Ischemic preconditioning induces autophagy and limits necrosis in human recipients of fatty liver grafts, decreasing the incidence of rejection episodes

Abstract

Whether ischemic preconditioning (IP) reduces ischemia/reperfusion (I/R) injury in human normal and fatty livers remains controversial. We compared two independent groups of liver donor transplants with versus without steatosis to evaluate IP consequences. Liver donors with (n=22) or without (n=28) steatosis either did or did not undergo IP before graft retrieval. Clinical data from the recipients, as well as histological and immunohistological characteristics of post-reperfusion biopsies were analyzed. Incidence of post-reperfusion necrosis was increased (10/10 versus 9/14, respectively; P<0.05) and the clinical outcome of recipients was worse for non-IP steatotic liver grafts compared with non-IP non-steatotic grafts. IP significantly lowered the transaminase values only in patients receiving a non-steatotic liver. An increased expression of beclin-1 and LC3, two pro-autophagic proteins, tended to decrease the incidence of necrosis (P=0.067) in IP steatotic livers compared with non-IP steatotic group. IP decreased the incidence of acute and chronic rejection episodes in steatotic livers (2/12 versus 6/10; P=0.07 and 2/12 versus 7/10; P<0.05, respectively), but not in non-steatotic livers. Thus, IP may induce autophagy in human steatotic liver grafts and reduce rejection in their recipients.