Enumeration of B-Lymphocytes in Human Peripheral Blood by a Rosette Method for the Detection of Surface-Bound Immunoglobulin

A rosette method is described for the identification and enumeration of B-lymphocytes in human peripheral blood. Sheep red blood cells coated with purified goat anti-human F(ab′)2 were mixed with mononuclear cells separated from blood by density centrifugation on Ficoll-Hypaque. Rosettes were formed by the mononuclear cells with immunoglobulin determinants on their surfaces. The rosetteforming cells were identified as either lymphocytes or monocytes on the basis of their ability to phagocytose polystyrene particles. The percentage and total number of B-lymphocytes in the peripheral blood were calculated after correcting for the rosettes formed by monocytes. The mean values for these determinations in 10 normal subjects were 23% and 485/mm3, respectively. Elevated values were found in one patient with thymic aplasia and in another with chronic lymphatic leukemia. Markedly decreased values were observed in a patient with congenital agammaglobulinemia.