Relation of blood group carbohydrates to differentiation patterns of normal and pathological odontogenic epithelium.

The distribution of epithelial cell surface antigens was studied in normal odontogenic epithelium from 20 fetuses and in odontogenic epithelium from 15 ameloblastomas, 16 odontogenic keratocysts, 15 follicular and 15 radicular cysts. The cell surface carbohydrates were detected using antibodies with reactivity for the blood group antigens A, B, H type 2 (A and B precursor) and N-acetyllactosamine (N-lac, H type 2 precursor) by an immunofluorescence technique. The expression of the blood group carbohydrates differed considerably in normal fetal odontogenic epithelium from that in ameloblastomas and odontogenic cysts. The A, B and H type 2 antigens were demonstrated in odontogenic keratocysts and in follicular and radicular cysts. Expression of the blood group carbohydrates was similar in follicular and radicular cysts but differed from that seen in odontogenic keratocysts by the failure to detect N-lac in the latter. The antigens A, B, H type 2 and N-lac were not expressed in any of the ameloblastomas including types with palisading of basal cells and polarization of basal cell nuclei and types with a plexiform pattern with cuboidal or polyhedral shaped peripheral cells. The findings indicate that epithelium of ameloblastomas can be distinguished from odontogenic cyst epithelium by differences in expression of cell surface carbohydrates with blood group specificity.