[In vitro studies of allergen activity and the depot effect of semi-depot extracts of grass pollen].

Employing two different techniques--Al-RAST and RAST inhibition test--we studied semi-depot extracts of grass pollen from six producers. On one hand, we measured the amount of allergens absorbed by Al(OH)3 gel; on the other hand, we determined the quantity of allergens solved in the aqueous phase. Furthermore, we checked up the continuous release of allergens from the depot by means of a simple in vitro model. The six different semi-depot extracts revealed different amounts of allergens in the depot (Al[OH]3) as well as in the aqueous phase. As we measured the continuous release of allergens, we found that all six extracts behaved nearly identically regarding their function as depots, but were different respecting the released amount of allergens. Summing up, it may be said that therapy extracts--analogous to previously examined test extracts--show differences with regard to their allergenic activities but very similar properties in respect to their function as depots.