Allosensitization following bone graft

It is recognised that patients may become sensitized to donor-specific HLA antigens as a result of previous antigenic exposures, classically through previous transplantation, pregnancy or blood transfusion. We present an unusual case of a patient who unexpectedly developed a range of anti-HLA antibodies following orthopaedic surgery where a bone graft was deployed intraoperatively.
We describe the case of a 52-year-old male awaiting a renal transplantation, undergoing elective orthopaedic surgery requiring a small volume bone graft. His post operative antibody profile was found to be substantially changed compared to his previous negative samples, with the presence of HLA-DR, DQ and DP specificities, at levels that would be likely to give a positive flow cytometry crossmatch and therefore according to local procedures required listing as unacceptable antigens for organ allocation. We perform a literature review of all previous cases of allosensitization following bone graft.
This case is the first to demonstrate allosensitization following minor surgery with low volume bone graft. Previous evidence is very limited and pertains only to massive osteochondral surgery for trauma or malignancy, and is confounded by potential concomitant blood transfusion. Clinicians should be aware of the risk of allosensitization where bone grafts are used.