Fc receptors on myeloid leukaemic cells: comparison between assays of rosette-forming cells.

A comparison has been made between assays of Fc receptor bearing cells among blood leucocytes from normal individuals and from patients with myeloid leukaemia, using human anti-D coated erythrocytes (HEA) and sheep erythrocytes sensitised with a rabbit anti-sheep erythrocyte antibody (SEA). Differences were found between the assays in both groups, demonstrating the heterogeneity of Fc receptors with respect to affinity for marker, and for Fc bearing leucocytes. Monocytoid cells reacted more readily with both markers than myeloid cells. The HEA rosette assay may be useful selective diagnostic aid for Fc+ myeloid leukaemia since the SEA assay detects Fc receptors on mature granulocytes.