Various biochemical indexes discriminate neoplastic from nonneoplastic
ascites. However, within the latter group, the distinction between cirrhotic
ascites and
ascites caused by hepatocarcinoma (HC) is usually based on liver biopsy or cytology. HC-derived
ascites is included in the group of nonneoplastic
ascites because it is not associated with peritoneal spreading of neoplastic cells. In 54 cases of cirrhotic
ascites and 17 cases of HC
ascites, all histologically diagnosed, ascitic
pseudouridine concentrations discriminated cirrhotic from HC
ascites. For example, using the cutoff value of 4.25 mumol/L (obtained by ROC curve analysis) resulted in a diagnostic sensitivity of 88.2% and a diagnostic specificity of 90.8%. Moreover, in
cirrhosis, the ascitic concentrations of
pseudouridine were lower than serum concentrations, and the two sets of values were correlated; in HC, however, ascitic
pseudouridine concentrations were higher than serum concentrations, and the two were unrelated. These findings strongly suggest that in cirrhotic patients ascitic
pseudouridine derives from serum by diffusion, whereas in HC patients the mechanism appears to be more complex.