GALACTOSE ALPHA-1-3 GALACTOSE AND ANTI-ALPHA GALACTOSE ANTIBODY IN NORMAL AND PATHOLOGICAL PREGNANCIES

The galactose alpha 1-3 galactose (Gala α 1-3 Gal) residue is a carbohydrate widely distributed in many non-human mammals. Since Gal α 1-3 Gal residues are described on the cell surface of tumor cells, we have examined the possibility of their expression on human trophoblastic cells at different stages of placental implantation and in various pregnancy-associated conditions. Using immunohistochemical methods, Gal α 1-3 Gal was demonstrated on interstitial and vascular trophoblast during pregnancy. For villous trophoblast, the staining disappeared in second trimester pregnancies. The density of staining for Gal α 1-3 Gal was increased in highly invasive trophoblast (mole and choriocarcinoma) and decreased in poorly invasive specimens (spontaneous abortion, XO monosomia). No cells displaying Gal α 1-3 Gal at their surface were identified in some segments of spiral arteries from preeclamptic women. The anti-Gal antibody titer increased in the first trimester of pregnancy and in the sera of pre-eclamptic and eclamptic patients. These findings suggest that Gal a 1-3 Gal residues could be considered as markers for trophoblast invasive capacity and that the binding of maternal anti-Gal antibodies to the trophoblast could contribute to limit trophoblastic invasion and thus participate to the immunological control of implantation. © 1992.