Utility and appropriateness of the fatty liver inhibition of progression (FLIP) algorithm and steatosis, activity, and fibrosis (SAF) score in the evaluation of biopsies of nonalcoholic fatty liver disease

Prognostic value of liver fibrosis and steatosis biomarkers in type-2 diabetes and dyslipidaemia

BACKGROUND

In cardiometabolic disorders, non-alcoholic fatty liver disease is frequent and presumably associated with increased mortality and cardiovascular risk.

AIM

To evaluate the prognostic value of non-invasive biomarkers of liver fibrosis (FibroTest) and steatosis (SteatoTest) in patients with type-2 diabetes and/or dyslipidaemia.

METHODS

A total of 2312 patients with type-2 diabetes and/or dyslipidaemia were included and prospectively followed up for 5-15 years. The cardiovascular Framingham-risk score was calculated; advanced fibrosis and severe steatosis, were defined by FibroTest >0.48 and SteatoTest >0.69, respectively, as previously established.

RESULTS

During a median follow-up of 12 years, 172 patients (7.4%) died. The leading causes of mortality were cancer (31%) and cardiovascular-related death (20%). The presence of advanced fibrosis [HR (95% CI)] [2.98 (95% CI 1.78-4.99); P < 0.0001] or severe steatosis [1.86 (1.34-2.58); P = 0.0002] was associated with an increased risk of mortality. In a multivariate Cox model adjusted for confounders: the presence of advanced fibrosis was associated with overall mortality [1.95 (1.12-3.41); P = 0.02]; advanced fibrosis at baseline [n = 50/677; 1.92 (1.04-3.55); P = 0.04] and progression to advanced fibrosis during follow-up [n = 16/127; 4.8 (1.5-14.9); P = 0.007] were predictors of cardiovascular events in patients with type-2 diabetes. In patients with a Framingham-risk score ≥20%, the presence of advanced fibrosis was predictive of cardiovascular events [2.24 (1.16-4.33); P < 0.05].

CONCLUSIONS

Liver biomarkers, such as FibroTest and SteatoTest, have prognostic values in patients with metabolic disorders. FibroTest has prognostic value for predicting overall survival in patients with type-2 diabetes and/or dyslipidaemia. In type-2 diabetes, FibroTest predicted cardiovascular events and improved the Framingham-risk score.

Pathological features of fatty liver disease

Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are significant causes of chronic liver disease worldwide. Both are characterized by histological lesions that can include steatosis, and each can lead to cirrhosis. It might be possible for pathologists to identify lesions and patterns of ALD and NAFLD; we review these lesions and propose methods to distinguish between the disorders. Any form of ALD can lead to end-stage liver disease, according to long-term studies of biopsy specimens and patient outcomes. Although steatosis can be a significant cofactor in progression of established chronic liver disease, or even development of hepatocellular carcinoma, only steatohepatitis indicates the presence of progressive liver disease in patients with NAFLD. Pediatric and adolescent NAFLD differ from adult nonalcoholic steatohepatitis and should be recognized as distinct conditions. Benign and malignant liver tumors have been more frequently reported with the increasing prevalence of obesity and diabetes. Histological scoring systems for ALD and NAFLD have been proposed to monitor efficacy in clinical trials and serve as prognostic factors. We review what we have learned from pathological analyses about the development of these disorders and how this information might be used to detect and treat them.

TM6SF2 rs58542926 influences hepatic fibrosis progression in patients with non-alcoholic fatty liver disease

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.

Non-alcoholic fatty liver disease (NAFLD) is characterized by increased hepatic triglyceride content (HTGC) in the absence of high alcohol consumption. Here the authors show that a genetic variant in TM6SF2, which is known to be associated with HTGC, is a clinically relevant modifier of hepatic fibrogenesis and increases the risk of progressive NAFLD.