Acute humoral rejection of an ABO-unmatched liver allograft in a pediatric recipient.

Acute humorally mediated rejection of organ allografts has long been recognized in kidney transplantation as the syndrome of hyperacute rejection. This reaction precludes renal transplantation across the major blood-group system and in many other instances in which preformed antibodies are present in the host. There is increasing evidence of the importance of humoral rejection in graft survival following liver transplantation. Although the antibodies responsible for this process have seldom been definitively identified, it is clear that the antibodies of the major blood-group system are of particular importance. Humoral rejection of a transplanted liver has not been well documented previously in a pediatric recipient. We present a case illustrating acute hepatic graft failure resulting from circulating anti-B IgM isohemagglutinins following an ABO-unmatched liver transplantation.