Putative antibody-mediated rejection (AMR) in HLA-identical sibling transplantation has rarely been reported and occurred before routine calcineurin inhibitor use. A 29-year-old male developed allograft dysfunction following an HLA-identical renal transplant from his sibling. A pretransplant panel-reactive antibody (PRA) was elevated, pre-transplant crossmatch was negative and no donor-specific antibody (DSA) was identified. Induction with alemtuzumab was followed by maintenance immunosuppression with corticosteroids, tacrolimus and mycophenolate. A biopsy for allograft dysfunction suggested AMR, but DSA could not be detected. Treatment for rejection was transiently successful. Undetectable minor histocompatibility antibodies may have contributed.
