Survival of donor epithelial cells after limbal stem cell transplantation.

PURPOSE To determine the long-term fate of donor epithelial cells after limbal allograft transplantation. METHODS Corneal buttons and peripheral blood leukocytes were obtained at the time of penetrating keratoplasty from three patients who had undergone a successful limbal allograft transplantation. Microdissection was used to remove the corneal epithelial cells from the button. The presence of donor and recipient epithelial cells in each sample was determined by using PCR for DNA microsatellites. Phenotypic analysis of the epithelium was performed by immunohistochemistry. RESULTS Various patterns of DNA microsatellites were observed. Nonrecipient cells (presumed to be donor) were consistently detected in all three corneal buttons. In two of the three cases, recipient cells were also detected, whereas in the third case, exclusively donor epithelial cells were found at 3.5 years after limbal allograft transplantation. Mild T-lymphocytes and macrophages were observed in one of the corneal buttons. CONCLUSIONS This study provides evidence for the persistence of donor epithelial cells up to 3.5 years after limbal allograft transplantation and supports the use of systemic immunosuppressive therapy.