Noninvasive diagnosis and monitoring of nonalcoholic steatohepatitis: present and future

Noninvasive evaluation of hepatic fibrosis using acoustic radiation force-based shear stiffness in patients with nonalcoholic fatty liver disease

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD), the most common form of chronic liver disease in developed countries, may progress to nonalcoholic steatohepatitis (NASH) in a minority of people. Those with NASH are at increased risk for cirrhosis and hepatocellular carcinoma. The potential risk and economic burden of utilizing liver biopsy to stage NAFLD in an overwhelmingly large at-risk population are enormous; thus, the discovery of sensitive, inexpensive, and reliable noninvasive diagnostic modalities is essential for population-based screening.

METHODS

Acoustic Radiation Force Impulse (ARFI) shear wave imaging, a noninvasive method of assessing tissue stiffness, was used to evaluate liver fibrosis in 172 patients diagnosed with NAFLD. Liver shear stiffness measures in three different imaging locations were reconstructed and compared to the histologic features of NAFLD and AST-to-platelet ratio indices (APRI).

RESULTS

Reconstructed shear stiffnesses were not associated with ballooned hepatocytes (p=0.11), inflammation (p=0.69), nor imaging location (p=0.11). Using a predictive shear stiffness threshold of 4.24kPa, shear stiffness distinguished low (fibrosis stage 0-2) from high (fibrosis stage 3-4) fibrosis stages with a sensitivity of 90% and a specificity of 90% (AUC of 0.90). Shear stiffness had a mild correlation with APRI (R(2)=0.22). BMI>40kg/m(2) was not a limiting factor for ARFI imaging, and no correlation was noted between BMI and shear stiffness (R(2)=0.05).

CONCLUSIONS

ARFI imaging is a promising imaging modality for assessing the presence or absence of advanced fibrosis in patients with obesity-related liver disease.

Noninvasive predictors for liver fibrosis in patients with nonalcoholic steatohepatitis

AIM

To evaluate certain anthropometric, clinical and laboratory features indicating liver fibrosis in nonalcoholic steatohepatitis and to establish the noninvasive markers for liver fibrosis.

METHODS

Eighty-one patients (40 male, 41 female) who were diagnosed with fatty liver by ultrasonographic examination and fulfilled the inclusion criteria participated in the study. Anamnesis, anthropometric, clinical and laboratory features of all cases were recorded and then liver biopsy was performed after obtaining patient consent. Steatosis, necroinflammation and liver fibrosis were examined according to age ≥ 45, gender, body mass index, central obesity, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) > 1, γ-glutamyltransferase (GGT)/ALT > 1, platelet count, insulin, c-peptide levels and the presence of hypertension, diabetes, hypertriglyceridemia and insulin resistance.

RESULTS

Eighty-one patients with non-alcoholic steatohepatitis (NASH) enrolled in the study. 69 of 81 patients were diagnosed with NASH, 11 were diagnosed with simple fatty liver and 1 was diagnosed with cirrhosis. AST/ALT > 1, GGT/ALT > 11, high serum ferritin and fasting insulin levels, the presence of diabetes, hypertension, hypertriglyceridemia and insulin resistance seemed to enhance the severity of steatosis, necroinflammation and fibrosis but these results were not statistically significant.

CONCLUSION

Liver steatosis and fibrosis can occur in individuals with normal weight. There was no significant concordance between severity of liver histology and the presence of predictors for liver fibrosis including metabolic risk factors.

Prepubertal gynecomastia in two monozygotic twins with Peutz-Jeghers syndrome: two years' treatment with anastrozole and genetic study

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder characterized by multiple gastrointestinal hamartomatous polyps, mucocutaneous pigmentation and increased predisposition to neoplasms. Endocrine manifestations in PJS include gynecomastia and advanced bone age due to estrogen production by large-cell calcifying Sertoli cell tumors (LSCT). We present two 9-year-old male monozygotic twins, with PJS, bilateral progressive prepubertal gynecomastia and testicular bilateral multifocal calcifications, suggesting a diagnosis of LSCT. Their father had PJS but no history of gynecomastia or testicular calcifications. No mutations were found in the tumor suppressor gene LKB1/STK11, which is responsible for about 60% of PJS cases. The genotype of the aromatase cytochrome P450 19, a key enzyme involved in estrogen biosynthesis, was the same in the father and his twins. To reduce gynecomastia and delay skeletal maturation, the children started treatment with anastrozole, an aromatase inhibitor. Growth velocity decreased and gynecomastia diminished. After 2 years of treatment, anastrozole is still currently used at a dosage of 1 mg once daily with no side effects. In this study, a couple of monozygotic twins with PJS, prepubertal gynecomastia and LSCT is reported for the first time and anastrozole appears to be an efficacious medical treatment, as an alternative to orchidectomy, to control the effects of estrogen excess.

Endoplasmic reticulum stress and the unfolded protein response in nonalcoholic fatty liver disease

The underlying causes of nonalcoholic fatty liver disease (NAFLD) are unclear, although recent evidence has implicated the endoplasmic reticulum (ER) in both the development of steatosis and progression to nonalcoholic steatohepatitis. Disruption of ER homeostasis, often termed "ER stress," has been observed in liver and adipose tissue of humans with NAFLD and/or obesity. Importantly, the signaling pathway activated by disruption of ER homeostasis, the unfolded protein response, has been linked to lipid biosynthesis, insulin action, inflammation, and apoptosis. Therefore, understanding the mechanisms that disrupt ER homeostasis in NAFLD and the role of ER-mediated signaling have become topics of intense investigation. The present review will examine the ER and the unfolded protein response in the context of NAFLD.

Quantification of liver fat in mice: comparing dual-echo Dixon imaging, chemical shift imaging, and 1H-MR spectroscopy

We evaluated dual-echo Dixon in-phase and out-of-phase (IP-OP), chemical shift imaging (CSI), and (1)H MRS (hydrogen MR spectroscopy) in estimating fat content (FC) in phantoms and in livers of mice. Phantoms were made according to the volume percentage of fat ranging from 0% to 100%. The three MR methods were performed to measure FC in phantoms and in livers of obese leptin-deficient (ob/ob), human BSCL2/seipin gene knockout (SKO), and wild-type (WT) mice. The results were compared with known FC in phantoms and to a reference standard from mice by histological semiautomatic vacuole segmentation (HIS-S) procedure and liver lipid (LL) chemical analysis. In phantoms, CSI underestimated FC from 50% to 100%, to a lesser extent than IP-OP. In vivo, liver FC in ob/ob and SKO mice measured by the three MR methods were all significantly higher than that in WT mice. Liver FC measured by IP-OP were significantly lower than that measured by CSI and MRS, with no significant difference between CSI and MRS. CSI and MRS showed a linear correlation with LL analysis and with each other. IP-OP underestimated FC, whereas CSI and MRS were more accurate for quantifying FC in both phantoms and liver. CSI and MRS have the potential to replace HIS-S and LL analysis in longitudinal studies.

The effect of the Spanish Ketogenic Mediterranean Diet on nonalcoholic fatty liver disease: a pilot study

The "Spanish Ketogenic Mediterranean Diet" (SKMD) has been shown to be an effective and safe way to cure patients suffering from metabolic syndrome (MS). Keeping in mind that nonalcoholic fatty liver disease (NAFLD) is closely associated with MS, the purpose of this study was to evaluate the potential therapeutic properties under free living conditions of the SKMD in patients with MS (following the International Diabetes Federation [IDF] consensus guidelines) and NAFLD (suspected by using a cutoff value of alanine aminotransferase [ALT] levels of >40 U/L and confirmed by abdominal ultrasonography) over a 12-week period. A prospective study was carried out in 14 obese men meeting the inclusion criteria and whose body mass index (BMI) and age were 36.58±0.54 kg/m² and 41.18±2.28 years, respectively. Statistical differences between the parameters studied before and after administration of the SKMD (week 0 and 12) were analyzed by paired Student's t test (continuous variables) and the χ² test (discontinuous variables). P<.05 was considered statistically significant. There was an extremely significant (P<.001) improvement in body weight (from 109.79 kg to 95.86 kg), low-density lipoprotein-cholesterol (from 123.43 mg/dL to 100.35 mg/dL), ALT (from 71.92 U/L to 37.07 U/L), aspartate aminotransferase (from 47.71 U/L to 29.57 U/L), steatosis degree (complete fatty liver regression was observed in 21.4% of the patients, and an overall reduction was found in 92.86% of the patients), and all the parameters studied associated with the MS: BMI (from 36.99 kg/m² to 32.42 kg/m²), waist circumference (from 114.01 cm to 98.59 cm), fasting plasma glucose (from 118.57 mg/dL to 90.14 mg/dL), triacylglycerols (from 232.64 mg/dL to 111.21 mg/dL), high-density lipoprotein-cholesterol (HDLc) (from 42.81 mg/dL to 58.71 mg/dL), systolic blood pressure (from 142.86 mm Hg to 125.36 mm Hg), and diastolic blood pressure (from 89.64 mm Hg to 77.86 mm Hg). After the diet all the subjects were free of MS according to the IDF definition, and 100% of them had normal triacylglycerols and HDLc levels, in spite of the fact that 100% of them still had a BMI of >30 kg/m². We conclude that the SKMD could be an effective and safe way to treat patients suffering from MS and the associated NAFLD.

A proton nuclear magnetic resonance metabonomics approach for biomarker discovery in nonalcoholic fatty liver disease

This study was undertaken to discover novel biomarkers for the noninvasive early diagnosis of nonalcoholic fatty liver disease (NAFLD). A methionine and choline deficient (MCD) diet was used to represent different stages of NAFLD in male C57BL/6 mice. (1)H NMR spectroscopy and principal components analysis (PCA) were used to investigate the time-related biochemical changes in mice sera induced by the MCD diet. Many serum metabolites' concentrations changed between control and MCD-fed mice. Hierarchical cluster analysis (HCA) and artificial neural networks (ANNs) were used to select the least number of metabolites to be used for the noninvasive diagnosis of various stages of NAFLD; four potential biomarkers, serum glucose, lactate, glutamate/glutamine, and taurine were selected. To verify the diagnostic accuracy of these selected metabolites, their serum concentrations were measured in healthy controls (n = 28), NAFLD patients with steatosis (n = 15), steatosis patients with necro-inflammatory disease (n = 11), and NASH patients (n = 6). On the basis of results from MCD-fed mice model, clinical tests, and previous reports, we propose using the levels of the four metabolites for diagnosing NAFLD at various stages. Furthermore, the probability of developing NAFLD at a particular stage was assessed by multinomial logistic regression (MLR) based on the clinical results of the four serum metabolites.

Noninvasive tools to assess liver disease

PURPOSE OF REVIEW

To improve understanding of recent developments in the noninvasive assessment of fibrosis and their potential clinical application to a range of chronic liver diseases.

RECENT FINDINGS

Many noninvasive tests have evolved from their primary validation in chronic hepatitis C virus (HCV) infection to integration into clinical management algorithms for chronic liver disease of varying cause. Recent studies consider the use of these techniques in sequence or in combination, and compare the performance of serum and imaging-based noninvasive techniques to identify patients with significant fibrosis, or those at most risk of clinical sequelae from advanced-stage disease. Methods developed in chronic hepatitis C have now been applied in different chronic liver diseases, including nonalcoholic fatty liver disease, alcoholic liver disease, HIV/HCV co-infection and primary biliary cirrhosis. A number of new management algorithms have been developed to facilitate the integration of noninvasive techniques into clinical practice.

SUMMARY

Noninvasive tools to assess liver diseases continue to evolve. New imaging technologies have been developed. Existing biomarkers and imaging modalities have been better integrated into clinical practice algorithms, and applied to different chronic liver diseases. Noninvasive techniques will likely continue to be refined and play an important role in the future management of patients with chronic liver disease.

Serum cytokeratin 18 M30 antigen level and its correlation with nutritional parameters in middle-aged Japanese males with nonalcoholic fatty liver disease (NAFLD)

Cytokeratin (CK) 18 M30 antigen has been proposed as a diagnostic marker of nonalcoholic fatty liver disease (NAFLD). We studied serum CK18 M30 antigen level and examined the correlations among CK18 and biological data, dietary intake, and plasma fatty acid composition in middle-aged Japanese males with (NAFLD; n=42) and without NAFLD (control; n=35). NAFLD was diagnosed if subjects showed fatty liver on abdominal ultrasonography and their alcohol consumption was <20 g/d. They were also confirmed to have negative serological results for tests of autoimmune liver disease and hepatitis B and C. In the NAFLD group, body mass index, waist circumference, serum M30 antigen, alanine transaminase (ALT), cholinesterase, triacylglycerol, LDL-cholesterol, and HbA1c were significantly higher than in the control group. In the fatty acid analysis of plasma phospholipids, significantly higher dihomo-γ-linolenic acid (DGLA), total saturated fatty acids (SFA), and palmitic/linoleic acid ratio as well as lower arachidonic acid/DGLA ratio were observed in the NAFLD group compared with the control group. In the NAFLD group, M30 antigen was correlated positively with serum ALT, plasma DGLA, dietary SFA, and serum TNF-α as determined by partial correlation analysis controlled for BMI. On the basis of multivariate regression analysis using a stepwise method, M30 antigen was significantly associated with ALT and plasma DGLA. Regarding the determinants of NAFLD as revealed by logistic regression analysis, a high odds ratio was observed for plasma DGLA. In conclusion, members of the NAFLD group showed higher levels of serum CK18 M30 antigen and M30 antigen was strongly associated with serum ALT and plasma DGLA. Abnormal fatty acid metabolism may be a factor that causes aggravation of NAFLD.

Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease

The diagnostic procedures in patients with suspected fatty liver disease-with or without known alcohol consumption-should be standardized and generally accepted. We therefore present a guideline, summarizing the current concepts of etiology, diagnostic as well as differential diagnostic of patients with fatty liver disease. Alcoholic as well as and non-alcoholic fatty liver are characterised by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected. Liver biopsy represents the "golden standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease. The differential diagnosis of ASH vs. NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present. People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis. Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease

The diagnostic procedures in patients with suspected fatty liver disease-with or without known alcohol consumption-should be standardized and generally accepted. We therefore present a guideline, summarizing the current concepts of etiology, diagnostic as well as differential diagnostic of patients with fatty liver disease. Alcoholic as well as and non-alcoholic fatty liver are characterised by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected. Liver biopsy represents the "golden standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease. The differential diagnosis of ASH vs. NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present. People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis. Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease

The diagnostic procedures in patients with suspected fatty liver disease-with or without known alcohol consumption-should be standardized and generally accepted. We therefore present a guideline, summarizing the current concepts of etiology, diagnostic as well as differential diagnostic of patients with fatty liver disease. Alcoholic as well as and non-alcoholic fatty liver are characterised by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected. Liver biopsy represents the "golden standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease. The differential diagnosis of ASH vs. NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present. People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis. Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Systematic review: the diagnosis and staging of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent cause of liver disease in Western countries. The development of non-alcoholic steatohepatitis (NASH) and fibrosis identifies an at-risk group with increased risk of cardiovascular and liver-related deaths. The identification and management of this at-risk group remains a clinical challenge.

AIM

To perform a systematic review of the established and emerging strategies for the diagnosis and staging of NAFLD.

METHODS

Relevant research and review articles were identified by searching PubMed, MEDLINE and EMBASE.

RESULTS

There has been a substantial development of non-invasive risk scores, biomarker panels and radiological modalities to identify at-risk patients with NAFLD without recourse to liver biopsy on a routine basis. These modalities and algorithms have improved significantly in their diagnosis and staging of fibrosis and NASH in patients with NAFLD, and will likely impact on the number of patients undergoing liver biopsy.

CONCLUSIONS

Staging for NAFLD can now be performed by a combination of radiological and laboratory techniques, greatly reducing the requirement for invasive liver biopsy.

Tracking cellular metabolomics in lipoapoptosis- and steatosis-developing liver cells

Palmitate (PA) is known to induce reactive oxygen species (ROS) formation and apoptosis in liver cells, whereas concurrent treatment of oleate (OA) with PA predominately induces steatosis without ROS in liver cells. We previously reported that PA treatment induces the decoupling of glycolysis and tricarboxylic acid cycle (TCA cycle) fluxes, but OA co-treatment restored most metabolic fluxes to their control levels. However, the mechanisms by which metabolites are linked to metabolic fluxes and subsequent lipoapoptotic or steatotic phenotypes remain unclear. To determine the link, we used GC-MS-based polar and non-polar metabolic profiling in lipoapoptosis- or steatosis-developing H4IIEC3 hepatoma cells, to examine the metabolome at different time points after treatment with either PA alone (PA cells) or both PA and OA (PA/OA cells). Metabolic profiles revealed various changes in metabolite levels for TCA cycle intermediates, pentose phosphate pathway (PPP) intermediates, and energy storage metabolites between PA and PA/OA cells. For example, adenosine was markedly increased only in PA cells, whereas gluconate was increased in PA/OA cells. To assess the interaction among these metabolites, the metabolite-to-metabolite correlations were calculated and correlation networks were visualized. These correlation networks demonstrate that a dissociation among PPP metabolites was introduced in PA-treated cells, and this dissociation was restored in PA/OA-treated cells. Thus, our data suggest that abnormal PPP fluxes, in addition to increased adenosine levels, might be related to the decoupling of glycolysis and the resulting lipoapoptotic phenotype.

Non-alcoholic fatty liver disease: An early mediator predicting metabolic syndrome in obese children?

AIM

To investigate if non-alcoholic fatty liver disease (NAFLD) is an early mediator for prediction of metabolic syndrome, and if liver B-ultrasound can be used for its diagnosis.

METHODS

We classified 861 obese children (6-16 years old) into three subgroups: group 0 (normal liver in ultrasound and normal transaminases); group 1 (fatty liver in ultrasound and normal transaminases); and group 2 (fatty liver in ultrasound and elevated transaminases). We measured the body mass index, waist and hip circumference, blood pressure, fasting blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), whole-body insulin sensitivity index (WBISI), lipid profile and transaminases in all the participants. The risk of developing metabolic syndrome (MS) was assessed according to the degree of liver fatty infiltration based on the B-ultrasound examination.

RESULTS

Among the 861 obese children, 587 (68.18%) were classified as having NAFLD, and 221 (25.67%) as having MS. The prevalence of MS in NAFLD children (groups 1 and 2) was 37.64% (221/587), which was much higher than that in non-NAFLD group (group 0, 12.04%) (P < 0.01). There were significantly higher incidences concerning every component of MS in group 2 compared with group 0 (P < 0.05). The incidence of NAFLD in MS patients was 84.61% (187/221), which was significantly higher than that of hypertension (57.46%, 127/221) and glucose metabolic anomalies (22.62%, 50/221), and almost equal to the prevalence of dyslipidemia (89.14%, 197/221). Based on the B-ultrasound scales, the presence of moderate and severe liver fatty infiltration carried a high risk of hypertension [odds ratio (OR): 2.18, 95% confidence interval (95% CI): 1.27-3.75], dyslipidemia (OR: 7.99, 95% CI: 4.34-14.73), impaired fasting glucose (OR: 3.65, 95% CI: 1.04-12.85), and whole MS (OR: 3.77; 95% CI: 1.90-7.47, P < 0.01). The state of insulin resistance (calculated by HOMA-IR and WBISI) deteriorated as the degree of fatty infiltration increased.

CONCLUSION

NAFLD is not only a liver disease, but also an early mediator that reflects metabolic disorder, and liver B-ultrasound can be a useful tool for MS screening.

Non-invasive diagnosis of nonalcoholic fatty liver and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the USA and many other parts of the world. Its prevalence continues to rise; currently affecting about one in four adults and 10% of children in the USA. NAFLD represents a wide spectrum of conditions ranging from fatty liver, which in general follows a benign, no-progressive clinical course, to nonalcoholic steatohepatitis (NASH), a more serious form of NAFLD that may progress to cirrhosis and end-stage liver disease. Currently, the diagnosis of NASH requires an invasive liver biopsy with drawbacks of sampling and interpretation error. Clinical risk factors for NASH include diabetes and the metabolic syndrome; however, these are not sufficiently predictive of the condition by themselves. Routine liver enzyme levels are not reliable; however, novel plasma hepatocyte cell death markers either alone or in combination with clinical risk factors are potential non-invasive diagnostic tools for the future. This review provides a concise overview of the role non-invasive diagnostic tools for the differentiation of fatty liver from NASH as well as for the determination of presence and extent of fibrosis.

A combination of the pediatric NAFLD fibrosis index and enhanced liver fibrosis test identifies children with fibrosis

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) encompasses diseases from simple steatosis, to steatohepatitis, to fibrosis, and cirrhosis. The pediatric NAFLD fibrosis index (PNFI) and the enhanced liver fibrosis (ELF) test are potential noninvasive markers for fibrosis. We prospectively evaluated the performance of PNFI and ELF in assessing fibrosis in children with biopsy-proven NAFLD.

METHODS

We analyzed 111 consecutive children with NAFLD. The stage of fibrosis was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network. PNFI was calculated based on age, waist circumference, and levels of triglycerides. The ELF test was used to determine levels of hyaluronic acid, the amino-terminal propeptide of type III collagen, and tissue inhibitor of metalloproteinase-1.

RESULTS

Some degree of fibrosis was detected in 68.5% of patients (62 had stage 1, 5 had stage 2, and 9 had stage 3). PNFI and ELF test values was higher among patients with fibrosis (P < .001). The area under the receiver operating characteristic (ROC) curve for predicting fibrosis using the PNFI and ELF test was 0.761 and 0.924, respectively. The best performance was obtained by combining PNFI and ELF test with (area under the receiver operating characteristic curve = 0.944). The combined results from the PNFI and ELF test predicted the presence or absence of fibrosis in 86.4% of children with NAFLD.

CONCLUSIONS

In children with NAFLD, the combined results from the PNFI and ELF test can accurately assess the presence of liver fibrosis and identify patients that should be evaluated by liver biopsy.

A simple clinical scoring system using ferritin, fasting insulin, and type IV collagen 7S for predicting steatohepatitis in nonalcoholic fatty liver disease

BACKGROUND

Liver histology is the gold standard for the diagnosis of nonalcoholic steatohepatitis (NASH). Noninvasive, simple, reproducible, and reliable biomarkers are greatly needed to differentiate NASH from nonalcoholic fatty liver disease (NAFLD).

METHODS

To construct a scoring system for predicting NASH, 177 Japanese patients with biopsy-proven NAFLD were enrolled. To validate the scoring system, 442 biopsy-proven NAFLD patients from eight hepatology centers in Japan were also enrolled.

RESULTS

In the estimation group, 98 (55%) patients had NASH. Serum ferritin [≥200 ng/ml (female) or ≥300 ng/ml (male)], fasting insulin (≥10 μU/ml), and type IV collagen 7S (≥5.0 ng/ml) were selected as independent variables associated with NASH, by multilogistic regression analysis. These three variables were combined in a weighted sum [serum ferritin ≥200 ng/ml (female) or ≥300 ng/ml (male) = 1 point, fasting insulin ≥10 μU/ml = 1 point, and type IV collagen 7S ≥5.0 ng/ml = 2 points] to form an easily calculated composite score for predicting NASH, called the NAFIC score. The area under the receiver operating characteristic (AUROC) curve for predicting NASH was 0.851 in the estimation group and 0.782 in the validation group. The NAFIC AUROC was the greatest among several previously established scoring systems for detecting NASH, but also for predicting severe fibrosis.

CONCLUSIONS

NAFIC score can predict NASH in Japanese NAFLD patients with sufficient accuracy and simplicity to be considered for clinical use.

[Fatty liver and its clinical management in obese adolescents]

Liver steatosis, also called non-alcoholic fatty liver, is characterized by a pathological fat accumulation in the liver, leading to liver damage in the form of inflammation and fibrosis. These histological features are similar to those in alcoholic hepatitis. Obesity is known to be the most common cause of simple steatosis in the preadolescent and adolescent population with a consequent serious health risk. The aim of this study was to provide an update on the concepts, pathophysiology and clinical management of hepatic steatosis secondary to obesity at an early age.

Fatty acids and the endoplasmic reticulum in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) represents a burgeoning public health concern in westernized nations. The obesity-related disorder is associated with an increased risk of cardiovascular disease, type 2 diabetes and liver failure. Although the underlying pathogenesis of NAFLD is unclear, increasing evidence suggests that excess saturated fatty acids presented to or stored within the liver may play a role in both the development and progression of the disorder. A putative mechanism linking saturated fatty acids to NAFLD may be endoplasmic reticulum (ER) stress. Specifically, excess saturated fatty acids may induce an ER stress response that, if left unabated, can activate stress signaling pathways, cause hepatocyte cell death, and eventually lead to liver dysfunction. In the current review we discuss the involvement of saturated fatty acids in the pathogenesis of NAFLD with particular emphasis on the role of ER stress.

Noninvasive assessment of liver fibrosis

Liver biopsy has long been an important tool for assessing the degree of liver fibrosis. Information on the presence and degree of liver fibrosis is useful before making therapeutic decisions or predicting disease outcomes. The need to stage liver fibrosis, however, should decrease as treatment options become more successful (as has occurred with viral hepatitis). In recent years, noninvasive tests have demonstrated a reasonable ability to identify significant fibrosis, cirrhosis in particular, nor is it surprising that liver disease specialists and patients favor a noninvasive approach. However, only those tests with the highest diagnostic accuracy, cost-effectiveness, and availability should be implemented. Apart from their diagnostic accuracy, the potential ability of these tests to predict disease outcomes (a more relevant endpoint) should be compared with that of liver biopsy. Indeed, the use of a standardized system to evaluate the utility of biomarkers would facilitate their implementation in clinical practice.

Reliability of transient elastography for the detection of fibrosis in non-alcoholic fatty liver disease and chronic viral hepatitis

BACKGROUND & AIMS

Transient elastography (TE) is validated in chronic hepatitis C (CHC) to evaluate hepatic fibrosis; however, limited data are available in chronic hepatitis B (CHB) and non-alcoholic fatty liver disease (NAFLD). This prospective study is aimed to assess the accuracy and the efficacy of TE for the detection of fibrosis in patients with chronic liver disease of different etiology and to evaluate the effect of steatosis on the liver stiffness measurement (LSM).

METHODS

TE was performed in 219 consecutive patients with chronic liver disease (35% CHC, 32% CHB, and 33% NAFLD) within 6 months of the liver biopsy.

RESULTS

LSM was related to the fibrosis stage in each group (CHC: p = 0.596, p < 0.001; CHB: p = 0.418, p < 0.001; NAFLD: p = 0.573, p < 0.001), but the correlation was less strong in CHB and NAFLD than in CHC patients. In CHB patients with histological cirrhosis (F4), the median stiffness value was almost two times lower than in patients with severe fibrosis (F3). In NAFLD patients with advanced fibrosis (F3) and severe steatosis (> 33%), the LSM values were lower than expected and were similar to those of patients with initial fibrosis (F1) and fat < 33%. TE underestimated the stage of fibrosis in 75% of patients with F3 and steatosis > 33%. At multiple logistic regression analysis, in CHC and CHB patients, LSM was the only predictive variable of severe fibrosis/cirrhosis (OR = 1.42, p = 0.003 and OR = 1.354, p = 0.003, respectively), while in NAFLD subjects BMI and AST (OR = 1.433, p = 0.002 and OR = 1.053, p = 0.020, respectively) but not LSM were independently related with advanced fibrosis and cirrhosis.

CONCLUSIONS

This study confirms that TE can be considered a valid support to detect fibrosis in chronic liver disease related to HCV but it should be interpreted cautiously in CHB and NAFLD patients, where host or disease-related factors may modify its accuracy.

Noncirrhotic human nonalcoholic fatty liver disease induces portal hypertension in relation to the histological degree of steatosis

INTRODUCTION

We earlier showed in an animal model that steatosis, in the absence of fibrosis or inflammation, induces a significant rise in portal pressure. The relevance of these findings for human pathology is unknown till date.

AIMS

To study portal pressure in nonalcoholic fatty liver disease patients and to identify factors possibly related to steatosis-induced changes in liver haemodynamics.

MATERIALS AND METHODS

Patients presenting with a problem of overweight and with noninvasive signs of liver involvement were proposed for transjugular liver biopsy. The biopsy was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network scoring system.

RESULTS

Fifty consecutive patients were studied. Mean age was 47.9 ± 13.6 years; 31 (62%) of them were female. Hepatic venous pressure gradient (HVPG) was normal in 27 patients (54%), borderline (5 mmHg) in nine (18%) and elevated in 14 patients (28%). For further analysis those with a HVPG of 5 mmHg were considered normal (group 1). HVPG was 8.8 ± 2.6 mmHg in those with an elevated HVPG (group 2) versus 3.4 ± 1.2 mmHg in group 1 (P < 0.0001). In both the groups, only one patient had cirrhosis; 26 of 36 (group 1) and nine of 14 patients (group 2) had fibrosis score 0. Fibrosis score was not significantly different (P = 0.530). Perisinusoidal fibrosis score was not significantly different (P = 0.186). Steatosis was the only histological feature that significantly differed between the groups (P = 0.016). The degree of steatosis (P = 0.010) was the only independent predictor of the presence of portal hypertension.

CONCLUSION

Human nonalcoholic fatty liver disease can, even in the absence of significant fibrosis, induce portal hypertension, correlated with the severity of the steatosis.

A fourth dimension in decision making in hepatology

Today, the assessment of liver function in patients suffering from acute or chronic liver disease is based on liver biopsy and blood tests including synthetic function, liver enzymes and viral load, most of which provide only circumstantial evidence as to the degree of hepatic impairment. Most of these tests lack the degree of sensitivity to be useful for follow-up of these patients at the frequency that is needed for decision making in clinical hepatology. Accurate assessment of liver function is essential to determine both short- and long-term prognosis, and for making decisions about liver and non-liver surgery, TIPS, chemoembolization or radiofrequency ablation in patients with chronic liver disease. Liver function tests can serve as the basis for accurate decision-making regarding the need for liver transplantation in the setting of acute failure or in patients with chronic liver disease. The liver metabolic breath test relies on measuring exhaled (13) C tagged methacetin, which is metabolized only by the liver. Measuring this liver-specific substrate by means of molecular correlation spectroscopy is a rapid, non-invasive method for assessing liver function at the point-of-care. The (13) C methacetin breath test (MBT) is a powerful tool to aid clinical hepatologists in bedside decision-making. Our recent findings regarding the ability of point-of-care (13) C MBT to assess the hepatic functional reserve in patients with acute and chronic liver disease are reviewed along with suggested treatment algorithms for common liver disorders.

Histopathology of nonalcoholic fatty liver disease

Histological analysis of liver biopsies remains a standard against which other methods of assessment for the presence and amount of hepatic injury due to nonalcoholic fatty liver disease (NAFLD) are measured. Histological evaluation remains the sole method of distinguishing steatosis from advanced forms of NAFLD, i.e. nonalcoholic steatohepatitis (NASH) and fibrosis. Included in the lesions of NAFLD are steatosis, lobular and portal inflammation, hepatocyte injury in the forms of ballooning and apoptosis, and fibrosis. However, patterns of these lesions are as distinguishing as the lesions themselves. Liver injury in adults and children due to NAFLD may have different histological patterns. In this review, the rationale for liver biopsy, as well as the histopathological lesions, the microscopically observable patterns of injury, and the differential diagnoses of NAFLD and NASH are discussed.

Noninvasive investigations for non alcoholic fatty liver disease and liver fibrosis

Non-alcoholic fatty liver disease (NAFLD) includes a spectrum of diseases that have insulin resistance in common and are associated with metabolic conditions such as obesity, type 2 diabetes mellitus, and dyslipidemia. NAFLD ranges from simple liver steatosis, which follows a benign course, to nonalcoholic steatohepatitis (NASH), a more severe entity, with necroinflammation and fibrosis, which can progress to cryptogenic cirrhosis and end-stage liver disease. Liver biopsy remains the gold standard for evaluating the degree of hepatic necroinflammation and fibrosis; however, several noninvasive investigations, such as serum biomarkers, have been developed to establish the diagnosis and also to evaluate treatment response. These markers are currently neither available in all centers nor validated in extensive studies. Examples include high-sensitivity C reactive protein and plasma pentraxin 3, which are associated with extensive liver fibrosis in NASH. Interleukin-6 correlates with inflammation, and cytokeratin-18 represents a marker of hepatocyte apoptosis (prominent in NASH and absent in simple steatosis). Tissue polypeptide specific antigen seems to have a clinical utility in the follow-up of obese patients with NASH.

Role and cellular source of nicotinamide adenine dinucleotide phosphate oxidase in hepatic fibrosis

Reactive oxygen species (ROS) generated by nicotinamide adenine dinucleotide phosphate oxidase (NOX) is required for liver fibrosis. This study investigates the role of NOX in ROS production and the differential contribution of NOX from bone marrow (BM)-derived and non-BM-derived liver cells. Hepatic fibrosis was induced by bile duct ligation (BDL) for 21 days or by methionine-choline-deficient (MCD) diet for 10 weeks in wild-type (WT) mice and mice deficient in p47phox (p47phox knockout [KO]), a component of NOX. The p47phox KO chimeric mice were generated by the combination of liposomal clodronate injection, irradiation, and BM transplantation of p47phox KO BM into WT recipients and vice versa. Upon BDL, chimeric mice with p47phox KO BM-derived cells, including Kupffer cells, and WT endogenous liver cells showed a ∼25% reduction of fibrosis, whereas chimeric mice with WT BM-derived cells and p47phox KO endogenous liver cells, including hepatic stellate cells, showed a ∼60% reduction of fibrosis. In addition, p47phox KO compared to WT mice treated with an MCD diet showed no significant changes in steatosis and hepatocellular injury, but a ∼50% reduction in fibrosis. Cultured WT and p47phox KO hepatocytes treated with free fatty acids had a similar increase in lipid accumulation. Free fatty acids promoted a 1.5-fold increase in ROS production both in p47phox KO and in WT hepatocytes.

CONCLUSION

NOX in both BM-derived and non-BM-derived cells contributes to liver fibrosis. NOX does not play a role in experimental steatosis and the generation of ROS in hepatocytes, but exerts a key role in fibrosis.

In vivo 3T spectroscopic quantification of liver fat content in nonalcoholic fatty liver disease: Correlation with biochemical method and morphometry

BACKGROUND & AIMS

The clinical application of liver fat quantification has increased in recent years, paralleling the epidemic increase in nonalcoholic fatty liver disease. The aim of this study was to perform a diagnostic evaluation of spectroscopy by comparing its measurement of total lipid content with that from liver biopsies and morphometry in normal subjects and patients with nonalcoholic fatty liver disease.

METHODS

Patients with symptomatic cholelithiasis underwent 3T MR cholangiography with spectroscopic quantification of TLC. A laparoscopic cholecystectomy was performed on the day of admission, with liver samples taken during surgery. Microcolorimetric assessment quantified lipid content in liver samples and morphometric evaluation in stained slides. Statistical analysis included bivariate correlation, regression, and ROC analysis.

RESULTS

The study was conducted in 18 patients, 5 men (mean age, 35.2+/-11.03 years; range, 27-54 years) and 13 women (mean age, 46.77+/-11.77 years; range, 21-61 years). Using a cut-off value >5% for fat content, 8 patients presented with steatosis and 10 patients presented with normal liver fat content. A significant correlation was observed between fat spectroscopy and lipid content (r=0.876, p<0.001). A lower and non-significant correlation was observed between lipid content and morphometry (r=0.190, p>0.05).

CONCLUSIONS

The accuracy of spectroscopy in assessing fat concentration with a cut-off level of 7.48% was 100%. Spectroscopy showed a strong and significant correlation with lipid content. It may reliably replace liver biopsy for the assessment of liver fat content.

Nonalcoholic steatohepatitis: risk factors and diagnosis

Nonalcoholic steatohepatitis (NASH) represents the progressive form of nonalcoholic fatty liver disease with greater potential to lead to liver-related morbidity and mortality. Diagnosing NASH mandates more intensive clinical management and consideration for clinical trials. Currently, the diagnosis of NASH requires a liver biopsy, which is invasive, with drawbacks in sampling and interpretation error. Clinical risk factors for NASH include diabetes and the metabolic syndrome; however, these are not sufficiently predictive of the condition by themselves. Routine liver aminotransaminase levels are not reliable; however, novel plasma hepatocyte apoptosis markers, either alone or in combination with clinical risk factors, are potential noninvasive diagnostic tools for the future.

Serum levels of CK18 M30 and leptin are useful predictors of steatohepatitis and fibrosis in paediatric NAFLD

BACKGROUND

With the alarming growth in prevalence of paediatric nonalcoholic fatty liver disease (NAFLD), there is a need for noninvasive methods of stratifying disease severity. Our aim was to evaluate a combination of serum biomarkers as a measure of disease activity in paediatric NAFLD.

PATIENTS AND METHODS

Forty-five children with biopsy-proven NAFLD were enrolled. Caspase-cleaved CK18 fragments (CK18 M30), hyaluronic acid, leptin, and adiponectin were measured in serum using enzyme-linked immunosorbent assays and high-sensitivity C-reactive protein using a colorimetric assay.

RESULTS

Median age was 12.7 years (55% boys). Median body mass index z score was 1.7. CK18 M30 levels were significantly higher in patients with NAFLD versus controls, median 288 IU/L versus 172 IU/L (P < 0.001), and in those with steatohepatitis, median 347 IU/L versus simple steatosis (NAFLD activity score < 3), median 191 IU/L (P = 0.006). Significant fibrosis (≥F2) could be differentiated from no/minimal fibrosis (<F2), median 393 IU/L versus 243 IU/L (P = 0.03). Leptin could distinguish <F2 from ≥F2; 28.9 ng/mL versus 70.1 ng/mL (P = 0.037). Adiponectin, hyaluronic acid, and high-sensitivity C-reactive protein did not achieve significance in predicting steatohepatitis nor significant fibrosis.

CONCLUSIONS

The present study combines use of markers for different processes in the development of steatohepatitis. Serum biomarkers, especially CK18 M30, are useful in stratifying disease severity in paediatric NAFLD.

Tissue-engineered model for real-time monitoring of liver inflammation

Tissue-engineered in vitro models have the potential to be used for investigating inflammation in the complex microenvironment found in vivo. We have developed an in vitro model of hepatic tissue that facilitates real-time monitoring of endothelium activation in liver tissue. This was achieved by creating a layered coculture model in which hepatocytes were embedded in collagen gel and a reporter clone of endothelial cells, which synthesizes green fluorescent protein in response to nuclear factor-kappa B (NF-κB) activation, was overlaid on top of the gel. The efficacy of our approach was established by monitoring in real time the dynamics of NF-κB-regulated fluorescence in response to tumor necrosis factor α. Our studies revealed that endothelial cells in coculture with hepatocytes exhibited a similar NF-κB-mediated fluorescence to both pulse and step stimulation of lipopolysaccharide. By contrast, endothelial cells in monoculture displayed enhanced NF-κB-regulated fluorescence to step in comparison to pulse lipopolysaccharide stimulation. The NF-κB-mediated fluorescence correlated with endothelial cell expression of NF-κB-regulated genes such as intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-Selectin, as well as with leukocyte adhesion. These findings suggest that our model provides a powerful platform for investigating hepatic endothelium activation in real time.

Clinical, laboratory and histological associations in adults with nonalcoholic fatty liver disease

The Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) was formed to conduct multicenter studies on the etiology, contributing factors, natural history, and treatment of nonalcoholic steatohepatitis (NASH). The aim of this study was to determine the associations of readily available demographic, clinical, and laboratory variables with the diagnosis of NASH and its key histological features, and determine the ability of these variables to predict the severity of nonalcoholic fatty liver disease (NAFLD). A total of 1266 adults were enrolled in NASH CRN studies between October 2004 and February 2008, of whom 1101 had available liver histology. The median age was 50 years; 82% were white and 12% Hispanic. The median body mass index was 33 kg/m(2); 49% had hypertension and 31% had type 2 diabetes. On liver biopsy, 57% were judged to have definite NASH and 31% bridging fibrosis or cirrhosis. Using data from the 698 patients with liver biopsies within 6 months of clinical data, patients with definite NASH were more likely to be female and have diabetes, higher levels of aspartate and alanine aminotransferases, alkaline phosphatase, gamma glutamyl transpeptidase, and homeostasis model assessment of insulin resistance (HOMA-IR). Progressive models for predicting histological diagnoses performed modestly for predicting steatohepatitis or ballooning (area under receiver operating characteristic curves [AUROC] ranged from 0.70-0.79), and better for advanced fibrosis (AUROC 0.73-0.85).

CONCLUSION

Readily available clinical and laboratory variables can predict advanced fibrosis in adults with NAFLD, but additional information is needed to reliably predict the presence and severity of NASH. Prospective studies of this well-characterized population and associated tissue bank samples offer a unique opportunity to better understand the cause and natural history of NAFLD and develop more precise means for noninvasive diagnosis.

Lower circulating levels of dehydroepiandrosterone, independent of insulin resistance, is an important determinant of severity of non-alcoholic steatohepatitis in Japanese patients

AIM

  The biological basis of variability in histological progression of non-alcoholic fatty liver disease (NAFLD) remains unknown. Dehydroepiandrosterone (DHEA), the most abundant steroid hormone, has been shown to influence sensitivity to reactive oxygen species, insulin sensitivity and expression of peroxisome proliferator-activated receptor-α. Our aim was to determine whether more histologically advanced NAFLD is associated with low circulating levels of DHEA in Japanese patients.

METHODS

  Serum samples were obtained in 133 Japanese patients with biopsy-proven NAFLD and in 399 sex- and age-matched healthy people undergoing health checkups. Serum levels of sulfated DHEA (DHEA-S) were measured by chemiluminescent enzyme immunoassay.

RESULTS

  Serum DHEA-S levels in NAFLD patients were similar to those in the control group. Of 133 patients, 90 patients were diagnosed as non-alcoholic steatohepatitis (NASH): 73 patients had stage 0-2, and 17 had stage 3 or 4. Patients with advanced NAFLD (NASH with fibrosis stage 3 or 4) had lower plasma levels of DHEA-S than patients with mild NAFLD (simple steatosis or NASH with fibrosis stage 0-2). The area under the receiver operating characteristic curve for DHEA in separating patients with and without advanced fibrosis was 0.788. A "dose effect" of lower DHEA-S and incremental fibrosis stage was observed with a mean DHEA-S of 170.4 ± 129.2, 137.6 ± 110.5, 96.2 ± 79.3, 61.2 ± 46.3 and 30.0 ± 32.0 µg/dL for fibrosis stages 0, 1, 2, 3, and 4, respectively. The association between DHEA-S and severity of NAFLD persisted after adjusting for age, sex and insulin resistance.

CONCLUSION

  Low circulating DHEA-S might have a role in the development of advanced NASH.

Vitiligo at Injection Site of PEG-IFN-α 2a in Two Patients with Chronic Hepatitis C: Case Report and Literature Review

A 72-year-old female and a 57-year-old male with chronic hepatitis C were treated with a combination therapy of pegylated interferon (PEG-IFN)-α 2a (180 μg s.c. once a week) and ribavirin (1,000 mg orally daily). This resulted in the destruction of melanocytes at the injection site in both patients. In the male patient, the depigmentation progressed to the surrounding skin area. The dermatologist concurred with vitiligo as the diagnosis in both patients. Injection and surrounding site vitiligo associated with PEG-IFN-α 2b treatment for hepatitis C was noticed in previous case studies. For the first time, the case reports below highlight the same immunological adverse event secondary to PEG IFN-α 2a/ribavirin combination therapy and explain, in part, the complex interaction between host immune response and viral genotype. In addition, we systematically review drug-induced vitiligo and autoimmune diseases associated with the depigmentation disorder.

[Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease. Grade 2 consensus-based guidelines]

Both alcoholic (AFL) and non-alcoholic fatty liver (NAFL) are characterized by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver ". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected.Liver biopsy represents the "gold standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease.The differential diagnosis of ASH-NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present.People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis (CASH).Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Mass spectrometric profiling of oxidized lipid products in human nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Oxidative stress is a core abnormality responsible for disease progression in nonalcoholic fatty liver disease (NAFLD). However, the pathways that contribute to oxidative damage in vivo are poorly understood. Our aims were to define the circulating profile of lipid oxidation products in NAFLD patients, the source of these products, and assess whether their circulating levels reflect histological changes in the liver. The levels of multiple structurally specific oxidized fatty acids, including individual hydroxy-eicosatetraenoic acids (HETE), hydroxy-octadecadenoic acids (HODE), and oxo-octadecadenoic acids (oxoODE), were measured by mass spectrometry in plasma at time of liver biopsy in an initial cohort of 73 and a validation cohort of 49 consecutive patients. Of the markers monitored, 9- and 13-HODEs and 9- and 13-oxoODEs, products of free radical-mediated oxidation of linoleic acid (LA), were significantly elevated in patients with nonalcoholic steatohepatitis (NASH), compared with patients with steatosis. A strong correlation was revealed between these oxidation products and liver histopathology (inflammation, fibrosis, and steatosis). Further analyses of HODEs showed equivalent R and S chiral distribution. A risk score for NASH (oxNASH) was developed in the initial clinical cohort and shown to have high diagnostic accuracy for NASH versus steatosis in the independent validation cohort. Subjects with elevated oxNASH levels (top tertile) were 9.7-fold (P < 0.0001) more likely to have NASH than those with low levels (bottom tertile). Collectively, these findings support a key role for free radical-mediated linoleic acid oxidation in human NASH and define a risk score, oxNASH, for noninvasive detection of the presence of NASH.

Measurement of spleen volume is useful for distinguishing between simple steatosis and early-stage non-alcoholic steatohepatitis

AIM

Although non-alcoholic fatty liver disease (NAFLD) is now a common cause of chronic liver disease, discriminating between simple steatosis and non-alcoholic steatohepatitis (NASH), especially early-stage NASH, remains difficult. We investigated the clinical usefulness of measuring the spleen volume as a marker of early-stage NASH.

METHODS

We evaluated computed tomography (CT) images obtained in 84 patients with histologically diagnosed NAFLD (22 with simple steatosis, 62 with NASH with mild fibrosis [stages 1-2]). We defined the data obtained by the following formula as a spleen-body index (SBI): SBI = maximal CT axial section area of the spleen (cm(2))/body surface area (BSA) (cm(2)) x 10(4). We compared the SBI between patients with simple steatosis and those with NASH with mild fibrosis.

RESULTS

The mean SBI of the simple steatosis group was 15.8 +/- 3.9, while that of the NASH with mild fibrosis group was 18.7 +/- 5.7. This difference between the two groups was significant (P = 0.0314). A multiple logistic regression analysis showed that the SBI was significantly correlated with the discrimination of simple steatosis and NASH with mild fibrosis. The area under the receiver-operator curve was 0.661 for distinguishing between simple steatosis and NASH with mild fibrosis (P = 0.026, 95% confidence interval = 0.532-0.789).

CONCLUSION

Spleen enlargement may be a distinct feature of NASH, especially early-stage NASH. SBI might be a non-invasive and simple method of differentiating NASH and simple steatosis.

Severity of liver injury and atherogenic lipid profile in children with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. The aim of this study was to assess the relationship between severity of liver injury and atherogenic lipid profile in a large group of children with NAFLD. A total of 118 consecutive children with biopsy-proven NAFLD were included. Patients underwent extensive metabolic profiling. The NAFLD activity and fibrosis scores showed a significant positive correlation with triglyceride/HDL, total cholesterol/HDL, and LDL/HDL ratios (p<0.05) but not with apolipoprotein B/apolipoprotein A-1 ratio (p=0.58). After adjusting for BMI, homeostatic model assessment, impaired glucose tolerance, and presence of metabolic syndrome, both the NAFLD activity score and stage of fibrosis remained independent predictors of proatherogenic lipid profile. All lipid ratios, except for apolipoprotein B/apolipoprotein A-1, were found to be markedly higher in children with nonalcoholic steatohepatitis compared with those with simple steatosis or borderline disease (p<0.05). This study shows for the first time that in children with NAFLD, the severity of liver injury is strongly associated with the presence of a more atherogenic lipid profile, having potential significant diagnostic and therapeutic implications.

Nonalcoholic fatty liver disease/nonalcoholic steatohepatitis: histological diagnostic criteria and scoring systems

Nonalcoholic fatty liver disease (NAFLD) is recognized as the most common cause of chronic liver disease in western countries. NAFLD is etiologically associated with systemic and hepatic insulin resistance and is considered by many as the hepatic manifestation of the metabolic syndrome. NAFLD has a wide histological spectrum ranging from 'simple' steatosis to nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis. Hepatocellular carcinoma may occur in NASH-related cirrhosis. The diagnosis of NAFLD/NASH is based on clinico-pathological criteria. Currently available noninvasive tests for the diagnosis of NASH lack specificity and sensitivity, so liver biopsy, despite its limitations, still remains the 'golden standard' for confirming or excluding NASH in a patient with chronically-elevated liver enzymes and image-detected steatosis. This review examines the currently used criteria for the histopathological diagnosis of NAFLD/NASH in adults and children and the relevant histological scoring systems.

Effects of a 1-year dietary intervention with n-3 polyunsaturated fatty acid-enriched olive oil on non-alcoholic fatty liver disease patients: a preliminary study

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is a worldwide diffuse condition due to alimentary, environment and genetic factors. The aim of our preliminary study was to evaluate the effectiveness of long-term consumption of food enriched with n-3 polyunsaturated fatty acids (PUFA) in patients with NAFLD.

METHODS

Eleven patients were enrolled; six (four males, two females) were planned for oral administration of 6.5 ml olive oil enriched with n-3 PUFA for 12 months, while five (four males, one female) were used as controls.

RESULTS

Consumption of olive oil enriched with n-3 PUFA demonstrated a significant improvement of liver echo-texture and of the Doppler Perfusion Index after 12 months (after: 0.19 ± 0.02 vs. pre: 0.15 ± 0.03; P < 0.05), whereas no significant changes were seen at the end of follow-up in controls. Moreover, patients who consumed the olive oil enriched with n-3 PUFA showed a significant amelioration of liver enzymes, and of triglycerides (post: 132.8 ± 63.7 vs. pre: 164.5 ± 85.5 mg/dl; P = 0.04) in a general linear model adjusted for age and gender. Interestingly, patients reported to have a significant increase of adiponectin levels (post: 1,487.9 ± 96.7 vs. pre: 1,143 ± 24.8 μg/ml; P = 0.04).

CONCLUSION

The results of this preliminary study showed that long-term consumption of olive oil enriched with n-3 PUFA in patients with NAFLD is able to decrease circulating liver enzymes and triglycerides, with a significant improvement of adiponectin levels.

Inhibition of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2) prevents dietary cholesterol-associated steatosis by enhancing hepatic triglyceride mobilization

Acyl-CoA:cholesterol O-acyl transferase 2 (ACAT2) promotes cholesterol absorption by the intestine and the secretion of cholesteryl ester-enriched very low density lipoproteins by the liver. Paradoxically, mice lacking ACAT2 also exhibit mild hypertriglyceridemia. The present study addresses the unexpected role of ACAT2 in regulation of hepatic triglyceride (TG) metabolism. Mouse models of either complete genetic deficiency or pharmacological inhibition of ACAT2 were fed low fat diets containing various amounts of cholesterol to induce hepatic steatosis. Mice genetically lacking ACAT2 in both the intestine and the liver were dramatically protected against hepatic neutral lipid (TG and cholesteryl ester) accumulation, with the greatest differences occurring in situations where dietary cholesterol was elevated. Further studies demonstrated that liver-specific depletion of ACAT2 with antisense oligonucleotides prevents dietary cholesterol-associated hepatic steatosis both in an inbred mouse model of non-alcoholic fatty liver disease (SJL/J) and in a humanized hyperlipidemic mouse model (LDLr(-/-), apoB(100/100)). All mouse models of diminished ACAT2 function showed lowered hepatic triglyceride concentrations and higher plasma triglycerides secondary to increased hepatic secretion of TG into nascent very low density lipoproteins. This work demonstrates that inhibition of hepatic ACAT2 can prevent dietary cholesterol-driven hepatic steatosis in mice. These data provide the first evidence to suggest that ACAT2-specific inhibitors may hold unexpected therapeutic potential to treat both atherosclerosis and non-alcoholic fatty liver disease.

Proteomic analysis of serum in patients with non-alcoholic steatohepatitis using matrix-assisted laser desorption ionization time-of-flight mass spectrometry

OBJECTIVE

We sought to investigate whether serum proteomic pattern analysis obtained using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF-MS) may help to diagnose non-alcoholic steatohepatitis (NASH) in the setting of non-alcoholic fatty liver disease (NAFLD).

MATERIAL AND METHODS

We enrolled 80 patients with biopsy-proven NAFLD and 19 healthy comparison subjects. Patients with NAFLD were classified according to their liver histology as having definite NASH (n = 48), borderline NASH (n = 22) or simple steatosis (n = 10). Liver ultrasound scanning was performed to assess the degree of steatosis. Mass spectra of serum samples were obtained using a Ultraflex II mass spectrometer.

RESULTS

The highest accuracy for NASH diagnostics was reached using 15 peaks. Corresponding sensitivity and specificity values were 73.95% +/- 3.38% and 88.71% +/- 1.39%, respectively. However, mass spectra did not allow us to distinguish NASH from simple steatosis.

CONCLUSIONS

We conclude that proteomic analyses of serum samples from NAFLD patients by MALDI TOF-MS do not seem to have a major clinical value for diagnosing NASH. However, the identification of 15 peaks in our study may help to further elucidate the pathophysiology of NASH and merits further investigation.

Hepatic complications of obesity

Obesity is associated with a spectrum of chronic liver disease. Because obesity increases the risk for advanced forms of liver disease (ie, cirrhosis and liver cancer), the obesity epidemic is emerging as a major factor underlying the burden of liver disease in the United States and many other countries. This article reviews mechanisms that mediate the pathogenesis of obesity-related liver disease, summarizes clinical evidence that demonstrates obesity-related liver disease can be life-threatening, and discusses whether or not treatments for obesity or related comorbidities impact liver disease outcomes.

Non-alcoholic fatty liver disease: the hepatic consequence of obesity and the metabolic syndrome

Non-alcoholic fatty liver disease (NAFLD) is now the most common liver disease in both adults and children worldwide. As a disease spectrum, NAFLD may progress from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. An estimated 20–35% of the general population has steatosis, 10% of whom will develop the more progressive non-alcoholic steatohepatitis associated with markedly increased risk of cardiovascular- and liver-related mortality. Development of NAFLD is strongly linked to components of the metabolic syndrome including obesity, insulin resistance, dyslipidaemia and type 2 diabetes. The recognition that NAFLD is an independent risk factor for CVD is a major public health concern. There is a great need for a sensitive non-invasive test for the early detection and assessment of the stage of NAFLD that could also be used to monitor response to treatment. The cellular and molecular aetiology of NAFLD is multi-factorial; genetic polymorphisms influencing NAFLD have been identified and nutrition is a modifiable environmental factor influencing NAFLD progression. Weight loss through diet and exercise is the primary recommendation in the clinical management of NAFLD. The application of systems biology to the identification of NAFLD biomarkers and factors involved in NAFLD progression is an area of promising research.