Reduced Fc-receptor bearing cells in peripheral bloods of patients with systemic lupus erythematosus and in rheumatoid synovial fluids.

Previous reports described that human red cells sensitized with one of Rh antisera (Ripley) make rosette formations (Fc-rosette with some lymphocytes. These Fc-rosettes were well inhibited by aggregated human IgG as well as hypocomplementemic systemic lupus erythematosus (SLE) sera and rheumatoid synovial fluids. In the present study, Fc-receptor bearing lymphocytes were considerably reduced in peripheral bloods of SLE (16.0 +/- 7.6%) and rheumatoid synovial fluids (15.6 +/- 5.3%). On the other hand, EAC-rosette formation rates of peripheral bloods of SLE (32.0 +/- 13.2%) and rheumatoid synovial fluids (30.3 +/- 11.2%) did not significantly differ from normal peripheral bloods (28.3 +/- 2.9%). E-rosette forming lymphocytes were reduced in peripheral bloods of SLE (48.7 +/- 15.7%) and in rheumatoid synovial fluids (49.0 +/- 14.6%) whereas 61.7 +/- 8.6% in normal peripheral bloods. Reduced Fc-rosette formation rates correlated well with the Fc-rosette inhibitory rates. In addition, eluates from the lymphocytes in rheumatoid synovial fluids also inhibited Fc-rosette formation. These results suggested that immune complexes present in peripheral bloods of SLE and rheumatoid synovial fluids are bound to the Fc-receptors on the lymphocytes, block the additional binding of the sensitized red cells, and result in the reduction of Fc-rosette formation.