Adenosine deaminase isoenzymes and neopterin in liver cirrhosis

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 ADA(1). 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, ADA(1), ADA(2) 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 ADA(2) 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 ADA(2) and neopterin. Our data show that liver insufficiency and HCV infection increase the serum levels of ADA and its major isoenzyme ADA(2). Furthermore, ADA isoenzyme determination adds no value to total ADA value. The absence of a correlation between ADA(2) and neopterin suggests that different physiologic processes are involved in their increase.