STUDIES ON IMMUNITY IN A TYPE OF HUMAN ALLERGY (HAY FEVER): SEROLOGIC RESPONSE OF NON-SENSITIVE INDIVIDUALS TO POLLEN INJECTIONS.

Large injections of ragweed pollen extract into normal non-sensitive volunteers did not produce a sensitization to ragweed. Group 1 volunteers in whose skin many reactions were induced by injections of ragweed extract mixed with ragweed sensitive serum failed to show any serological changes. The theory that the immune substance found in the serum of treated ragweed sensitive cases was due to the reaction or to some substance created by it and not to the ragweed per se was not upheld. On the contrary in group 2, volunteers who received larger amounts of ragweed but no sensitive serum, serological changes were induced resembling those previously observed to occur in ragweed sensitive patients after treatment. They were demonstrable by an inhibition of the immediate reaction and by interference with the neutralization of sensitive serum by its antigen. These serological changes are therefore independent of the specific reaction characteristic of this type of allergy. The inhibiting factor was found to be related to the pseudoglobulin fraction of the serum and was shown to be specific.