Charalampos Grigoriadis, Aliki Tympa, Maria Creatsa, Panagiotis Bakas, Angelos Liapis, Agathi Kondi-Pafiti, Georgios Creatsas
PURPOSE: In placentas from uncomplicated pregnancies, Hofbauer cells either disappear or become scanty after the fourth to fifth month of gestation. lmmunohistochemistry though, reveals that a high percentage of stromal cells belong 1o Hofbauer cells. The aim of this study was to investigate the changes in morphology and density of Hofbauer cells in placentas from normal and pathological pregnancies. METHODS: Seventy placentas were examined: 16 specimens from normal term pregnancies, 10 from first trimester’s miscarriages, 26 from cases diagnosed with chromosomal abnormality of the fetus, and placental tissue specimens complicated with intrauterine growth restriction (eight] or gestational diabetes mellitus !1 OJ. A histological study of hematoxylin-eosin (HE) sections was performed and immunohistachemical study was performed using the markers: CD 68, Lysazyme, Al Antichymotrypsine, CK-7, vimentin, and Ki-67. RESULTS: In normal term pregnancies, HE study revealed Hofbauer cells in 37.5% of cases while immunohistochemistry revealed in 87.5% of cases. In first trimester’s miscarriages and in cases with prenatal diagnosis of fetal chromosomal abnormalities, both basic and immunohistochemical study were positive for Hofbauer cells. In pregnancies complicated with intrauterine growth restriction or gestationa I diabetes mellitus, a positive immunoreaction was observed in 100 and 70% of cases, respectively. CONCLUSIONS: Hofbauer cells are present in placental villi during pregnancy, but with progressively reducing density. The most specific mark.er for their detection seems to be A 1 Antichymotrypsine. It is remark.able that no mitotic activity of Hofbauer cells was noticed in our study, as the mark.er of cellular multiplication Ki-67 was negative in all examined specimens.