Patients with nonalcoholic fatty liver disease (NAFLD) and advanced liver fibrosis are at the highest risk for progressing to end-stage liver disease. We constructed and validated a scoring system consisting of routinely measured and readily available clinical and laboratory data to separate NAFLD patients with and without advanced fibrosis. A total of 733 patients with NAFLD confirmed by liver biopsy were divided into 2 groups to construct (n ‫؍‬ 480) and validate (n ‫؍‬ 253) a scoring system. Routine demographic, clinical, and laboratory variables were analyzed by multivariate modeling to predict presence or absence of advanced fibrosis. Age, hyperglycemia, body mass index, platelet count, albumin, and AST/ALT ratio were independent indicators of advanced liver fibrosis. A scoring system with these 6 variables had an area under the receiver operating characteristic curve of 0.88 and 0.82 in the estimation and validation groups, respectively. By applying the low cutoff score (؊1.455), advanced fibrosis could be excluded with high accuracy (negative predictive value of 93% and 88% in the estimation and validation groups, respectively). By applying the high cutoff score (0.676), the presence of advanced fibrosis could be diagnosed with high accuracy (positive predictive value of 90% and 82% in the estimation and validation groups, respectively). By applying this model, a liver biopsy would have been avoided in 549 (75%) of the 733 patients, with correct prediction in 496 (90%). Conclusion: a simple scoring system accurately separates patients with NAFLD with and without advanced fibrosis, rendering liver biopsy for identification of advanced fibrosis unnecessary in a substantial proportion of patients. (HEPATOLOGY 2007;45:846-854.)

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Contrary to current dogma, this study suggests that steatosis can progress to NASH and clinically significant fibrosis.

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The incidence of non-alcoholic fatty liver disease (NAFLD) increases with age. Cellular senescence refers to a state of irreversible cell-cycle arrest combined with the secretion of proinflammatory cytokines and mitochondrial dysfunction. Senescent cells contribute to age-related tissue degeneration. Here we show that the accumulation of senescent cells promotes hepatic fat accumulation and steatosis. We report a close correlation between hepatic fat accumulation and markers of hepatocyte senescence. The elimination of senescent cells by suicide gene-meditated ablation of p16Ink4a-expressing senescent cells in INK-ATTAC mice or by treatment with a combination of the senolytic drugs dasatinib and quercetin (D+Q) reduces overall hepatic steatosis. Conversely, inducing hepatocyte senescence promotes fat accumulation in vitro and in vivo. Mechanistically, we show that mitochondria in senescent cells lose the ability to metabolize fatty acids efficiently. Our study demonstrates that cellular senescence drives hepatic steatosis and elimination of senescent cells may be a novel therapeutic strategy to reduce steatosis.

The detection of fibrosis within nonalcoholic fatty liver disease (NAFLD) is important for ascertaining prognosis and the stratification of patients for emerging therapeutic intervention. We validated the Original European Liver Fibrosis panel (OELF) and a simplified algorithm not containing age, the Enhanced Liver fibrosis panel (ELF), in an independent cohort of patients with NAFLD. Furthermore, we explored whether the addition of simple markers to the existing panel test could improve diagnostic performance. One hundred ninety-six consecutively recruited patients from 2 centers were included in the validation study. The diagnostic accuracy of the discriminant scores of the ELF panel, simple markers, and a combined panel were compared using receiver operator curves, predictive values, and a clinical utility model. The ELF panel had an area under the curve (AUC) of 0.90 for distinguishing severe fibrosis, 0.82 for moderate fibrosis, and 0.76 for no fibrosis. Simplification of the algorithm by removing age did not alter diagnostic performance. Addition of simple markers to the panel improved diagnostic performance with AUCs of 0.98, 0.93, and 0.84 for the detection of severe fibrosis, moderate fibrosis, and no fibrosis, respectively. The clinical utility model showed that 82% and 88% of liver biopsies could be potentially avoided for the diagnosis of severe fibrosis using ELF and the combined panel, respectively. The ELF panel has good diagnostic accuracy in an independent validation cohort of patients with NAFLD. The addition of established simple markers augments the diagnostic performance across different stages of fibrosis, which will potentially allow superior stratification of patients with NAFLD for emerging therapeutic strategies. (HEPATOLOGY 2008;47:455-460.)

OBJECTIVES:Non-invasive fibrosis scores are widely used to identify/exclude advanced fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). However, these scores were principally developed and validated in patients aged between 35 and 65 years of age. The objective of this study was to assess the effect of age on the performance of non-invasive fibrosis tests in NAFLD.METHODS:Patients were recruited from European specialist hepatology clinics. The cohort was divided into five age-based groups: ≤35 (n=74), 36–45 (n=96), 46–55 (n=197), 56–64 (n=191), and ≥65 years (n=76), and the performance of the aspartate aminotransferase (AST)/alanine transaminase (ALT) ratio, fibrosis 4 (FIB-4), and NAFLD fibrosis score (NFS) for advanced fibrosis (stage F3–F4) for each group was assessed using liver biopsy as the standard.RESULTS:Six hundred and thirty-four patients were included. The diagnostic accuracy of the AST/ALT ratio was lower than NFS and FIB-4 in all the age groups. The AST/ALT ratio, NFS, and FIB-4 score performed poorly for a diagnosis of advanced fibrosis in those aged ≤35 years (area under the receiver operating characteristic curves (AUROCs 0.52, 0.52, and 0.60, respectively). For all groups >35 years, AUROCs for advanced fibrosis were similar for the NFS and FIB-4 score (range 0.77–0.84). However, the specificity for advanced fibrosis using the FIB-4 and NFS declined with age, becoming unacceptably low in those aged ≥65 years (35% for FIB-4 and 20% for NFS). New cutoffs were derived (and validated) for those aged ≥65 years, which improved specificity to 70% without adversely affecting sensitivity (FIB-4 2.0, sensitivity 77% NFS 0.12, sensitivity 80%).CONCLUSIONS:The NFS and FIB-4 scores have similar accuracy for advanced fibrosis in patients aged >35 years. However, the specificity for advanced fibrosis is unacceptably low in patients aged ≥65 years, resulting in a high false positive rate. New thresholds for use in patients aged ≥65 years are proposed to address this issue.

Non-alcoholic fatty liver disease (NAFLD) is an increasingly common condition, strongly associated with the metabolic syndrome, that can lead to progressive hepatic fibrosis, cirrhosis and hepatic failure. Subtle inter-patient genetic variation and environmental factors combine to determine variation in disease progression. A common non-synonymous polymorphism in TM6SF2 (rs58542926 c.449 C>T, p.Glu167Lys) was recently associated with increased hepatic triglyceride content, but whether this variant promotes clinically relevant hepatic fibrosis is unknown. Here we confirm that TM6SF2 minor allele carriage is associated with NAFLD and is causally related to a previously reported chromosome 19 GWAS signal that was ascribed to the gene NCAN. Furthermore, using two histologically characterized cohorts encompassing steatosis, steatohepatitis, fibrosis and cirrhosis (combined n=1,074), we demonstrate a new association, independent of potential confounding factors (age, BMI, type 2 diabetes mellitus and PNPLA3 rs738409 genotype), with advanced hepatic fibrosis/cirrhosis. These findings establish new and important clinical relevance to TM6SF2 in NAFLD.