In vitro generation of IFN-gamma in relationship to in vivo concentration of IgE and IgG subclasses and Fc epsilon Rl/CD23 positive circulating lymphocytes in patients with severe atopic dermatitis (AD).

In fifteen patients with severe atopic dermatitis (AD) and ten healthy controls we investigated the in vitro generation of IFN-gamma and analysed the number of Fc epsilon RL/CD23 (low affinity Fc receptor for IgE) positive lymphocytes. We found a significantly impaired capacity to secrete IFN-gamma after PHA-stimulation compared to controls in a significant proportion of patients. Serum IgG4 levels in patients were higher compared to controls. A significant portion of lymphocytes bearing the low affinity Fc receptor for IgE (CD23) was observed with the moab Tü1 in patients. Lymphocytes from healthy donors were completely negative or less than 2% positive for Tü1. Despite small numbers of patients a significant correlation was found between IFN-gamma generation in vitro and IgE serum concentration in patients, whereas the IFN-gamma generation and IgG4 concentration were negatively correlated in the patient group. The number of Fc epsilon RL/CD23 positive lymphocytes in patients was positive correlated with the serum IgG4 and IgE concentration and negative correlated with IFN-gamma generation in vitro. Our data suggest that a possible dysregulation of IFN-gamma, Interleukin 4 or other lymphokine production may be related to increased IgE and IgG4 production.