IN-VIVO EFFECTS OF GLUCOCORTICOIDS ON IGE PRODUCTION

Recent in vitro investigations have demonstrated that corticosteroids in combination with interleukin-4 induce the synthesis of IgE. Cortico steroids are increasingly being used to treat the inflammatory compone nt of asthma, This has raised concern over the potential in vivo effec ts of corticosteroids on IgE production and the correlation of IgE-enh ancing effects with clinical effects on asthma. In this study 10 patie nts with asthma were given a 7-day course of 20 mg of prednisone, admi nistered orally two times a day. All of the patients had a rise in ser um IgE levels after the course of prednisone (p = 0.005). Detection of specific IgE to pollen and perennial allergens demonstrated that the rise in serum IgE was polyclonal. Peripheral blood mononuclear cells f rom patients treated with prednisone produced increased levels of IgE in vitro when exogenous IL-4 was added to their cultures. Peripheral b lood mononuclear cells obtained from patients before and after adminis tration of prednisone revealed a significant decrease in interferon-ga mma synthesis (p = 0.005), but not in interleukin-4 (p = 0.6), after t he course of prednisone. These findings were paralleled by a significa nt decrease in the frequency of interferon-gamma (p = 0.03), bur not i nterleukin-4 (p = 1.0) expressing cells. Despite the increase in IgE s ynthesis, there was a significant increase in forced expiratory volume in 1 second after the course of prednisone (p = 0.01). These data sug gest that the observed rise in IgE production associated with predniso ne treatment is not clinically deleterious bur reflects the immunomodu latory effects of corticosteroids on T lymphocytes.