral risk factors (prior transfusion and intravenous drug use) was independently associated with false-reactive anti-HCV tests.

CONCLUSION

Blood donors with reactive anti-HCV screening tests with no risk factors for parenterally acquired HCV infection are more likely to present with false-reactive results.

Acetaminophen-associated hepatic injury: evaluation of acetaminophen protein adducts in children and adolescents with acetaminophen overdose

Acetaminophen protein adducts (APAP adducts) were quantified in 157 adolescents and children presenting at eight pediatric hospitals with the chief complaint of APAP overdose. Two of the patients required liver transplantation, whereas all the others recovered spontaneously. Peak APAP adducts correlated with peak hepatic transaminase values, time-to-treatment with N-acetylcysteine (NAC), and risk determination per the Rumack-Matthews nomogram. A population pharmacokinetic analysis (NONMEM) was performed with post hoc empiric Bayesian estimates determined for the elimination rate constants (k(e)), elimination half-lives (t(1/2)), and maximum concentration of adducts (C(max)) of the subjects. The mean (+/-SD)k(e) and half-life were 0.486 +/- 0.084 days(-1) and 1.47+/- 0.30 days, respectively, and the C(max) was 1.2 (+/-2.92) nmol/ml serum. The model-derived, predicted adduct value at 48 h (Adduct 48) correlated with adductC(max), adduct T(max), Rumack-Matthews risk determination, peak aspartate aminotransferase (AST), and peak alanine aminotransferase (ALT). The pharmacokinetics and clinical correlates of APAP adducts in pediatric and adolescent patients with APAP overdose support the need for a further examination of the role of APAP adducts as clinically relevant and specific biomarkers of APAP toxicity.

Secondary sclerosing cholangitis after intensive care unit treatment: clues to the histopathological differential diagnosis

Secondary sclerosing cholangitis (SSC) is a chronic cholestatic disorder caused by mechanical, infectious, toxic, or ischemic factors. A new variant of SSC occurring after long-term treatment in intensive care units (ICU) has been recently described and characterized from the clinical point of view. The aim of this study was the histomorphological characterization of ICU-treatment-related SSC (ICU-SSC) and the definition of histological changes occurring over time based on the morphological findings. Liver biopsies of ten patients affected by ICU-SSC obtained at different time points (1.5 to 57 months) after the initial injury were analyzed. The main morphological alterations included degenerative changes of portal bile ducts, portal edema, inflammation, and fibrosis as well as biliary interface activity and bilirubinostasis. Perivenular necroses and bile infarcts were found in eight and six patients, respectively. Bile duct loss was not observed. No correlation between morphological features of biopsies and liver chemistry tests or outcome could be established. Based on the morphological observation, a possible disease-progression model starting with an initial damage of portal bile ducts (primary insult) with associated portal/periportal changes (inflammation, ductular reaction) and resulting in secondary parenchymal changes is proposed.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist healthcare professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Consensus recommendations for managing asymptomatic persistent non-virus non-alcohol related elevation of aminotransferase levels: suggestions for diagnostic procedures and monitoring

A persistent increase in non-virus non-alcohol related aminotransferase levels can have multiple causes, which differ in terms of prevalence and clinical importance. In the general population, the most frequent cause is non-alcoholic hepatic steatosis, which can evolve into steato-hepatitis and cirrhosis. The treatment for steatosis and non-alcoholic steato-hepatitis consists of modifying lifestyles, whereas the effectiveness of drug treatment remains to be determined. Other much less frequent (yet not rare) causes of persistent non-virus non-alcohol related elevations in aminotransferase levels are celiac disease and hemochromatosis, whereas autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, and alpha-1-anti-trypsin deficit are rare. Given that some of these conditions are susceptible to treatment, early diagnosis is important. No epidemiological data are available for evaluating the prevalence of elevated aminotransferase levels correlated with the toxicity of drugs or other xenobiotics, including herbal products. The present document, created by a panel of experts based on a systematic review of scientific evidence, is mainly geared towards physicians working in General Medicine and Transfusion Centres, who generally represent the first contact of persons with elevated aminotransferase levels. The document includes suggestions for diagnosing causes of persistent non-virus non-alcohol related increases in aminotransferase levels, considering the frequency and response to treatment. The conditions requiring specialized visits are also indicated.

Rate of bilirubin regression after stenting in malignant biliary obstruction for the initiation of chemotherapy: how soon should we repeat endoscopic retrograde cholangiopancreatography?

BACKGROUND

This study was conducted to evaluate the rate of regression of bilirubin after stent placement for malignant biliary obstruction.

METHODS

Records were reviewed from October 2002 to September 2005 for patients who underwent endoscopic retrograde cholangiopancreatography with stent placement. The time to achieve a bilirubin level <or=2 mg/dL was the primary endpoint because this is the level required by most chemotherapy protocols. Patient variables included type of cancer, liver metastasis, recent chemotherapy, baseline creatinine, and international normalized ratio (INR). Stent variables included type, dimension, stricture location, and sphincterotomy.

RESULTS

In total, 156 patients were included in the analysis: Ninety-three patients achieved a poststent bilirubin level <or=2 mg/dL, 29 patients failed because of stent failure, and 34 patients failed because of inadequate follow-up. The time required for 80% of patients to achieve normalization was more than doubled in those who had prestent bilirubin levels >or=10 mg/dL (6 weeks) compared with those who had prestent bilirubin levels <10 mg/dL (3 weeks). The following variables were identified as statistically significant: prestent bilirubin level, stricture location, liver metastasis, and INR. The cancer type, recent chemotherapy, stent type and diameter, and sphincterotomy were not statistically significant variables.

CONCLUSIONS

The rate of bilirubin normalization after biliary stenting was highly dependent on the prestent bilirubin level. Endoscopic intervention should be considered in patients who fail to achieve adequate normalization of serum bilirubin in 6 weeks if prestent bilirubin level was >or=10 mg/dL and in 3 weeks if their prestent bilirubin level was <10 mg/dL. Independent variables, such as diffuse liver metastases, stricture outside the common bile duct, and elevated INR had predictive value for bilirubin normalization.

[Acute intermittent porphyria and chronic transaminase elevation]

Acute intermittent porphyria is an autosomal dominant inherited disorder resulting from a deficiency of porphobilinogen deaminase activity, the third enzyme in the heme biosynthesis pathway. This disease is uncommon, although the prevalence is higher in asymptomatic heterozygotic carriers; however, this prevalence is difficult to establish because of the absence of symptoms. Although acute intermittent porphyria is a multisystemic disease, its most common form of presentation is abdominal pain and neurological or mental symptoms, which can sometimes be due to precipitating factors such as reduced energy intake, smoking, alcohol, some drugs, and stress. Diagnosis can be made by testing urinary porphobilinogen levels, with subsequent measurement of enzyme activity and DNA testing. Treatment is based on prevention of porphyria attacks by avoiding precipitating factors and early administration of intravenous glucose or hemin therapy. We present the case of a patient diagnosed with acute intermittent porphyria based on study of chronic mild alanine aminotransferase (ALT) elevation.

Serum aminotransferase activity and mortality risk in a United States community

Serum aminotransferase [such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT)] is commonly used as an indicator of liver disease. The aim of the study was to determine the degree to which aminotransferase results are associated with increased mortality at the population level. All adult residents of Olmsted County, Minnesota, who had a health care encounter at Mayo Clinic, Rochester, in 1995 were identified and their AST or ALT results extracted from a laboratory database. These subjects were followed forward from January 1995 to April 2006 and their survival determined. To exclude patients with abnormal results because of a terminal illness, deaths within the first 2 years were excluded. The main outcome measure was survival. Standardized mortality ratios (SMRs) were calculated, based on Minnesota White death rates. During 1995, AST was measured at least once in 18,401 community residents, of whom 2,350 (13%) had results greater than the upper limit of normal (ULN). Of 6,823 subjects who had their ALT measured, 911 (13%) had results higher than ULN. Abnormal AST was associated with a significantly increased SMR (1.32 for 1-2x ULN and 1.78 for >2x ULN). SMR was also higher for abnormal ALT (SMR = 1.21 for 1-2x ULN and 1.51 for >2x ULN). In contrast, normal AST or ALT was associated with a risk of death lower than expected (SMR 0.95 for AST, 0.61 for ALT).

CONCLUSION

Serum levels of AST and ALT obtained in a routine medical care setting are associated with future mortality in community residents.

Hepatic stress in hereditary tyrosinemia type 1 (HT1) activates the AKT survival pathway in the fah-/- knockout mice model

BACKGROUND/AIMS

The AKT survival pathway is involved in a wide variety of human cancers. We investigated the implication of this pathway in hereditary tyrosinemia type 1 (HT1), a metabolic disease exhibiting hepatocellular carcinoma (HCC), despite treatment with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexadione (NTBC) which prevents liver damage. HT1 is an autosomal recessive disorder caused by accumulation of toxic metabolites due to a deficiency in fumarylacetoacetate hydrolase (FAH), the last enzyme in the catabolism of tyrosine.

METHODS

NTBC withdrawal in the murine fah(-/-) knockout model was used to analyze in vivo the correlation between pathophysiological, biochemical and histological features consistent with hepatocarcinogenesis and activation of the AKT survival pathway.

RESULTS

The HT1 stress initiated by NTBC discontinuation causes a progressive increase of liver and kidney pathophysiology. A stable activation of the AKT survival pathway is observed in the liver but not in kidneys of fah(-/-) mice. Hepatic survival is reinforced by inhibition of mitochondrial-mediated apoptosis through inactivation of Bad and induction of BCl-X(L) and BCl-2.

CONCLUSIONS

The chronic stress induced by liver disease in HT1 activates the AKT survival signal and inhibits intrinsic apoptosis to confer cell death resistance in vivo and favor hepatocarcinogenesis.

The significance of isolated elevation of serum aminotransferases in infants and young children

INTRODUCTION

The aim of this study was to assess the clinical significance and prognosis of a prolonged isolated elevation of serum aminotransferases without cholestasis (>3 months) in infants and young children, investigated for a variety of conditions, and to determine a protocol for their follow-up and investigation.

METHODS

A combined prospective-retrospective analysis of apparently healthy babies and young children with isolated elevation of serum aminotransferases of at least 1.5 times above the norm for age which persisted for at least 3 months and whose creatine phosphokinase (CK), gamma glutamyltransferase (GGT), alkaline phosphatase and bilirubin levels remained normal throughout the study duration. The children underwent the following investigations: abdominal ultrasound and infectious, metabolic and/or immunological investigation depending on the duration of the abnormality.

RESULTS

Six children were eliminated following the finding of positive cytomegalovirus (CMV) antigen in the urine. 72 children were investigated (47 males and 25 females). The duration of serum aminotransferases elevation was 3-36 months (average 12.4, median 11.5 months). The initial, maximal and final alanine aminotransferase (ALT) values were 85.5, 140.5 and 39.8 IU/l, respectively. Of seven children who had liver biopsies performed, three (42.8%) were suspected of having a glycogen storage disease which was not confirmed enzymatically. Four biopsies revealed non-specific histological changes.

CONCLUSIONS

Isolated elevation of serum aminotransferases in healthy looking young children is mostly a benign condition that usually resolves within a year. If no pathology is found during routine investigation, these children can be followed conservatively. Liver biopsy does not contribute much to the diagnosis and is probably unnecessary.

The liver in celiac disease

Celiac disease is a common (1% prevalence) chronic immune-mediated disorder of the small intestine induced by dietary wheat, barley, and rye. Several hepatic disorders have been described in association with celiac disease. Isolated hypertransaminasemia with nonspecific histologic changes in a liver biopsy is the commonest hepatic presentation of celiac disease. A gluten-free diet normalizes liver enzymes and histologic changes in most patients. Moreover, celiac disease can coexist with autoimmune liver disorders such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis. Celiac disease has increasingly been reported with a variety of other liver diseases. Thus, the hepatologist needs to consider celiac disease in the differential of abnormal liver blood tests and to be aware of the clinical implications of this frequent disease in patients with liver disorders. The possible mechanisms of liver injury and those common factors that explain the association of celiac disease with liver disorders are discussed. The aims of this article are (1) to review the spectrum and pathogenesis of liver injury related to celiac disease and (2) to provide direction to those caring for patients with chronic liver diseases regarding the detection and effective treatment of celiac disease.

Evaluating patients with mildly elevated transaminase levels

CASE STUDY

S.B. is a 52-year-old woman with recurrent stage IV ovarian cancer. She initially presented three and a half years ago with complaints of abdominal pain, increased abdominal girth, and abdominal bloating. A CA-125 blood test was elevated, and a computed tomography scan of the abdomen and pelvis revealed bilateral ovarian masses highly suspicious for malignancy. She was taken to surgery for a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and suboptimal tumor reduction. Pathology revealed poorly differentiated papillary serous ovarian cancer. Metastatic disease was noted in the rectosigmoid area and vaginal apex. Postoperatively, she received six cycles of paclitaxel and carboplatin. At completion, her CA-125 normalized and imaging studies showed no evidence of disease. However, within three months, her CA-125 was elevated and a palpable mass at the vaginal apex was proven by biopsy to be recurrent disease.

Liver function tests and their interpretation

Liver function tests (LFT) are a helpful screening tool, which are an effective modality to detect hepatic dysfunction. Since the liver performs a variety of functions so no single test is sufficient to provide complete estimate of function of liver. Often clinicians are faced with reports that do not tally with the clinical condition of the patient and they face difficulty in interpreting the LFT. An attempt is being made to study and understand the LFT and simplify their interpretation with algorithms.

Monitoring liver safety in drug development: the GSK experience

To promptly identify and evaluate liver safety events, an evidence-based liver safety system was created for global Phase I-III clinical trials. The goals of this system included improving clinical trial subject safety, expanding information on liver safety events, and improving data quality across studies by establishing and communicating: Two different algorithms for liver stopping criteria were developed. The most stringent criteria were selected for healthy volunteers in Phase I studies, where no treatment benefit is anticipated and clinical safety data are limited. With an interest in assessing potential liver "tolerance" or adaptation with accruing safety information, slightly higher liver chemistry thresholds were set for Phase II-III studies. This paper will describe the importance of liver safety in drug development, laboratory tests used to monitor liver safety, the rationale for selected liver chemistry subject stopping criteria, and implementation of this safety system.

NAFLD and hyperinsulinemia are major determinants of serum ferritin levels

BACKGROUND/AIMS

There is an increasing body of evidence that serum ferritin is associated with the metabolic syndrome. However, no study has tested for NAFLD. The aim was to test the assumption that the association between serum ferritin and the metabolic syndrome is mediated by NAFLD.

METHODS

A cross-sectional study of a sub-sample of the first Israeli national health survey. Exclusion criteria were any known etiology for secondary NAFLD. Participants underwent an abdominal ultrasound (US), biochemical tests, and dietary and anthropometric evaluations.

RESULTS

Three hundred and forty-nine subjects were included in the analysis. Serum ferritin was higher in the NAFLD group (92.4+/-63.1 vs. 65.1+/-58.0, P<0.001). After adjusting for age and gender, the following variables were significantly associated with increased ferritin levels: abdominal obesity, hyperglycemia, hyperinsulinemia, HOMA, hypertriglyceridemia and the metabolic syndrome itself. After further adjusting for NAFLD, only abdominal obesity [2.1 (1.1-3.9)] and hyperinsulinemia [2.3 (1.3-4.2)] were still significantly associated with ferritin. In a multivariate analysis the interaction between NAFLD and hyperinsulinemia was the second strongest predictor of serum ferritin (P=0.005).

CONCLUSIONS

The association between serum ferritin and the metabolic syndrome is mediated by undiagnosed NAFLD. The interaction between NAFLD and hyperinsulinemia is a major determinant of serum ferritin levels at the population level.

Gamma glutamyltransferase and long-term survival: is it just the liver?

BACKGROUND

Increased gamma glutamyltransferase (GGT) is associated with cardiovascular disease. To date, however, few studies with sufficient sample size and follow-up have investigated the association of GGT with all-cause mortality.

METHODS

The relation of GGT to the risk of death was examined in a cohort of 283 438 first attendants (inpatients or outpatients) of the Vienna General Hospital with request for GGT analysis as part of a routine screening panel and was monitored for up to 13 years. To evaluate GGT as a predictor, Cox proportional hazards models were calculated, which were adjusted for age and sex.

RESULTS

In both men and women, GGT above the reference category (GGT > or = 9 U/L in women, > or = 14 U/L in men) was significantly (P <0.001) associated with all-cause, cancer, hepatobiliary, and vascular mortalities. Hazard ratios (HRs) for men and women were similar in all categories. Among patients who presented with GGT above the reference category, those younger than 30 years had higher all-cause mortality rates than did older individuals (HR 1.5-3.3 vs HR 1-1.3 >80 years, respectively).

CONCLUSIONS

GGT is associated with mortality in both men and women, especially in patients younger than 30 years, and even high-normal GGT is a risk factor for all-cause mortality.

Best practice in primary care pathology: review 5

This fifth best practice review examines three series of common primary care questions in laboratory medicine: (1) minor liver function test abnormalities; (2) laboratory monitoring of patients receiving lithium; and (3) investigation of possible venous thromboembolism. The review is presented in question-answer format, referenced for each question series. The recommendations represent a precis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus-based rather than evidence-based. They will be updated periodically to take account of new information.

A patient with abdominal pain and markedly elevated transaminase levels after cholecystectomy

BACKGROUND

A 33-year-old white female with a history of cholecystectomy presented to the emergency department with intermittent severe abdominal pain radiating from the left upper quadrant to the right upper quadrant, associated with nausea and emesis. Three weeks previously the patient had presented to the emergency department with similar pain in the abdomen. Laboratory investigations had revealed elevated bilirubin, transaminase, and alkaline phosphatase levels. At that time, pain and liver chemistry test results improved and the patient was discharged on hospital day 3. She denied a history of alcohol use, new medications, or the ingestion of other toxins.

INVESTIGATIONS

History and physical examination, liver chemistry tests, viral hepatitis serology tests, autoimmune serology tests, abdominal ultrasound, liver biopsy, and an endoscopic retrograde cholangiopancreatogram.

DIAGNOSIS

Choledocholithiasis.

MANAGEMENT

Endoscopic retrograde cholangiopancreatogram with sphincterotomy, removal of an 8 mm distal common bile duct stone, and pancreatic stent placement.

An official ATS statement: hepatotoxicity of antituberculosis therapy

Drug-induced liver injury (DILI) is a problem of increasing significance, but has been a long-standing concern in the treatment of tuberculosis (TB) infection. The liver has a central role in drug metabolism and detoxification, and is consequently vulnerable to injury. The pathogenesis and types of DILI are presented, ranging from hepatic adaptation to hepatocellular injury. Knowledge of the metabolism of anti-TB medications and of the mechanisms of TB DILI is incomplete. Understanding of TB DILI has been hampered by differences in study populations, definitions of hepatotoxicity, and monitoring and reporting practices. Available data regarding the incidence and severity of TB DILI overall, in selected demographic groups, and in those coinfected with HIV or hepatitis B or C virus are presented. Systematic steps for prevention and management of TB DILI are recommended. These include patient and regimen selection to optimize benefits over risks, effective staff and patient education, ready access to care for patients, good communication among providers, and judicious use of clinical and biochemical monitoring. During treatment of latent TB infection (LTBI) alanine aminotransferase (ALT) monitoring is recommended for those who chronically consume alcohol, take concomitant hepatotoxic drugs, have viral hepatitis or other preexisting liver disease or abnormal baseline ALT, have experienced prior isoniazid hepatitis, are pregnant or are within 3 months postpartum. During treatment of TB disease, in addition to these individuals, patients with HIV infection should have ALT monitoring. Some experts recommend biochemical monitoring for those older than 35 years. Treatment should be interrupted and, generally, a modified or alternative regimen used for those with ALT elevation more than three times the upper limit of normal (ULN) in the presence of hepatitis symptoms and/or jaundice, or five times the ULN in the absence of symptoms. Priorities for future studies to develop safer treatments for LTBI and for TB disease are presented.

Biochemical "liver function tests"

This article considers two common scenarios of “abnormal” liver test results that may be seen in primary care. It looks at the pitfalls in liver testing and summarises guidance, including further investigations that may or may not be warranted

Alteraciones hepáticas en la enfermedad celíaca del adulto. Caracterización clínico-patológica y evolución

BACKGROUND AND AIM

The clinical manifestations of adult celiac disease are highly varied and may include liver disease. The present study aimed to characterize liver abnormalities and outcome after a gluten-free diet in patients with celiac disease diagnosed in a hepatology clinic.

MATERIAL AND METHOD

The clinical records of patients diagnosed with celiac disease during a 7-year period were reviewed.

RESULTS

Of 1916 patients attending a first consultation at the clinic, 10 were finally diagnosed with celiac disease. All patients had been referred for evaluation of persistent elevation of liver enzyme levels. All patients were young (mean age 30 years, range 21-39 years) and there were more women than men (eight women, 80%). Six patients (60%) had additional manifestations attributable to undiagnosed celiac disease, sometimes since childhood. In all patients, elevation of liver enzyme levels was moderate and overall liver function was preserved. Liver biopsy was performed in five patients and all showed chronic periportal infiltrate. Immunohistochemical studies revealed that the infiltrate was mainly composed of CD8-positive T lymphocytes. In all patients, a gluten-free diet was followed by normalization of liver enzyme levels.

CONCLUSIONS

Although celiac disease is not highly frequent, it should be considered in the differential diagnosis of patients with persistent abnormalities of liver markers. The most conspicuous histopathological change is periportal T-cell infiltrate. Liver abnormalities in celiac disease are generally mild and improve after a gluten-free diet.

Breath biomarkers and non-alcoholic fatty liver disease: preliminary observations

Breath biomarkers have the potential to offer information that is similar to conventional clinical tests or they are entirely unique. Preliminary data support the use of breath biomarkers in the study of liver disease, in particular non-alcoholic fatty liver disease (NAFLD). It was evaluated whether breath ethanol, ethane, sulfur compounds and acetone would be associated with hepatic histopathology amongst morbidly obese patients presenting for bariatric surgery. Breath samples were collected during a preoperative visit and compared with liver biopsies obtained during the surgery. A Student's two-tailed t-test was used to compare differences between the two groups. Linear regression was used to analyse associations between the concentrations of breath molecules and independent predictor variables. It was found that breath ethanol, ethane and acetone can be useful biomarkers in patients with NAFLD. In particular, breath ethanol can be associated with hepatic steatosis, and breath acetone can be associated with non-alcoholic steatohepatitis.

Prediction of liver fibrosis in human immunodeficiency virus/hepatitis C virus coinfected patients by simple non-invasive indexes

BACKGROUND

Liver biopsy is an invasive technique with associated major complications. There is no information on the validity of five non-invasive indexes based on routinely available parameters, estimated and validated in hepatitis C virus (HCV) monoinfected patients, in human immunodeficiency virus (HIV)/HCV coinfected patients.

AIM

To validate these predictive models of liver fibrosis in HIV/HCV coinfected patients.

PATIENTS

A total of 357 (90%) of 398 patients from five hospitals were investigated, who underwent liver biopsy and who had complete data to validate all of the models considered.

METHODS

The predictive accuracy of the indexes was tested by measuring areas under the receiver operating characteristic curves. Diagnostic accuracy was calculated by estimating sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values.

RESULTS

The models performed better when liver biopsies>or=15 mm were used as reference. In this setting, the Forns and Wai indexes, models aimed at discriminating significant fibrosis, showed PPV of 94% and 87%, respectively. Using these models, 27-34% of patients could benefit from exclusion of liver biopsy. If both models were applied sequentially, 41% of liver biopsies could be spared. The indexes aimed at predicting cirrhosis achieved NPV of up to 100%. However, they showed very low PPV.

CONCLUSIONS

The diagnostic accuracy of these models was lower in HIV/HCV coinfected patients than in the validation studies performed in HCV monoinfected patients. However, simple fibrosis tests may render liver biopsy unnecessary in deciding anti-HCV treatment in over one third of patients with HIV infection and chronic hepatitis C.

[Hypertransaminasemia greater than 400 U/l in adults seen at a tertiary hospital. Prospective study of etiology]

AIM

To investigate the frequency of distinct causes of elevated transaminase levels in the range of acute viral hepatitides in patients attended in a hospital.

PATIENTS AND METHOD

Patients attended in a tertiary hospital over a 3-month period who had elevation of transaminase levels (aspartate aminotransferase [AST] or alanine aminotransferase [ALT]) above 400 U/l were identified and their medical records were reviewed to determine etiology.

RESULTS

A total of 106 patients were studied, of which 22 had undergone liver transplantation. In these patients, the causes of hypertransaminasemia were ischemic/reperfusion injury in 6 (27%), ischemic hepatitis in 4 (18%), acute hepatitis in 2 (9%), cellular rejection in 3 (14%), chronic hepatitis C in 4 (18%) and cholestasis in 3 (14%). In the 84 patients who did not undergo transplantation, the causes were hepatic ischemia in 24 (28%), chronic viral hepatitis in 19 (22%), toxic hepatitis in 12 (14%), pancreatico-biliary disease in 11 (13%), acute viral or bacterial hepatitis in 10 (12%), liver tumor in 3 (4%), cholestasis of pregnancy in one and unknown in 4 (5%). Ischemic lesions and pancreatico-biliary disease were more frequent in hospitalized patients while acute and chronic hepatitides were more frequent in outpatients. The worst outcomes were found in ischemic lesions and pancreatico-biliary disease.

CONCLUSION

Marked elevation of transaminase levels has multiple causes. Acute viral hepatitides were a relatively infrequent cause. In transplant recipients, the most frequent causes were ischemia/reperfusion injury, while in non-transplanted patients the most frequent causes were ischemic hepatitides and acute episodes of chronic viral hepatitides. The AST/ALT ratio did not contribute to etiologic diagnosis.

Liver enzyme alteration: a guide for clinicians

Isolated alterations of biochemical markers of liver damage in a seemingly healthy patient can present a challenge for the clinician. In this review we provide a guide to interpreting alterations to liver enzyme levels. The functional anatomy of the liver and pathophysiology of liver enzyme alteration are briefly reviewed. Using a schematic approach that classifies enzyme alterations as predominantly hepatocellular or predominantly cholestatic, we review abnormal enzymatic activity within the 2 subgroups, the most common causes of enzyme alteration and suggested initial investigations.

Contrasting liver function test patterns in obstructive jaundice due to biliary strictures [corrected] and stones

BACKGROUND

Obstructive jaundice is believed to be characterized by abnormalities of alkaline phosphatase (ALP), rather than aspartate transaminase (AST).

AIM

To compare liver function tests (LFTs) in obstructive jaundice due to malignant strictures with those of jaundice due to gallstones.

METHODS

LFTs were measured immediately before endoscopic retrograde cholangio-pancreatography (ERCP) in 207 jaundiced patients. Group 1 (n = 69) had malignant strictures, group 2 (n = 97) had common bile duct stone(s), and group 3 (n = 41) appeared to have recently passed a stone. LFTs in groups 2 and 3 were also analysed at maximal liver enzyme derangement, maximum hyperbilirubinaemia and during acute pain episodes.

RESULTS

Group 1 had higher median bilirubin, AST and ALP levels than groups 2 or 3 (p < 0.001). In group 1, median rise in ALP exceeded that in AST (4.3 x normal upper limit (NUL) vs. 2.6 x NUL, p < 0.01), but in groups 2 and 3, AST and ALP were similarly elevated (both approximately 2 x NUL). At the time of maximum enzyme derangement in groups 2 and 3, median AST elevation (4.4 x NUL, 185 IU/l) exceeded that for ALP (2.4 x NUL, 276 U/l), (p < 0.001), and this was also true at peak hyperbilirubinaemia in these groups (AST 3.6 x NUL, ALP 2.4 x NUL, p < 0.01. Similarly, severe pain episodes in groups 2 and 3 were accompanied by greater elevations in bilirubin and AST, but not ALP, compared with levels at ERCP.

DISCUSSION

The conventional wisdom that ALP rises more than AST in obstructive jaundice holds true where the jaundice is due to strictures, but in obstructive stone disease, the rise in AST may equal that in ALP, or even exceed it during maximum jaundice and during painful episodes. Clinicians should consider the possibility of extrahepatic biliary obstruction, even when AST is the predominantly elevated enzyme.

Noninvasive diagnosis of fibrosis in chronic liver disease

Laboratory tests for the noninvasive diagnosis of liver fibrosis were studied extensively in the past. However, no test is yet accepted to replace liver biopsy as the gold standard. The establishment of widely accepted semiquantitative histologic scoring systems for the grading and staging of chronic liver disease (e.g., Ishak, Metavir and Scheuer) was paralleled by a significant upturn of research in circulating markers of liver fibrosis. We are now experiencing the renaissance of standard clinical chemistry markers, which are assembled to multiparameter scores (e.g., aspartate aminotransferase-to-platelet ratio index, FibroTest, Forns' index). These scores still require comprehensive evaluation in comparison with histology. Better understanding of the pathophysiology of liver fibrosis provided new options regarding circulating markers of hepatic matrix metabolism (e.g., hyaluronic acid, laminin, matrix metalloproteinase-2, aminoterminal propeptide of procollagen type III and tissue inhibitors of metalloproteinases-1). Several promising studies have been published to date. Thus, a redefinition of the role of liver biopsy is expected in the foreseeable future.

Leflunomide for the treatment of rheumatoid arthritis in clinical practice: incidence and severity of hepatotoxicity

OBJECTIVE

Leflunomide is a novel disease modifying antirheumatic drug (DMARD). Because of reports on possible hepatotoxicity and adaptations in the recommendations for monitoring liver function during leflunomide treatment, we conducted a study to evaluate the incidence and severity of hepatotoxicity.

METHODS

We included consecutive rheumatoid arthritis patients starting treatment with leflunomide in the region of Friesland (The Netherlands) between January 2000 and January 2002. During follow-up patient characteristics, disease characteristics, and clinical and laboratory data on liver functions were registered. Severity of hepatotoxicity was categorised using the National Cancer Institute Common Toxicity Criteria, as moderate (grade 2), severe (grade 3) or life threatening (grade 4).

RESULTS

One hundred and one patients were followed for a median period of 10 months (range 0.5-12). Grade 2 or 3 elevations in any liver function blood test were recorded in a total of nine patients (8.9%). No grade 4 elevations were recorded. Four patients (4%) showed grade 2-3 aminotransferase elevations. Due to grade 2 hepatotoxicity one patient (1%) was withdrawn from leflunomide treatment, and one patient continued leflunomide at a reduced dose. In eight of nine patients with grade 2-3 liver function blood tests, these elevated liver function tests occurred within 6 months after starting leflunomide. None of the patients with grade 2 or 3 toxicity had a history of hepatic disease, eight patients concomitantly used potential hepatotoxic co-medication. Eight (8%) patients used leflunomide in combination with methotrexate, and one of these patients developed hepatotoxicity. No clinical signs of serious hepatotoxicity were recorded during follow-up.

DISCUSSION

In 8.9% of the patients, grade 2 or 3 hepatotoxicity was recorded within the first year after the start of leflunomide therapy based on liver enzyme determinations. In the majority of the patients liver enzyme elevations occurred within the first 6 months of therapy and resolved during continued follow-up. None of the patients showed clinical signs of hepatotoxicity.

CONCLUSION

Under continued monitoring of liver functions hepatotoxicity during leflunomide use does not seem to be a major problem in our population.

Controversies in liver biopsy: who, where, when, how, why?

Liver biopsy continues to have a central role in the evaluation of patients with suspected liver disease. The procedure is often indicated to evaluate otherwise unexplained liver biochemical test abnormalities, but the precise degree of serum aminotransferase elevations that should prompt a liver biopsy is controversial, as is the need for liver biopsy in all patients with suspected nonalcoholic fatty liver disease and chronic hepatitis C. Standard liver biopsy is contraindicated in patients with severe coagulopathy and ascites, although the degree of coagulopathy that contraindicates a liver biopsy is controversial. A transjugular approach is an alternative in patients with coagulopathy or ascites. Controversy surrounds all the technical aspects of liver biopsy, particularly the choice of needle (cutting vs suction) and the use of ultrasound to mark or guide the biopsy site. Bleeding is the major complication of liver biopsy, with a risk of 0.3%; cutting needles are more likely to cause hemorrhage than are suction needles. Traditionally, liver biopsy has been the province of the hepatologist/ gastroenterologist. However, an increasing number of liver biopsies are performed by radiologists. The implications of this trend with respect to patient outcome, safety, and training of fellows is unclear.

Hepatobiliary pathology

Insights provided by molecular biology, immunohistochemistry, and transmission electron microscopy have increased our understanding of the pathogenesis and histopathology of hepatitis C virus (HCV) infection, nonalcoholic steatohepatitis (NASH), and bile ductular proliferative reactions in a number of liver diseases. Human and chimpanzee liver infected with HCV showed viral-like particles (50 to 60 nm in diameter) as well as aggregates of short tubules that represent viral envelope material. Interactions of HCV core protein with apolipoproteins have a role in the pathogenesis of HCV-related steatosis. Pathologists should be aware of the spectrum of liver pathology described with the use of highly active antiretroviral therapy (HAART) agents for the human immunodeficiency virus infection, which includes microvesicular steatosis and more severe hepatic injury with confluent necrosis. Proliferation of bile ductular structures is influenced by specific molecules and proteins (eg, the mucin-associated trefoil proteins and estrogens). The interplay between Notch receptors and Jagged 1 protein, as expressed by many cells of the liver (including bile duct epithelium) varies in primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). Cholangiocarcinoma does not appear to be a long-term complication of small duct PSC. The fatty liver diseases, both alcoholic and nonalcoholic, are characterized by production of reactive oxygen species that have detrimental effects such as opening mitochondrial permeability transition pores with resultant release of cytochrome c into the cytosol. Hepatocellular carcinoma is now a recognized late complication of NASH. The derivation of hepatic stem cells, the roles of HFE protein and other hepatic and intestinal transport proteins in hemochromatosis, and the histopathologic interpretive challenge of centrilobular lesions in posttransplant liver biopsies are among other recent studies considered in this review.