Human carcinoma-associated precursor antigens of the NM blood group system.

Blood group NM specificities occur in healthy, benign and carcinomatous breast glands and those of the gastrointestinal (G.I.) tract, but the precursors in their biosynthesis, T (Thomsen-Friedenreich) and Tn, are found in adenocarcinomata and not in benign or healthy tissues. T- and Tn-antigenic specificities are thus human carcinoma-associated. All humans possess anti-T and anti-Tn antibodies. Patients with breast or G.I. tract carcinoma show statistically significant alteration of anti-T titer levels when compared to patients with benign disease and to healthy controls. Breast carcinoma patients but not healthy people showed cellular immunity to T antigen in vitro and in vivo. Most striking was the delayed-type hypersensitivity reaction, which was positive in over 90% of ductal breast carcinoma patients tested and negative in all presumably healthy individuals. T antigen is readily prepared from healthy human red blood cells in uncontaminated form, and free of HL-A and Au antigens. T antigen and anti-T antibodies may be useful in combating some human adenocarcinomata.