Abstract
Preparations of chopped human and monkey lung were used to estimate the reaginic activity of serum from allergic patients. The lung preparation was passively sensitized by incubation with serum taken from the patients, and then challenged with the antigen responsible for the allergy. Measurement of the histamine released from the lung gave a quantitative assessment of the level of reaginic activity in the patient's serum. Tests were done on patients allergic to four natural antigens, including grass pollen, and to penicillin. Human lung proved more sensitive and possibly more specific than monkey lung in testing for natural allergies. The results of testing for penicillin allergies were less satisfactory, possibly because of the difficulty of reconstructing the appropriate antigen.