Antigenicity of tympano-ossicular homografts of the middle ear: analyses of immune response to viable and preserved grafts in animal models.

Primary and secondary response transplantation experiments in allograft tympanoplasty reveal that after various preservation procedures at least part of the original histoincompatibility between donor and recipient still exists. Clinical pathologic data are in accordance with this phenomenon. The abolished immune reactivity in successful allograft-tympanoplasty is placed in the light of acquired immunotolerance. The consequences of prior tissue-typing are discussed.