Liver stiffness in extrahepatic cholestasis correlates positively with bilirubin and negatively with alanine aminotransferase

Aim: Transient elastography is a non-invasive tool to measure liver stiffness (LS), which has been reported to correlate with stage of liver fibrosis. Extrahepatic cholestasis was reported to cause elevated LS, which is considered to be attributed to the increased hydrostatic pressure in the liver. In the present study, the correlation of LS with laboratory data was investigated in extrahepatic cholestasis. The change of LS after biliary drainage was also assessed. Methods: LS was measured in 29 patients with extrahepatic cholestasis due to carcinomas in 12 and non-neoplastic diseases of biliary tract or pancreas in 17. Results: In 15 patients, LS was 11.4kPa or higher which suggested liver cirrhosis in chronic infection of hepatitis C virus. LS significantly correlated positively with serum bilirubin levels (r=0.726, P<0.0001) and negatively with serum aspartate aminotransferase (AST) levels (r=-0.481, P=0.0082) and alanine aminotransferase (ALT) levels (r=-0.631, P=0.0002). Biliary drainage led to a reduction of bilirubin by 13.5 to 0.9mg/dL which was significantly correlated with a reduction of LS by 14.3 to 0.5kPa (r=0.524, P=0.0257). Conclusion: In extrahepatic cholestasis, the elevation of LS which is probably attributed to the increased hydrostatic pressure in the liver, correlates positively with the accumulation of bilirubin but negatively with damage of hepatocytes indicated by ALT levels. Further studies on the mechanism underlying the elevation of LS should be helpful to elucidate the pathogenesis of extrahepatic cholestasis.