[Autoantibody pattern in scleritis and episcleritis]

Episcleritis and scleritis can be caused by various systemic disorders, which can be triggered by infectious diseases. We studied the autoantibody pattern against various organ-specific and non-organ-specific antigens in episcleritis and scleritis patients.

Sera from 46 patients (episcleritis n = 28, scleritis n = 18) were studied for antibodies against nuclei, smooth muscle cells, mitochondria, endothelial cells, sarcolemma, liver cells, heart muscle fibrils, parietal cells and thyroid cells by immunofluorescence testing. Titers of antibodies against thyroglobulin, laminin, keratin and microsomes were evaluated by ELISA.

In patients with episcleritis the pattern of autoantibodies found was different from that in scleritis patients. Thus, in episcleritis the levels of antibodies against sarcolemma (32%), parietal cells (25%), laminin (38%), keratin (58%) and microsomes (28%) were elevated, while scleritis patients, besides keratin antibodies (50%), demonstrated anti-nuclear antibodies (ANA) in 28% of cases. These differences were not significant. Approximately 5% of normal control patients show these antibodies.

Previous studies have shown that episcleritis rarely develops into scleritis. Our results suggest that this may be due to different underlying diseases. While 28% of scleritis patients had ANA, which may suggest an autoimmune disposition related to collagenosis, episcleritis patients had a different autoantibody pattern such as has been found in various infectious diseases and diseases for which triggering by infectious organisms seems possible, such as anterior uveitis, ankylosing spondylitis and Behçet disease. Investigations in larger groups of patients are needed to check the statistical significance of these differences.