Studies of the association of the A, B and Lewis Blood group antigens with carcinoembryonic antigen (CEA).

Carcinoembryonic antigen (CEA) was purified from primary tumour or from hepatic metastases obtained from ten cases of carcinoma of the colon. In nine cases the blood group antigens A, B, Lea or Leb were detected in CEA preparations by the binding of 125I-labelled CEA by blood group antibodies. The extent of binding appeared to preclude simple contamination of CEA preparations by blood group glycoprotein. In all cases the blood group antigens detected were consistent with the patients' known blood groups. Blood group I and i activities were not detected. It is concluded that the determinants of A, B and Lewis antigens and of CEA share the same glycoprotein carrier molecules.