Abstract:
Background. Angiopoietins are part of vasculo- and angiogenesis with an important role in the
formation of a functional placental vascular network, capable of supporting the intrauterine
development of the embryo and fetus. Disruption of Ang1 expression is associated with the
dysregulation of vascular network maturation and stabilization.
Aim of the study. Evaluation of the immunohistochemical expression profile of Ang1 in the
choriovillary germinal status of patients with early-term pregnancy disturbances.
Methods and materials. Tissue samples from 62 patients experiencing early-term pregnancy
disturbances were obtained via uterine aspiration at the Mother and Child Institute's Perinatal Center
in 2020. Patients were categorized into three groups: early spontaneous abortion (ESA) – 8 cases;
missed abortions (MA) – 39 cases; and 15 cases of pregnancy termination for social reasons/desire (TS
or TD). Each group was further stratified by gestational age (3-5 weeks, 6-9 weeks, and 10-12 weeks).
Methods included hematoxylin-eosin staining, immunohistochemistry assessing anti-Tie1.
Immunohistochemical expression was evaluated in cytotrophoblasts, syncytiotrophoblasts, endothelial
cells, Hofbauer cells, and stroma, graded from 0 to +3. Statistical analysis involved intensity
assessment, Spearman's correlations (rs), and Mann-Whitney (U test).
Results. Cytoplasmic immunohistochemical expression ranged from 0 to +2, predominantly negative
in controls (68,9%) versus 80% positivity in syncytiotrophoblasts. In the MA group, anti-Ang1
expression rose slightly to +2 (71,7%), peaking at 94,8% in villous syncytiotrophoblasts. ESA group
showed significant positivity only in syncytiotrophoblasts (75%), with the rest within 50% positive-
negative limits. Statistically significant differences were observed between ESA and control groups in
syncytiotrophoblasts (p=0,02) and within MA 10-12 weeks versus MA 3-5 weeks: cytotrophoblasts
(p=0,004), vascular endothelium (p=0,02), and cellular stroma (p=0,05); MA 10-12 weeks versus MA
6-9 weeks (p=0,01, p=0,02, and p=0,03). Cytotrophoblasts and vascular endothelium expression
negatively correlated with gestational age (GA) (rs=-0,33/0,02 and -0,32/0,02) and age (rs=-0,41/0,01
and -0,36/0,01) in the MA group. In ESA 6-9 weeks, there was a strong positive correlation between
age and cytotrophoblasts (rs=0,89; p=0,02), and in ESA total between GA and syncytiotrophoblasts
(rs=-0,62/0,05).
Conclusion. During placental development, Ang1's angiogenic environment differs in pregnancies
disrupted early, leading to a relatively weak angiogenic milieu. Cellular expression varies with
gestational term and patient age.
