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

Background: Recent 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.

Objective: To 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.

Methods: The serum concentrations of SEA- and SEB-IgE in 172 adults with asthma were measured with a fluorescent enzyme immunoassay.

Results: The 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.

Conclusion: Our findings indicate that sensitization to SE, in particular SEA rather than SEB, is associated with poor asthma control in adults with asthma.