PERIPHERAL IMMUNOGLOBULIN-SECRETING CELLS IN IMMUNODEFICIENCIES - EFFECTS OF INTRAVENOUS IMMUNE GLOBULIN

Peripheral blood B cells secreting IgG, IgA, IgM, and IgE were quantit ated in normal adults (n = 12), newborns (n = 8), patients with antibo dy deficiency (n = 5), and patients with elevated IgE (four patients) using a reverse enzyme-linked immunospot (RELISPOT) assay. This techni que measures immunoglobulin secreted by B cells by capture on an antib ody-coated plate, and identified as a plaque on a nitrocellulose-membr ane plate. Hypogammaglobulinemic patients and newborns (cord blood) sh owed no detectable IgG, IgA, or IgE secreting cells. Several cord bloo d and hypogammaglobulinemic patients, however, showed normal adult num bers of IgM secreting cells. One IgA-deficient patient showed increase d numbers of IgA secreting cells, but a second IgA-deficient patient s howed normal numbers of IgA secreting cells. Three patients with the h yper-IgE syndrome and a patient with severe eczema had very high numbe rs of IgE secreting cells. The effects of intravenous immunoglobulin o n this system in vivo and in vitro were also examined. High dose intra venous immunoglobulin therapy did not decrease the immunoglobulin secr eting cells in two neurologic patients given high dose IVIG. In vitro exposure of normal B cells to either IVIG or cycloheximide (a protein synthesis inhibitor) decreased the number of IgA and IgM secreting B c ells. Cycloheximide also decreased the number of IgG secreting B cells in vitro. IgG spots, however, were present when cycloheximide-treated cells were incubated with a high concentration of IVIG. Since IVIG ma y bind directly to cells, its effect on in vitro B-cell IgG synthesis could not be determined.