EXPRESSION OF CELL-ADHESION MOLECULES IN THE EXTRAVILLOUS TROPHOBLASTIS ALTERED IN IUGR

PROBLEM: The invasion of trophoblast cells into the uterine wall and i ts arterial system is essential for the normal development of pregnanc y. Cell adhesion molecules (CAM), such as the immunoglobulin superfami ly and integrins, play a crucial role in a number of immunological rea ctions and in the invasion of the human trophoblast. Intrauterine grow th restriction (IUGR) has been associated with abnormal trophoblast in vasion. Therefore, the expression of CAM in the extravillous trophobla st of pregnancies complicated by IUGR might be different from normal p regnancies. METHOD OF STUDY: Normal (n = 21) and IUGR (n = 19) placent as were collected and stored at -70 degrees C. Immunohistochemistry (a vidin-biotin complex peroxidase-doublestaining) of frozen tissue secti ons was performed using antibodies specific for the immunoglobulin sup erfamily vascular adhesion molecule-1 (VCAM-1;CD 106), intercellular a dhesion molecule (ICAM-1) (CD 54), ICAM-2 (CD 102), ICAM-3 (CD 50), th e integrins alpha 2 beta 1, alpha 3 beta 1, alpha 4 beta 1, alpha 5 be ta 1, alpha 6 beta 1 and cytokeratin. The percentage of immunopositive extravillous trophoblast cells (EVT) and the intensity of the immunor eactivity for the various CAM and integrin antibodies was assessed. RE SULTS: In IUGR placentas, there was less expression of VCAM-1 (CD 106) , alpha 2 beta 1, alpha 3 beta 1, and alpha 5 beta 1 (P < 0.05) in the extravillous trophoblast than in normal pregnancies. Finally we obser ved for the first time that ICAM-3 was expressed on EVT and that its e xpression was markedly up-regulated in the EVT of IUGR placentas. No d ifferences were found for ICAM-1 (CD 54), ICAM-2 (CD 102), alpha 4 bet a 1 and alpha 6 beta 1. CONCLUSION: Our data show that there are signi ficant differences in the expression of cell adhesion molecules of the extravillous trophoblast from IUGR and normal pregnancies. These diff erences might reflect changes in the immunological reactions and cell- cell interactions between mother and the developing fetus which could interfere with fetal growth.