Defective reticuloendothelial system function in rheumatoid arthritis.

The function of the splenic reticuloendothelial system in patients with rheumatoid arthritis (R.A.) was assessed by determining the clearance of autologous heat-damaged erythrocytes from the circulation. 11/13 patients with active R.A. had a defect in the clearance of red cells and there was a significant inverse correlation between splenic function and the level of circulating immune complexes detected by a Clq-binding assay. Splenic function was normal in 13 patients with inactive disease who had been treated with either gold or prednisone. A serial study on 1 patient with active R.A. showed a clear correlation between fluctuations in disease activity, splenic function, and the level of circulating immune complexes.