Association between specific IgE to Staphylococcus aureus enterotoxins A and B and asthma control

Abstract

BackgroundRecent studies have found that serum levels of Staphylococcus aureus enterotoxin (SE)–IgE are higher in patients with severe asthma compared with patients with nonsevere asthma. However, the association between SE-IgE and asthma control is not fully understood. Furthermore, SEA and SEB were the first reported SEs and subdivided into different groups. The influences of SEA-IgE and SEB-IgE on asthma control have not been elucidated. ObjectiveTo determine the relevance of SEA- and SEB-IgE in patients with adult asthma and to investigate the association of SEA-IgE, SEB-IgE, and asthma control, respectively. MethodsThe serum concentrations of SEA- and SEB-IgE in 172 adults with asthma were measured with a fluorescent enzyme immunoassay. ResultsThe prevalence of SEA- and SEB-IgE was 16.2% and 22.1%, respectively. Total IgE levels and the prevalence of atopic dermatitis were higher in SEA-IgE– and SEB-IgE–positive patients than in SEA-IgE– and SEB-IgE–negative patients, respectively; more SEA-IgE– and SEB-IgE–positive patients owned pets. Sensitization to SEA was associated with a younger mean age and a younger mean age at asthma onset. Multiple regression analysis indicated an association between total IgE levels and SEB-IgE. The prevalence of poorly uncontrolled asthma was significantly higher in SEA-IgE–positive patients than in SEA-IgE–negative patients. In addition, fractional exhaled nitric oxide levels were higher in SEA-IgE–positive patients than in SEA-IgE–negative patients. Logistic regression analysis also identified an association between SEA-IgE and poor asthma control. ConclusionOur findings indicate that sensitization to SE, in particular SEA rather than SEB, is associated with poor asthma control in adults with asthma.