The preparation and standardization of pollen extracts for the treatment of hay fever

Abstract

T HE necessity for uniformity or standardization of the extracts of pollen used in the diagnosis and treatment of hay fever was apparent to the earliest workers in the field of allergy, and attempts were made to standardize extracts. Noon1 used as a unit that quantity of pollen toxin extracted from one-millionth gram of pollen. Cooke? standardized saline extracts of pollen by the total nitrogen content. Clock” recommended a standardization method depending upon the complement fixation capacity of pollen extracts against antipollen serum. Noon’s unit is used by some and modified by others. Both the methods of Noon and of Cooke are subject to the errors that will be pointed out in this paper. Armstrong and Harrison” showed that the complement-fixation capacity of ragweed pollen was not related to the essential desensitizing factor of the pollen extract. No accurate method has heretofore been presented. Investigation by the writers51 6, 7, 8 with Chobot and with Barnard has shown that in giant (~~zb~osia trifida) and low ragweed (Ambrosia artemesia.efolia) , timothy (P7dezcm pretense) and certain other grass pollens, an albumin fraction of t,he pollen, which gave characteristic tests and analysis for protein, was the allergically active factor producing hay fever. This work opened the way for the standardization of pollen extracts on a protein basis. Such a method would give a unit directly related to the content of active material. Saline extracts of these pollens contained traces of inactive protein material (probably globulin), but the amounts were so small in proportion to the albumin that they did not interfere with the method of standardization presented here. Evidence of the inaccuracy of present methods of standardization was