Naturally occurring antibodies to bovine and human retinal S antigen: a comparison between uveitis patients and healthy volunteers.

The antibody responses to human and bovine retinal S antigen in the sera of patients with uveitis from various causes were compared with those of a group of healthy volunteers who were fully screened for signs of eye disease. Antiretinal antibodies were found with equal frequency and through the same range of titres in patients and controls, irrespective of the nature or activity of the uveitis. These findings were confirmed by spectrotypic analysis of sera from patients and controls where the predominant serum antibody response was polyclonal. In a small group of patients with retinal vasculitis there was an additional monoclonal response, indicating clonal expansion of a single lymphocyte subset. The prevalence of serum antibodies to retinal antigens in the normal population may indicate a protective role for 'natural' autoantibodies, as has recently been suggested for autoimmune diseases generally.