Functional heterogeneity within the human peripheral blood B cell pool engaged in IgE synthesis

Fractionation of human peripheral blood leukocytes (PBL) B cells by differential sedimentation on percoll gradients separates B cell subpopulations which vary markedly in rates of spontaneous IgE synthesis, in their response to identical populations of autologous T cells and in their response to soluble T cell factors. This B cell fractionation technique often reveals the presence of active IgE-secreting cells which are totally suppressed within unfractionated PBL B cell preparations and greatly improves the efficiency of detection of T cell-responsive, IgE-producing B cells in PBL of atopics.