Fetuin A is a Predictor of Liver Fat in Preoperative Patients with Nonalcoholic Fatty Liver Disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are frequent comorbidities in perioperative patients. However, the predictive role of the hepatokine fetuin A was not evaluated in this collective. OBJECTIVE: To study fetuin A as predictor of NAFLD/NASH in preoperative patients. METHODS: 58 subjects were included. Fetuin A was studied in patients undergoing open abdominal surgery and in a subset with acute liver failure. Blood and liver specimens were sampled. NAFLD was histologically evaluated. Liver fat was additionally analyzed by an enzymatic approach, circulating fetuin A by enzyme linked-immunosorbent assay, fetuin A mRNA by reverse-transcription PCR. RESULTS: Univariate correlation studies linked fetuin A to liver steatosis (r = 0.40, p = .029) and hepatocellular ballooning degeneration (r = 0.34, p = .026). Compared to non-NAFLD subjects fetuin A was increased in NAFLD (p = .009) and in NASH (p = .029). However, when corrected for main confounders by linear modeling, fetuin A remained related to hepatic steatosis, but not to ballooning degeneration or other NAFLD features. In support of this, biochemically analyzed liver lipids correlated with fetuin A in plasma (r = 0.34, p = .033) and with hepatic fetuin A mRNA (r = 0.54, p < .001). In addition, plasma fetuin A was related to hepatic mRNA (r = 0.32, p = .036), while circulating levels were reduced by 64% with acute liver failure (p < .001), confirming the liver as main fetuin A source. CONCLUSION: Fetuin A is suggested as noninvasive biomarker of hepatic steatosis in preoperative settings.

Elevated hepatic chemerin mRNA expression in human non-alcoholic fatty liver disease.

OBJECTIVE: Adipose tissue-derived factors link non-alcoholic fatty liver disease (NAFLD) with obesity, which has also been reported for circulating chemerin. On the other hand, hepatic chemerin and chemokine-like receptor 1 (CMKLR1) mRNA expression has not yet been studied in an extensively characterized patient collective. DESIGN: This study was cross-sectional and experimental in design. METHODS: Liver tissue samples were harvested from 47 subjects and histologically examined according to the NAFLD activity score (NAS). The concentrations of chemerin and CMKLR1 were measured using semi-quantitative real-time PCR, and the concentration of serum chemerin was measured using ELISA. To evaluate potential effects of chemerin and CMKLR1, cultured primary human hepatocytes (PHHs) were exposed to selected metabolites known to play a role in NAFLD (insulin, glucagon, palmitoic acid, and interleukin-6 (IL6)). RESULTS: Chemerin and CMKLR1 mRNA levels were elevated in the human liver. Their expression was correlated with the NAS (R(2)=0.543; P<0.001 and R(2)=0.355; P=0.014 respectively) and was significantly elevated in patients with definite non-alcoholic steatohepatitis (NASH) (P<0.05 respectively). Linear regression analysis confirmed an independent association of liver fibrosis, steatosis, inflammation, and hepatocyte ballooning with hepatic chemerin mRNA expression (P<0.05 respectively). The expression of hepatic chemerin and CMKLR1 was correlated with the measures of obesity (P<0.05). The incubation of PHHs with IL6 significantly increased the expression of CMKLR1 mRNA (P=0.027), while that of chemerin remained unaffected (P>0.05). None of the other metabolites showed an influence (P>0.05). CONCLUSION: This is the first study to show that chemerin mRNA expression is significantly elevated in the liver of NASH patients and that CMKLR1 expression is upregulated in liver inflammation, whereby IL6 could play a causal role.