A Short Burst of Oral Corticosteroid for Children with Acute Asthma: Is There an Impact on Immunity?

Background: We wished to examine the impact of a short course of oral corticosteroids on the immune function of children with acute asthma and explore the mechanism of immune suppression, if any. Methods: We conducted a prospective cohort study of children aged 3-17 years presenting with acute asthma to the emergency department. The exposure of interest was a short course of systemic corticosteroids. In emergency department, corticosteroid-treated and nonexposed children were immunized with 3 antigens, namely, a neoantigen (Bacteriophage phi X 174) and 2 recall antigens (diphtheria and tetanus). After 5 +/- 1 weeks, children were reimmunized with Bacteriophage phi X 174. Antibody titers were measured 1, 2 (peak), and 5 weeks after the primary immunization, and 1 week (peak) after the secondary one. Results: We enrolled 41 children, 27 treated with and 14 unexposed to oral corticosteroids. Corticosteroid-treated children displayed an 85% lower adjusted total (IgG and IgM) peak titers to the primary Bacteriophage immunization compared to controls [ratio of geometric means (95% confidence interval): 15% (5% to 43%)]. There were no group differences in the rise of diphtheria or tetanus antibodies. After the secondary Bacteriophage immunization, corticosteroid-treated patients showed no significant group difference in peak total titers [ratio of geometric means (95% confidence interval): 1.84% (0.66%, 5.10%)], amplification and absolute, and percent lgG titers as compared to unexposed children. Conclusions: In children with acute asthma, a short course of oral corticosteroids may be associated with depressed immune response to a new antigen, with recovery within 6 weeks and no apparent impact on response to known antigens.