Studies in Hypersensitiveness

Abstract

Summary The atopic reagins, discovered by Prausnitz and KÜster, have been found to be demonstrable in the blood of all subjects of hay fever and asthma in whom the cutaneous reaction to the injection of the atopen is positive. Not all normal skins are susceptible to local passive sensitization. About 84 per cent of normal skins are receptive; about 11 per cent are non-receptive; and about 5 per cent are slightly receptive. The duration of the local passive sensitiveness is at least four weeks. Heating for one-half hour at 56°C. injures the atopic reagins. The normal human skin could not be passively sensitized with an anti-egg precipitating serum or an anti-ragweed pollen precipitating serum, both from an injected rabbit. The atopic reagin is neutralizable in the test tube or in the tissues. It does not produce a visible precipitate nor complement fixation, when mixed with the related atopen. The atopic reagin does not conform, in its successive fractional neutralization, with the quantitative law governing the fractional neutralization of precipitin. The atopic reagin is unable to sensitize the guinea-pig, confirming Prausnitz and Küster, or the guinea-pig uterus. Atopic reagins could not be demonstrated in 5 cases of drug idiosyncrasy, nor in a case of hypersensitiveness to green pea, without asthmatic symptoms. The atopic reagin is specific. In the blood of individuals sensitive to more than one substance, more than one reagin can be demonstrated. With the method of desensitization of the passively sensitized skin site, the identity or non-identity of atopens of different origin can be determined. Sensitizing bodies could not be demonstrated with the method of Prausnitz and Küster in the blood of individuals sensitive to tuberculin or to poison ivy.