Distribution of cells binding erythrocyte-antibody (EA) complexes in human lymphoid populations.

Cells bearing Fc receptors were studied using a rosette technique with chicken erythrocytes coated with rabbit antibodies (EA). By comparison with other markers and by selective depletion of T and B cells it was demonstrated that EA rosettes were formed by about 10% of the monocytes, 7% of the T lymphocytes, and 45% of the B cells. In addition, 26% of EA-rosette-forming cells (EA-RFC) in the peripheral blood carried on other markers than C3 receptors. Marked differences were found in the percentages of EA-RFC in cell suspensions from various lymphoid organs: peripheral blood, 15.2%; spleen, 26.6%; bone marrow, 30.9%; lymph nodes, 2.8%; thymus, 0.3%; and tonsils, 0.5%. It was concluded that Fc receptors were present on subsets of different lymphocyte subpopulations; their presence could not be regarded as a specific marker of one of these subpopulations.