Frequency and activity of IgE-secreting peripheral blood B-cells in atopic eczema
Thomas P, Pfützner W, Przybilla B
Increased immunoglobulin (Ig) E-levels are frequently found in the sera of patients with atopic eczema. To further understand the mechanisms underlying this increase of IgE, like enlarged number of IgE-producing cells, enhanced activity of IgE-producing cells or altered IgE metabolism, we analyzed the frequency and activity of IgE-producing B-lymphocytes within peripheral blood mononuclear cells of patients with atopic eczema. By use of a sensitive solid phase enzyme-linked immunospot assay (ELISPOT), IgE-secreting cells could be visualized within peripheral blood mononuclear cells of 14 individuals (12 patients with atopic eczema, one patient with impetigo contagiosa, one patient with allergic contact dermatitis) at a frequency of 10-1,120 IgE-secreting cells/10(5) B-lymphocytes. The number of IgE-secreting cells was markedly correlated with the corresponding serum IgE-level (r = 0.97). Secretory activity was also reflected by in vitro IgE production, which was assessed in parallel 7-day cultures and found to be related with actual serum IgE-levels. The enhanced serum IgE-levels in patients with atopic eczema seem to result primarily from an increased number of circulating IgE-secreting B-cells, which may also be found, however, in patients with elevated serum IgE-levels, showing different skin diseases.