Background: The aim of this study was to gain more information about the possible immunological mechanisms in glaucoma. We analyzed the complex autoantibody patterns against human optic nerve antigens in sera of patients with glaucoma and tried to identify important antigens.
Methods: Sera of 133 patients were included: healthy control subjects (n = 44), primary open-angle glaucoma (n = 44), and normal tension glaucoma patients (n = 45). The sera were tested against Western blots of human optic nerve, and antibody bands were visualized with chloronaphthol. IgG antibody patterns were analyzed by multivariate statistical techniques, and the most significant antigens were identified by mass spectrometry (Maldi-TOFTOF).
Results: All subjects, even healthy ones, showed different and complex antibody patterns. Glaucoma groups showed specific up- and down-regulations of antibody reactivities compared to the control group. The multivariate analysis of discriminance found significant differences (P < 0.05) in IgG antibody profiles against human optic nerve antigens between both glaucoma groups and healthy subjects. The identified antigens include: myelin basic protein (up-regulated in the POAG group), glial fibrillary acidic protein (down-regulated in the glaucoma groups), and vimentin (down-regulated in the glaucoma groups in comparison to controls).
Conclusions: Using human optic nerve antigen, we were able to demonstrate that complex IgG autoantibody patterns exist in sera of patients with glaucoma. Large correlations between the given and our previous studies using bovine optic nerve antigens could be seen. Furthermore, anti-myelin basic protein antibodies, which can also be detected in patients with multiple sclerosis, were found in sera of glaucoma patients.