title: Evolution of IgM, IgE and IgG(1-4 )antibody responses in early childhood monitored with recombinant allergen components: implications for class switch mechanisms.
abstract: The formation of IgE antibodies against environmental allergens represents the hallmark of type I allergy. Data from in vitro cultured cells and experimental animal models provide controversial evidence for isotype switching from IgM to IgE production via sequential as well as non-sequential (i.e. direct) class switch. We analyzed the evolution of IgE responses in 11 children developing birch pollen and/or grass pollen allergy during the first 7 years of life using purified recombinant allergen molecules (major birch pollen allergen, Bet v 1; major timothy grass pollen allergens, Phl p 1, Phl p 2, Phl p 5). Demographic, clinical and serological data indicated a postnatal sensitization to pollen allergens. A parallel development of IgG(1-4) and IgE responses to recombinant allergen molecules compatible with a strictly sequential class switch to IgE was observed only in one child. The only partly synchronized and dissociated development of allergen-specific antibody responses found in all other cases can be best explained by a partly sequential class switch involving few switch stations or, more likely, by direct class switching. Kinetics and courses of allergen-specific antibody responses (IgM, IgG(1-4), IgE) during the first years of life suggest that, once established, allergen-specific IgE responses are driven by antigen contact rather than by cytokines controlling class switch to IgE.
authors.affiliation: Department of Otorhinolaryngology, Vienna General Hospital, University of Vienna, Waeringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Verena
authors.initials: V
authors.lastname: Niederberger
authors.forename: Bodo
authors.initials: B
authors.lastname: Niggemann
authors.forename: Dietrich
authors.initials: D
authors.lastname: Kraft
authors.forename: Susanne
authors.initials: S
authors.lastname: Spitzauer
authors.forename: Rudolf
authors.initials: R
authors.lastname: Valenta
mesh_terms: D000367:Age Factors; D000485:Allergens / Q000276:immunology*; D000818:Animals; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology* / Q000235:genetics / Q000276:immunology*; D017578:Immunoglobulin Class Switching; D007073:Immunoglobulin E / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification; D007075:Immunoglobulin M / Q000096:biosynthesis; D007223:Infant; D008297:Male; D018448:Models, Immunological; D011058:Pollen / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology / Q000235:genetics / Q000276:immunology
chemical_list: D000485:Allergens; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E