Anti-retinal S-antigen antibodies in human sera: a comparison of reactivity in Elisa with human or bovine S-antigen

Abstract

Various studies have demonstrated anti-retinal S-antigen (S-ag) antibodies in uveitis sera in assays using bovine S-ag. Because of its molecular similarity and cross-reactivity with human S-ag, reactions with bovine S-ag have been considered a reliable indication of anti-S-ag autoimmunity. To test this assumption, the cross-reactivity of purified human and bovine S-ags was quantitated by ELISA titration of various anti-human and anti-bovine S-ag immune reagents raised in mice, rats and rabbits. Anti-human S-ag reagents appeared to be largely cross-reactive with bovine S-ag, whereas anti-bovine S-ag reagents were 6-10 times less reactive with the cross-reacting human S-ag than with bovine S-ag, thus showing a predominant role of species-specific epitopes on bovine S-ag. Furthermore, a large number of human control and uveitis sera was tested in ELISA with both human S-ag- and bovine S-ag-coated microwells. Both the numbers of positive sera and the levels of anti-S-ag antibodies in the two tests significantly correlated, but many exceptions were found, and the predictive value of reactions with bovine S-ag for the presence and levels of anti-S-ag autoantibodies was low. For individual human sera, assessment of anti-S-ag autoantibodies requires the use of human S-ag in immunoassays.

Proliferative Vitreoretinopathy May Be a Risk Factor in Combined Macular Hole Retinal Detachment Cases

“…Immune tolerance, usually maintained by mechanisms described earlier, could be lost or modulated. This was demonstrated in a study showing that heat shock protein (HSP) 91 can modulate APC function, resulting in loss of tolerance in an animal model. 121 HSPs, especially microbial, have been implicated in the pathogenesis of Behçet's disease 122 and demonstrated to induce inflammation in the eye in animal studies.…”

“…There is no common pattern of lymphocyte response in clinical studies reported so far. Early clinical studies on the humoral response showed the presence of antiretinal autoantibodies, including anti-S-antigen antibodies in the sera of some uveitis patients 90,91 (Fig. 27.3), but there was no good correlation between presence or levels of autoantibodies and clinical disease.…”

Importance of Autoimmune Responses in Progression of Retinal Degeneration Initiated by Gene Mutations

“…Some patients with RP may have serum AAbs against retinal proteins that were subject to disease-causing mutation ( 8 , 39 ). For example, AAbs against arrestin were detected in the patients with RP as well in the patients with autoimmune uveitis or autoimmune retinopathy ( 84 , 85 ). However, the degree of immune reactivity against arrestin and the severity of disease in the patients with RP are not strongly correlated.…”

Autoimmunity, Autoinflammation, and Infection in Uveitis

“…[31][32][33] Results have been inconsistent and self-reactivity to retinal antigens has been observed in healthy individuals. 32,[34][35][36][37] Similar confounding results have been observed in nonocular diseases, and the number of definitive autoimmune diseases, in which autoreactive T cells or autoantibodies have been shown to be pathogenic, is limited. In addition, restoration of immunologic tolerance in patients with diseases such as multiple sclerosis, rheumatoid arthritis, and uveitis, although clearly effective in experimental models 38 that use experimental therapies such as mucosal tolerance induction, has not yet reached the clinic.…”