Serum angiotensin-converting enzyme level for evaluating significant fibrosis in chronic hepatitis B

AIM To evaluate the diagnostic performance of angiotensinconverting enzyme(ACE)on significant liver fibrosis in patients with chronic hepatitis B(CHB). METHODS In total,100 patients with CHB who underwent liver biopsy in our hospital were enrolled,and 70 patients except for 30 patients with hypertension,fatty liver or habitual alcoholic consumption were analyzed.We compared histological liver fibrosis and serum ACE levels and evaluated the predictive potential to diagnose significant liver fibrosis by comparison with several biochemical marker-based indexes such as the aspartate aminotransferase(AST)-to-platelet ratio index(APRI),the fibrosis index based on four factors(FIB-4),the Mac-2 binding protein glycosylation isomer(M2BPGi)level and the number of platelets(Plt). RESULTS Serum ACE levels showed moderately positive correlation with liver fibrotic stages(R2=0.181).Patients with significant,advanced fibrosis and cirrhosis(F2-4)had significantly higher serum ACE levels than those with early-stage fibrosis and cirrhosis(F0-1).For significant fibrosis(≥F2),the 12.8 U/L cut-off value of ACE showed 91.7%sensitivity and 75.0%specificity.The receiver-operating characteristic(ROC)curves analysis revealed that the area under the curve(AUC)value of ACE was 0.871,which was higher than that of APRI,FIB-4,M2BPGi and Plt. CONCLUSION The serum ACE level could be a novel noninvasive,easy,accurate,and inexpensive marker of significant fibrosis stage in patients with CHB.

DNA methylation of angiotensin Ⅱ receptor gene in nonalcoholic steatohepatitis-related liver fibrosis

AIM To clarify whether Agtr1 a methylation is involved in the development of nonalcoholic steatohepatitis(NASH)-related liver fibrosis in adult rats.METHODS A choline-deficient amino acid(CDAA) diet model was employed for methylation analysis of NASH-related liver fibrosis.Agtr1 a methylation levels were measured in the livers of CDAA- and control choline-sufficient amino acid(CSAA)-fed rats for 8 and 12 wk using quantitative methylation-specific PCR.Hepatic stellate cells(HSCs) were isolated by collagenase digestion of the liver,followed by centrifugation of the crude cell suspension through a density gradient.Agtr1 a methylation and its gene expression were also analyzed during the activation of HSCs.RESULTS The mean levels of Agtr1 a methylation in the livers of CDAA-fed rats(11.5% and 18.6% at 8 and 12 wk,respectively) tended to be higher(P = 0.06 and 0.09,respectively) than those in the livers of CSAA-fed rats(2.1% and 5.3% at 8 and 12 wk,respectively).Agtr1 a was not methylated at all in quiescent HSCs,but was clearly methylated in activated HSCs(13.8%,P < 0.01).Interestingly,although Agtr1 a was hypermethylated,the Agtr1 a m RNA level increased up to 2.2-fold(P < 0.05) in activated HSCs compared with that in quiescent HSCs,suggesting that Agtr1 a methylation did not silence its expression but instead had the potential to upregulate its expression.These findings indicate that Agtr1 a methylation and its upregulation of gene expression are associated with the development of NASH-related liver fibrosis.CONCLUSION This is the first study to show that DNA methylation is potential y involved in the regulation of a renin-angiotensin system-related gene expression during liver fibrosis.