Reticuloendothelial Fc receptor function in patients with Sjogren's syndrome

The functional status of the reticuloendothelial Fc receptor in patients with Sjogren's Syndrome was examined by determining the clearance from the circulation of IgG coated erythrocytes which had been obtained from a single donor. 18 patients with Sjogren's Syndrome were studied and the results compared with those obtained from 18 patients with Rheumatoid Arthritis and 27 healthy controls. Abnormal Fc mediated clearance was observed in 3 individuals with Sjogren's Syndrome and 2 patients with Rheumatoid Arthritis. Extraglandular disease was not associated with abnormal Fc function and there was no correlation between the clearance rates and the immune complex levels, complement levels or rheumatoid factor titre. A comparison of the clearance rates obtained using the patients own red cells with those derived from using a single donor showed that the source of cells used had a significant effect on the clearance rate. Our findings provide no support for the idea that defective Fc function may be of pathogenic significance in the development of more extensive disease in patients with Sjogren's Syndrome.