isologous antiserum and isologous indicator erythrocytes, (b) isologous antiserum and not isologous indicator erythrocytes, (c) antiserum absorbed with isologous erythrocytes, and (d) antiserum neutralized with isologous purified blood group

The isoantigens A, B, and H of the red blood cells of Groups A, B, and 0 are also present in the normal epithelial cells of the exocrine glands of the pancreas. They are absent in Langerhans's islands and in the connective tissue. They are readily demonstrable with the Coombs' mixed-cell agglutination reaction. We studied the effect of cancerous transformation on the three antigens in primary and metastatic carcinomas of the pancreas. They could not be demonstrated in over 80% of the cases. With rare exceptions, the loss of demonstrable antigen paralleled morphological anaplasia. This technique promises to be useful in the early diagnosis and prognosis of carcinoma of the pancreas.