Epithelial metaplasia of the corneal endothelium in Fuchs endothelial dystrophy.
OBJECTIVE
To evaluate the immunohistochemical characteristics of human corneas with the diagnosis of Fuchs endothelial dystrophy (FED).


METHODS
Formalin-fixed, paraffin-embedded sections of corneas with the diagnosis of FED (15 patients) and 10 control corneas were stained with hematoxylin-eosin and periodic acid-Schiff (PAS). Adjacent histologic sections were stained with monoclonal antibodies that react with epithelial antigens: pancytokeratin, cytokeratins (CK) 7 and 20 CAM 5.2, epithelial membrane antigen (EMA), and Ber EP4. Eight corneas were stained with antibodies to vimentin, smooth-muscle actin (SMA), and CD 68.


RESULTS
The endothelial cells in FED were attenuated and atrophic; some contained pigment consistent with melanin. The endothelial cells stained for pancytokeratin, CK 7, and vimentin in all corneas of FED, whereas variable staining was noted with CAM 5.2. No staining of endothelium was noted with CK 20, EMA, BerEP4, SMA, or CD 68.


CONCLUSIONS
Some cytokeratins that are normally restricted to true epithelium are present in the endothelium of FED. Epithelial metaplasia of endothelium in FED may represent a nonspecific response of distressed endothelial cells, as previously reported in posterior polymorphous dystrophy, congenital hereditary endothelial dystrophy, and iridocorneal endothelial syndrome.
Hidayat
Ahmed A
AA
Division of Ophthalmic Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA. hidayata@afip.osd.mil
Cockerham
Glenn C
GC
D000199:Actins / Q000378:metabolism; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D004728:Endothelium, Corneal / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D019573:Epithelium, Corneal / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000601:surgery*; D006801:Humans; D053554:Keratin-20 / Q000378:metabolism; D053552:Keratin-7 / Q000378:metabolism; D007633:Keratins / Q000378:metabolism; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism; D010503:Periodic Acid-Schiff Reaction; D014746:Vimentin / Q000378:metabolism
D000199:Actins; D015415:Biomarkers; C400901:CAM 5.2 antigen; D053554:Keratin-20; D053552:Keratin-7; D018396:Mucin-1; D014746:Vimentin; D007633:Keratins