Abstract
Abstract: :
Purpose: Glaucoma is characterized by a progressive loss of retinal ganglion cells. In previous studies changes in the antibody profiles have been shown in the sera of glaucoma patients. These findings suggest a role for autoimmune involvement in the pathogenesis of glaucoma. The aim of this study was to compare the antibody profiles against optic nerve antigens in glaucoma patients in two different study populations from Germany and the United States. Methods: 120 patients were included in this study, 60 from Germany and 60 from the United States: a control group (CTRL, n=20), a group consisting of patients with primary open–angle glaucoma (POAG, n=20), and one of normal tension glaucoma patients (NPG, n=20) from each country. Western blots against bovine optic nerve antigens were used to detect the IgG antibody patterns present in patient serum. The complex antibody profiles were analyzed by multivariate statistical techniques. Results: Complex IgG autoantibody repertoires were present in all glaucoma patients as well as healthy subjects from both the German and the United States study population. A large similarity between all antibody profiles in both study populations could be demonstrated in the number and frequency of both up– and down–regulation of antibody reactivities in glaucoma patients of both national cohorts.. The multivariate analysis of discriminance found a significant difference between the glaucoma groups and healthy subjects against optic nerve antigens. As in previous studies, the NPG group revealed the highest variance from controls (P<0.01). Furthermore, a newly described antibody biomarker in both study populations was identified as alpha–fodrin. Conclusions: We found that complex IgG antibody patterns against optic nerve antigens can be reproducibly identified in the serum of study populations from the US and Germany. Glaucoma patients have characteristic differences of serum autoantibody repertoires from control patients that are similar in both cohorts. A newly described autoantibody to alpha fodrin found in other neurodegenerative diseases such as Alzheimer’s, further implicate a role for autoimmunity and the neurodegenerative processes in glaucoma. The high correspondence of the autoantibody patterns found in the study populations from different continents provides further evidence that serum autoantibody patterns might be useful biomarkers for glaucoma detection or prognosis in future studies by means of pattern matching algorithms.
Keywords: autoimmune disease • clinical research methodology