Dactylis glomerata pollen allergen extract (Orchard grass pollen extract)

Dactylis glomerata pollen allergen extract is a complex mixture of allergenic proteins derived from the pollen of Orchard grass (also known as Cocksfoot grass), which is a major source of seasonal aeroallergens worldwide [1, 10]. The extract contains several well-characterized allergens, including Dac g 1 (a beta-expansin) and Dac g 5 (a ribonuclease), which trigger Type I hypersensitivity reactions by cross-linking IgE on the surface of mast cells and basophils [8, 11]. While it is not a traditional molecular target like a receptor or enzyme, it serves as the active antigenic component in allergen-specific immunotherapy (AIT) and diagnostic skin prick tests [4, 5, 14]. The therapeutic goal of using this extract is to desensitize the patient's immune system through controlled exposure, leading to the induction of regulatory T cells and the production of 'blocking' IgG4 antibodies that prevent future allergic responses [1, 14]. This treatment is primarily indicated for patients with moderate-to-severe allergic rhinitis, conjunctivitis, or asthma who have not responded adequately to symptomatic medications [2, 10]. Notable safety concerns include the risk of local and systemic allergic reactions, with anaphylaxis being the most severe potential adverse event [1, 5].

Other names

Orchard grass pollen extractCocksfoot grass pollen extractDactylis glomerata pollen polymerized extractDac g allergensDactylis glomerata pollen liquid extract

Allergen-specific immunotherapy (AIT) induces immunological tolerance by shifting the immune response from a Th2-dominated profile to a Th1/Treg-dominated profile, increasing the production of IL-10 and TGF-beta, and promoting the synthesis of allergen-specific IgG4 antibodies that block IgE-mediated mast cell degranulation [1, 14].