Grass pollen allergen extracts (GPAE)

Grass pollen allergen extracts are complex biological mixtures containing the allergenic proteins derived from the pollen of various grass species, such as Phleum pratense (Timothy grass) and Dactylis glomerata (Orchard grass) [1, 2]. These extracts are not traditional molecular targets like receptors or enzymes; rather, they are the active therapeutic agents used in allergen immunotherapy (AIT) to treat IgE-mediated allergic rhinitis and conjunctivitis [3]. The biological function of these extracts is to modulate the patient's immune system by inducing peripheral T-cell tolerance and promoting the expansion of regulatory T cells (Tregs) [4]. This shift in the immune profile leads to a reduction in Th2-mediated allergic inflammation and an increase in the production of allergen-specific IgG4 blocking antibodies, which compete with IgE for allergen binding [4, 5]. Clinically, these extracts are administered sublingually or subcutaneously to provide long-term desensitization and symptom relief [1, 3]. They are particularly effective for patients who do not respond adequately to conventional pharmacotherapy like antihistamines [2]. However, their administration carries a significant risk of systemic allergic reactions, including life-threatening anaphylaxis, necessitating careful patient selection and monitoring [1, 2]. Additionally, long-term use has been associated with the development of eosinophilic esophagitis in some patients [1].

Other names

Timothy grass pollen extract5-grass pollen extractOralairGrastekItulatekPhleum pratense extractDactylis glomerata extractAnthoxanthum odoratum extractLolium perenne extractPoa pratensis extract

Induction of immune tolerance through regulatory T-cell activation and production of allergen-specific IgG4 blocking antibodies