Interleukin-4 induced IgE and IgG4 secretion by B cells from atopic dermatitis patients

Peripheral blood mononuclear cells from 8 normals and 8 patients with atopic dermatitis (AD) were cultured with recombinant interleukin-4 (IL-4) and the IgE and IgG subclass levels in the culture supernatants measured by radioimmunoassays. IL-4 induced IgE and IgG4 secretion by B cells from both normals and AD patients whereas it has no consistent effect on IgG1, IgG2 and IgG3 secretion. The IL-4 dose response was similar for IgE and IgG4 secretion by cells from both normals and AD patients. On the average, the patients' cells secreted more IgE and less IgG4 than the cells from normals, but because of a large variation, the differences were not significant. However, the ratio of IgG4:IgE secretion was significantly greater for normals than AD patients (mean +/- SEM 7.1 +/- 1.6:1 vs. 1.5 +/- 0.4:1; p less than 0.01). The data demonstrate that IL-4 induces IgE and IgG4 secretion by B cells from both normals and AD patients and suggest that the IL-4 induced switch from IgM to IgG4 or IgE secretion may proceed preferentially to IgE in AD patients as compared to normals.