Does humoral autoimmunity play a role in the pathogenesis of primary open-angle glaucoma?

Purpose: To determine if primary open-angle glaucoma (POAG) patients have circulating antibodies to retinal ganglion cells. Methods: We used Western blot analysis, immunohistochemistry and molecular biological techniques to detect autoantibodies to retinal ganglion cells in sera obtained from 12 ocular hypertensive (OHTN), 22 high tension open-angle glaucoma (HTOAG ), 6 normal tension glaucoma (NTG) and 13 age-matched normal (NL) patients. Results. Western blot analysis indicated all sera blotted against a human retrobulbar optic nerve homogenate produced many bands, suggesting that these samples contained many antibodies that cross-reacted with optic nerve proteins. No bands were consistently more prevalent in patients with OHTN, HTOAG or NTG compared to controls. Immunohistochemical reaction of sera from one patient with HTOAG, one patient with NTG and 2 NL patients with sections of normal human optic nerve and retinal tissue did not produce staining of retinal ganglion cells. Next neonatal rat retinal ganglion cells were isolated using the panning technique.¹ We used these cells to generate an expression cDNA library in E. coli. We screened this library with our sera and did not find any positive clones. Conclusion: Our preliminary data do not identify circulating antibodies to retinal ganglion cells in POAG but our knowledge of retinal ganglion cell-specific antigens is limited. Perhaps further analysis of our retinal ganglion cell cDNA library will help expand our knowledge of these important cells.