Girard, Sylvie

Abstract Pre-eclampsia (PE) affects 5–8% of pregnancies and has detrimental effects on maternal–fetal health. PE is characterized by de novo hypertension after 20 wk of gestation and end-organ damage. Systemic inflammatory imbalance has been associated with PE, but its contribution to the pathology is poorly understood. Our objective was to investigate maternal systemic immune changes in early-onset PE (EOPE) and late-onset PE (LOPE) versus uncomplicated pregnancies (control [CTRL]), and their contribution to endothelial activation, hallmark of hypertension. Blood samples were analyzed by flow cytometry, multiplex assay, intracellular cytokine staining, and single-cell RNA sequencing. We performed cocultures between circulating immune cells and HUVECs to assess endothelial activation. We found that EOPE had decreased regulatory T cells (4.64±0.33, p < 0.05) and monocytes (33.92±3.08, p < 0.01), whereas LOPE had decreased regulatory T cells (4.60±0.30, p < 0.05) and Th2 cells (7.50±0.62, p < 0.01) versus CTRL. Compared to CTRL, elevated cytokines/chemokines, and growth factors were observed in LOPE, whereas EOPE primarily showed decreased levels. Using intracellular cytokine staining, we observed more monocytes producing IL-12, TNF-α, and IL-1β (all p < 0.05) in LOPE versus CTRL. At the transcriptomic level, we found differentially expressed genes between EOPE and CTRL, predominantly related to upregulation of immune activation pathways. Lastly, EOPE PBMCs induced heightened endothelial activation in vitro observed by increased ICAM-1 and ET-1 (p < 0.05), whereas LOPE PBMCs required LPS stimulation. Although significant proteomic changes are observed in the LOPE group, the EOPE displayed changes mostly at the transcriptomic levels and could induce endothelial activation in vitro.

ABSTRACTProblemPreeclampsia (PE) and fetal growth restriction (FGR) are often associated with maternal inflammation and an increased risk of cardiovascular and metabolic disease in the affected mothers. The mechanism responsible for this increased risk of subsequent disease may involve reprogramming of innate immune cells, characterized by epigenetic modifications.Method of StudyCirculating monocytes from women with PE, FGR, or uncomplicated pregnancies (control) were isolated before labor. Cytokine release from monocytes following exposure to lipopolysaccharide (LPS) and the presence of lysine 4‐trimethylated histone 3 (H3K4me3) within TNF promoter sequences were evaluated. Single‐cell transcriptomic profiles of circulating monocytes from women with PE or uncomplicated pregnancies were assessed.ResultsMonocytes from women with PE or FGR exhibited increased IL‐10 secretion and decreased IL‐1β and GM‐CSF secretion in response to LPS. While TNFα secretion was not significantly different in cultures of control monocytes versus those from complicated pregnancies with or without LPS exposure, monocytes from complicated pregnancies had significantly decreased levels of H3K4me3 associated with TNF promoter sequences. Cluster quantification and pathway analysis of differentially expressed genes revealed an increased proportion of anti‐inflammatory myeloid cells and a lower proportion of inflammatory non‐classical monocytes among the circulating monocyte population in women with PE.ConclusionsMonocytes from women with PE and FGR exhibit an immune tolerance phenotype before initiation of labor. Further investigation is required to determine whether this tolerogenic phenotype persists after the affected pregnancy and contributes to increased risk of subsequent disease.

AbstractProblemThe COVID‐19 pandemic has been shown to have a detrimental impact on the mental health of pregnant individuals, and chronic stress can alter the immune profile. However, the effects of the COVID‐19 pandemic on the immune system in pregnancy are still poorly understood. We aimed to evaluate the impact of pandemic exposure on the maternal immune profile in uncomplicated pregnancies.Method of studyWe collected blood and placenta samples from pregnant individuals exposed and unexposed to the pandemic to compare their immune and inflammatory profiles. We performed co‐culture with circulating maternal immune cells and endothelial cells to assess endothelial activation. Statistical analysis was performed using unpaired t‐test, Mann‐Whitney, or Fisher's exact test as appropriate.ResultsIn exposed individuals, we observed a decreased proportion of Th2 cells (p < .0001) and Treg/Th17 ratio (p < .05), as well as an increased Th1/Th2 ratio (p < .0001). Levels of IL‐1β (p < .01) and IL‐18 (p < .01) were increased in the circulation of exposed participants, whilst other mediators were significantly decreased (IFNγ, IL‐8, MCP‐1, amongst others). Furthermore, we observed increased production of ICAM, hallmark of endothelial activation, when we co‐cultured endothelial cells with immune cells from exposed individuals. Vaccination status impacted the cellular profile with increased proportions of Th1 and B cells in vaccinated participants.ConclusionOverall, we observed a pro‐inflammatory bias in the circulation of pregnant individuals exposed to the COVID‐19 pandemic, with otherwise uncomplicated pregnancies. Our work also supports an association between the increased risk of endothelial activation/hypertension and SARS‐CoV2 infection, which might be driven in part by exposure to the pandemic and associated stressors.

Objective To evaluate maternal risk factors associated with chronic villitis of unknown etiology (VUE) and to describe cooccurring placental pathologies. Study Design A retrospective case–control study was conducted using placental pathology records from deliveries ≥ 20 weeks between 2010 and 2018. Cases were placentas with documented chronic villitis without infectious cause, hereafter called VUE. Controls were placentas without this diagnosis, matched to the cases 2:1. Maternal and neonatal demographic and clinical data were collected. Descriptive statistics are reported with Fisher's exact test or a chi-squared test, as appropriate, and multivariable conditional logistic regression was conducted. Results Our study included 352 cases with VUE and 657 controls. A diagnosis of gestational diabetes (p = 0.03) and gestational hypertension (p = 0.06) was 1.5 times more likely to occur in those with a VUE diagnosis. A trend was also seen for chronic hypertension (odds ratio [OR] = 1.7, p = 0.07) and preeclampsia (OR = 1.5, p = 0.09) compared with controls. Placentas with VUE, specifically high-grade VUE, were more likely to be small for gestational age (p = 0.01), and to be diagnosed with other placental findings including lymphoplasmacytic or chronic deciduitis (p < 0.01), maternal (p < 0.01) and fetal vascular malperfusion (p = 0.02), and chorionitis (acute or chronic; p < 0.01). Conclusion Gestational diabetes and hypertension were associated with a diagnosis of VUE, and overall, VUE placentas have more abnormal placental findings compared with control. Understanding VUE risk factors may facilitate prenatal care strategies and counseling to achieve the best outcomes for pregnant patients and their neonates. Key Points

The dynamic immunological changes occurring throughout pregnancy are well-orchestrated and important for the success of the pregnancy. One of the key immune adaptations is the maternal immune tolerance towards the semi-allogeneic fetus. In this review, we provide a comprehensive overview of what is known about the innate and adaptive immunological changes in pregnancy and the role(s) of specific immune cells during physiological and pathological pregnancy. Alongside this, we provided details of remaining questions and challenges, as well as future perspectives for this growing field of research. Understanding the immunological changes that occur can inform potential strategies on treatments for the optimal health of the neonate and pregnant individual both during and after pregnancy.

AbstractProblemIt is now recognized that SARS‐CoV‐2 infection and pandemic‐related stress impacts maternal health. However, their effects at the maternal‐fetal interface are still debated.Method of studyWe recruited 199 women between March 2020 and July 2021, 79 SARS‐CoV‐2+ and 120 negative (the latter exposed to pandemic stress only). We also included 40 historic controls (i.e. pre‐pandemic uncomplicated pregnancies recruited before March 2020). Placental samples were collected for protein and histological analysis.ResultsThe majority of SARS‐CoV‐2+ women were multiethnic, had higher pre‐pregnancy BMI and elevated preterm birth rate (17%) vs SARS‐CoV‐2– or historic control. Placental inflammatory profile revealed increased IL‐1Ra and CRP, independently of SARS‐CoV‐2 status, whilst MCP‐1, IL‐6 and IFNγ were elevated in the negative, but pandemic stress‐exposed, group. These changes were predominant in placentas with inflammatory lesions on histopathological analysis. Furthermore, we observed elevated immune cells (CD45+) in placentas from SARS‐CoV‐2+ and negative pregnancies vs historic controls, even when individuals with pregnancy complications were excluded.ConclusionsPlacental inflammatory profiles differed between SARS‐CoV‐2 statuses, namely exposed to pandemic stress +/‐ SARS‐CoV‐2 infection. This highlights the need to understand the differences between the effects of pandemic‐related stress and the added burden of SARS‐CoV‐2 infection on placental health.

Pregnancy complications can have long-term negative effects on the health of the affected mothers and their children. In this review, we highlight the underlying inflammatory etiologies of common pregnancy complications and discuss how aberrant inflammation may lead to the acquisition of innate immune memory. The latter can be described as a functional epigenetic reprogramming of innate immune cells following an initial exposure to an inflammatory stimulus, ultimately resulting in an altered response following re-exposure to a similar inflammatory stimulus. We propose that aberrant maternal inflammation associated with complications of pregnancy increases the cross-generational risk of developing noncommunicable diseases (i.e., pregnancy complications, cardiovascular disease, and metabolic disease) through a process mediated by innate immune memory. Elucidating a role for innate immune memory in the cross-generational health consequences of pregnancy complications may lead to the development of novel strategies aimed at reducing the long-term risk of disease.

Pregnancy complications including preeclampsia, preterm birth, recurrent pregnancy loss, and fetal growth restriction affect over 12% of all pregnancies worldwide [...]

Blockade of the interleukin-1 (IL-1) pathway has been used therapeutically in several inflammatory diseases including arthritis and cryopyrin-associated periodic syndrome (CAPS). These conditions frequently affect women of childbearing age and continued usage of IL-1 specific treatments throughout pregnancy has been reported. IL-1 is involved in pregnancy complications and its blockade could have therapeutic potential. We systematically reviewed all reported cases of IL-1 blockade in human pregnancy to assess safety and perinatal outcomes. We searched several databases to find reports of specific blockade of the IL-1 pathway at any stage of pregnancy, excluding broad spectrum or non-specific anti-inflammatory intervention. Our literature search generated 2439 references of which 22 studies included, following extensive review. From these, 88 different pregnancies were assessed. Most (64.8%) resulted in healthy term deliveries without any obstetrical/neonatal complications. Including pregnancy exposed to Anakinra or Canakinumab, 12 (15.0%) resulted in preterm birth and one stillbirth occurred. Regarding neonatal complications, 2 cases of renal agenesis (2.5%) were observed, and 6 infants were diagnosed with CAPS (7.5%). In conclusion, this systematic review describes that IL-1 blockade during pregnancy is not associated with increased adverse perinatal outcomes, considering that treated women all presented an inflammatory disease associated with elevated risk of pregnancy complications.