COMPLEMENT INACTIVATION BY ALLERGENIC PLANT POLLEN EXTRACTS

Dialyzed aqueous extracts of plant pollen are widely used in the clini cal practice of allergy for diagnostic and therapeutic purposes. The p resent investigation shows that such allergenic extracts are capable o f consuming complement in every human serum, independent of the clinic al condition. Complement is engaged by way of the first component C1, but without the participation of allergen-specific antibodies. The cap acity of distinct pollen extracts to inactivate haemolytic complement was found to depend on the plant species, the most potent extracts bei ng from the pollen of the weeds and trees. Analysis by UV-spectroscopy of the flavonoids remaining firmly bound to the proteins gives rise t o the proposal-that complement inactivation by allergenic and non-alle rgenic pollen extracts is due to polyphenolic (flavonoid) structures c omplexed with, or chemically conjugated to, the pollen proteins.