Allergen-specific Ig classes in non-allergic individuals.

Allergic rhinitis (AR) is characterized by Th2 polarized immune response, such as increased IL-4 and reduced IFN-gamma production, and by a functional defect of T regulatory cells. This impaired immune response profile influences the pattern of immunoglobulin production in allergic patients. However, there is no study that has explored the pattern of allergen-specific Immunoglobulin (Ig) classes in normal subjects. Therefore, the aim of this study is to investigate the allergen-specific IgE, IgG, IgG4, and IgA serum level pattern in a group of non-allergic individuals. Forty healthy non-allergic subjects were enrolled. Serum allergen-specific IgE, IgG, IgG4, and IgA for mites, cat, Parietaria, grasses, and birch were quantitatively determined by ELISA method. Allergen-specific IgE, IgG, IgG4, and IgA serum levels were significantly different for each tested allergen (p=0.0001 for each class). In conclusion, the present study provides the first evidence that immunoglobulin production pattern depends on the specificity of the allergenic response in non-allergic subjects as well as in allergic patients. In addition, this study is the first that quantitatively evaluates the Ig classes.