Yonsei Med J.  2024 Apr;65(4):202-209. 10.3349/ymj.2023.0309.

Evidence of Placental Villous Inflammation and Apoptosis in Third-Trimester Symptomatic SARS-CoV-2 Maternal Infection

• Wardhana MP
• Kuntaman K
• Utomo B
• Aryananda RA
• Rifdah SN
• Wafa IA
• Shahnaz AA
• Ningrum D
• Marcianora NIC
• Ariani G
• Lith JMV
• Dachlan EG

• KMID: 2554220
• DOI: http://doi.org/10.3349/ymj.2023.0309

Abstract

Purpose
In view of conflicting reports on the ability of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) to infect placental tissue, this study aimed to further evaluate the impact of inflammation and placental damage from symptomatic thirdtrimester maternal COVID-19 infection.
Materials and Methods
This case-control study included 32 placenta samples each from symptomatic COVID-19 pregnancy and normal non-COVID-19 pregnancy. The villous placental area’s inflammatory expression [angiotensin converting enzyme-2 (ACE-2), transmembrane protease serine-2 (TMPRSS2), interferon-γ (IFN-γ), interleukin-6 (IL-6), and SARS-CoV-2 spike protein] and apoptotic rate were examined using immunohistochemistry and Terminal deoxynucleotidyl transferase dUTP Nick- End Labeling (TUNEL) assay. Comparison and correlation analysis were used based on COVID-19 infection, placental SARS-CoV-2 spike protein evidence, and maternal severity status.
Results
Higher expressions of TMPRSS2, IFN-γ, and trophoblast apoptotic rate were observed in the COVID-19 group (p<0.001), whereas ACE-2 and IL-6 expressions were not significantly different from the control group (p>0.05). Additionally, SARS-CoV-2 spike protein was detected in 8 (25%) placental samples of COVID-19 pregnancy. COVID-19 subgroup analysis revealed increased IFN-γ, trophoblast, and stromal apoptosis (p<0.01). Moreover, the results of the current study revealed no correlation between maternal COVID-19 severity and placental inflammation as well as the apoptotic process.
Conclusion
The presence of SARS-CoV-2 spike protein as well as altered inflammatory and apoptotic processes may indicate the presence of placental disturbance in third-trimester maternal COVID-19 infection. The lack of correlation between placental disruption and maternal severity status suggests the need for more research to understand the infection process and any potential long-term impacts on all offsprings born to COVID-19-infected pregnant women.

Keyword

COVID-19; pregnancy; placenta; inflammation; apoptosis