Immune response to retinal antigens in patients with gyrate atrophy and other hereditary retinal dystrophies

Purpose: Gyrate atrophy (GA) is a rare hereditary disease that causes retinal destruction. Retinal damage in GA and other heredodegenerative diseases such as retinitis pigmentosa (RP) releases sequestered antigens and may trigger immune response to these molecules. Here, we studied the immune response to retinal antigens in patients with GA and RP and compared it with that of patients with inactive posterior uveitis and normal volunteers. Patients and methods: Peripheral blood was collected from 24 patients with RP, 10 patients with GA, 10 patients with inactive posterior uveitis, and 16 normal volunteers. Cell-mediated immune responses to human S-antigen (HS-Ag), bovine S-antigen (BS-Ag), and interphotoreceptor retinoid-binding protein (IRBP) were investigated by lymphocyte proliferation assay. In addition, serum levels of soluble intercellular adhesion molecule-r (sICAM-I) and soluble vascular cell adhesion molecule-I (sVCAM-I) were studied by ELISA. Immunologic data were correlated with clinical and electrophysiological findings. Results: Patients with GA or RP responded to HS-Ag and BS-Ag more vigorously than patients with uveitis or healthy controls, as shown by higher mean stimulation indices and larger proportions of responders. Unlike S-Ag, IRBP stimulated low lymphocyte responses in only a small proportion of RP patients. The mean sVCAM-I levels were significantly higher in the sera from patients with GA than in that from normal controls. Conclusion: An elevated cellular immune response to S-Ag is common in patients with GA and RP. This elevated cellular immune response to S-Ag may exacerbate retinal destruction in patients with GA and RP.