PHENOTYPIC ANALYSIS OF ADHESION MOLECULES IN FIRST-TRIMESTER DECIDUALTISSUE FROM CHORION VILLUS SAMPLES

PROBLEM: First-trimester decidua contain CD56(bright)/CD16(neg) lympho cytes that phenotypically resemble a subset of peripheral blood natura l killer (NK) cells. Factors controlling their localization to decidua are unknown, but they may relate to trophoblast invasion, endometrial decidualization, and adhesion molecule expression. METHOD OF STUDY: N inety-one chorion villous samples (CVS) were screened for the presence of decidua, and selected specimens were analyzed for the expression o f adhesion molecule pairs using a panel of monoclonal antibodies. RESU LTS: Lymphoid cells in CVS-derived decidua expressed CD56, PECAM, intr acellular adhesion molecule-1 (ICAM-1), and the integrins LFA-1, alpha E beta 7, and alpha 4 beta 1, and co-receptors for these molecules we re expressed by decidual stromal cells, invasive trophoblasts, and ven ule endothelium. Some endothelium expressed a cuboidal phenotype. CONC LUSIONS: The expression of complimentary pairs of adhesion molecules b y maternal lymphoid cells and by either extravillous cytotrophoblast o r decidual stromal cells supports the hypothesis that these cells inte ract within decidua. Also, both LFA-1 and alpha 4 beta 1 may contribut e to decidual localization of CD56(bright) NK cells.