Lectin histochemistry of complex carbohydrates in human cervix

Complex carbohydrates in the human cervix were studied histochemically using lectins conjugated to horseradish peroxidase and correlated procedures. Stratified squamous epithelium of the exocervix and columnar epithelium of the endocervix in some, but not all specimens showed staining for terminal alpha-N-acetyl-D-galactosamine, alpha-D-galactose, beta-D-galactose and alpha-L-fucose. The staining for alpha-N-acetylgalactosamine and alpha-galactose, the terminal sugars in blood group A and B antigens respectively, corresponded to a large extent with ABO blood type. One exception was the lack of staining for terminal alpha-N-acetylgalactosamine in endocervical secretions in three of nine blood type A patients. A second exception was the staining for terminal alpha-galactose in endocervical secretions in about half of blood type O and A specimens. The type and amount of glycoprotein formed by endocervical columnar cells differed according to location in superficial compared with deep portions of the glands and according to location at the junction with exocervix compared with the more internal regions. Staining of endothelial cells for blood group A and B antigens was confined to subjects of blood type A and B respectively, although three of nine type A specimens showed no lectin reactivity for group A antigen. Endothelial cells evidenced affinity for Ulex europeus I agglutinin demonstrative of fucose in all specimens. Mast cells disclosed lectin affinity consistent with the presence of terminal or internal mannose or N-acetylglucosamine residues. Two blood type O specimens were examined with conjugated lectins at the ultrastructural level. Secretory granules stained for content of terminal alpha-galactose, beta-galactose and fucose. These results support and concur with biochemical studies of complex carbohydrates in human cervical tissues. They reveal, in addition, the location of the blood group antigens in the human exocervix and endocervix and the marked heterogeneity among endocervical columnar cells in glycoprotein production.