Immunohistochemical study of blood group activities in the alimentary canal in normal and pathologic conditions with reference to the nature of epithelial mucopolysaccharides.

ABO(H)- and Lewis-activities in the human alimentary canal were investigated by the avidin-biotin-peroxidase complex method using commercial mouse monoclonal antibodies in order to clarify (1) the changes apparent in these activities in carcinoma of the digestive tract or premalignant intestinal metaplasia of the stomach and (2) the relationship of the activities to the histochemical properties of epithelial mucins examined by Alcian blue (pH 2.5)/periodic acid-Schiff (PAS) double staining. In intestinal metaplasia, ectopic goblet cells showed various degrees of ABO(H)-activities according to the PAS stainability of mucins and revealed Lea-activity even in a Le(a-b+) group. In carcinoma of the alimentary canal, ABO(H)- and Lewis-activities compatible with the donors' blood groups were located mainly at the PAS-positive cell surface, and in the Golgi bodies and secretions. It was thus concluded that quantitative and/or qualitative changes in blood group activities were closely associated with those of epithelial mucopolysaccharides.