The objective of these studies is to apply quality control techniques used to determine the potency of standardized allergenic extracts to assess the quality of non-standardized weight/volume, PNU, and alum adsorbed extracts. An outcome of this objective is the determination of appropriate methods to manufacture consistent well-characterized extracts.

Non-standardized birch, English plantain, and olive pollen extracts were tested. Multiple consecutive lots manufactured over 2-3 years were measured for major allergens Bet v 1, Pla l 1, and Ole e 1 using direct binding ELISAs obtained from ALK-Abelló, Madrid and validated in our laboratory. IgE binding ELISAs were performed using sera pools from at least 5 patients allergic to the allergen. Electrophoresis and immunoblotting were also performed.

Most extracts had good consistency by either IgE binding or major allergen, although some lots show a significant deviation from the average. English plantain and birch had a few lots that were much lower in major allergen than the average. Aqueous extracted olive pollen extracts showed consistency as did glycerin extracted pollen, however a significant reduction in extractability of the major allergen with glycerin was observed. Some olive pollen raw material source lots showed significant differences in Ole e 1. IgE binding ability was well correlated with Bet v 1 in birch extracts. Major allergens were also measured in alum adsorbed extracts.

These studies demonstrate the benefit for testing potency in non-standardized extracts and will provide the means to produce consistent products in the interim before FDA standardized products become available.