Enumeration of immunoglobulin-bearing lymphocytes in whole peripheral blood

A new method is described for the detection by immunofluorescence of lymphocyte populations in whole peripheral blood. Lymphocytes are identified by their lack of intracellular peroxidase, and the absolute number of different populations can be accurately enumerated by avoiding procedures for isolating mononuclear cells before fluorescent staining. Among twenty-two normal individuals the mean +/- s.d. percentage and absolute number of lymphocytes with stable surface immunoglobulin were as follows: IgM, 8-1+/-2-3%, 142+/-60/mu1; IgD,8-9+/-2-2%, 212+/-85/mu1;IgA, 2-2+/-1-0%, 41+/-24/mu1; IgG, 2-3+/-1-6%, 60+/-47/mu1. It was confirmed that the detection of true IgG-bearing lymphocytes depends on washing the blood at 37degrees before staining or the use of F(ab)2 anti-IgG antibodies. The proportion of lymphocytes stained by whole IgG polyvalent anti-immunoglobulin antibody, which detects both true immunoglobulin-bearing lymphocytes (B cells) and Fc receptor cells was constant (20-5+/-1-0%) both in and between individuals, but the absolute numbers (380+/-117/mu1) varied with the lymphocyte count.