Background/aims: Hepatic innervation in liver diseases is not fully understood. We here evaluated S100B expression as a marker of hepatic nerves in patients with various chronic liver diseases, topographically and semi-quantitatively.
Methods: Liver specimens were obtained from 70 subjects (three controls, and 32 chronic hepatitis B, 14 chronic hepatitis C, 14 liver cirrhosis, and seven hepatocellular carcinoma patients). The hepatic nerve density was calculated based on immunohistochemical staining of S100B protein in the portal tracts and hepatic lobules. S100B mRNA levels were semi-quantitatively assessed as the S100B/glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA ratio.
Results: The densities of the hepatic nerves in portal tracts of chronic liver diseases were not significantly different from those of normal controls but the hepatic nerve densities in lobular areas of liver cirrhosis were significantly decreased (p = 0.025). Compared to the control, the S100B/GAPDH mRNA ratio was significantly decreased in chronic liver diseases (p = 0.006) and most decreased in chronic hepatitis C patients (p = 0.023). In chronic liver diseases, The S100B/GAPDH mRNA ratio tended to decrease as the fibrosis score > 0 (p = 0.453) but the overall correlation between the S100B/GAPDH mRNA ratio and fibrosis score was not statistically significant (r = 0.061, p = 0.657).
Conclusions: Hepatic innervation is decreased in cirrhotic regenerating nodules compared to the control group and seems to decrease in early stages of fibrosis progression. Further studies are needed to clarify the association between changes of hepatic innervation and chronic liver disease progression.
Keywords: Chronic liver disease; Fibrosis; Hepatitis; Nerve fibers; S100 proteins.