The distribution of macrophages in spiral arteries of the placental bed inpre-eclampsia differs from that in healthy patients

Placental bed biopsies taken during caesarean section from 10 patients with pre-eclampsia and six healthy pregnancies were studied. We applied antibod ies against cytokeratin and different macrophage markers to analyse the dis tribution of invasive estravillous trophoblast cells as compared to that of macrophages in myometrial segments of uteroplacental arteries. The data we re evaluated quantitatively. We found a clear inverse relationship between local infiltration with macrophages and trophoblast invasion. In pre-eclamp sia, vessel cross-sections prevailed which were characterized by large numb ers of macrophages but a low degree of trophoblast invasion. In contrast, i n normal third trimester pregnancies the respective arterial segments had a high degree of trophoblast invasion but were largely void of macrophages. These data suggest causal links between macrophages and inhibition of intra -arterial trophoblast invasion in pre-eclampsia. (C) 1999 W. B. Saunders Co mpany Ltd.