P-400 Pregnancy-specific glycoproteins - potential markers for risk associated with preeclampsia during gestational SARS-CoV-2 Infection
Authors: Tang Y , Rao Boggavarapu N , Aronsson A , Gemzell-Danielsson K , Parameswaran Grace L  K 
Published: July 2024

Abstract

Study question
Could pregnancy-specific glycoproteins serve as potential markers for the risk of developing preeclampsia during gestational SARS-CoV-2 Infection?

Summary answer
Pregnancy-specific glycoproteins (PSGs) are significantly down-regulated in women with gestational SARS-CoV-2 infection, which could be used to diagnose high-risk pregnancies in assisted reproductive treatment (ART).

What is known already
In vitro fertilization (IVF) pregnancies are precious and face increased risks of preeclampsia. Similarly, SARS-CoV-2 infection during pregnancy increases the risk for preeclampsia. Precious pregnancies with ART along with SARS-CoV-2 infection can further exacerbate the risk for preeclampsia, affecting both maternal and fetal health. Thus, identifying molecular markers associated with preeclampsia risk in the context of SARS-CoV-2 infection is crucial for maternal and fetal health management, specifically in pregnancies with IVF.

Study design, size, duration
Placental samples (n = 16) were collected at term delivery from SARS-CoV-2 positive women (n = 7) and negative healthy women (n = 9). We studied separately, the gene expression pattern in maternal and fetal placental compartments. Interesting genes from RNA sequencing results were validated using real-time PCR.

Participants/materials, setting, methods
All pregnant women at their term delivery were clinically tested for SARS-CoV-2 infection by PCR. Maternal and fetal sides of placenta were collected in total RNA was extracted from the snap-frozen tissues. cDNA libraries were constructed using Smart-seq2 method and sequenced using Illumina NovaSeq 6000 sequencing platform. Bioinformatic analysis was using Partek® Flow® software, v9.0, DEGs were identified by applying FDR ≤ 0.05. qPCR was for validating the interesting genes.

Main results and the role of chance
Our analysis revealed 635 DEGs in the maternal placental tissue, with 518 upregulated and 117 downregulated genes in SARS-CoV-2-positive women compared with the healthy SARS-CoV-2-negative women. In contrast, the fetal compartment did not exhibit any significant changes in gene expression with SARS-CoV-2 infection. In the maternal compartment, we observed significant downregulation of nine genes belonging to the pregnancy-specific glycoprotein related to the immunoglobulin superfamily with active SARS-CoV-2 infection (fold change range from −13.70 to − 5.28; FDR ≤ 0.01). Additionally, comparing symptomatic women with healthy women, we identified 1788 DEGs. Furthermore, pathway enrichment analysis revealed that pathways related to oxidative phosphorylation, insulin secretion, cortisol synthesis, estrogen signaling, oxytocin signaling, and antigen processing were altered significantly in symptomatic women.

Limitations, reasons for caution
We have a limited sample size in this study, though we collected placental samples from all the women who were positive for SARS-CoV-2, at admission for delivery. Studies with larger sample sizes are warranted to further reconfirm the results. In vitro studies may help us to deepen our understanding.

Wider implications of the findings
This study sheds light on PSGs as potential biomarkers for risk for preeclampsia during gestational SARS-CoV-2 and reveals molecular pathways associated with an increased clinical risk of preeclampsia with COVID-19 during pregnancy. The findings offer valuable insights that could be further explored clinically in managing pregnant women with COVID-19.

Trial registration number
not applicable