PMC9846883_01
Histopathological and immunohistochemical findings in placental tissues from mothers infected with SARS-CoV-2. A-C) Prominent perivillous fibrin deposition (arrowheads), placental infarction (in), partial obliteration of fetal vessels (asterisks), and intervillositis with polymorphonuclear cell accumulations (in) (x100). D-F) SARS-CoV-2 nucleocapsid staining, mainly observed at the periphery of the chorionic villi (arrows), suggesting a trophoblast infection (x200).
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An acute placental infarction compromising over 30% of the placental disc was identified (Fig. 1C). SARS-CoV-2 RT-PCR testing in placental tissue was positive and IHC analysis identified multifocal positivity for viral particles in mesenchymal and endothelial cells of the chorionic villi, with a positive staining in some syncytial cells (Fig. 1F) (Table 2).
PMC9846883_02
Histopathological and immunohistochemical findings in placental tissues from mothers infected with SARS-CoV-2. A-C) Prominent perivillous fibrin deposition (arrowheads), placental infarction (in), partial obliteration of fetal vessels (asterisks), and intervillositis with polymorphonuclear cell accumulations (in) (x100). D-F) SARS-CoV-2 nucleocapsid staining, mainly observed at the periphery of the chorionic villi (arrows), suggesting a trophoblast infection (x200).
gr1_lrg.jpg
PMC9846883_03_gr1_lrg.jpg
f0005
An acute placental infarction compromising over 30% of the placental disc was identified (Fig. 1C). SARS-CoV-2 RT-PCR testing in placental tissue was positive and IHC analysis identified multifocal positivity for viral particles in mesenchymal and endothelial cells of the chorionic villi, with a positive staining in some syncytial cells (Fig. 1F) (Table 2).
Double immunofluorescence assay in the placenta infected with SARS-CoV-2. Viral antigen detected mainly in the trophoblast layer of chorionic villi where CD68-positive cells (macrophages) were also observed. The red, green, and blue signals indicate Alexa 555, 488, and DAPI, respectively. SARS-CoV-2 IF, x400 magnification.
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IHC analysis identified multifocal positive staining of SARS-CoV-2 viral particles in mesenchymal and endothelial cells of the chorionic villi (Fig. 1E). In the simultaneous detection of SARS-CoV-2 viral antigens and macrophages (CD68), the viral antigens were located mainly in the peripheral regions of the chorionic villi, where numerous CD68-positive macrophages were also found (Fig. 2 ).
PMC9846883_03
Histopathological and immunohistochemical findings in placental tissues from mothers infected with SARS-CoV-2. A-C) Prominent perivillous fibrin deposition (arrowheads), placental infarction (in), partial obliteration of fetal vessels (asterisks), and intervillositis with polymorphonuclear cell accumulations (in) (x100). D-F) SARS-CoV-2 nucleocapsid staining, mainly observed at the periphery of the chorionic villi (arrows), suggesting a trophoblast infection (x200).
gr1_lrg.jpg
PMC9846883_03_gr1_lrg.jpg
f0005
An acute placental infarction compromising over 30% of the placental disc was identified (Fig. 1C). SARS-CoV-2 RT-PCR testing in placental tissue was positive and IHC analysis identified multifocal positivity for viral particles in mesenchymal and endothelial cells of the chorionic villi, with a positive staining in some syncytial cells (Fig. 1F) (Table 2).