Expression of IgGFc receptors on human plasma cells

Plasma cells that were obtained in bone marrow aspirates from patients with plasma cell dyscrasias were assessed for the expression of IgGFc receptors. A sensitive EA rosette assay and direct immunofluorescence were combined to quantitate plasma cells that expressed IgGFc receptors. Two patients with nonsecretory disorders had large numbers of receptor positive cells (98 and 78%). The remaining patients, all of which had been treated with cytotoxic drugs prior to testing, had significant numbers of IgGFc receptor positive cells (36-86%) and the number of FC receptor positive cells was increased by storing the cells at 4 degrees C for 18 hours prior to performing the rosette assay.