Steatosis correlates with hepatic expression of death receptors and activation of nuclear factor-kappaB in chronic hepatitis C.

BACKGROUND

Steatosis is recognized as a predictor of the severity as well as the progression of fibrosis in chronic hepatitis C. The mechanisms that cause increased hepatocellular injury associated with steatosis remain largely unknown.

METHODS

We studied the correlation of hepatic expression of death receptors: Fas and tumour necrosis factor-alpha receptor 1 (TNF-R1), and downstream caspase (caspase-3) with hepatic steatosis by immunohistochemical study in chronic hepatitis C and determined the role of nuclear factor-kappaB (NF-kappaB).

RESULTS

Ninety patients (49 males and 41 females, mean age of 50.5 +/- 10.4 years, genotype 1 or 2) with chronic hepatitis C virus infection were recruited. The factors associated with steatosis grade were body mass index (P=0.004) and fibrosis stage (P=0.034). Moderate/severe steatosis was an independent variable associated with advanced fibrosis stage by stepwise logistic regression analysis. The expression of immunoreactivity for Fas, TNF-R1 and active caspases-3 in liver tissues was significantly correlated with the steatosis grade (P<0.001, P<0.001 and P<0.001 respectively). The extent of active caspases-3 correlated significantly with the expression of Fas (r=0.659, P<0.001) and TNF-R1 (r=0.617, P<0.001). NF-kappaB p65 expression correlated significantly with the extent of Fas (r=0.405, P<0.001), TNF-R1 (r=0.448, P=0.002) and active caspase-3 (r=0.313, P=0.003), and correlated with steatosis grade (P<0.001) but not with inflammatory and fibrosis scores.

CONCLUSION

Our observations suggest a mechanism whereby steatosis contributes to the progression of liver injury in chronic hepatitis C through upregulation of death receptors and activation of NF-kappaB.