Individualized Preconditioning for ABO-Incompatible Living-Donor Kidney Transplantation: An Initial Report of 48 Cases from China

Background: ABO-incompatible (ABOi) living-donor kidney transplantation (KTx) is well established in developed countries, but not yet in China. Material/Methods: We developed individualized preconditioning protocols for ABOi KTx based on initial ABO antibody titers. After propensity score matching of ABOi with ABO-compatible (ABOc) KTx, post-transplant outcomes were compared. Results: Between September 2014 and June 2018, 48 ABOi living-donor KTx candidates received individualized preconditioning, and all underwent subsequent KTx (median initial ABO titers: 16 for IgM and 16 for IgG). Thirty-one recipients (64.6%) were preconditioned with rituximab (median dose: 200 mg, range: 100-500 mg). Among 37 patients (77.1%) who received pre-transplant antibody removal, the median number of sessions of antibody removal required to achieve ABOi KTx was 2 (range: 1-5), which was conducted between days -10 and -1. Eleven ABOi recipients (22.9%) were preconditioned with oral immunosuppressants alone. Hyperacute rejection led to the loss of 2 grafts in the ABOi group. After a median follow-up of 27.6 months (ABOi group) and 29.8 months (ABOc group), there were no significant differences in graft/recipient survival, rejection, and infection. There were marginally higher rates of severe thrombocytopenia (<50x10(9)/L) (P=0.073) and delayed wound healing (P=0.096) in ABOi recipients. Conclusions: Our individualized preconditioning protocol evolved as our experience grew, and the short-term clinical out- comes of ABOi KTx did not differ from those of matched ABOc patients. ABOi KTx may be a major step forward in expanding the kidney living-donor pool in China.