Enzyme-linked immunosorbent assay (ELISA) for isotype-specific quantitation of antibodies to Staphylococcus aureus in patients with atopic dermatitis.

An enzyme-linked immunosorbent assay (ELISA) was developed to study the serum antibody response against Staphylococcus aureus within four immunoglobulin classes (IgG, IgA, IgM and IgE) in patients with atopic dermatitis (AD) and in normal controls. Soluble antigens released from S. aureus Wood 46 (protein A deficient) were partially purified by gel filtration of supernatant culture fluid. Median ELISA activity against S. aureus antigens within the IgG and IgE classes was significantly higher in patients than in controls (IgG, p less than 0.005; IgE, p less than 0.05). Patients with severe disease had significantly higher (p less than 0.05) IgG antibody levels than those with mild AD. No such clinical association was found for IgE activity. The antibody levels showed no relation to the serum concentrations of total IgE.