Living-Donor Kidney Transplant From a Type A Donor to a Type A Subgroup Recipient

Type A subgroup is rare in Japan, and kidney transplant to a type A subgroup recipient is rare worldwide. A 65-year-old man presented for living-donor kidney transplant. Blood group testing showed that his wife (kidney donor) had blood group type A. The patient (recipient) had a type A subgroup because reverse blood grouping showed a weak reaction with A(1) antigen. Further testing showed that the recipient had type A subgroup between A(x) and A(ei) because adsorption elution experiments and flow cytometry showed a few A antigens that were not detected on forward grouping, and DNA analysis was not consistent with A(ei). The patient was given a milder protocol for immunosuppressive preoperative therapy than typically used for ABO-incompatible kidney transplant; mycophenolate mofetil and prednisolone were started 3 weeks and cyclosporine 2 weeks before transplant, rituximab (100 mg) was given once, and double filtration plasmapheresis and plasma exchange were not used. Follow-up at 9 months after transplant showed stable clinical status and no allograft rejection. In summary, the present case showed that when type A subgroup recipient has low level of anti-A(1) antibody and is receiving a kidney transplant from a blood type A donor, milder immunosuppressive preoperative therapy appears safe.