Successful ABO-incompatible renal transplantation of blood group A1 donor into A2 recipient with anti-A1 isoagglutinins: case report and review of literature
Siyang Sun, Ramasamy Bakthavatsalam, Nicolae Leca, Kami L Sneddon, Wenyu Pan, Nina Sen, Tayler Reeves, Albert Budhipramono, Rida A Hasan, Maryam Asif, Monica B Pagano, Yevgen ChornenkyyAbstract
Objectives
To report a successful kidney transplant from an A1 donor into a genetically confirmed A2 recipient with preformed anti-A1 antibodies identified during pretransplant evaluation.
Methods
The donor and recipient were typed for ABO blood group, including serologic subgroup testing and molecular genotyping. The recipient was evaluated for ABO and non-ABO antibodies. Human leukocyte antigen typing, T- and B-cell flow cytometry crossmatches, and donor-derived cell-free DNA (AlloSure) testing were performed using standard protocols.
Results
The recipient was a 73-year-old woman with end-stage kidney disease secondary to AL amyloidosis and a history of several RBC alloantibodies (anti-C, anti-Jk(a), anti-K, and warm autoantibody with anti-e specificity). An ABO discrepancy during transplant evaluation prompted further testing, confirming an A2 blood subgroup (ABO*A2.01/O.01.02) and low-titer anti-A1 antibodies (IgM 1:2; IgG 1:1). Despite the donor being A1, final T- and B-cell flow cytometry crossmatches were negative. The transplant proceeded without desensitization. The patient had immediate graft function, with serum creatinine decreasing from 4.45 mg/dL pretransplant to 1.3 mg/dL by postoperative day 7 and remained stable at 30 days. At 10 months posttransplant, her course remained uneventful, with stable renal function and no signs of rejection or intolerance.
Conclusions
Kidney transplantation across the A1/A2 blood group barrier may be safe in the setting of low-titer anti-A1 antibodies, even when detectable in the antiglobulin phase, and may not require desensitization.