LIVER-TYPE ARGINASE IN SERUM DURING AND AFTER LIVER-TRANSPLANTATION -A NOVEL INDEX IN MONITORING CONDITIONS OF THE LIVER GRAFT AND ITS CLINICAL-SIGNIFICANCE

We quantified Liver-type arginase in sera of 47 patients undergoing pa rtial Liver transplantation with use of an ELISA method. The level of liver-type arginase fluctuated slightly beyond the normal range in suc cessful Liver recipients, while it changed more drastically or precipi tously in unsuccessful ones, accompanying or unaccompanying elevation of AST and ALT levels. A higher elevation pattern of the arginase leve l (above 100 ng ml(-1)) was observed in each of the unsuccessful recip ients with critical condition, except for one patient. Other hepatic m arkers (LDH, ALP, and T-BIL) remained relatively unchanged until the t erminal stage of deceasing patients. The finding that the liver-type a rginase emerged in large quantity in the blood stream immediately afte r reperfusion of the liver graft indicates that the enzyme leaks out o f hepatocytes damaged, presumably, by storage in the absence of circul ation. A half-life of the liver-type arginase in the human blood was e stimated to be 1 h, that is clearly shorter than that of BST. The shor t half-life of the arginase appears to be ascribable, at least partly, to formation of an immune complex with circulating autoantibody which appears in many liver recipients. These results suggest that liver-ty pe arginase behaves uniquely in the serum among many hepatic enzymes, and could serve as a distinct marker of hepatic lesions, particularly during and after liver transplantation. (C) 1998 Elsevier Science B.V.