title: Longterm survival of transplanted human corneal epithelial cells and corneal stem cells.
abstract: OBJECTIVE
  To investigate the survival of donor-derived epithelial cells in conventional penetrating keratoplasty (PKP) and in homologous penetrating central limbal keratoplasty (HPCLK).
  
  
  METHODS
  Epithelial cells from 26 eyes of 26 patients were analysed. All cases were sex-mismatched (i.e. the transplant and patient were of different genders). At suture removal more than 1 year post surgery, epithelial cells were obtained by gently wiping the removed sutures on glass slides. The cell samples were analysed using fluorescent in situ hybridization (FISH) of the sex chromosomes. This technique makes it possible to allocate the origin of each cell nucleus to either the donor or the recipient.
  
  
  RESULTS
  All 19 conventional PKPs were clear and seven had donor-derived epithelial cells at suture removal. Five of the seven HPCLK grafts were clear at the time of investigation (365-1355 days post surgery), and donor-derived epithelial cells were found in two grafts.
  
  
  CONCLUSIONS
  Harvesting cells from removed sutures in combination with FISH enables the clinical study of cell survival in corneal transplants without jeopardizing functioning grafts. From the limited sample investigated, the following tentative conclusions can be made. Donor-derived epithelial cells can remain in conventional PKP for over 1 year. In combined stem cell and corneal grafts (HPCLK), donor-derived epithelial cells may also be retrieved at 1 year or beyond following surgery but the correlation between their presence and a remaining clear graft is uncertain.
authors.affiliation: Institute of Clinical Neurosciences, Section of Ophthalmology, Sahlgren University Hospital, Mölndal, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Egarth
authors.forename: Josefine
authors.initials: J
authors.lastname: Hellkvist
authors.forename: Margareta
authors.initials: M
authors.lastname: Claesson
authors.forename: Charles
authors.initials: C
authors.lastname: Hanson
authors.forename: Ulf
authors.initials: U
authors.lastname: Stenevi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002470:Cell Survival / Q000502:physiology; D041321:Chromosomes, Human, X / Q000378:metabolism; D041322:Chromosomes, Human, Y / Q000378:metabolism; D003316:Corneal Diseases / Q000601:surgery; D004847:Epithelial Cells / Q000502:physiology; D019573:Epithelium, Corneal / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*; D013536:Suture Techniques; D014019:Tissue Donors