Grass pollen allergoid

Grass pollen allergoids are chemically modified allergen extracts derived from grass species such as Phleum pratense (Timothy grass) and Dactylis glomerata (Orchard grass), primarily utilized in allergen-specific immunotherapy (AIT). The modification process, typically involving polymerization with agents like glutaraldehyde or formaldehyde, alters the molecular structure of the allergens to reduce their IgE-binding capacity while maintaining their immunogenicity. This allows for the administration of higher allergen doses with a reduced risk of immediate systemic allergic reactions compared to native extracts. Biologically, the source allergens often include proteins from the beta-expansin family (Group 1 allergens) and ribonuclease-like proteins (Group 5 allergens), which naturally play roles in plant cell wall extension and pollen germination. In clinical practice, grass pollen allergoids are used to treat allergic rhinitis and allergic asthma by restoring immune tolerance. These agents target the immune system by modulating the T-cell response, inducing regulatory T cells, and promoting a shift from pro-inflammatory Th2 responses to tolerogenic profiles. This shift results in the production of allergen-specific blocking antibodies, particularly IgG4, which inhibit the IgE-mediated activation of mast cells and basophils. While effective for long-term disease modification, safety challenges include the potential for anaphylaxis and interactions with drugs such as beta-blockers or MAOIs, which can impede the effectiveness of emergency epinephrine treatment.

Other names

Modified grass pollen extractGlutaraldehyde-modified grass pollen allergensFormaldehyde-treated grass pollen extractGrass pollen allergen extract, modifiedAllergoids

Induces peripheral T-cell tolerance by promoting regulatory T-cell (Treg) activity, shifting the immune response from a Th2 to a Th1/Treg profile, and stimulating the production of allergen-specific IgG4 blocking antibodies that compete with IgE for allergen binding.