Studies in Absorption of Undigested Proteins in Human Beings: I. A Simple Direct Method of Studying the Absorption of Undigested Protein

Summary A technic for the demonstration of the absorption of undigested protein in human beings is presented in detail. In contradistinction to all previous immunological methods employed in human beings for the same purpose, this test is a direct one, and is performed on the subject himself. It employs the principle of passive local sensitization as its basis. By the intradermal injection of serum, taken from certain fish or egg hypersensitive cases, it is possible to passively locally sensitize an individual to these proteins. Upon the ingestion of such proteins, under proper circumstances, a wheal develops at the sensitized area, which has been proved to indicate the absorption into the circulation of these proteins in an undigested form. The individual steps in the technic and the factors affecting them have been discussed at length. The advantages and limitations of the procedure have been reviewed. The fact that the reaction occurs in most individuals when physiological amounts of fish and egg protein are taken under physiological circumstances, indicates that the absorption of these undigested proteins is a normal phenomenon.