Changes in some nucleoside metabolizing enzymes of lymphocytes and granulocytes from patients with cirrhosis of the liver

Abstract

Some purine metabolizing enzymes of lymphocytes and granulocytes were determined in 13 patients with cirrhosis of the liver and in a control group consisting of 18 healthy blood donors. Furthermore cytidine deaminase (EC 3, 5, 4, 5) (CRD) activity was determined in the granulocytes of these patients and in 16 controls. An increase of adenosine deaminase (EC 3, 5, 4, 4) (ADA) activity was found in granulocytes (P < 0.01) as well as in lymphocytes (P < 0.01) of the cirrhotic patients as compared to controls. Purine nucleoside phosphorylase (EC 2, 4, 2, 1) (PNP) activity in granulocytes and lymphocytes was identical in the two groups. In lymphocytes of cirrhotic patients decreased hypoxanthine guanine phosphoribosyltransferase (EC 2, 4, 2, 8) (HGPRT) (P < 0.01), adenine phosphoribosyltransferase (EC 2, 4, 2, 7) (APRT) (P < 0.02) and adenosine kinase activities (EC 2, 7, 1, 20) (AK) (P < 0.05) were demonstrated. 5′-nucleotidase (5′-N (EC 3, 1, 3, 5) activity in lymphocytes of cirrhotic patients was slightly increased, the increase being correlated to the level of serum gamma globulin. Granulocytes from cirrhotic patients showed a decrease of CRD (P < 0.05).

The finding that ADA activity is increased in mature lymphocytes and granulocytes from cirrhotic patients argues against the possibility that increase of lymphocytes ADA activity is a consequence of malignant transformation or immaturity.

Key Words:

• adenine phosphoribosyltransferase
• adenosine deaminase
• adenosine kinase, cytidine deaminase
• hypoxanthine guanine phosphoribosyltransferase
• 5′-nucleotidase
• purine nucleoside phosphorylase