The evaluation of selected parameters of immune function in asthmatics after long-term corticosteroid therapy.

The availability of inhaled beclomethasone diproprionate permitted the discontinuation of continuous, long-term systemic corticosteroid therapy (SCT) in a group of asthmatics who had previously required SCT to control their asthma. Twelve patients had been on SCT for a period of 2-22 years with an average duration of 7 years. To determine whether this previous long-term SCT and the current use of inhaled beclomethasone diproprionate had an effect on leucocyte functions, a variety of studies reflecting T lymphocyte, B lymphocyte and granulocyte function was done. The results were compared with those of twelve asthmatic patients of similar age ranges who had never received steroids. Results showed that the two patient populations could not be differentiated on the basis of phytohaemagglutinin stimulation of lymphocytes, sheep erythrocyte rosette formation, IgG, IgA, IgM and IgE concentrations or granulocyte bactericidal activity. Delayed skin reactivity was present in both groups, with more positive reactions in the non-SCT group. Polymorphonuclear adherence values were slightly lower in the SCT female population using beclomethasone diproprionate. The latter two minor differences may be due to the previous SCT, the use of beclomethasone diproprionate or the limited population of patients studied. We conclude from these studies that the long-term use of SCT at the low doses required for control of asthma resulted in little permanent effect on the variety of lymphocyte and granulocyte functions tested.