Anti-retinal S-antigen antibodies in human sera: a comparison of reactivity in ELISA with human or bovine S-antigen.
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.
Doekes
G
G
Department of Ophthalmo-Immunology, The Netherlands Ophthalmic Research Institute, Amsterdam.
Luyendijk
L
L
Gerritsen
M J
MJ
Kijlstra
A
A
D000818:Animals; D000941:Antigens / Q000276:immunology*; D019393:Arrestin; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D002417:Cattle; D003429:Cross Reactions / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005136:Eye Proteins / Q000276:immunology*; D006801:Humans; D051379:Mice; D011237:Predictive Value of Tests; D011817:Rabbits; D013045:Species Specificity; D014606:Uveitis, Anterior / Q000276:immunology*; D015866:Uveitis, Posterior / Q000276:immunology*
D000941:Antigens; D019393:Arrestin; D001323:Autoantibodies; D001324:Autoantigens; D005136:Eye Proteins