In vitro IgE-secretion in atopic eczema: influence of allergens and mitogens and role of CD8 T cell subpopulation.

In cultures of peripheral blood mononuclear cells (PBMC) from 23 atopic patients and 14 controls the influence of mitogens, allergens and CD8 suppressor T lymphocytes on the in vitro IgE response was studied. The in vitro IgE levels in lymphocyte culture supernatants reached a plateau after 6 days of culture, whereby low levels of IgE could be reproducibly measured down to 0.5 ng/ml. The spontaneous in vitro IgE secretion from PBMC of atopic eczema patients was elevated in comparison to the control group and showed a direct correlation (r = 0.72) to the serum IgE levels. Pokeweed mitogen rather suppressed the in vitro IgE production. After removal of the CD8 subpopulation of T lymphocytes by using an indirect erythrocytes rosetting technique we found increased in vitro levels pointing to a role of IgE regulating T suppressor subpopulations.