Levels of serum IgE, serum soluble-Fc epsilon RII, and Fc epsilon RII(+) peripheral blood lymphocytes in atopic dermatitis.

Levels of serum IgE, serum soluble-Fc epsilon RII (S-Fc epsilon RII), and Fc epsilon RII(+) peripheral blood lymphocytes (PBL) were examined in 73 patients with atopic dermatitis (AD) and 17 control subjects with no atopic disease, in order to investigate the correlation of these parameters with AD. AD patients showed increases in IgE, S-Fc epsilon RII and Fc epsilon RII(+)PBL as compared with control subjects. In AD patients, levels of serum IgE and Fc epsilon RII(+)PBL increased as the extent of dermatitis became more severe, while levels of serum S-Fc epsilon RII showed no correlation with the extent of dermatitis. In 8 of the 73 AD patients who showed an improvement in their symptoms with treatment with topical corticosteroids or antihistamine, IgE, Fc epsilon RII(+)PBL, and S-Fc epsilon RII were measured before and after treatment. Fc epsilon RII(+)PBL correlated with disease activity; IgE and S-Fc epsilon RII did not show any such correlation. Patients with elevated IgE levels (IgE greater than 5,000 U/ml) showed low levels of S-Fc epsilon RII. Severely affected cases with a history of respiratory atopy also showed decreased S-Fc epsilon RII levels. It is believed that S-Fc epsilon RII binds to IgE in serum and may neutralize or down-regulate IgE mediated allergic reactions. A low level of S-Fc epsilon RII may cause an elevation of IgE and an exacerbation of the disease.