IgG and IgE immune response against the surface glycoprotein gp200 of Saccharomyces cerevisiae in patients with atopic dermatitis

The heat-stable and soluble glycoprotein gp200 (molecular weight 200 kDa) is part of the cell wall of S. cerevisiae. Recently, an association was shown between IgA and IgG against gp200 and inflammation in Crohn's disease. Gp200 is able to induce a proliferation of human lymphocytes in vitro, together with a natural killer cell associated cytotoxicity. Specific IgE against Saccharomyces cerevisiae (baker's or brewer's yeast) may be detected in approximately 73%, against Candida albicans in 68% of those patients suffering from severe atopic dermatitis. The aim of this study was to elucidate the possible role of an anti-gp200 immune response for the pathogenesis of atopic dermatitis by immunoblot analysis. Anti-gp200 IgE was found in 55% of healthy individuals, in 67% of individuals with atopic predisposition without eczema, in 63% of the patients with mild atopic dermatitis, and in 86% of patients with severe atopic dermatitis, respectively. On the contrary, anti-gp200 IgG could be shown in 55% of healthy individuals, in 89% of individuals with atopic predisposition but without eczema, in 100% of patients with mild atopic dermatitis, and in 79% with severe atopic dermatitis, respectively. No immunoreactivity was found when an extract of Arxula adeninivorans was used as antigen. These results underline the specificity of the immunoblot results with gp200 from Saccharomyces cerevisiae. It can be concluded that occurrence of specific IgE against Saccharomyces cerevisiae cannot be explained by a cross reactivity, e.g., against Candida albicans allergens. Further investigations with the recombinant gp200 will give information on the role of this glycoprotein both in atopic dermatitis and Morbus Crohn.