Primary Rejection of Thyroid Allografts in the Anterior Chamber of the Rabbit eye

¹ Wilmer Institute, The Johns Hopkins University School of Medicine, Baltimore, Md. 21205
² Wilmer Institute, The Johns Hopkins University School of Medicine, Baltimore, Md. 21205.; Dr. Prendergast is a Research to Prevent Blindness, Inc., Professor.

The fate of primary thyroid allografts placed within the anterior chamber of the rabbit eye toas followed in temporal sequence from eight to 126 days following transplantation to normal recipients. Allografts showed an intense mononuclear cell infiltrate at day 8 which persisted until complete destruction of normal thyroid architecture was noted after 52 days. Within the interstitial connective tissue of these allografts, greatly distended lymphatics were evident which contained large numbers of lymphocytes and monocytes. Thyroid auto grafts, on the other hand, showed only moderate distention of graft lymphatics and complete preservation of normal colloid structure throughout the course of the experiment. Primary rejection of thyroid allografts occurs over a more prolonged time compared to skin or lymph node fragments transplanted to the anterior chamber. The longer survival of this endocrine tissue may be due to lack of direct lymphatic drainage of the anterior chamber, combined with a less effective antigenic stimulus than is provided by skin or lymph node grafts. Alternatively, prolonged survival may result from graft fibrosis impeding access of effector cells to surviving graft remnants. In any case, the anterior chamber of the rabbit eye is nota generally privileged site for allografts, and sensitization of the host to allografts placed within this alifmphatic site must occur.

Key Words: transplant • allograft • anterior chamber • lymphatics • sensitization

Accepted on June 26, 1972