Müller cell-specific autoantibodies in a patient with progressive loss of vision.

To study the specificity of circulating retinal autoantibodies in a patient with progressive loss of vision resembling cancer-associated retinopathy in the absence of systemic malignancy.Patient's serum was tested for the presence of antiretinal antibodies by Western blot analysis, and immunohistochemical analysis was performed on cryosections of rat retina and on cultured rat retinal Müller cells.Western blot analysis revealed that the serum contained a high titer of autoantibodies against a 35-kDa retinal antigen. A protein of similar molecular weight and antigenicity has been found to be present in protein extracts of bovine, rat, and fish retina. Immunohistochemical analysis suggested that the autoantibodies did not localize to retinal neural cells, as reported for several other putative autoimmune retinal disorders, but rather to the retinal Müller cells. This cell type-specificity could be confirmed using purified cultured retinal Müller cells.These results suggest that an autoimmune response directed against the retinal Müller cells, in the absence of overt systemic malignancy, may lead to a slow-developing visual deterioration.