scholarly journals Defining Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Placentitis: A Report of 7 Cases with Confirmatory In Situ Hybridization, Distinct Histomorphologic Features, and Evidence of Complement Deposition

Author(s):  
Jaclyn C. Watkins ◽  
Vanda F. Torous ◽  
Drucilla J. Roberts

Abstract Context.–Case reports and rare case series have demonstrated variable placental pathology in the setting of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In rare small studies demonstrating infection of the placental parenchyma, histologic manifestations have included variable degrees of histiocytic intervillositis, perivillous fibrin deposition, and syncytiotrophoblast necrosis. Objective.–To characterize the placental pathological features of SARS-CoV-2 infected placentas, irrespective of fetal-maternal transmission, and to examine the frequency of C4d activation in such cases. Design.–Retrospective study of seven placentas from mothers with active SARS-CoV-2 infection and placental infection as demonstrated by RNA in situ hybridization. Results.–Six placentas were from live-born neonates (5 singletons, 1 non-fused diamniotic-dichorionic twin placenta), and one was from a stillbirth. Five of the eight neonates (including the stillbirth) tested negative for SARS-CoV-2, and all were negative for neonatal infection. The remaining three neonates were well at time of discharge. All placentas were positive for SARS-CoV-2 infection by RNA in situ hybridization and demonstrated variable degrees of histiocytic intervillositis, perivillous fibrin deposition, and trophoblast necrosis. Three cases demonstrated features of fetal vascular malperfusion. CD68 highlighted intervillous histiocytes. C4d expression was present along the villous borders in 6 of 7 cases. Conclusions.–SARS-CoV-2 placentitis is defined by the triad of histiocytic intervillositis, perivillous fibrin deposition, and trophoblast necrosis. The features may occur in cases without confirmed transplacental transmission. The damage caused by SARS-CoV-2 placentitis is likely mediated by complement activation.

Author(s):  
Anja C. Roden ◽  
Julie A. Vrana ◽  
Justin W. Koepplin ◽  
Angela E. Hudson ◽  
Andrew P. Norgan ◽  
...  

Abstract Context: Small case series have evaluated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-detection in formalin-fixed paraffin-embedded (FFPE) tissue using reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC) and/or RNA-in situ hybridization (RNAish). Objective: To compare droplet digital PCR (ddPCR), IHC, and RNAish to detect SARS-CoV-2 in FFPE tissue in a large series of lung specimens from coronavirus disease 2019 (COVID-19) patients. Design: ddPCR and RNAish used commercially available probes; IHC utilized clone 1A9. Twenty-six autopsies of COVID-19 patients with FFPE tissue blocks of 62 lung specimens, 22 heart specimens, 2 brain specimens, and 1 liver, and 1 umbilical cord were included. Control cases included 9 autopsy lungs from patients with other infections/inflammation and virus-infected tissue or cell lines. Results: ddPCR had the highest sensitivity for SARS-CoV-2 (96%) when compared to IHC (31%) and RNAish (36%). All 3 tests had a specificity of 100%. Agreement between ddPCR and IHC or RNAish was fair (κ=0.23, κ=0.35, respectively). Agreement between IHC and ISH was substantial (κ=0.75). Interobserver reliability was almost perfect for IHC (κ=0.91) and fair to moderate for RNAish (κ=0.38–0.59). Lung tissues from patients who died earlier after onset of symptoms revealed higher copy numbers by ddPCR (P=.03, pearson corr = −0.65) and were more likely to be positive by RNAish (P=.02) than lungs from patients who died later. SARS-CoV-2 was identified in hyaline membranes, pneumocytes, and rarely in respiratory epithelium. ddPCR showed low copy numbers in 7 autopsy hearts from ProteoGenex Inc. All other extrapulmonary tissues were negative. Conclusions: ddPCR was the most sensitive and highly specific test to identify SARS-CoV-2 in lung specimens from COVID-19 patients.


Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1308
Author(s):  
David A. Schwartz ◽  
Denise Morotti

The mechanism(s) by which neonates testing positive for coronavirus disease 2019 (COVID-19) acquire their infection has been largely unknown. Transmission of the etiological agent, SARS-CoV-2, from mother to infant has been suspected but has been difficult to confirm. This communication summarizes the spectrum of pathology findings from pregnant women with COVID-19 based upon the infection status of their infants and addresses the potential interpretation of these results in terms of the effects of SARS-CoV-2 on the placenta and the pathophysiology of maternal-fetal infection. Placentas from pregnant women with COVID-19 and uninfected neonates show significant variability in the spectrum of pathology findings. In contrast, placentas from infected maternal-neonatal dyads are characterized by the finding of mononuclear cell inflammation of the intervillous space, termed chronic histiocytic intervillositis, together with syncytiotrophoblast necrosis. These placentas show prominent positivity of syncytiotrophoblast by SARS-CoV-2, fulfilling the published criteria for transplacental viral transmission as confirmed in fetal cells through identification of viral antigens by immunohistochemistry or viral nucleic acid using RNA in situ hybridization. The co-occurrence of chronic histiocytic intervillositis and trophoblast necrosis appears to be a risk factor for placental infection with SARS-CoV-2 as well as for maternal-fetal viral transmission, and suggests a potential mechanism by which the coronavirus can breach the maternal-fetal interface.


Author(s):  
Biyan Nathanael Harapan ◽  
Hyeon Joo Yoo

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, is responsible for the outbreak of coronavirus disease 19 (COVID-19) and was first identified in Wuhan, China in December 2019. It is evident that the COVID-19 pandemic has become a challenging world issue. Although most COVID-19 patients primarily develop respiratory symptoms, an increasing number of neurological symptoms and manifestations associated with COVID-19 have been observed. In this narrative review, we elaborate on proposed neurotropic mechanisms and various neurological symptoms, manifestations, and complications of COVID-19 reported in the present literature. For this purpose, a review of all current published literature (studies, case reports, case series, reviews, editorials, and other articles) was conducted and neurological sequelae of COVID-19 were summarized. Essential and common neurological symptoms including gustatory and olfactory dysfunctions, myalgia, headache, altered mental status, confusion, delirium, and dizziness are presented separately in sections. Moreover, neurological manifestations and complications that are of great concern such as stroke, cerebral (sinus) venous thrombosis, seizures, meningoencephalitis, Guillain–Barré syndrome, Miller Fisher syndrome, acute myelitis, and posterior reversible encephalopathy syndrome (PRES) are also addressed systematically. Future studies that examine the impact of neurological symptoms and manifestations on the course of the disease are needed to further clarify and assess the link between neurological complications and the clinical outcome of patients with COVID-19. To limit long-term consequences, it is crucial that healthcare professionals can early detect possible neurological symptoms and are well versed in the increasingly common neurological manifestations and complications of COVID-19.


2021 ◽  
Vol 4 (1) ◽  
pp. 20
Author(s):  
Mujeeb Shittu ◽  
Tessa Steenwinkel ◽  
William Dion ◽  
Nathan Ostlund ◽  
Komal Raja ◽  
...  

RNA in situ hybridization (ISH) is used to visualize spatio-temporal gene expression patterns with broad applications in biology and biomedicine. Here we provide a protocol for mRNA ISH in developing pupal wings and abdomens for model and non-model Drosophila species. We describe best practices in pupal staging, tissue preparation, probe design and synthesis, imaging of gene expression patterns, and image-editing techniques. This protocol has been successfully used to investigate the roles of genes underlying the evolution of novel color patterns in non-model Drosophila species.


2005 ◽  
Vol 36 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Wun-Ju Shieh ◽  
Cheng-Hsiang Hsiao ◽  
Christopher D. Paddock ◽  
Jeannette Guarner ◽  
Cynthia S. Goldsmith ◽  
...  

Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 611-621 ◽  
Author(s):  
S.K. De ◽  
M.T. McMaster ◽  
S.K. Dey ◽  
G.K. Andrews

Oligodeoxyribonucleotide excess solution hybridization, Northern blot and in situ hybridization were used to analyze metallothionein gene expression in mouse decidua and placentae during gestation. Metallothionein (MT) -I and -II mRNA levels were constitutively elevated, 11- and 13-fold, respectively, relative to the adult liver, in the deciduum (D8), and decreased coordinately about 6-fold during the period of development when the deciduum is replaced by the developing placenta (D10-16). Coincident with this decline, levels of MT mRNA increased dramatically in the visceral yolk sac endoderm. In situ hybridization established that MT-I mRNA was present at low levels in the uterine luminal epithelium (D4), but was elevated at the site of embryo implantation exclusively in the primary decidual zone by D5, and then in the secondary decidual zone (D6-8). Although low levels of MT mRNA were detected in total placental RNA, in situ hybridization revealed constitutively high levels in the outer placental spongiotrophoblasts. Analysis of pulse-labeled proteins from decidua and placentae established that these tissues are active in the synthesis of MT. The constitutively high levels of MT mRNA in decidua were only slightly elevated following injection of cadmium (Cd) and/or zinc (Zn), whereas in placentae they increased several-fold. MT mRNA levels were equally high in decidua and experimentally induced deciduomata (D8) which establishes that decidual MT gene expression is not dependent on the presence of the embryo or some embryo-derived factor. Although the functional role of MT during development is speculative, these results establish the concept that, from the time of implantation to late in gestation, the mouse embryo is surrounded by cells, interposed between the maternal and embryonic environments, which actively express the MT genes. This suggests that MT plays an important role in the establishment and maintenance of normal pregnancy.


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