Etiology of preeclampsia: maternal vascular predisposition and couple disease--mutual exclusion or complementarity?

Th17 / Treg ratio: A prospective study in a group of pregnant women with preeclampsia and fetal growth restriction

INTRODUCTION

During pregnancy, the maternal immune system is challenged to tolerate a semi-allogenic fetus. A proinflammatory profile has been linked to adverse pregnancy outcomes and poor placental development. In this study, the authors evaluated the number of circulating Tregs and Th17 cells in a group of patients diagnosed with preeclampsia(PE) and fetal growth restriction(FGR).

METHODS

Prospective longitudinal observational study where peripheral blood lymphocyte subsets were analyzed in a cohort of pregnant patients with PE, FGR, and a control group of healthy pregnant women.

RESULTS

The diagnosis of PE was associated with a significative higher number of circulating Th17 cells and a significative relative reduction in the Treg cell count. This proinflammatory profile was also expressed in the evolution of the Th17/ CD4+CD25highFOXP3+ Treg ratio. In the FGR group, the Th17 cell count was significantly higher during the third trimester of pregnancy. This proinflammatory profile was also expressed in the evolution of the Th17/ CD4+CD25highFOXP3+ Treg ratio. When we compare the immunological profiles of patients with PE and FGR we observed a higher number of proinflammatory Th17 cells and a significative lower number of Treg cells in PE patients. This is particularly expressed in the differences found between the Th17/ CD4+CD25highFOXP3+ Treg ratios of these two groups. Discussion/Conclusion Our data showed a that a proinflammatory profile and a relative excess of Th17 cells was associated with the diagnosis of PE and FGR. A more exuberant systemic proinflammatory profile present in the PE patients is absent in patients with FGR without preeclampsia.

Maternal age at birth and neonatal mortality: Associations from 67 low-income and middle-income countries

BACKGROUND

Both young and advanced maternal age have been associated with higher risks of neonatal mortality, but most studies are from high-income countries and the evidence from low- and middle-income countries (LMICs) is scarce.

OBJECTIVE

To investigate the association between maternal age at delivery and neonatal mortality in LMICs.

METHODS

This is a cross-sectional study using data from 159 Demographic and Health Surveys in 67 LMICs between 2000 and 2018. Maternal age at the time of the birth was the exposure variable, and neonatal mortality was the outcome. Multivariable logistic regression model taking into consideration complex survey design was performed with adjustments for maternal education level, paternal education level, rural/urban residence, country, and survey year. Subgroup analyses were performed by time of death, sex, the country's World Bank income classification, the World Health Organization region, and survey year.

RESULTS

A total of 1 395 746 mother-neonate pairs were included. Overall, compared with neonates born to mothers aged 25-29 years, those born to younger mothers aged 20-24, 16-19 and 12-15 years were at an increased risk of mortality (adjusted odds ratio [OR] 1.24, 95% confidence interval [CI] 1.17, 1.30; OR 1.81, 95% CI 1.71, 1.93; OR 2.29, 95% CI 1.96, 2.67, respectively). Neonates born to mothers aged 30-34, 35-39, 40-44, and ≥45 years were also at an increased risk of mortality (OR 1.09, 95% CI 1.03, 1.15; OR 1.30, 95% CI 1.21, 1.39; OR 1.50, 95% CI 1.38, 1.64; OR 1.84, 95% CI 1.54, 2.20, respectively). The results were consistent across most subgroup analyses.

CONCLUSIONS

Neonates born to younger (<25 years) and older mothers (≥30 years) are at increased risk of neonatal death in LMICs.

The blurring boundaries between placental and maternal preeclampsia: a critical appraisal of 1800 consecutive preeclamptic cases

Objectives: To present a comprehensive overview of different risk factors for early onset preeclampsia (<34 weeks gestation, EOP) vs. late onset (LOP).Study design: South-Reunion University's maternity (Reunion Island, Indian Ocean). 18.5 year-observational population-based cohort study (2001-2019). Epidemiological perinatal database with information on obstetrical and neonatal risk factors. All consecutive singleton pregnancies (>21 weeks) compared with all preeclamptic pregnancies delivered in the south of Reunion island.Main outcome measures: Comparing risk factors between EOP and LOP.Results: Among 1814 singleton preeclamptic pregnancies (600 EOP and 1214 LOP), EOP women were older than LOP 29.5 vs. 28.6 years, p = .009, primigravidas (OR 0.78 [0.63-0.96], p = .02) were prone to LOP. History of preeclampsia (PE) (aOR 12.8 vs. 7.1), chronic hypertension (aOR 6.5 vs. 4.5) had much higher adjusted odds ratios for EOP than for LOP, p < .001. Specific to EOP: coagulopathies (aOR 2.95, p = .04), stimulated pregnancies (aOR 3.9, p = .02). Specific to LOP: renal diseases (aOR 2.0, p = .05) and protective effect for smoking (aOR 0.75, p = .008). EOP women were prone to have a lower BMI.Conclusion: "Placental preeclampsia" (defective placentation) being linked to early onset PE (<34 weeks gestation) while "maternal preeclampsia" (maternal cardiovascular predisposition) being typically manifesting as the late form of the disease LOP is not systematically verified. Future researches are needed to propose a more adapted paradigm.Highlights  Risk factors for different preeclampsia phenotypes (early/late); challenging proposed models.

The relationship of hyperlipidemia with maternal and neonatal outcomes in pregnancy: A cross-sectional study

Background

Concentrations of plasma lipids levels during pregnancy clearly increases. According to some studies, dyslipidemia is effective in the incidence of preeclampsia and insulin resistance. Objective: This study aimed to examine the relationship between hyperlipidemia and maternal and neonatal outcomes in pregnant women.

Materials and Methods

This is a cross-sectional study which was conducted on two groups of pregnant women with hyperlipidemia and normal ones to assess maternal and neonatal outcomes. Maternal data including gestational age, mother's age, body mass index, and maternal weight gain during pregnancy, gestational diabetes mellitus, preeclampsia, cholestasis, and delivery method. Also, birth weight and Apgar score were gathered as the neonatal outcomes.

Results

The results showed that the prevalence of abnormal lipid parameters increased with increasing gestational age. In pregnant women with dyslipidemia in combination with increased triglyceride, cholesterol and Low-density lipoprotein, and decreased High-density lipoprotein, the incidence rates of gestational diabetes (p < 0.001), preeclampsia (p < 0.001), cholestasis (p = 0.041), fetal growth retardation (p < 0.001), and macrosomia (p < 0.001) were statistically higher.

Conclusion

Dyslipidemia was associated with some adverse effects of pregnancy and harmful fetal outcomes. Therefore, it seems that adding laboratory assessment of lipid profiles before and during pregnancy can be effective in early diagnosis of dyslipidemia.

Comparison of risk factors and perinatal outcomes in early onset and late onset preeclampsia: A cohort based study in Reunion Island

Clinical differences, maternal risk factors and pregnancy outcomes of deliveries complicated by early- (delivery<34 weeks) and late-onset (delivery≥34 weeks) preeclampsia were studied in a cohort of women in Reunion Island during 15 years (period 2001-2015; N=62,230 pregnancies). The overall preeclampsia rate in singleton pregnancies was 2.37%. Early- and late-onset preeclampsia rates were 0.75% and 1.5% respectively, and the trend for each type of disease was stable over time. In both form of preeclampsia, smoking during pregnancy was a protective factor and associated risk factors were: older age, primiparity, pre-existing diabetes, chronic hypertension, higher pre-pregnancy body mass index and obesity, infertility treatment, history of renal disease and hypercholesterolemia (all p<0.05). The rate of caesarean section, medically-induced delivery and impaired foetal and neonatal outcomes were significantly higher in preeclamptic women (all p<0.0001). When comparing early- versus late-onset preeclampsia, the only difference was the older maternal age in primiparae with early-onset preeclampsia (p=0.02), and the two groups of preeclamptic women were similar in terms of maternal risk factors, with the exception of higher rates of chronic hypertension in early-onset preeclampsia (p=0.02). Foetal and neonatal outcomes were evaluated after adjustment for gestational age at delivery and no difference was detected between early- and late-onset preeclamptic women. These analyses failed to identify a specific phenotype of preeclampsia in terms of predisposition or pre-existing risk factors for one form or another. Gestational age at delivery was the most important predictor for offspring outcome.

Placental Hofbauer cells and complications of pregnancy

Hofbauer cells (HBCs) are placental macrophages that are present in the villus across gestation. Despite their identification more than 100 years ago, their specific role in placental function remains largely unelucidated. We initially review aspects of their history and biology as well as evidence for putative sites of origin. To gain insight into their potential function, we then describe complications of pregnancy including villitis of unknown etiology (VUE) and histological chorioamnionitis (HCA), in which alterations in numbers, gene expression, or other characteristics of HBCs have been documented to occur. We further review methods for isolation of HBCs and in vitro studies that explore their role in relation to other major cell types in the placenta and examine their actions in cytokine-mediated inflammation. We conclude that HBCs play a key role in placental pathophysiology, and future advances in their isolation and culture would enable mechanistic insight into their villus function.

The etiology of preeclampsia: the role of the father

Preeclampsia is often considered as simply a maternal disease with variable degrees of fetal involvement. More and more the unique immunogenetic maternal-paternal relationship is appreciated, and also the specific 'genetic conflict' that is characteristic of haemochorial placentation. From that perspective, pre-eclampsia can be seen as a disease of an individual couple with primarily maternal and fetal manifestations. The maternal and fetal genomes perform different roles during development. Heritable paternal, rather than maternal, imprinting of the genome is necessary for normal trophoblast development. Large population studies have estimated that 35% of the variance in susceptibility to preeclampsia is attributable to maternal genetic effects; 20% to fetal genetic effects (with similar contributions of both parents), 13% to the couple effect, less than 1% to the shared sibling environment and 32% to unmeasured factors. Not one of these large population studies focussed on the paternal contribution to preeclampsia, which is demonstrated by (1) the effect of the length of the sexual relationship; (2) the concept of primipaternity versus primigravidity; and (3) the existence of the so-called 'dangerous' father, as demonstrated in various large population studies. It is currently unknown how the father exerts this effect. Possible mechanisms include seminal cytokine levels and their effect on maternal immune deviation, specific paternal HLA characteristics and specific paternal single nucleotide polymorphisms (SNPs), in particular in the paternally expressed genes affecting placentation. Several large cohort studies, including the large international SCOPE consortium, have identified paternal SNPs with strong associations with preeclampsia.

Epidemiological studies on primipaternity and immunology in preeclampsia--a statement after twelve years of workshops

Hypertensive disorders of pregnancy (HDP) represent 10% of human births globally and the major complication preeclampsia has a 3-5% prevalence. The etiology of HDP remains uncertain; however, major advances have been made over the last 25 years. The Seventh International Workshop on Reproductive Immunology, Immunological Tolerance and Immunology of Preeclampsia 2010 celebrated its 12th Anniversary in Tioman Island in 2010. Over this period, these seven workshops have contributed extensively to immunological, epidemiological, anthropological, and even vascular debates. The defect of trophoblastic invasion encountered in preeclampsia, intra-uterine growth restriction, and to some extent preterm labor, was understood only at the end of the 1970s. On the other hand, clinical and epidemiological findings at the end of the 20th century permitted us to apprehend that "preeclampsia, the disease of primiparae" may well be a disease of first pregnancy for a couple. Among the important advances, reproductive immunology is certainly the topic where knowledge has exploded in the last decade. This paper relates some major steps in the comprehension of this disease and provides a review of epidemiological studies on the "primipaternity paradigm". It focuses on the relevance of new developments and new concepts in immunology. At the beginning of the 21st century we are possibly closer than ever to understanding the etiology of this obstetrical enigma and also the pathophysiology of global endothelial inflammation in preeclamptic women. In this quest, reproductive immunology will certainly emerge as one of the main players.

Isolation of hofbauer cells from human term placentas with high yield and purity

PROBLEM  Placental villus macrophages (i.e., Hofbauer cells, HBCs) were identified more than 100 years ago. Alterations in their numbers and characteristics are associated with several complications of pregnancy. Although HBCs have previously been isolated and cultured, there is no consensus methodology to obtain these cells with high yield and purity for in vitro studies. METHOD OF STUDY  Hofbauer cells were isolated from human term placentas using protocols in which cytotrophoblasts (CTs) and fibroblasts (FIBs), other major villous cell types, were isolated in parallel. Enzymatic digestion, Percoll gradients, and immunoselection were used to isolate the three cell types. Purity was assessed by morphology, flow cytometry, and phagocytosis assays. RESULTS  Hofbauer cells were isolated with 98-99% purity and a yield of 130-200 × 10(6) cells/80-100 g of tissue. HBCs exhibited a pleiomorphic and vacuolated appearance for at least 5 days in culture medium with and without serum. High levels of phagocytosis in HBCs, but not in CTs or FIBs, confirmed macrophage function in HBCs. Phagocytotic activity was maintained across several days in culture. CONCLUSION  Hofbauer cells were isolated from term placenta with high yield and purity using protocols in which CTs and FIBs were also obtained. This methodology will foster future studies that examine the role of HBCs in regulating villus function.

Endometrial secretions: creating a stimulatory microenvironment within the human early placenta and implications for the aetiopathogenesis of preeclampsia

Endometrial glands represent an important source of nutrients for the conceptus during the first trimester. Their secretions are enriched with carbohydrates, and glycogen accumulates within the syncytiotrophoblast of the placenta. It has been assumed that fetal and placental metabolism follow adult pathways, although it is now appreciated that early development occurs in a low-oxygen environment. In past decades, a novel family of putative insulin mediators, inositol phosphoglycans (IPGs), was discovered. These molecules act as allosteric activators and/or inhibitors of enzymes and transduction proteins involved in the control of cell signalling and metabolic pathways, and determine the specificity of responses after activation of the insulin receptor. One member, IPG P-type, activates pyruvate dehydrogenase phosphatase (PDH-Pase), glycogen synthase phosphatase, and glycerol-3-phosphate acyltransferase. Activation of key phosphatases play a major role in the regulation of glucose disposal by oxidative metabolism via PDH, and the non-oxidative storage by glycogen synthesis, both pathways classically known to be regulated by insulin. High concentrations of IPG P-type in amniotic fluid suggest a role in the regulation of carbohydrate metabolism in the fetal-placental unit. Glycogen accumulation in the syncytiotrophoblast also occurs in preeclamptic pregnancies, and is consistently associated with higher placental levels of IPG P-type. Here, we explore the relationship between nutrients provided by the endometrial glands during early pregnancy, IPG P-type and fetal metabolic requirements. We also discuss whether a disconnect between the placental/fetal metabolic state and oxygen tension could lead to a preeclamptic-type syndrome via leakage of Warburg/IPG mediators into the maternal circulation.

Cytokines: Important for implantation?

PROBLEM

Cytokines are obviously very important in an established pregnancy, but what about human embryo implantation?

METHODS

Literature review.

RESULTS

We first discuss the necessity and limits of animal models, and then review the few cytokines which have been demonstrated by knock-out methods to be absolutely necessary for embryo implantation using in animal models. We then review what is known or discussed about the role of other cytokines as deduced from quantitative and/or qualitative dysregulation in animals and in humans.

CONCLUSIONS

Cytokines are indeed involved in implantation as they are in ongoing pregnancy and delivery. Relevance to infertility and recurrent pregnancy loss is discussed.