DIFFERENTIAL-EFFECTS OF INHALED BUDESONIDE AND ORAL PREDNISOLONE ON SERUM IMMUNOGLOBULIN-G AND ITS SUBCLASSES IN HEALTHY ADULT VOLUNTEERS

Background Glucocorticosteroid (GCS) treatment lowers serum IgG and Ig G subclass (IgG-SC) levels, but the minimal dose and duration of admin istration at which this occurs is not known. Objective The aim of this study was to define the daily dose of a 2-week course of GCS at which IgG(-SC) suppression occurs. Methods The effects of three GCS treatme nt schemes on serum IgG(-SC) levels in healthy adults were studied in a double-blind, randomized trial. Group 1 (n = 10) was treated with 40 mg oral prednisolone/day, group 2 (n = 10) with 10 mg oral prednisolo ne/day and group 3 (n = 10) with 3.2 mg inhaled budesonide/day. Blood sampling was performed at baseline and at the end of the 2-week treatm ent period. Results In group 1, IgG1, IgG2 and IgG3 levels were signif icantly decreased after treatment, while in group 2 this was only so f or IgG3. In both groups, the decrease of total IgG tended towards or j ust reached significance. In group 3, no statistically significant cha nges were observed. Conclusion A course of 40 mg oral prednisolone/day for 2 weeks induces significant suppression of serum IgG-SC levels; l ower doses cause more subtle changes, indicating that GCS-induced IgG- SC suppression is a dose-dependent phenomenon. Short courses of very h igh doses of inhaled budesonide appear to be devoid of this side-effec t.