Clinical and pathologic findings in human keratolimbal allograft rejection.
OBJECTIVE
To characterize the clinical and pathologic features of cadaveric keratolimbal allograft (KLAL) rejection.


METHODS
The study design is descriptive.


METHODS
Four patients (five eyes) with KLAL rejection are reported.


METHODS
All patients were subjected to slit-lamp biomicroscopy, treatment of rejection, and ultimately required repeat KLAL surgery. In three patients (four eyes), specimens obtained at the time of repeat surgery were subjected to immunohistochemical staining against the following immune and surface human antigens: CD4, CD8, CD19, CD3, DR, CK19, CK3, and vimentin.


RESULTS
Signs of allograft rejection included intense sectoral injection, diffuse or perilimbal conjunctival injection, edema, and infiltration of the KLAL grafts, leading to punctate epithelial erosions, epithelial defects, and surface keratinization. Rejected specimens revealed T-lymphocyte infiltration (CD4:CD8, 2:1) with strong HLA-DR (MHC class II) expression. The epithelium stain results were positive for cytokeratin 19 and weakly positive to absent for cytokeratin 3. The epithelial stain results were weakly positive for vimentin in only one specimen.


CONCLUSIONS
KLAL rejection is a newly recognized entity. Pathologic findings of rejected specimens indicate that this is a T-cell mediated rejection phenomenon. The pattern of cytokeratin staining provided little evidence that the epithelium covering KLALs had a corneal phenotype. The scarcity of vimentin-positive epithelial cells suggests that the stem-cell/transient-cell pool was probably depleted. Early recognition of clinical rejection is important, as treatment with immunosuppressive therapy may reverse the process.
Corneoplastic Unit, Queen Victoria Hospital, East Grinstead, West Sussex, United Kingdom. sdaya@compuserve.com
S M
SM
Daya
R W
RW
Bell
N E
NE
Habib
A
A
Powell-Richards
H S
HS
Dua
D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D017690:Cell Transplantation / Q000473:pathology*; D003316:Corneal Diseases / Q000473:pathology / Q000601:surgery; D016039:Corneal Transplantation / Q000473:pathology*; D019573:Epithelium, Corneal / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006084:Graft Rejection / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D006684:HLA-DR Antigens / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007633:Keratins / Q000378:metabolism; D016850:Limbus Corneae / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D013601:T-Lymphocytes / Q000276:immunology; D014184:Transplantation, Homologous; D014746:Vimentin / Q000378:metabolism
D015703:Antigens, CD; D006684:HLA-DR Antigens; D007166:Immunosuppressive Agents; D014746:Vimentin; D007633:Keratins