Recombinant allergens/allergen standardization.

Recombinant allergens are genetically engineered isoforms representing allergen molecules from allergen extracts. Immunologic responses of allergic patients toward allergen extracts define the major allergens. For the average allergic patient, the diagnostic sensitivity and treatment efficacy correlate with the concentration of major allergen. Standardization of allergen products (extracts or genetically engineered allergens) can therefore advantageously be performed using a selected recombinant major allergen as a standard. The standardization will furthermore require reagents for which both monospecific, monoclonal, or preferably, recombinant antibodies can be used. Due to differences in the allergenic activity of individual isoallergens and the naturally occurring mixture of isoallergens found in an allergen extract, and due to additional contribution to the allergenic activity from other molecules in the extract, a biologic potency assessment must always be performed as a supplement. This is also the case for a genetically engineered allergen product.