ABO-incompatible living donor liver transplantation is suitable in patients without ABO-matched donor

Background & aims: ABO-incompatible liver transplantation is usually contraindicated because of the risk of antibody-mediated humoral rejection of the graft. We describe 22 successful cases of patients who had living donor liver transplantation (LDLT) from ABO-incompatible donors.

Methods: The immunosuppressive protocol consisted of rituximab and plasmapheresis prior to LDLT. Plasmapheresis was planned for up to 2 weeks after LDLT aiming at maintaining levels of anti-ABO titers below 1:32.

Results: The median age of recipients was 54 years and the median MELD score was 13. The initial range of isoagglutinin IgM and IgG titers were 1:8-1:1024 and 1:2-1:1024, respectively. Preoperative isoagglutinin IgM and IgG titers were achieved less than or equal to 1:8 by performing therapeutic plasma exchange (TPE). While the median number of TPE was 4 (range, 2-18) in all patients, it was 4 (range, 2-8) in the initial low titer group (<1:256) and 8 (range, 6-18) in the high titer group (≥ 1:256). There were no statistically significant differences for liver function tests in the first 2 weeks after transplantation between the groups having high MELD score (≥ 20) vs. low MELD score (<20), local graft infusion vs. systemic infusion, or high initial isoagglutinin titer (≥ 1:256) vs. low initial isoagglutinin titer (<1:256). Patient and graft survival was 100% and there was no acute humoral rejection in recipients at a mean follow-up of 10months (range, 3-21).

Conclusions: ABO-incompatible LDLT can be safely performed when rituximab and TPE are used, and may be proposed when ABO-compatible donors are not available.