Adenosine deaminase isoenzymes and neopterin in liver cirrhosis.

The aim of this study was to define the pattern of neopterin and ADA isoenzymes in liver cirrhosis. A total of 117 patients with liver cirrhosis were included. Serum levels of ADA were assayed in the presence and absence of a specific inhibitor for ADA1. Serum neopterin was measured using a competitive enzyme-linked immunosorbent assay. The grade of liver insufficiency was assessed according to the Child-Pugh classification and the monoethylglycinexylidide test. Serum ADA, ADA1, ADA2 and neopterin were higher in cirrhotic patients than in control subjects. A stepwise increase in serum ADA level was observed with increasing severity of liver cirrhosis. The probability of ADA2 being greater than the mean was approximately 2.5 times higher (2.48, CI 95%: 1.36-4.52) in patients with liver cirrhosis due to hepatitis C virus (HCV) infection than in those patients with cirrhosis of a different etiology. No correlation was found between ADA2 and neopterin. Our data show that liver insufficiency and HCV infection increase the serum levels of ADA and its major isoenzyme ADA2. Furthermore, ADA isoenzyme determination adds no value to total ADA value. The absence of a correlation between ADA2 and neopterin suggests that different physiologic processes are involved in their increase.