Studies on the Sensitization of Animals with Simple Chemical Compounds Ix. Skin Sensitization Induced by Injection of Conjugates

In experimental work on sensitization with a group of simple chemical substances, strong evidence was obtained for the view that the production of hypersensitivity depended upon the formation of antigenic combinations in the body (1). As a corollary, the direct administration of in vitro conjugates in these cases should lead to skin sensitivity towards the corresponding low molecular substance. Yet in our previous attempts, the injection of protein compounds (even into the skin), analogous to older experiments with azoproteins in which an anaphylactic state was induced, was not satisfactory in eliciting skin sensitization. However, by employing a technique patterned upon the method used for inducing skin sensitivity by intraperitoneal injection of the simple substance (2), namely concomitant administration of killed tubercle bacilli, positive results were secured, as reported briefly (3). The complex antigen used was a conjugate made from the erythrocyte stromata of guinea pigs, which were coupled with picryl chloride or 2,4dinitrofluorobenzene. A recent paper by Haxthausen (4) which concerns this subject is discussed below.