Successful ABO-incompatible liver transplantation using A2 donors

The longer waiting time for a liver graft among patients with blood group O makes it necessary to expand the donor pool for these patients. We herein have reported our experience with ABO-incompatible liver transplantation using A(2) donors to blood group O recipients.

Between 1996 to 2005, 10 adult blood group O recipients received 10 A(2) cadaveric grafts. Mean recipient age was 52 +/- 7.7 years (mean +/- SD). The initial immunosuppression was induction with antithymocyte globulin (n = 2), interleukin-2-receptor antagonists (n = 3), or anti-CD20 antibody (rituximab, n = 1), followed by a tacrolimus-based protocol. No preoperative plasmapheresis, immunoadsorption, or splenectomies were performed.

Patient and graft survival was 10/10 and 8/10, respectively, at 8.5 months median follow-up (range 10 days to 109 months). Two patients were retransplanted because of bacterial arteritis (n = 1) and portal vein thrombosis (n = 1). The six acute rejections, which occurred in four patients, were all reversed by steroids or increased tacrolimus dosages. The pretransplant anti-A titers against A(1) red blood cells were 1:128 (NaCl technique) and 1:8 to 1024 (IAT technique). The maximum postoperative titers were 1:64 to 4000 (NaCl) and 1:256 to 32000 (IAT).

The favorable outcome of A(2) to O grafting, with a patient survival of 10/10 and graft survival of 8/10, makes it possible to consider this blood group combination also in nonurgent situations. There was no hyperacute rejection or increased rate of rejections. Anti-A/B titer changes seem to not play a significant role in the monitoring of A(2) to O liver transplantation.