Antigenicity of freeze-dried cortical bone allograft in human periodontal osseous defects.

The purpose of this investigation was to determine whether donor-specific anti-HLA antibodies could be detected against freeze-dried cortical bone allograft (FDBA) placed in human periodontal osseous defects. Twenty patients with multiple periodontal bony defects amenable to treatment in two allografting procedures were enrolled. No patient had pre-existing anti-HLA antibodies. FDBA used for all allografting procedures was obtained from one donor of known HLA antigens, and all patients were tissue-typed. Serum samples were taken two weeks after the first allograft (primary challenge), two weeks after the second allograft (secondary challenge) and at three months. Serum samples were assayed for the presence of anti-HLA antibodies using an Amos modified microcytotoxicity assay. At no time could any donor-specific anti-HLA antibodies be detected in any patient. All allografts were judged clinically successful, with no adverse tissue reactions to the donor material. FDBA may be regarded as a graft material lacking clinically significant antigenicity.