BACKGROUNDS OF EARLY INTRAGRAFT IMMUNE ACTIVATION AND REJECTION IN LIVER-TRANSPLANT RECIPIENTS - IMPACT OF GRAFT REPERFUSION QUALITY

In solid organ transplantation, acute rejections are most frequent dur ing the first weeks, The aim of this study was to investigate the rela tionship between graft reperfusion injury and later immune responses a gainst the graft, Intragraft immune activation was routinely monitored by transplant aspiration cytology in 47 recipients of hepatic allogra fts, As a parameter of reperfusion quality, oxygen saturation of hemog lobin (So(2)) in hepatic tissue was determined intraoperatively by a n ear-infrared spectroscopy. Grafts that presented aspiration cytology s cores of 2 or more (i.e., more than 10% of lymphocytes activated) at 1 week after operation (group I, n=14) were associated with a higher he terogeneity of hepatic tissue So(2) at the end of operation (coefficie nt of variation in 12 points 18.3+/-18.3%, mean+/-SD) than grafts with no or very mild intragraft immune activation (group II, n=33, 9.2+/-4 .2%; P<0.01), Group I was also accompanied by higher postoperative pea k glutamic oxalacetic transaminase level (corrected by graft size, P<0 .05) and higher donor age (43.9+/-12.9 vs. 32.6+/-13.9 years, P<0.02). Heterogenous reperfusion (P<0.01), higher peak glutamic oxalacetic tr ansaminase level (P<0.01), and higher donor age (P<0.05) were also ass ociated with clinical rejection at 1 week (n=10), but not with later-o nset rejection (n=11), These data suggest that intragraft immune activ ation and clinical rejection in the early phase after hepatic engraftm ent are strongly influenced by graft injury, which can be recognized e arly after reperfusion.