RPE-Hypersensitivity: Complement Involvement in Serum from Patients with Age-Related Macular Degenerations

Abstract

Abstract: : Purpose: To evaluate the role of complement in the inhibitory effects of serum from patients with Age-Related Macular Degenerations upon in vitro cultivated rhesus retinal pigment epithelial cells. Methods: Antibody activity with RPE was first identified by indirect immunohistochemistry using sectioned rhesus monkey eyes. Western blot reactions upon extracts of RPE cells were used to identify common antigen/antibody reactions with RPE proteins of similar size. A simple metabolic inhibition assay was used to evaluate the influence of each patient's serum upon the uptake of tritiated thymidine by RPE cells in the presence and absence of active complement. Comparison were made with sera from clinically normal controls.Results: Abnormal antibody activity with RPE can be demonstrated in some patients with ARMD. The antibodies involved can be shown to react with a small number of proteins and inhibit the metabolism of viable RPE cells. The inhibitory effects require complement.Conclusion: The degenerations of RPE cells in ARMD may include autoimmune reactions. We demonstrate the presence of antibodies that react with RPE cells and inhibit their metabolism and in some cases their viabilty. Complement activation can be shown to participate in this inhibition. The pathologic implications of these findings require further study. Supported by RPB and NEI core grant 1P30 EY12576-01

Keywords: 327 autoimmune disease • 308 age-related macular degeneration • 567 retinal pigment epithelium