Distribution of blood group antigens A, B and H in human fetal oral mucosal and odontogenic epithelium.

The distribution of blood group antigens A, B and H was examined in human fetal oral macosal and odontogenic epithelium. Tissue from 19 fetuses with crown-rump lengths of 57 mm to 189 nun, corresponding to a fertilization age of 10-20 weeks, was included in the study. The distribution of blood group antigens was studied by immunofluorescence methods on tissue sections. Cell membrane bound blood group antigen A or B was demonstrated in the oral mucosal epithelium of 10 fetuses, whereas blood group antigen H was found in all fetuses. All the epithelial cell layers of the tooth germs were devoid of the blood group antigens A, B and H independent of the age of the fetus. The blood group antigens A, B and H were located on the cell membranes of the upper cell layers of the oral epithelium, whereas the basal cells showed no reaction even in the youngest fetuses. Following the differentiation of the epithelial cells, changes were seen in the distribution of the blood group antigens. [ABSTRACT FROM AUTHOR]