Premium
Comparison of allergenicity and immunogenicity of an intact allergen vaccine and commercially available allergoid products for birch pollen immunotherapy
Author(s) -
Lund L.,
Henmar H.,
Würtzen P. A.,
Lund G.,
Hjortskov N.,
Larsen J. N.
Publication year - 2007
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2007.02687.x
Subject(s) - immunogenicity , allergen , immunology , immunoglobulin e , immunotherapy , allergy , histamine , antigen , medicine , chemistry , immune system , pharmacology , antibody
Summary Background Specific immunotherapy with intact allergen vaccine is a well‐documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10‐year period did not indicate increased safety of allergoids over intact allergens. Objective The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine. Methods Solid‐phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose. Results IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen‐specific IgG responses in mice. Conclusion While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid concept.