Non specific increased expression of class I major histocompatibility complex (MHC) antigens on rat liver grafts.

Major histocompatibility complex (MHC) antigens play a major role in the rejection reaction and their increased expression may increase the host response to the foreign graft [1]. Several clinical [2–5] and experimental studies [6, 7] have demonstrated increased expression of MHC antigens on the different cell components of liver allografts during rejection. However modified expression of MHC antigens may also occur in certain liver diseases [8–10], after cholestasis [11] or on a regenerating liver [11]. In this experimental study in inbred rats, we compared the expression of MHC antigens on liver cells during rejection and non-immunological situations (cholestasis, cytolysis, regeneration).