Cholestasis is the main determinant of abnormal CA 19-9 levels in patients with liver cirrhosis

Background/Aims: Altered CA19-9 levels are commonly found in patients with liver cirrhosis though a clear explanation for this finding has not yet been given. The aim of this study was to investigate whether CA19-9 levels might be related to alterations in biochemical parameters and/or to functional impairment in cirrhotic patients with and without hepatocellular carcinoma. Methods: We studied 126 patients with liver cirrhosis, 60 of whom also had hepatocellular carcinoma. CA19-9 values were related to clinical, biochemical and functional parameters. In half of the patients CA19-9 levels were related to the monoethylglycinexylidide test, which is a dynamic liver function test. Results: In more than half the cases CA19-9 values were above the upper limit. Liver function worsening as assessed by Child-Pugh's score and monoethylglycinexylidide test did not seem to influence the alteration of the marker. By contrast, in univariate analysis CA19-9 correlated with aminotransferases, gamma-glutamyltransferase and alkaline phosphatase. Multivariate analysis showed that besides alkaline phosphatase also the presence of hepatocellular carcinoma might influence the alteration of CA19-9, although the marker was of no use for the diagnosis of liver cancer in patients with altered though not diagnostic alpha-fetoprotein levels. Conclusions: In our study we confirmed the correlation of CA19-9 levels with cholestasis and cytolysis parameters. Moreover, we found no association between CA19-9 levels and impaired liver function as assessed by means of the Child-Pugh's score and the monoethylglycinexylidide test, which is cholestasis-independent and explores liver metabolic and clearance activities. The cholestatic picture that characterizes liver cirrhosis might enhance the expression and passage of the marker from the bile to the blood. The addition of CA19-9 assessment is not useful for the diagnosis of hepatocellular carcinoma in patients with non-diagnostic levels of alpha-fetoprotein. Caution should therefore be used when evaluating CA19-9 in cirrhotic patients with cholestasis, since false positive results may occur.