MULLER CELL-SPECIFIC AUTOANTIBODIES IN A PATIENT WITH PROGRESSIVE LOSS OF VISION

PURPOSE. To study the specificity of circulating retinal autoantibodie s in a patient with progressive loss of vision resembling cancer-assoc iated retinopathy in the absence of systemic malignancy. METHODS. Pati ent's serum was tested for the presence of antiretinal antibodies by W estern blot analysis, and immunohistochemical analysis was performed o n cryosections of rat retina and on cultured rat retinal Muller cells. RESULTS. Western blot analysis revealed that the serum contained a hi gh titer of autoantibodies against a 35-kDa retinal antigen. A protein of similar molecular weight and antigenicity has been found to be pre sent in protein extracts of bovine, rat, and fish retina. Immunohistoc hemical analysis suggested that the autoantibodies did not localize to retinal neural cells, as reported for several other putative autoimmu ne retinal disorders, but rather to the retinal Muller cells. This cel l type-specificity could be confirmed using purified cultured retinal Muller cells. CONCLUSIONS. These results suggest that an autoimmune re sponse directed against the retinal Muller cells, in the absence of ov ert systemic malignancy, may lead to a slow-developing visual deterior ation.