Anti-TPO-mediated specific features of the placenta immunohistochemical profile and possible mechanisms for fetal loss.

Passive transfer of antithyroid antibodies in mice leads to reproductive disorders. The purpose was to assess the placental tissue of experimental animals under the influence of the circulating thyroperoxidase antibodies. We performed an immunohistochemical examination of murine placentae after a passive transfer of thyroperoxidase antibodies. Placentae of mice that were passively transferred IgG from healthy donors were used as control samples. For histological examination, 30 placental samples were selected from mice from the anti-TPO group and 40 placental samples were taken from mice from the IgG group. Immunostaining for VEGFR1, THBS 1, Laminin, CD31, CD34, FGF-β, CD56, CD14, TNF-α, kisspeptin, MCL 1 and Annexin V was performed. There is a significant decrease in the relative area of the expression of: VEGFR1 (23.42±0.85 vs. 33.44±0.35, р<0.01), thrombospondin 1 (31.29±0.83 vs. 34.51±0.75, р<0.01), CD14 (25.80±0.57 vs. 32.07±0.36, р<0.01), CD56 (30.08±0.90 vs. 34.92±0.15, р<0.01), kisspeptin (25.94±0.47 vs. 31.27±0.57, р<0.01), MCL 1 (29.24±1.06 vs. 38.57±0.79, р<0.01) in the labyrinth zone of the placentae of mice from the anti-TPO group compare with control group. A significant increase in relative expression of laminin and FGF-β was noted in the group of mice to which antibodies to thyroperoxidase were transferred, compared with the control group (36.73±1.38 vs. 29.83±0.94, р<0.01 and 23.26±0.61 vs. 16.38±1.01, р<0.01respectively). Our study exposed an imbalance of pro- and anti-angiogenic factors, decreased representation of placental macrophages and NK cells, abnormal trophoblast invasion processes, insufficient expression of antiapoptotic factors in the placentae of mice in which anti-TPO antibodies were passively transferred.