Arian Afendy

Independent Predictors of Fibrosis in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. We investigated factors associated with advanced fibrosis in NAFLD. METHODS The study included 432 patients with histologically proven NAFLD (26.8% with nonalcoholic steatohepatitis [NASH] and 17.4% with moderate-to severe fibrosis). NASH was defined as steatosis, lobular inflammation, and ballooning degeneration with or without Mallory-Denk bodies and/or fibrosis. Fibrosis was classified into 2 groups: those with no or minimal fibrosis and those with moderate-to-severe fibrosis. Groups were compared using Mann-Whitney and chi-square method analyses. A model was constructed using a stepwise bidirectional method; its predictive power was measured using a 10-fold cross-validation technique. RESULTS Patients with NASH were more likely to be male (P < .0001); have lower hip-to-waist ratios (P = .03); were less likely to be African American (P = .06); have higher levels of alanine aminotransferase (ALT; P < .0001), aspartate aminotransferase (AST; P < .0001), and serum triglycerides (P = .0154), but lower levels of high-density lipoprotein cholesterol (P < .0001). Patients with moderate-to-severe fibrosis were older (P = .0245); more likely to be male (P = .0189), Caucasian (P = .0382), have diabetes mellitus (P = .0238), and hypertension (P = .0375); and have a lower hip-to-waist ratio (P = .0077) but higher serum AST (P < .0001) and ALT (P < .0001) levels. The multivariate analysis model to predict moderate-to-severe fibrosis included male sex, Caucasian ethnicity, diabetes mellitus, and increased AST and ALT levels (model P value < .0001). CONCLUSIONS In patients with NAFLD, diabetes mellitus and aminotransferase levels are independent predictors of moderate-to-severe fibrosis. They can be used to identify NAFLD patients at risk for advanced fibrosis.

A Biomarker Panel for Non-alcoholic Steatohepatitis (NASH) and NASH-Related Fibrosis

BackgroundPatients with biopsy-proven NASH and especially those with fibrosis are at risk for progressive liver disease, emphasizing the clinical importance of developing non-invasive biomarkers for NASH and NASH-related fibrosis.AimThis study examines the performance of a new biomarker panel for NASH and NASH-related fibrosis with a combination of clinical and laboratory variables.MethodsEnrolled patients had biopsy-proven NAFLD. Clinical data, laboratory data, and serum samples were collected at the time of biopsy. Fasting serum was assayed for adiponectin, resistin, glucose, M30, M65, Tissue inhibitor of metalloproteinases-1 (Timp-1), ProCollagen 3 N-terminal peptide (PIIINP), and hyaluronic acid (HA). Regression models predictive of NASH, NASH-related fibrosis, and NASH-related advanced fibrosis were designed and cross-validated.ResultsOf the 79 enrolled NAFLD patients, 40 had biopsy-proven NASH and 39 had non-NASH NAFLD. Clinical and laboratory data were from this cohort were used to develop a NAFLD Diagnostic Panel that includes three models (models for NASH, NASH-related fibrosis, and NASH-related advanced fibrosis). The model for predicting NASH includes diabetes, gender, BMI, triglycerides, M30 (apoptosis), and M65–M30 (necrosis) [AUC: 0.81, 95% CI, 0.70–0.89, 300 p value <9E 301 −06]. The NASH-related fibrosis prediction model includes the same predictors [AUC: 0.80, 95% CI 0.68–0.88, 307 p value <0.00014]. Finally, the NASH-related advanced fibrosis model includes type 2 diabetes, serum triglycerides, Timp-1, and AST [AUC: 0.81, 95% CI, 0.70–0.89; p value, 0.000062].ConclusionsThis NAFLD Diagnostic Panel based on a clinical and laboratory data has good performance characteristics and is easy to use. This biomarker panel could become useful in the management of patients with NAFLD.

Gene Expression of Leptin, Resistin, and Adiponectin in the White Adipose Tissue of Obese Patients with Non-Alcoholic Fatty Liver Disease and Insulin Resistance

Background: Adipose tissue is an active endocrine organ that secretes a variety of metabolically important substances including adipokines. These factors affect insulin sensitivity and may represent a link between obesity, insulin resistance, type 2 diabetes (DM), and nonalcoholic fatty liver disease (NAFLD). This study uses real-time polymerase chain reaction (PCR) quantification of mRNAs encoding adiponectin, leptin, and resistin on snap-frozen samples of intra-abdominal adipose tissue of morbidly obese patients undergoing bariatric surgery. Methods: Morbidly obese patients undergoing bariatric surgery were studied. Patients were classified into two groups: Group A (with insulin resistance) (N=11; glucose 149.84 ± 40.56 mg/dL; serum insulin 8.28 ± 3.52 μU/mL), and Group B (without insulin resistance) (N=10; glucose 102.2 ± 8.43 mg/dL; serum insulin 3.431 ± 1.162 μU/mL). Results: Adiponectin mRNA in intra-abdominal adipose tissue and serum adiponectin levels were significantly lower in Group A compared to Group B patients (P<0.016 and P<0.03, respectively). Although serum resistin was higher in Group A than in Group B patients (P<0.005), resistin gene expression was not different between the two groups. Finally, for leptin, neither serum level nor gene expression was different between the two groups. Serum adiponectin level was the only predictor of nonalcoholic steatohepatitis (NASH) in this study (P=0.024). Conclusions: Obese patients with insulin resistance have decreased serum adiponectin and increased serum resistin. Additionally, adiponectin gene expression is also decreased in the adipose tissue of these patients. This low level of adiponectin expression may predispose patients to the progressive form of NAFLD or NASH.

Predictors of health-related quality of life in patients with chronic liver disease

Background  Patient‐reported outcomes like health‐related quality of life (HRQL) have become increasingly important for full assessment of patients with chronic liver diseases (CLD).

Apnoeic–hypopnoeic episodes during obstructive sleep apnoea are associated with histological nonalcoholic steatohepatitis

Background: Nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnoea are associated with metabolic syndrome and atherosclerotic heart disease. This study evaluates the potential association between the NAFLD subtypes and a number of polysomnographical (PSG) parameters.

Validation of endogenous reference genes for qRT-PCR analysis of human visceral adipose samples

BackgroundGiven the epidemic proportions of obesity worldwide and the concurrent prevalence of metabolic syndrome, there is an urgent need for better understanding the underlying mechanisms of metabolic syndrome, in particular, the gene expression differences which may participate in obesity, insulin resistance and the associated series of chronic liver conditions. Real-time PCR (qRT-PCR) is the standard method for studying changes in relative gene expression in different tissues and experimental conditions. However, variations in amount of starting material, enzymatic efficiency and presence of inhibitors can lead to quantification errors. Hence the need for accurate data normalization is vital. Among several known strategies for data normalization, the use of reference genes as an internal control is the most common approach. Recent studies have shown that both obesity and presence of insulin resistance influence an expression of commonly used reference genes in omental fat. In this study we validated candidate reference genes suitable for qRT-PCR profiling experiments using visceral adipose samples from obese and lean individuals.ResultsCross-validation of expression stability of eight selected reference genes using three popular algorithms, GeNorm, NormFinder and BestKeeper found ACTB and RPII as most stable reference genes.ConclusionsWe recommend ACTB and RPII as stable reference genes most suitable for gene expression studies of human visceral adipose tissue. The use of these genes as a reference pair may further enhance the robustness of qRT-PCR in this model system.

A systems biology approach to the pathogenesis of obesity-related nonalcoholic fatty liver disease using reverse phase protein microarrays for multiplexed cell signaling analysis†

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. Omental adipose tissue, a biologically active organ secreting adipokines and cytokines, may play a role in the development of NAFLD. We tested this hypothesis with reverse‐phase protein microarrays (RPA) for multiplexed cell signaling analysis of adipose tissue from patients with NAFLD. Omental adipose tissue was obtained from 99 obese patients. Liver biopsies obtained at the time of surgery were all read by the same hepatopathologist. Adipose tissue was exposed to rapid pressure cycles to extract protein lysates. RPA was used to investigate intracellular signaling. Analysis of 54 different kinase substrates and cell signaling endpoints showed that an insulin signaling pathway is deranged in different locations in NAFLD patients. Furthermore, components of insulin receptor–mediated signaling differentiate most of the conditions on the NAFLD spectrum. For example, PKA (protein kinase A) and AKT/mTOR (protein kinase B/mammalian target of rapamycin) pathway derangement accurately discriminates patients with NASH from those with the non‐progressive forms of NAFLD. PKC (protein kinase C) delta, AKT, and SHC phosphorylation changes occur in patients with simple steatosis. Amounts of the FKHR (forkhead factor Foxo1)phosphorylated at S256 residue were significantly correlated with AST/ALT ratio in all morbidly obese patients. Furthermore, amounts of cleaved caspase 9 and pp90RSK S380 were positively correlated in patients with NASH. Specific insulin pathway signaling events are altered in the adipose tissue of patients with NASH compared with patients with nonprogressive forms of NAFLD. Conclusion: These findings provide evidence for the role of omental fat in the pathogenesis, and potentially, the progression of NAFLD. (HEPATOLOGY 2007;46:166–172.)

Expression of Cytokine Signaling Genes in Morbidly Obese Patients with Non-Alcoholic Steatohepatitis and Hepatic Fibrosis

BackgroundWhite adipose tissue (WAT) from visceral adiposity plays an important role in the pathogenesis of non-alcoholic steatohepatitis (NASH). Development of NASH and its progression to fibrosis is partially due to cytokines and adipokines produced by WAT. The aim of this study was to assess the association of hepatic fibrosis and NASH by evaluating the intrinsic differences in the inflammatory cytokine signaling in the visceral adipose tissue obtained from morbidly obese patients.MethodsWe used targeted microarrays representing human genes involved in the inflammatory and fibrogenic reactions to profile visceral adipose samples of 15 well-matched NASH patients with and without fibrosis. Additionally, visceral adipose samples were subjected to real-time polymerase chain reaction profiling of 84 inflammations related genes.ResultsEight genes (CCL2, CCL4, CCL18, CCR1, IL10RB, IL15RA, and LTB) were differentially expressed in NASH with fibrosis. Additionally, an overlapping but distinct list of the differentially expressed genes were found in NASH with type II diabetes (DM; IL8, BLR1, IL2RA, CD40LG, IL1RN, IL15RA, and CCL4) as compared to NASH without DM.ConclusionsInflammatory cytokines are differentially expressed in the adipose tissue of NASH with fibrosis, as well in NASH with DM. These findings point at the interaction of adipose inflammatory cytokines, DM, hepatic fibrosis in NASH, and its progression to cirrhosis and end-stage liver disease.

Early gene expression profiles of patients with chronic hepatitis C treated with pegylated interferon‐alfa and ribavirin

Responsiveness to hepatitis C virus (HCV) therapy depends on viral and host factors. Our aim was to assess sustained virologic response (SVR)‐associated early gene expression in patients with HCV receiving pegylated interferon‐alpha2a (PEG‐IFN‐α2a) or PEG‐IFN‐α2b and ribavirin with the duration based on genotypes. Blood samples were collected into PAXgene tubes prior to treatment as well as 1, 7, 28, and 56 days after treatment. From the peripheral blood cells, total RNA was extracted, quantified, and used for one‐step reverse transcription polymerase chain reaction to profile 154 messenger RNAs. Expression levels of messenger RNAs were normalized with six “housekeeping” genes and a reference RNA. Multiple regression and stepwise selection were performed to assess differences in gene expression at different time points, and predictive performance was evaluated for each model. A total of 68 patients were enrolled in the study and treated with combination therapy. The results of gene expression showed that SVR could be predicted by the gene expression of signal transducer and activator of transcription‐6 (STAT‐6) and suppressor of cytokine signaling‐1 in the pretreatment samples. After 24 hours, SVR was predicted by the expression of interferon‐dependent genes, and this dependence continued to be prominent throughout the treatment. Conclusion: Early gene expression during anti‐HCV therapy may elucidate important molecular pathways that may be influencing the probability of achieving virologic response. (HEPATOLOGY 2009.)

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.