The postoperative course of gamma-glutamyl transpeptidase - a marker of cytomegalovirus (CMV) replication risk?

Cytomegalovirus (CMV) infection is a common complication in the postoperati ve course of liver transplantation. In order to start early prophylactic th erapy, but to avoid unnecessary treatment, or expensive screening, a desira ble goal in post-transplant monitoring is to find appropriate markers in st andard laboratory diagnostics. In the present study, the results of a 6-wee k CMV replication monitoring schedule by the pp65 antigenemia assay in 100 liver graft recipients were included. The activities of transaminases, glut amate dehydrogenase and gamma -glutamyl transpeptidase (gamma -GT) were mea sured by routine laboratory methods. In contrast to the transaminases, the serum activity of gamma -GT increased during the first postoperative week. The maximum levels were 246 +/- 211 U/I in patients without (n = 46) and 14 0 +/- 89 U/I in patients with early CMV replication (n = 54; p = 0.02). Pat ients with gamma -GT levels below 200 U/I on the 5th postoperative day (n = 72) had a CMV replication risk of 65%, whereas those patients with gamma - GT levels above this threshold had a risk of 30% (n = 28; p = 0.0007; relat ive risk = 2.9). These findings provide a routinely usable marker for the i dentification of patients at an increased risk of CMV replication. It can b e considered that these phenomena may be caused by an additional immunosupp ressive effect of the CMV virus.