Experimental allergic uveitis: clinicopathologic features associated with varying doses of S antigen
N. A. Rao, W. B. Wacker and G. E. Marak Jr
Considerable differences were observed in the experimental autoimmune
disease elicited by retinal S antigen, depending on the immunizing dose. An
inoculum of 50 microgram produced a massive panophthalmitis containing many
polymorphonuclear leukocytes, eosinophils, and mononuclear cells. A less
severe endophthalmitis was seen in animals receiving 25 microgram of
antigen. Animals receiving between 5 and 10 microgram of antigen developed
a disease characterized by a granulomatous uveitis. The inflammatory
infiltrate consisted primarily of mononuclear and epithelioid elements and
appeared virtually identical to that seen in sympathetic ophthalmia. One
microgram of S antigen produced primarily a nongranulomatous posterior
uveitis composed chiefly of mononuclear cells. The principal change in the
character of the disease occurred at dose levels between 10 and 25
microgram. This change consisted of the disappearance of polymorphonuclear
leukocytes and eosinophils at the lower dose levels. These histopathologic
changes suggest that at higher dose levels an immune complex disease may be
superimposed on or replace a presumably cell-mediated hypersensitivity
response.
