Hypogammaglobulinemia in steroid-dependent asthmatics correlates with the daily dose of oral prednisolone

BACKGROUND: Steroid-induced adverse effects including suppression of humoral immunity should be considered in steroid-dependent severe asthma. Only a few studies have determined the exact steroid dose that could potentially suppress humoral immunity in asthmatics. METHODS: Randomly selected 100 adult asthmatics treated with inhaled beclomethasone dipropionate (BDP) were classified into three groups based on the dose of steroid to determine the serum IgG, IgA and IgM levels by radioimmunoassay. Relationships between serum immunoglobulin levels and the daily dose and duration of oral prednisolone (PSL) therapy were examined. RESULTS: None of the patients on inhaled corticosteroid alone had hypogammaglobulinemia. Patients on oral PSL at a dose >12.5 mg/day for at least 1 year had low serum IgG. There was no significant correlation between the duration of oral PSL therapy and serum IgG. CONCLUSIONS: Oral PSL can potentially suppress humoral immunity in severe asthma. In asthmatics, hypogammaglobulinemia could develop in those on a daily dose of PSL >12.5 mg, but is independent of the duration of such treatment. No suppression of humoral immunity was noted on inhaled corticosteroid therapy alone, either at low or high dose.