IGE IN STOOLS AS INDICATOR OF FOOD SENSITIZATION

The fragment of the Fc segment of IgE resistant to proteolytic enzymes was determined by a radioimmunologic method in fecal extracts from se veral groups of patients. IgEs remained undetectable in the 95 healthy subjects studied. IgEs were detected in 16/27 carriers of intestinal parasites (60%), with a mean of 92.4 IU/g dry weight. IgEs were also d etected in 236/312 food-sensitization patients, with the sensitizing f oodstuffs being identified by searching for the specific IgEs in circu lation (75%), with a mean of 63.9 IU/g dry weight. The simultaneous de termination of alpha-1-antitrypsin in fecal extracts and in sera from 21 control subjects and 21 food-sensitization carriers demonstrated th at extravasation of plasma proteins into the gut lumen cannot be respo nsible for the presence of IgE in stools. Testing for IgE in stools th erefore appears to be a simple and economical means of identifying pat ients without parasites who present with food sensitization.