Preliminary immunologic characterization of glycoprotein antigens (CEA) of tumors of gastrointestinal tract in humans.

Using the method of double diffusion in agar and precipitation, inhibition test and specific antitumor immune sera, perchloric extracts of carcinomas of the stomach and lower parts of the gastrointestinal tract were found to contain a carcinoembryonic antigen with electrophoretic mobility of gamma-globulins. Antigens from carcinomas of all studied parts of the gastrointestinal tract (stomach, sigmoid, colon and rectum) gave lines of identity in the test of double diffusion in agar. This antigen was not demonstrable in the mucous membranes surrounding the carcinomas of the gastrointestinal tract or in normal organs (gastrointestinal mucosa, liver, kidneys, spleen, plasma), or in perchloric extracts of gastrointestinal tissues of human fetuses.