Limbal stem cell transplantations from HLAcompatible living-related donors. Long-term observation

Introduction
The assessment of clinical outcome in patients after lr-CLAL procedure.

Material and methods
Retrospective, interventional case series including 11 patients (12 eyes), all with nonambulatory visual acuity (from light perception to hand movements). Mean age was 39,4 years (ranging from 18 to 76 years). In 7 eyes Limbal Stem Cells Deficiency (LSCD) resulted from chemical burn, in 2 eyes from ocular cicatricial pemphigoid, in one eye from Stevens-Johnson syndrome (SJS). In one eye congenital LSCD was diagnosed and in another one post-inflammatory LSCD. Mean follow-up was 16,2 months (from 10 to 32). Among donors prospective class I HLA matching was performed. Maximal two mismatches were accepted. General immunosuppressive therapy was switched-on in all subjects. Surgical excision of corneal pannus with clearing of limbal area was performed. Five clock hours stem cells tissue grafts from living related donors were harvested and transplanted to the recipient eye. Three penetrating keratoplasty, one deep lamellar keratoplasty and seven amniotic membrane transplantations were additionally performed. Main outcome measures were graft survival as a restoration of corneal epithelium, visual acuity improvement and complication in donors and recipients. Kaplan- Meyer survival curve and generalized Peto test were used for comparison.

Results
The graft survival was 83,6% in mean 20,3 months follow-up (from 10 to 32 months). Two cases of graft failure concern eye with SJS and eye with PKP regrafting after chemical burn. Visual improvement in 7 cases (58,3%), the same visual acuity in 4 cases (33,3%) and deterioration one case (8,3%) were noted. Ambulatory vision in 50% of patients was achieved. Graft rejection syndrome in four eyes was noticed also when ideal matching and CsA serum level 220 ng/ml. Two cases were treated with success and another two grafts failed. No complications in donors eyes were noticed. Impression cytology in eyes with successful grafts not related to pathological changes.

Conclusions
Lr-CLAL are effective in ocular surface restoration. Living-related donors are suitable source of stem cells for cultivation in vitro. The prognosis for stem cells grafting is definitely worse when eyelid anomaly and adhesions exist.