Donor stromal and endothelial cells persist long after transplantation

Invest Ophthalmol Vis Sci. 2009;50(6):2673-2678.

Donor-derived stromal and endothelial cells were found in all corneal transplants removed from patients who required regrafting, a study said. However, all donor epithelial cells were replaced by the recipient epithelium.

"Although donor epithelial cells are promptly replaced, a high proportion of donor stromal and endothelial cells can survive within the corneal transplant in the long term," the study authors said. "The proportion of surviving donor cells is highly variable; however, the source of this variability remains unknown."

The study included 52 transplanted corneal buttons removed during a 2-year interval from patients who needed regrafting and had received corneal tissue from donors of the opposite sex.

Investigators performed fluorescence in situ hybridization of the sex chromosomes of the epithelial, stromal and endothelial cells in histologic sections collected from newly explanted grafts. They used fluorescence microscopy to gauge the proportion of donor and recipient cells in each cell type.

At almost 3 months postop, donor epithelial cells were completely supplanted by the recipient epithelial layer in all grafts. However, donor stromal cells (4% to 95%) and endothelial cells (6% to 95%) were found in all grafts, the authors said.

"No significant correlation between donor cell proportion and the age of the graft could be found," they said. "Donor-derived cells were found in significant numbers up to 32 years after transplantation. Eight corneas in this study were transparent, compensated grafts, and a similar long-term survival of donor stromal and endothelial cells was found in these cases."