Studies on the antigenicity of bone. II. Donor-specific anti-HLA antibodies in human recipients of freeze-dried allografts

Freeze-dried bone allografts from donors of known tissue type evoked donor-specific anti-HLA antibodies in nine of forty-three patients (forty-four procedures). Eight of the nine sensitized patients were followed roentgenographically for an average of twenty-three months and were known to have had a satisfactory resolution of the benign process for which the graft was employed. The ninth patient was doing well when lost to follow-up four months after receiving a bone allograft. Clinical Relevance: The questions of whether immune responses to bone allografts occur in humans and, if so, adversely influence the incorporation of the graft can be answered at this time only by demonstrating the presence and frequency of such responses and how they correlate with clinical events. A large variety of techniques can be used to demonstrate immune responses. The technique that we used revealed that a small group of patients became sensitized to HLA antigens that were known to be present in the allograft donor but none of the recipients had evidence of adverse effects caused by the graft, as judged non-invasively.