title: Results of a phase I/II clinical trial: standardized, non-xenogenic, cultivated limbal stem cell transplantation.
abstract: BACKGROUND
  To determine if a standardized, non-xenogenic, reduced manipulation cultivation and surgical transplantation of limbal stem cell grafts is a safe and effective treatment option for patients with total and partial limbal stem cell deficiency.
  
  
  METHODS
  In vitro cellular outgrowth and phenotype of the limbal epithelial cell and composite grafts were validated using a new protocol. Patients received either autologous (n = 15) or allogenic (n = 3) explants cultured using a standardized protocol free from xenogenic products. The resulting grafts were transplanted using a reduced manipulation surgical technique.
  
  
  RESULTS
  The majority of cells (>50%) displayed a progenitor phenotype typified by positive immunofluorescence for ∆Np63, CK14 and ABCG2 and low immunofluorescence for CK3/12 and desmoglein 3 proteins. The surgical protocol was designed to minimize manipulation and the graft itself was secured without sutures. The transplant recipients were followed for a mean of 24 months. Twelve of the 18 transplant recipients were graded as anatomically successful (67%), based on the defined success parameters. There was a significant reduction in corneal neovascularization, which was accompanied by an improvement in pain though not photophobia or central corneal opacity post transplant. The transplantation protocol showed no measureable effect on visual acuity.
  
  
  CONCLUSIONS
  We conclude that this standardized culture system and surgical approach is safe and effective in reducing corneal neovascularization. The technique is free from animal contaminants and maintains a large proportion of progenitor cells. Although this technique did not improve visual function, restoring a functional epithelial cell layer and reducing corneal neovascularization provides an improved platform for a penetrating keratoplasty to ultimately improve visual function.
authors.affiliation: Centre for Cell Therapy and Regenerative Medicine, Antwerp University Hospital, Edegem 2650, Belgium. Nadia.Zakaria@uza.be.
authors.forename: Nadia
authors.initials: N
authors.lastname: Zakaria
authors.forename: Tine
authors.initials: T
authors.lastname: Possemiers
authors.forename: Sorcha Ní
authors.initials: SN
authors.lastname: Dhubhghaill
authors.forename: Inge
authors.initials: I
authors.lastname: Leysen
authors.forename: Jos
authors.initials: J
authors.lastname: Rozema
authors.forename: Carina
authors.initials: C
authors.lastname: Koppen
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Timmermans
authors.forename: Zwi
authors.initials: Z
authors.lastname: Berneman
authors.forename: Marie-Jose
authors.initials: MJ
authors.lastname: Tassignon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000650:Amnion / Q000166:cytology; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D002648:Child; D003316:Corneal Diseases / Q000503:physiopathology / Q000601:surgery / Q000628:therapy; D004847:Epithelial Cells / Q000166:cytology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016850:Limbus Corneae / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011300:Preoperative Care; D015203:Reproducibility of Results; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*; D014183:Transplantation, Heterologous; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult