Allergoid
DefinitionThis section has been translated automatically.
Allergen modified by chemical modifications (e.g. by polymerisation, depigmentation), usually adsorbed on aluminium hydroxide (see allergoidisation). As a result, the IgE or B-cell epitopes of the allergen are altered or destroyed. The molecule thereby changes its conformation; refolding and oligomerisation occur. The molecule is no longer recognized by IgE antibodies or only to a reduced extent. Its allergenicity is reduced (in comparative tests with intact allergens this thesis could not always be confirmed). However, since the amino acid sequence of the allergen does not change, it is assumed that the T-cell epitopes are retained and that the desired immunogenicity remains unchanged (this thesis is also doubted by some authors).
Pharmacodynamics (Effect)This section has been translated automatically.
Antigen-presenting cells take up the allergoids via unspecific mechanisms such as pino- and phagocytosis, break them down into small fragments and present these oligopeptides on their surfaces to the T-cells. However, the IgE-dependent side effects are attenuated by largely destroyed IgE epitopes. The efficacy of this method has since been confirmed in numerous in vitro investigations and clinical studies.
Note(s)This section has been translated automatically.
- Allergoids are available both for subcutaneous application and, more recently, as a sublingual form of administration.
Remember! The decisive advantage of allergoids in practice is that the allergen dose required for immunotherapy (see below: immunotherapy, specific and immunotherapy, specific, oral) can be administered more safely and faster than that of conventional allergens. A treatment therefore seems to be less stressful and time-consuming for allergy sufferers. In practice, however, this theory could not be upheld, as allergoids can also cause severe systemic reactions.
LiteratureThis section has been translated automatically.
- Casanovas M et al (2007) Safety of immontherapy with therapeutic vaccines containing depigmented and polymerized allergen extracts. Clin Exper Allergy 37: 434-440
- Palma-Carlos AG et al (2006) Clinical efficacy and safety of preseasonal sublingual immunotherapy with grass pollen carbamylated allergoid in rhinitic patients. A double-blind, placebo-controlled study. Allergol Immuopathol 34: 194-198