Atopic dermatitis in adults: Augmented circulating IgG4 and IgE antibodies against Staphylococcus aureus enterotoxin B

Abstract

The aim of this study was to evaluate the profile of anti-Staphylococcus aureus enterotoxin B (SEB) antibody (Ab) response in adults with AD. We selected 38 patients diagnosed as AD (Hanifin & Rajka's criteria), aged between 18 and 65, and 26 healthy controls (HC), aged between 20 and 47 years. Severity of the disease was established according to EASI (Eczema Area and Severity Index) and patients were graded as mild (28%), moderate (58%) and severe (14%). Sera were assessed for IgG subclasses, IgA, IgM and IgE against SEB by ELISA. The humoral response in AD patients to SEB showed elevated circulating IgE and IgG4 levels (p < 0.05 and p δ 0.001, respectively), and decreased IgA and IgM levels (p < 0.05). Severity of atopic dermatitis was related with low IgG1 and IgG3 levels (p < 0.05), and high IgE antibody response (p < 0.05) to SEB. Interestingly, absence of IgE and IgG1 response to SEB was seen in some AD patients (26.3% and 18.4% respectively). In AD, the immunoglobulin-related subtype Th2 lymphocytes, such as IgE and IgG4, appear to be relevant in the response to superantigens. These results emphasize an altered pattern of Ab response to SEB in AD, which is impaired according the disease severity.