ABSTRACT

In order to study liver alloimmunity, the authors review the expression of major histocompatibility complex (MHC) antigens of various cell populations in the liver of humans in the normal state and after transplantation during periods of quiescence as well as in the setting of acute liver allograft rejection. Furthermore, the histology of liver allograft rejection provides insight into potential alloimmune mechanisms involved in the rejection process. The results of clinical studies have the advantage of being directly applicable to transplantation of various allografts in humans, but at the same time carry the disadvantage of producing variable results due to variation in the human study population. Experimental systems employing various animal models to study liver alloimmunity can be more precisely controlled than clinical studies to answer specific questions, but the results may not be directly applicable to humans; nevertheless, results from experimental systems guide the design of clinical studies.