Distribution of A and B antigens in organs of blood group AB individuals: observations disclosed by a double immunoenzymatic labeling method.

The localization of A and B antigens in the organs of blood group AB individuals has been studied using a double immunoenzymatic labeling method. Both A and B antigens were found in the various epithelial cells of these organs, but the epithelial cells could be classified into the following four types depending on the reaction pattern with anti-A and anti-B sera: type 1: cells that stained positive with both anti-A and anti-B sera; type 2: cells that stained positive with anti-A serum only; type 3: cells that stained positive with anti-B serum only; type 4: cells that were negative with both sera. The distribution of each of these epithelial cell types varied considerably, even in the same tissue and individual. Our results seem to suggest that a dissociation in the conversion to the A and B antigens occurs in the tissue of individuals belonging to blood group AB and that the degree of this dissociation varies from tissue to tissue and from cell to cell.