Abstract
Purpose: :
The aim of this study was to compare the IgG antibody patterns against retinal antigens in sera of patients with age–related macular degeneration (AMD) and healthy subjects to learn more about possible immunological aspects of this disease.
Methods: :
Sera of 140 patients were analyzed: healthy volunteers (CO, n=101) and patients with "wet" age–related macular degeneration (AMD, n=39). The sera were tested against Western blots of bovine retinal antigens. The IgG antibody patterns were digitized and subsequently analyzed by multivariate statistical techniques. Some of the antibody peaks were identified by Mass Spectrometry (Maldi–TOFTOF).
Results: :
All patients showed complex patterns of IgG antibodies against retinal antigens. The discriminant analysis revealed a statistical significant difference between the antibody profiles of patients with "wet" AMD and controls (P=0.000023). Not only up–regulations of antigen–antibody–reactivity in the AMD group at some molecular weight ranges, e.g. at 52 and 64 kDa, could be seen, but also down–regulations, e.g. at 18 and 36 kDa. The peak at approximately 52 kDa has been identified as glial fibrillary acidic protein (GFAP) and the peak at approx. 18 kDa as αA–crystallin.
Conclusions: :
We could demonstrate that both groups (wet AMD and CO) show complex IgG antibody patterns against retinal antigens, which are highly specific for each group. This provides further hints for an immunological basis of the disease. These changes in the antibody profiles in "wet" AMD could represent a secondary response to retinal damage or can play a causative role in the disease.
Keywords: age-related macular degeneration • retina • autoimmune disease