Autoimmunity to a cornea-associated stromal antigen in patients with Mooren's ulcer.
OBJECTIVE
To purify and characterize a cornea-associated antigen (CO-Ag) and to determine antibody levels to CO-Ag in patients with Mooren's ulcer.


METHODS
Standard ion exchange and gel filtration chromatographies were used to isolate and purify CO-Ag from crude bovine stromal extracts. The serum of a patient with Mooren's ulcer, containing a high level of antibodies directed against CO-Ag, was used to monitor isolation procedures. Using this newly purified CO-Ag, an enzyme-linked immunoabsorbent assay was used to detect the presence of antibodies to CO-Ag in the sera of other patients with Mooren's ulcer.


RESULTS
CO-Ag was purified to apparent homogeneity from bovine corneal stromal extracts by a series of ion exchange chromatographies and gel filtration. Polyacrylamide gel electrophoresis showed that CO-Ag was a tetramer with a molecular weight of 30,000 d that may dissociate under denaturing conditions into a monomer of 7000 d. Strong indirect immunofluorescent staining was demonstrated of the stroma by guinea pig anti-CO-Ag antibody. A statistically significant difference in the level of specific antibodies to CO-Ag between patients with Mooren's ulcer and controls was found (P < 0.001). The antibody level was elevated in patients with Mooren's ulcer (mean antibody level, 0.58 +/- 0.13) compared with the controls (mean antibody level, 0.22 +/- 0.04).


CONCLUSIONS
These results suggest that an autoantigen exists in the corneal stroma that reacts with serum antibodies from patients with Mooren's ulcer. The availability of a purified corneal antigen could facilitate the diagnosis and define the pathogenetic mechanisms in Mooren's ulcer.
Gottsch
J D
JD
Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21205, USA.
Liu
S H
SH
Minkovitz
J B
JB
Goodman
D F
DF
Srinivasan
M
M
Stark
W J
WJ
D000818:Animals; D001323:Autoantibodies / Q000032:analysis; D001324:Autoantigens / Q000276:immunology* / Q000302:isolation & purification; D001327:Autoimmune Diseases / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003319:Corneal Stroma / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D003320:Corneal Ulcer / Q000276:immunology* / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D006801:Humans; D005779:Immunodiffusion
D001323:Autoantibodies; D001324:Autoantigens