Sampling variability of liver biopsy in nonalcoholic fatty liver disease

BACKGROUND & AIMS: In nonalcoholic fatty liver disease (NAFLD), the distinction between steatosis and steatohepatitis (NASH) and the assessment of the severity of the disease rely on liver histology alone. The aim of this study was to assess the sampling error of liver biopsy and its impact on the diagnosis and staging of NASH. METHODS: Fifty-one patients with NAFLD underwent percutaneous liver biopsy with 2 samples collected. The agreement between paired biopsy specimens was assessed by the percentage of discordant results and by the kappa reliability test. RESULTS: No features displayed high agreement; substantial agreement was only seen for steatosis grade; moderate agreement for hepatocyte ballooning and perisinusoidal fibrosis; fair agreement for Mallory bodies; acidophilic bodies and lobular inflammation displayed only slight agreement. Overall, the discordance rate for the presence of hepatocyte ballooning was 18%, and ballooning would have been missed in 24% of patients had only 1 biopsy been performed. The negative predictive value of a single biopsy for the diagnosis of NASH was at best 0.74. Discordance of 1 stage or more was 41%. Six of 17 patients with bridging fibrosis (35%) on 1 sample had only mild or no fibrosis on the other and therefore could have been under staged with only 1 biopsy. Intraobserver variability was systematically lower than sampling variability and therefore could not account for most of the sampling error. CONCLUSIONS: Histologic lesions of NASH are unevenly distributed throughout the liver parenchyma; therefore, sampling error of liver biopsy can result in substantial misdiagnosis and staging inaccuracies.     

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.     

Interactions between non-alcoholic fatty liver disease and hepatitis C viral infection

Abstract   This paper discusses nonalcoholic fatty liver disease (NAFLD) and hepatitis C virus (HCV) in terms of their clinical presentation, natural history, pathogenesis and treatment. Important interactions between these two diseases are then discussed, as well as fertile areas for further research.     

Non-alcoholic steatohepatitis (NASH) in patients with polycystic ovarian syndrome (PCOS)

Abstract

Background. Both non-alcoholic steatohepatitis (NASH) and polycystic ovary syndrome (PCOS) are associated with metabolic syndrome (MS) and insulin resistance (IR). Except for a few case reports, there are no systematic assessments of NASH in PCOS patients. Aim. To determine the prevalence of NASH and independent factors associated with NASH in a cohort of patients with documented PCOS. Methods. Patients with established diagnosis of PCOS and matched controls (matched for gender, age, and body mass index (BMI)) were included in the study. Causes of other liver diseases were systematically excluded by clinical and laboratory tests. Excessive alcohol use was defined as alcohol consumption of greater than 10 g/day. All liver biopsies were read by a single pathologist blinded to the clinical data. Histologic NASH was defined as steatosis with lobular inflammation and ballooning degeneration of hepatocytes with or without Mallory–Denk bodies or pericellular fibrosis. Univariate and multivariate analyses with logistic regression were performed to compare PCOS to matched controls. Results. Sixty-six patients were included in the study (34 PCOS and 32 matched controls). Of PCOS patients, 73% had a liver biopsy while 78% of the matched controls had a liver biopsy. In comparing PCOS patients to the matched controls, clinical (BMI, waist circumference, type 2 diabetes, MS, or its components, any alcohol consumption in the prior year, ethnic background, age, gender, etc.) and laboratory data (aminotransferases, ferritin, glucose, etc.) were not significantly different (p > 0.05). However, PCOS patients tended to have more histologic NASH on their liver biopsies (44.0% vs. 20.8%, p = 0.08). Independent predictors of histologic NASH in PCOS patients were elevated aspartate aminotransferase (AST), high triglycerides and small amounts of alcohol consumption (p = 0.019, 10-fold cross-validated AUC = 0.80, 95% CI = 0.56–0.94). Although about half of PCOS patients did not report any alcohol consumption, 50% did report rare alcohol use. In fact, PCOS patients with histologic NASH tended to report higher alcohol consumption per week than PCOS without NASH (3.80 ± 6.16 vs. 1.11 ± 1.87 g/week, p = 0.1). Nevertheless, these amounts of alcohol consumption were quite minimal. Conclusions. Despite similar clinical and laboratory profiles to the matched controls, PCOS patients seem to have more histologic NASH. Although alcohol consumption was rare for both PCOS and controls, even rare alcohol consumption in PCOS patients was independently associated with histologic NASH.     

Evidence‐based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease in industrialized countries worldwide, and has become a serious public health issue not only in Western countries but also in many Asian countries including Japan. Within the wide spectrum of NAFLD, non‐alcoholic steatohepatitis (NASH) is a progressive form of disease, which often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma. In turn, a large proportion of NAFLD/NASH is the liver manifestation of metabolic syndrome, suggesting that NAFLD/NASH plays a key role in the pathogenesis of systemic atherosclerotic diseases. Currently, a definite diagnosis of NASH requires liver biopsy, though various non‐invasive measures are under development. The mainstays of prevention and treatment of NAFLD/NASH include dietary restriction and exercise; however, pharmacological approaches are often necessary. Currently, vitamin E and thiazolidinedione derivatives are the most evidence‐based therapeutic options, although the clinical evidence for long‐term efficacy and safety is limited. This practice guideline for NAFLD/NASH, established by the Japanese Society of Gastroenterology in cooperation with The Japan Society of Hepatology, covers lines of clinical evidence reported internationally in the period starting from 1983 through January 2012, and each clinical question was evaluated using the GRADE system. Based on the primary release of the full version in Japanese, this English summary provides the core essentials of this clinical practice guideline comprising the definition, diagnosis, and current therapeutic recommendations for NAFLD/NASH in Japan.     

Hepatocyte apoptosis and fas expression are prominent features of human nonalcoholic steatohepatitis

BACKGROUND & AIMS: The pathogenesis of nonalcoholic steatohepatitis (NASH) remains poorly understood. Although apoptosis is a common mechanism of liver injury, the extent and clinical significance of apoptosis in NASH has not been examined. Thus, the aims of this study were to quantify hepatocyte apoptosis in NASH, correlate it with disease severity, and identify possible mechanisms of apoptosis induction. METHODS: Hepatocyte apoptosis was assessed in NASH, simple steatosis, alcoholic hepatitis, and controls without liver disease using the TUNEL assay and immunohistochemistry for activated caspases 3 and 7. Liver specimens were also graded according to the magnitude of inflammation and fibrosis. RESULTS: TUNEL-positive cells were significantly increased in liver biopsy specimens from patients with NASH compared with simple steatosis and controls. Unexpectedly, TUNEL-positive cells were also greater in NASH vs. alcoholic hepatitis. Immunohistochemistry demonstrated active caspases 3 and 7 in NASH specimens, confirming the occurrence of apoptosis in this disease. A positive correlation was observed between hepatocyte apoptosis and hepatic fibrosis and inflammatory activity, respectively. The Fas receptor was strongly expressed in hepatocytes in liver specimens from NASH patients as compared with controls. CONCLUSIONS: Hepatocyte apoptosis is significantly increased in patients with NASH and correlates with disease severity, suggesting that antiapoptotic therapy may be useful in this syndrome.     

Accuracy of FibroScan Controlled Attenuation Parameter and Liver Stiffness Measurement in Assessing Steatosis and Fibrosis in Patients With Nonalcoholic Fatty Liver Disease

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Non‐alcoholic fatty liver disease from pathogenesis to management: an update

Non‐alcoholic fatty liver disease (NAFLD), the most common chronic liver disease in the Western world, is tightly associated with obesity and metabolic syndrome. NAFLD entails an increased cardiometabolic and liver‐related risk, the latter regarding almost exclusively non‐alcoholic steatohepatitis (NASH), the progressive form of NAFLD. Pathogenetic models encompass altered hepatic lipid partitioning and adipokine action, increased oxidative stress, free fatty acid lipotoxicity. On this basis, lifestyle‐, drug‐ or surgically induced weight loss, insulin sensitizers, antioxidants, lipid‐lowering drugs have been evaluated in NAFLD/NASH. Most trials are small, of short duration, nonrandomized, without histological end points, thus limiting assessment of long‐term safety and efficacy of proposed treatments. All NAFLD patients should be evaluated for their metabolic, cardiovascular and liver‐related risk. Liver biopsy remains the gold standard for staging NAFLD, but non‐invasive methods are under intense development. Weight loss through lifestyle intervention is the initial approach, because of established efficacy on NAFLD‐associated cardiometabolic abnormalities, and to emerging benefits on necroinflammation and overall disease activity in NASH. Bariatric surgery warrants further evaluation before it can be routinely considered in morbidly obese NASH. Larger‐ and longer‐duration randomized trials assessing safety and benefits of drugs on patient‐oriented outcomes are needed before pharmacological treatment can be routinely recommended for NASH.     

Patients with elevated liver enzymes are not at higher risk for statin hepatotoxicity

BACKGROUND & AIMS: Studies that evaluate the risk of hepatotoxicity from statins in hyperlipidemic subjects with elevated baseline serum transaminases are lacking. We conducted a study to test the hypothesis that patients with elevated baseline liver enzymes have higher risk of statin hepatotoxicity. METHODS: Our study consisted of the following 3 cohorts of patients seen between January 1, 1998 and June 31, 2002: Cohort 1: 342 hyperlipidemic patients with elevated baseline enzymes (AST >40 IU/L or ALT >35 IU/L) who were prescribed a statin; cohort 2: 1437 hyperlipidemic patients with normal transaminases who were prescribed a statin; and cohort 3: 2245 patients with elevated liver enzymes but who were not prescribed a statin. The effect of statins on liver biochemistries was assessed over a 6-month period after statins were prescribed. Elevations in liver biochemistries during follow-up were categorized into mild-moderate or severe based on predefined criteria. RESULTS: The incidence of mild-moderate elevations and severe elevations in liver biochemistries in cohort 1 were 4.7% and 0.6%, respectively. Compared with cohort 1, individuals in cohort 2 had lower incidence of mild-moderate elevations (1.9%, P = 0.002) but not severe elevations (0.2%, P = 0.2). However, between cohorts 1 and 3, there were no differences in the incidence of mild-moderate elevations (4.7% vs. 6.4%, respectively, P = 0.2) or severe elevations (0.6% vs. 0.4%, respectively, P = 0.6). Statin discontinuation during the follow-up was similar between cohorts 1 and 2 (11.1% vs. 10.7%, respectively, P = 0.8). CONCLUSIONS: These data suggest that individuals with elevated baseline liver enzymes do not have higher risk for hepatotoxicity from statins.