Abstract
Abstract: :
Purpose: The transplantation of limbal epithelial cells (LEC) is a recent method for the reconstruction of the ocular surface in limbal stem cell insufficiency (LSCI). Aim of the present study was to elucidate whether these LEC participate themselves in epithelial regeneration or whether they act by induction of the host's regenerative capacities. Methods: Case report. 50 year old patient with bilateral LSCI after chemical burn. Persistent erosions were treated with complete amniotic membrane transplantation. Development of conjunctival epithelial overgrowth could not be stopped, leading to loss of visual acuity. Limbal stem cell transplantation was performed in the 12 o'clock position. Outgrowth of corneal epithelium from the transplant was revealed by HLA class I and II typing, using PCR after isolation of cells from the upper and temporal cornea. Results: Post-operative reepithelialization was visible from the transplant site. Because of faster conjunctival epithelialization from nasally and temporally, repeated abrasions became necessary to remove that epithelium. HLA-typing showed that the new established corneal epithelium originated from the donor (HLA-A DQA1*0101, HLA-B DPB1, HLA class II A01, B18, DRB1*01, DRB5*0101), whereas overgrowing cells came from the patient (HLA-A A*02, 29, B*27, 35, HLA-B DRB1*0301, 1301, DRB3*0101, DR3*02, DQA1*0103, 05,HLA class II DQB102, *0603, DPB1*0201, *0401). Conclusion: The mechanism of LEC transplantation is not yet fully understood. Theoretically, epithelial regeneration might originate directly from the transplant or by serving as a barrier for conjunctival epithelial overgrowth or by induction of epithelial regeneration. Distinguishible differences between regenerative epithelium or early not yet vascular pannus is confirmed by HLA typing. The present results clearly demonstrate at least a participation of the transplanted LEC in the regeneration of the new epithelium.
Keywords: 372 cornea: epithelium