Phenotypic study of a case with successful transplantation of ex vivo expanded human limbal epithelium for unilateral total limbal stem cell deficiency

Abstract

ObjectiveTo minimize the risk to the donor eye when a conjunctival limbal autograft is performed for unilateral total limbal stem cell deficiency (LSCD), a new approach has been reported of expanding limbal epithelial progenitor cells from a small limbal biopsy cultured on amniotic membrane (AM). Herein, we present for the first time the morphologic and phenotypic outcome of one such patient. DesignInterventional case report. MethodsA 31-year-old male with a severe acid burn to his left eye received AM transplantation at the acute stage and a keratolimbal allograft (KLAL) at the chronic stage for total LSCD. As an alternative to combat the failed KLAL, the above-mentioned new surgical procedure was performed. The corneal button, obtained after a penetrating keratoplasty performed 5.5 months later, and a normal corneal button as a control were submitted to hematoxylin-eosin and immunofluorescence staining for keratin K3, connexin 43, goblet-cell mucin MUC 5AC, laminin 5, and integrins α3β1 and α6β4. Main outcome measuresClinical and immunohistologic features. ResultsThe resultant epithelium was stratified with five to six cell layers and anchored to laminin 5 of the amniotic basement membrane via integrins α3β1 and α6β4 in a manner similar to the normal corneal epithelium. Intriguingly, the epithelial phenotype was limbal and not corneal, based on the negative expression of keratin K3 and connexin 43 of the basal epithelium. ConclusionsThe technique described ensures the preservation of amniotic basement membrane, which allows formation of adhesion complexes and maintains normal corneal architecture. The preservation of a limbal epithelial phenotype on the reconstructed corneal surface indicates that AM provides a unique stromal environment conducive to the preservation and expansion of limbal epithelial progenitor cells.