Corneal autoimmunity in patients with peripheral ulcerative keratitis (PUK) in association with rheumatoid arthritis and Wegener's granulomatosis.

Serum antibodies to the cornea were investigated in patients with peripheral ulcerative keratitis (PUK) in isolation or in association with a systemic disease (rheumatoid arthritis or Wegener's granulomatosis). Indirect immunofluorescence on bovine corneal sections demonstrated that antibodies bound to epithelial antigens in two distinct patterns: a lattice-like pattern, probably staining intercellular membrane antigens, and a diffuse pattern covering the entire surface of the epithelium. Both patterns were associated with PUK rather than systemic disease whilst the presence of the lattice pattern was more associated with the onset of the PUK. Immunoblotting of sera to corneal epithelial protein extracts demonstrated that a number of corneal antigens were targeted by antibodies. Two antigens, 54 kDa and 70 kDa, were of particular interest. Antibodies to the 54 kDa antigen, the major corneal-specific antigen, were also detected by enzyme-linked immunosorbent assay (ELISA). Longitudinal studies showed that these antibodies often first occurred after an episode of PUK. Antibodies to the 70 kDa antigen were related to the Wegener's granulomatosis rather than the PUK.