Variable antigenicity of lyophilized allogeneic and lyophilized xenogeneic skin in guinea pigs

Intraoral use of freeze‐dried skin (EDS) allografts and xenografts has raised questions concerning host immunologic response to these transplanted tissues. Separate groups of outbred guinea pigs were sensitized with suspensions of xenogeneic (human) FDS (XFDS) or allogeneic FDS (AFDS). Intradermal challenge with saline, appropriate FDS suspension, and intact sections of the appropriate FDS was performed. Findings at 24 and 48 hours post‐challenge demonstrated positive skin reactions to the XFDS materials and an absence of any reaction to the AFDS materials. Positive (Freund's complete adjuvant) and negative (saline) controls were similarly tested and yielded expected results. In vitro findings using serological and migration inhibitory factor assays paralleled those of the skin tests. The results of this study indicate that allogeneic FDS grafts do not produce detectable host sensitivity and appear to be immunologically preferable to xenogeneic FDS grafts for intraoral use.