Characterization of the corneal surface in limbal stem cell deficiency and after transplantation of cultured allogeneic limbal epithelial cells.
OBJECTIVE
The objective of this study was to characterize the changes that occur in the cornea during Limbal Stem Cell Deficiency (LSCD) and on the corneal surface after transplantation of ex vivo cultured allogeneic limbal epithelial transplantation (CALET).


METHODS
Forty-one pannus were analyzed to characterize the changes found in the cornea in LSCD. Nineteen impression cytology samples, including 14 pannus and five corneal buttons, obtained during subsequent procedures from patients who had undergone CALET were examined to assess the effect of CALET and to determine the long-term fate of donor cells. The presence of donor and recipient epithelial cells in each sample was determined by short tandem repeat (STR) amplification and fluorescent-multiplex polymerase chain reaction (PCR). Phenotypic analysis of the epithelium was performed by immunohistochemistry and real-time PCR.


RESULTS
The expression of lineage markers was similar between pannus and conjunctivae, but not to corneas. Objective long-term benefits from the transplantation were recorded in most cases. After CALET, the lineage markers in the excised corneal buttons and pannus showed a limbus phenotype. DNA analysis of the 19 cases showed no donor cells present on the ocular surface beyond three months after CALET.


CONCLUSIONS
LSCD was characterized by ingrowth of abnormal, inflamed tissue with a conjunctival phenotype. CALET was a useful technique for restoring the ocular surface in LSCD. However, such benefits did not necessarily correlate with survival of measurable numbers of donor cells on the ocular surface. The absence of donor DNA beyond three months raises questions regarding the period of ongoing immunosuppression and the origin of the regenerated corneal epithelium.
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Peng
P
Chen
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Qingjun
Q
Zhou
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Junyi
J
Wang
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Xiaowen
X
Zhao
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Haoyun
H
Duan
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Yao
Y
Wang
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China.
Ting
T
Liu
Shandong Academy of Medical Sciences, Shandong Eye Institute, 5 Yan'erdao Road, Qingdao, 266071, China. lixin_xie@hotmail.com.
Lixin
L
Xie
D000293:Adolescent; D000328:Adult; D064591:Allografts; D017209:Apoptosis / Q000235:genetics; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D065306:Corneal Injuries / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D016039:Corneal Transplantation / Q000379:methods*; D005260:Female; D006801:Humans; D016850:Limbus Corneae / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012313:RNA / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D033581:Stem Cell Transplantation / Q000379:methods*; D014184:Transplantation, Homologous; D055815:Young Adult
D012313:RNA
Cultured allogeneic limbal epithelial cell; Limbal stem cell deficiency; Pannus; Phenotypic analysis; Transplantation