Syncytiotrophoblast intercellular adhesion molecule-1 expression in placental villitis of unknown cause

The purpose of this study was to determine syncytiotrophoblast intercellular adhesion molecule-1 expression in villitis and in normal chorionic villi from term (37-42 weeks of gestation) placentas with or without villitis.

A cross-sectional study was conducted to determine syncytiotrophoblast intercellular adhesion molecule-1 expression in villitis (n = 16) and in normal villi from placentas with or without villitis (n = 16). Villitis was diagnosed with antibodies to human leukocyte antigen-DR and CD3 and hematoxylin and eosin staining of serial sections; intercellular adhesion molecule-1 reactivity in syncytiotrophoblast was confirmed with antibodies to intercellular adhesion molecule-1 and cytokeratin.

Villitis lesions had higher syncytiotrophoblast intercellular adhesion molecule-1 expression than normal chorionic villi from placentas with (19.9% vs 3.5% villi; P < .001) or without (19.9% vs 0.31% villi; P < .001) villitis. Normal villi from placentas with villitis had higher syncytiotrophoblast intercellular adhesion molecule-1 than villi from placentas without villitis (3.5% vs 0.31% villi; P < .001).

Placentas with villitis have significantly more syncytiotrophoblast intercellular adhesion molecule-1 expression than placentas without villitis. The finding that normal villi from placentas with villitis have more syncytiotrophoblast intercellular adhesion molecule-1 than normal villi from placentas without villitis suggests that syncytiotrophoblast intercellular adhesion molecule-1 could be the first step in villitis development.