Acute atherosis. A histopathological hallmark of immune aggression?

Hypertensive disorders of pregnancy & vascular dysfunction

Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and fetal morbidity and mortality. One of the more severe HDP diagnoses is preeclampsia, which is recognized as a sex-specific cardiovascular risk enhancer with long-term implications for women's health, increasing lifetime risk of ischemic heart disease, stroke, and heart failure. Though the mechanisms accounting for the increased risk of cardiovascular disease following HDP are not yet well understood, vascular dysfunction has been implicated. In this perspective piece, we summarize the existing evidence for vascular dysfunction in HDP with a focus on non-invasive assessments, highlight advances in the field, and suggest future directions for improving risk stratification of women with HDP.

Fetal microchimerism and the two-stage model of preeclampsia

Fetal cells cross the placenta during pregnancy and some have the ability to persist in maternal organs and circulation long-term, a phenomenon termed fetal microchimerism. These cells often belong to stem cell or immune cell lineages. The long-term effects of fetal microchimerism are likely mixed, potentially depending on the amount of fetal cells transferred, fetal-maternal histocompatibility and fetal cell-specific properties. Both human and animal data indicate that fetal-origin cells partake in tissue repair and may benefit maternal health overall. On the other hand, these cells have been implicated in inflammatory diseases by studies showing increased fetal microchimerism in women with autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. During pregnancy, preeclampsia is associated with increased cell-transfer between the mother and fetus, and an increase in immune cell subsets. In the current review, we discuss potential mechanisms of transplacental transfer, including passive leakage across the compromised diffusion barrier and active recruitment of cells residing in the placenta or fetal circulation. Within the conceptual framework of the two-stage model of preeclampsia, where syncytiotrophoblast stress is a common pathophysiological pathway to maternal and fetal clinical features of preeclampsia, we argue that microchimerism may represent a mechanistic link between stage 1 placental dysfunction and stage 2 maternal cardiovascular inflammation and endothelial dysfunction. Finally, we postulate that fetal microchimerism may contribute to the known association between placental syndromes and increased long-term maternal cardiovascular disease risk. Fetal microchimerism research represents an exciting opportunity for developing new disease biomarkers and targeted prophylaxis against maternal diseases.

Investigation of CD56, ADAM17 and FGF21 Expressions in the Placentas of Preeclampsia Cases

Objective: In the present study, we investigated the expression of CD56, ADAM17 and FGF21 antibodies (Ab), which we think have an effect on the pathophysiology of preeclampsia (PE), in pregnant patients with healthy placentas and placentas with PE. The expression of these antibodies has been investigated in a limited amount of former research, but their role in PE has not yet been clarified. With this study, we aimed to contribute to the elucidation of the pathophysiology of PE and the detection of new target molecules for treatment. Materials and Methods: Parturients with singleton pregnancy at 32 weeks or above without any maternal or fetal pathology who were admitted to the Department of Obstetrics and Gynecology, Zonguldak Bülent Ecevit University Practice and Research Hospital between 11 January 2020 and 7 January 2022 were included in the present study. Pregnant women with coexisting disease or a pathology related to the placenta (ablation placenta, vasa previa, hemangioma, etc.) were excluded. CD56, ADAM17 and FGF21 antibodies were histopathologically and immunohistochemically detected in 60 placentas with PE (study group) and 43 healthy placentas (control group). Results: CD56, ADAM17 and FGF21 proteins were all more intensely expressed in preeclamptic placentas and a statistically significant difference was found between the two groups for all three antibodies (p < 0.001). Deciduitis, perivillous fibrin deposition, intervillous fibrin, intervillous hemorrhage, infarct, calcification, laminar necrosis and syncytial node were found to be significantly more common in the study group (p < 0.001). Conclusions: We observed that CD56, ADAM17 and FGF21 expressions increased in preeclamptic placentas. These Ab may be responsible for the pathogenesis of PE, which can be illuminated with further studies.

Placental pathology of preeclampsia from a clinical point of view: Correlation between placental histopathology, clinical signs of preeclampsia and neonatal outcome

AIM

To evaluate the associations between placental histopathology (signs of maternal and fetal vascular malperfusion, delayed villous maturation, villitis of unknown etiology) and subtypes of preeclampsia by onset, clinical aspects of the disease and neonatal outcome.

METHODS

Placental slides from preeclamptic pregnancies were retrospectively reviewed according to a uniform scheme. Information regarding obstetrical anamnesis, clinical data and perinatal outcome was collected from charts, and statistical analysis was performed in order to demonstrate associations between microscopic placental alterations and different aspects of preeclampsia.

RESULTS

A total of 49 cases were studied. Diffuse signs of maternal vascular malperfusion and avascular villi were more common in early-onset-preeclampsia associated with worse prognosis. Preeclampsia with fetal growth restriction had more often diffuse signs of maternal and fetal vascular malperfusion and villitis of unknown etiology. Recurring preeclampsia was associated with more common perivasculitis. Umbilical and uterine artery Doppler indices were associated with medial hypertrophy and/or acute atherosis of maternal decidual vessels. Large foci of avascular villi correlated with extent of maternal 24-h-proteinuria which itself correlated with outcome of preeclampsia. Rate of capillarisation of villi was significantly lower in case of hypertension requiring a three-drug combination of antihypertensive medications versus hypertension treated with one or two drugs, preeclampsia with growth restriction, and stillbirth versus live birth.

CONCLUSIONS

Early- versus late-onset-preeclampsia showed a markedly different profile of histopathological features and perinatal outcome, reflecting their distinguished pathogenesis and prognosis; preeclampsia complicated with fetal growth restriction also had distinctive features. Qualitative and quantitative changes define placental pathology of preeclampsia.

Atherosis of Trophoblast Type

CONTEXT.—

There are 3 types of decidual vasculopathy, namely, acute atherosis, fibrinoid medial necrosis, and mural arterial hypertrophy. Persistence of vascular trophoblasts is also known to be related to maternal vascular malperfusion, but detailed study is lacking.

OBJECTIVE.—

To define atherosis of trophoblast type and distinguish it from atherosis of macrophage type with clinical significance.

DESIGN.—

A total of 1322 placentas from 2021 were collected with clinical, neonatal, and placental information, and routine placental pathology examination was performed. Decidual vasculopathy was classified on the basis of the new classification scheme including atherosis of macrophage type, atherosis of trophoblast type, fibrinoid medial necrosis, mural arterial hypertrophy, and mixed-type vasculopathy. The significance of these morphologic changes was examined on the basis of clinical, neonatal, and placental pathology features.

RESULTS.—

Decidual vasculopathy is classified as classic type, mural hypertrophy, and mixed type. Classic-type vasculopathy is further separated as atherosis and fibrinoid medial necrosis. Atherosis is defined as atherosis of macrophage type and atherosis of trophoblast type. Each category of decidual vasculopathy was evaluated in association with maternal, neonatal, and placental pathologic findings. Atherosis of macrophage type and mixed-type vasculopathy showed statistically significant association with preeclampsia/pregnancy-induced hypertension (PIH), low birth weight, and low placental weight. Atherosis of trophoblast type was associated with lower placental weight but not with other specific clinical features. Neonates of female sex were associated with mural arterial hypertrophy.

CONCLUSIONS.—

Atherosis of trophoblast type is a distinct pathologic feature in late pregnancy, and it is associated with lower placental weight. New classification of decidual vasculopathy helps with better stratification and categorization of placental maternal vascular abnormalities of late pregnancy.

Failure of physiological transformation and spiral artery atherosis: their roles in preeclampsia

Physiological transformation with remodeling of the uteroplacental spiral arteries is key to a successful placentation and normal placental function. It is an intricate process that involves, but is not restricted to, complex interactions between maternal decidual immune cells and invasive trophoblasts in the uterine wall. In normal pregnancy, the smooth muscle cells of the arterial tunica media of uteroplacental spiral arteries are replaced by invading trophoblasts and fibrinoid, and the arterial diameter increases 5- to 10-fold. Poor remodeling of the uteroplacental spiral arteries is linked to early-onset preeclampsia and several other major obstetrical syndromes, including fetal growth restriction, placental abruption, and spontaneous preterm premature rupture of membranes. Extravillous endoglandular and endovenous trophoblast invasions have recently been put forth as potential contributors to these syndromes as well. The well-acknowledged disturbed extravillous invasion of maternal spiral arteries in preeclampsia is summarized, as are briefly novel concepts of disturbed extravillous endoglandular and endovenous trophoblast invasions. Acute atherosis is a foam cell lesion of the uteroplacental spiral arteries associated with poor remodeling. It shares some morphologic features with early stages of atherosclerosis, but several molecular differences between these lesions have also recently been revealed. Acute atherosis is most prevalent at the maternal-fetal interface, at the tip of the spiral arteries. The localization of acute atherosis downstream of poorly remodeled arteries suggests that alterations in blood flow may trigger inflammation and foam cell development. Acute atherosis within the decidua basalis is not, however, confined to unremodeled areas of spiral arteries or to hypertensive disorders of pregnancy and may even be present in some clinically uneventful pregnancies. Given that foam cells of atherosclerotic lesions are known to arise from smooth muscle cells or macrophages activated by multiple types of inflammatory stimulation, we have proposed that multiple forms of decidual vascular inflammation may cause acute atherosis, with or without poor remodeling and/or preeclampsia. Furthermore, we propose that acute atherosis may develop at different gestational ages, depending on the type and degree of the inflammatory insult. This review summarizes the current knowledge of spiral artery remodeling defects and acute atherosis in preeclampsia. Some controversies will be presented, including endovascular and interstitial trophoblast invasion depths, the concept of 2-stage trophoblast invasion, and whether the replacement of maternal spiral artery endothelium by fetal endovascular trophoblasts is permanent. We will discuss the role of acute atherosis in the pathophysiology of preeclampsia and short- and long-term health correlates. Finally, we suggest future opportunities for research on this intriguing uteroplacental interface between the mother and fetus.

Acute Atherosis Lesions at the Fetal-Maternal Border: Current Knowledge and Implications for Maternal Cardiovascular Health

Decidua basalis, the endometrium of pregnancy, is an important interface between maternal and fetal tissues, made up of both maternal and fetal cells. Acute atherosis is a uteroplacental spiral artery lesion. These patchy arterial wall lesions containing foam cells are predominantly found in the decidua basalis, at the tips of the maternal arteries, where they feed into the placental intervillous space. Acute atherosis is prevalent in preeclampsia and other obstetric syndromes such as fetal growth restriction. Causal factors and effects of acute atherosis remain uncertain. This is in part because decidua basalis is challenging to sample systematically and in large amounts following delivery. We summarize our decidua basalis vacuum suction method, which facilitates tissue-based studies of acute atherosis. We also describe our evidence-based research definition of acute atherosis. Here, we comprehensively review the existing literature on acute atherosis, its underlying mechanisms and possible short- and long-term effects. We propose that multiple pathways leading to decidual vascular inflammation may promote acute atherosis formation, with or without poor spiral artery remodeling and/or preeclampsia. These include maternal alloreactivity, ischemia-reperfusion injury, preexisting systemic inflammation, and microbial infection. The concept of acute atherosis as an inflammatory lesion is not novel. The lesions themselves have an inflammatory phenotype and resemble other arterial lesions of more extensively studied etiology. We discuss findings of concurrently dysregulated proteins involved in immune regulation and cardiovascular function in women with acute atherosis. We also propose a novel hypothesis linking cellular fetal microchimerism, which is prevalent in women with preeclampsia, with acute atherosis in pregnancy and future cardiovascular and neurovascular disease. Finally, women with a history of preeclampsia have an increased risk of premature cardiovascular disease. We review whether presence of acute atherosis may identify women at especially high risk for premature cardiovascular disease.

Phenotypic Switch of Endovascular Trophoblasts in Decidual Vasculopathy with Implication for Preeclampsia and Other Pregnancy Complications

BackgroundThis study aims to investigate decidual vasculopathy in preeclampsia at term and its relationship to spiral artery remodeling at implantation sites. Study design: Implantations sites with endovascular trophoblasts were reviewed from abortions with immunostaining for CD56. Placentas from patients with preeclampsia were also reviewed in association with other pathological features using placentas with decidual vasculopathy but not preeclampsia as controls. Results: Endovascular trophoblasts were phenotypically switched to express CD56 upon entering the spiral artery at implantation. CD56 expression is identified in classic decidual vasculopathy at term with or without preeclampsia. CD56 expression in addition to cytokeratin in decidual vasculopathy demonstrated the fetal trophoblastic origin, establishing the presence of endovascular trophoblasts at implantation and the decidual vasculopathy at term. Conclusion: Decidual vasculopathy at term contains the same CD56 positive extravillous endovascular trophoblasts seen with spiral artery remodeling in early pregnancy. CD56 may serve as a possible marker for decidual vasculopathy in the later stages of pregnancy.

Exploring the Molecular Mechanism of Action of Yinchen Wuling Powder for the Treatment of Hyperlipidemia, Using Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation

Background

Yinchen Wuling powder is often used to treat clinical hyperlipidemia, although its mechanism of action remains unclear. In this study, we aimed to investigate the active ingredients found in Yinchen Wuling powder and find its mechanism of action when treating hyperlipidemia, using a combination of network pharmacology, molecular docking, and molecular dynamics simulation approaches.

Methods

The TCMSP database was used to obtain the principle active ingredients found in Yinchen Wuling powder and the NCBI and DisGeNet databases were used to obtain the main target genes involved in hyperlipidemia, and the intersectional targets were obtained by EXCEL. We also used Cytoscape 3.7.2 software to construct a “Traditional Chinese Medicine-Active Ingredient-Target” network and use STRING platform to conduct “protein-protein interactional” (PPI) analyses on the intersection targets. Bioconductor software and RX 64 4.0.0 software were then used to perform GO functional enrichment analysis and KEGG pathway enrichment analysis on the targets. Molecular docking of core protein-ligand interactions was modeled using AutoDock Vina software. A simulation of molecular dynamics was conducted for the optimal core protein-ligand obtained by molecular docking using Amber18 software.

Results

A total of 63 active ingredients were found in Yinchen Wuling powder, corresponding to 175 targets, 508 hyperlipidemia targets, and 55 intersection targets in total. Cytoscape 3.7.2 showed that the key active ingredients were quercetin, isorhamnetin, taxifolin, demethoxycapillarisin, and artepillin A. The PPI network showed that the key proteins involved were AKT1, IL6, VEGFA, and PTGS2. GO enrichment analysis found that genes were enriched primarily in response to oxygen levels and nutrient levels of the vesicular lumen and were associated with membrane rafts. These were mainly enriched in AGE-RAGE (advanced glycation end products-receptor for advanced glycation end products) signaling pathway in diabetic complications, fluid shear stress, and atherosclerosis, as well as other pathways. The molecular docking results indicated key binding activity between PTGS2-quercetin, PTGS2-isorhamnetin, and PTGS2-taxifolin. Results from molecular dynamics simulations showed that PTGS2-quercetin, PTGS2-isorhamnetin, and PTGS2-taxifolin bound more stably, and their binding free energies were PTGS2-quercetin -29.5 kcal/mol, PTGS2-isorhamnetin -32 kcal/mol, and PTGS2-taxifolin -32.9 kcal/mol.

Conclusion

This study is based on network pharmacology and reveals the potential molecular mechanisms involved in the treatment of hyperlipidemia by Yinchen Wuling powder.

Defective Uteroplacental Vascular Remodeling in Preeclampsia: Key Molecular Factors Leading to Long Term Cardiovascular Disease

Preeclampsia is a complex hypertensive disorder in pregnancy which can be lethal and is responsible for more than 70,000 maternal deaths worldwide every year. Besides the higher risk of unfavorable obstetric outcomes in women with preeclampsia, another crucial aspect that needs to be considered is the association between preeclampsia and the postpartum cardiovascular health of the mother. Currently, preeclampsia is classified as one of the major risk factors of cardiovascular disease (CVD) in women, which doubles the risk of venous thromboembolic events, stroke, and ischemic heart disease. In order to comprehend the pathophysiology behind the linkage between preeclampsia and the development of postpartum CVD, a thorough understanding of the abnormal uteroplacental vascular remodeling in preeclampsia is essential. Therefore, this review aims to summarize the current knowledge of the defective process of spiral artery remodeling in preeclampsia and how the resulting placental damage leads to excessive angiogenic imbalance and systemic inflammation in long term CVD. Key molecular factors in the pathway-including novel findings of microRNAs-will be discussed with suggestions of future management strategies of preventing CVD in women with a history of preeclampsia.

Decidua basalis and acute atherosis: Expression of atherosclerotic foam cell associated proteins

INTRODUCTION

Uteroplacental acute atherosis is frequently observed in preeclampsia, and shares features with early atherosclerotic lesions, including artery wall foam cells. The lipid-associated proteins FABP4 (fatty acid binding protein 4), perilipin-2, and LOX-1 (lectin-like oxidized LDL-receptor 1) are involved in atherosclerotic foam cell formation. Increased levels of these proteins have been associated with preeclampsia systemically and in placental tissue. Their role in acute atherosis is yet unidentified. Our aim was to describe the presence of these proteins in acute atherosis, and compare our findings to what is known in early atherosclerotic lesions.

METHODS

Serial sections of decidua basalis tissue from 12 normotensive (4 with acute atherosis) and 23 preeclamptic pregnancies (16 with acute atherosis) were stained with HE and immunostained for CK7, CD68, FABP4, perilipin-2, and LOX-1. Artery wall and perivascular protein expression was assessed in 190 spiral artery sections; 55 with acute atherosis.

RESULTS

Acute atherosis foam cells were commonly positive for perilipin-2 (55%), less often for FABP4 (13%), and never for LOX-1. LOX-1 was frequently observed in intramural trophoblasts of normal spiral arteries. Perivascularly, LOX-1 positivity of decidual stromal cells surrounding arteries with acute atherosis was significantly increased as compared to arteries lacking acute atherosis (38% vs. 15%, p < 0.001).

DISCUSSION

We found that perilipin-2 and FABP4 are expressed by acute atherosis foam cells, similar to atherosclerosis, supporting possible shared pathways for foam cell generation. Unlike atherosclerosis, LOX-1 is not present in acute atherosis, possibly explained by pregnancy-specific routes to decidua basalis foam cell generation.

Pathogenesis of uteroplacental acute atherosis: An update on current research

Uteroplacental acute atherosis is a type of arterial vascular disease that affects the placenta during pregnancy and predominates in the maternal spiral arteries in the decidua basalis layer of the pregnant uterus. This condition is characterized by fibrin-like necrosis of the blood vessel walls, the accumulation of macrophages containing fat (foam cells), and the infiltration of macrophages around blood vessels. Uteroplacental acute atherosis is rare in normal pregnancy but occurs more frequently in patients with pregnancy complications, including preeclampsia, spontaneous preterm labor, preterm prelabor rupture of membranes, mid-trimester spontaneous abortion, fetal death, and small-for-gestational age. It is believed that the mechanisms underlying the development of uteroplacental acute atherosis are related to the incomplete physiological transformation of spiral arteries, placental inflammation, abnormal lipid metabolism, and oxidative stress. In this review, we describe the pathogenesis of uteroplacental acute atherosis to provide reference guidelines for the future prevention and treatment of uteroplacental acute atherosclerotic disease.

Understanding decidual vasculopathy and the link to preeclampsia: A review

Preeclampsia is the archetype of a spectrum of clinical disorders related to abnormal placental development or function, characterized by placental histological lesions. Among those lesions, decidual vasculopathy is a term used to describe lesions of maternal spiral arteries, which are encountered on placental examination in about half of the women with preeclampsia. The morphological features of the lesions include perivascular lymphocytic infiltration, fibrinoid necrosis and foam cell incorporation within the vessel wall. Due to the resemblance of the latter characteristic to atherosclerosis, they are alternatively termed acute atherosis. Decidual vasculopathy correlates with worse maternal and neonatal outcomes, as well as placental pathology. In this article, we review the available literature on decidual vasculopathy and address the pitfalls in histological analysis of the lesions, including the varying definitions of the lesions and sample collection methods. We also discuss the current evidence on the etiology of the lesions and propose a novel hypothesis linking the three etiological pathways to the formation of decidual vasculopathy and, ultimately, the emergence of the heterogeneous group of placental dysfunction disorders, known as the great obstetric syndromes.

Decidual vasculopathy and spiral artery remodeling revisited II: relations to trophoblastic dependent and independent vascular transformation

Background: There are three types of decidual vasculopathy at term, acute atherosis, fibrinoid medial necrosis, and mural arterial hypertrophy with two separate mechanisms. Acute atherosis and fibrinoid medial necrosis demonstrate the replacement of the muscular wall by the fibrinoid material and "foamy cells", whereas mural arterial hypertrophy depicts thickened hypertrophic muscular wall with a narrowed lumen.Methods: In this review, decidual vasculopathy is reexamined using the knowledge of CD56 expression on endovascular trophoblasts (EVTs) at term with perspective in diagnosis and pathogenesis.Results: All three types of vasculopathy can be identified in both decidua basalis and decidua vera (capsularis/parietalis) at term. Decidual vasculopathy at basalis is related to the persistence of EVTs in spiral artery remodeling at implantation and phenotypic switch to express CD56. However, no trophoblastic invasion of spiral artery is present at decidua vera. At implantation, the spiral artery undergoes a trophoblastic-dependent remodeling in decidua basalis whereas the spiral artery undergoes trophoblastic-independent remodeling in decidual vera.Conclusions: Decidual vasculopathy at term is related to spiral artery remodeling at implantation and this is associated with factors other than trophoblastic invasion alone. The spiral artery remodeling at implantation and pathogenesis of decidual vasculopathy at term is likely through circulating factors in relation to complex physiological and pathological conditions in pregnancy.

A practical guide to placental examination for forensic pathologists

The placenta is a complex interface organ that may hold clues to the reasons for fetal, neonatal or maternal demise. For this reason, placental examination should be a mandatory part of all perinatal or maternal autopsies. While published protocols for the examination of the placenta exist, they are often not adopted. The following review provides practical guidelines for placental examination, with discussion of specific medical conditions that can negatively impact upon the fetus, neonate or mother involving placental pathology to cause death. The review aims to discuss concepts, with illustrations, that forensic pathologists may not routinely focus on in death investigations that may either contribute or mask the cause of a fetal or neonatal death, or are associated with a recurrence risk. While it is recognized that many forensic facilities do not have formal guidelines for placental examination, involvement of local perinatal pathology services in cases is one way of obtaining additional specialist expertise.

The immunophenotype of decidual macrophages in acute atherosis

PROBLEM

Acute atherosis is a uteroplacental arterial lesion that is associated with pregnancy complications such as preeclampsia and preterm birth, the latter being the leading cause of perinatal morbidity and mortality worldwide. However, the immunobiology of acute atherosis is poorly understood.

METHOD OF STUDY

Placental basal plate samples were collected from women who delivered with (n = 11) and without (n = 31) decidua basalis lesions of acute atherosis. Multicolor flow cytometry was used to quantify M1- and M2-like macrophage subsets and the expression of iNOS and IL-12 by decidual macrophages. Multiplex fluorescence staining and phenoptics were performed to localize M1-, MOX-, and Mhem-like macrophages in the decidual basalis.

RESULTS

Macrophages displayed diverse phenotypes in the decidua basalis with acute atherosis. M2-like macrophages were the most abundant subset in the decidua; yet, this macrophage subset did not change with the presence of acute atherosis. Decidual M1-like macrophages were increased in acute atherosis, and such macrophages displayed a pro-inflammatory phenotype, as indicated by the expression of iNOS and IL-12. Decidual M1-like pro-inflammatory macrophages were localized near both transformed and non-transformed vessels in the decidua basalis with acute atherosis. MOX and Mhem macrophages were also identified near transformed vessels in the decidua basalis with acute atherosis. Finally, monocyte-like cells were present on the vessel wall of non-transformed decidual vessels, indicating a possible intravascular source for macrophages in acute atherosis.

CONCLUSION

Decidual macrophages display different phenotypes, namely M1-like, M2-like, MOX, and Mhem subsets. Yet, pro-inflammatory macrophages are enriched in the decidua basalis with acute atherosis. These findings provide a molecular foundation for future mechanistic inquiries about the role of pro-inflammatory macrophages in the pathogenesis of acute atherosis.

The combination of maternal KIR-B and fetal HLA-C2 is associated with decidua basalis acute atherosis in pregnancies with preeclampsia

Acute atherosis is an arterial lesion most often occurring in pregnancies complicated by preeclampsia, a hypertensive pregnancy disorder. Acute atherosis predominates in the maternal spiral arteries in the decidua basalis layer of the pregnant uterus. This layer forms the fetal-maternal immunological interface, where fetal extravillous trophoblasts interact with maternal immune cells to promote decidual spiral artery remodeling and maternal immune tolerance towards the fetus. Of the classical polymorphic class I HLAs, extravillous trophoblasts express only HLA-C. HLA-C is a ligand for killer immunoglobulin-like receptors (KIR) on NK- and T-cells. Genetic combinations of fetal HLA-C and maternal KIRs affect pregnancy outcome. However, the role of HLA and KIR genes in acute atherosis is unknown. We hypothesized that specific genetic combinations of fetal HLA and maternal KIR are associated with the presence of acute atherosis lesions in the decidua basalis. We genotyped HLA class-I and II loci in paired fetal and maternal DNA samples from 166 pregnancies (83 preeclamptics, 83 controls). Acute atherosis was identified in 38 of these. Maternal KIR-loci were also genotyped. We found that the combination of maternal KIR-B haplotype and fetal HLA-C2 was significantly associated with acute atherosis in preeclampsia. In preeclamptic pregnancies with acute atherosis, 60% had this combination, compared to 24.5% in those without acute atherosis (p = 0.001). We suggest that interactions between fetal HLA-C2 and activating KIRs on maternal decidual NK-cells or T-cells may contribute to the formation of acute atherosis by promoting local decidual vascular inflammation.

From Pregnancy to Preeclampsia: A Key Role for Estrogens

Preeclampsia (PE) results in placental dysfunction and is one of the primary causes of maternal and fetal mortality and morbidity. During pregnancy, estrogen is produced primarily in the placenta by conversion of androgen precursors originating from maternal and fetal adrenal glands. These processes lead to increased plasma estrogen concentrations compared with levels in nonpregnant women. Aberrant production of estrogens could play a key role in PE symptoms because they are exclusively produced by the placenta and they promote angiogenesis and vasodilation. Previous assessments of estrogen synthesis during PE yielded conflicting results, possibly because of the lack of specificity of the assays. However, with the introduction of reliable analytical protocols using liquid chromatography/mass spectrometry or gas chromatography/mass spectrometry, more recent studies suggest a marked decrease in estradiol levels in PE. The aim of this review is to summarize current knowledge of estrogen synthesis, regulation in the placenta, and biological effects during pregnancy and PE. Moreover, this review highlights the links among the occurrence of PE, estrogen biosynthesis, angiogenic factors, and cardiovascular risk factors. A close link between estrogen dysregulation and PE occurrence might validate estrogen levels as a biomarker but could also reveal a potential approach for prevention or cure of PE.

Failure of physiologic transformation of spiral arteries, endothelial and trophoblast cell activation, and acute atherosis in the basal plate of the placenta

BACKGROUND

Failure of physiologic transformation of spiral arteries has been reported in preeclampsia, fetal growth restriction, fetal death, and spontaneous preterm labor with intact or ruptured membranes. Spiral arteries with failure of physiologic transformation are prone to develop atherosclerotic-like lesions of atherosis. There are striking parallels between preeclampsia and atherosclerotic disease, and between lesions of atherosis and atherosclerosis. Endothelial activation, identified by intercellular adhesion molecule-1 expression, is present in atherosclerotic-like lesions of heart transplantation, and is considered a manifestation of rejection. Similarly, endothelial activation/dysfunction has been implicated in the pathophysiology of atherosclerosis and preeclampsia. Intercellular adhesion molecule-1-overexpressing-activated endothelial cells are more resistant to trophoblast displacement than nonactivated endothelium, and may contribute to shallow spiral artery trophoblastic invasion in obstetrical syndromes having failure of physiologic transformation.

OBJECTIVE

We sought to determine whether failure of spiral artery physiologic transformation was associated with activation of interstitial extravillous trophoblasts and/or spiral artery endothelium and presence of acute atherosis in the placental basal plate.

STUDY DESIGN

A cross-sectional study of 123 placentas (19-42 weeks' gestation) obtained from normal pregnancies (n = 22), preterm prelabor rupture of membranes (n = 26), preterm labor (n = 23), preeclampsia (n = 27), intrauterine fetal death (n = 15), and small for gestational age (n = 10) was performed. Failure of spiral artery physiologic transformation and presence of cell activation was determined using immunohistochemistry of placental basal plates containing a median of 4 (minimum: 1; maximum: 9) vessels per placenta. Endothelial/trophoblast cell activation was defined by the expression of intercellular adhesion molecule-1. Investigators examining microscopic sections were blinded to clinical diagnosis. Pairwise comparisons among placenta groups were performed with Fisher exact test and Wilcoxon rank sum test using a Bonferroni-adjusted level of significance (.025).

RESULTS

We found that 87% (94/108) of placentas having spiral arteries with failure of physiologic transformation (actin-positive and cytokeratin-negative) in the basal plate, and 0% (0/15) of placentas having only spiral arteries with complete physiologic transformation (cytokeratin-positive and actin-negative), had arterial endothelial and/or interstitial extravillous trophoblasts reactive with the intercellular adhesion molecule-1 activation marker (P < .001). A significant correlation (R² = 0.84) was found between expression of spiral artery endothelial and interstitial extravillous trophoblast intercellular adhesion molecule-1 (P < .001) in activated placentas. Lesions of atherosis were found in 31.9% (30/94) of placentas with complete and/or partial failure of physiologic transformation of spiral arteries that were intercellular adhesion molecule-1-positive, in none of the 14 placentas with failure of physiologic transformation that were intercellular adhesion molecule-1-negative, and in none of the 15 placentas with complete spiral artery physiologic transformation without failure (P = .001). All placentas (30/30, 100%) with atherosis were identified in placentas having concomitant spiral artery endothelial and interstitial extravillous trophoblast activation.

CONCLUSION

Failure of spiral artery physiologic transformation in the placental basal plate is associated with interstitial extravillous trophoblast and arterial endothelial activation along with increased frequency of spiral artery atherosis. These findings may be used to improve the characterization of different disorders of the placental bed such as in refining the existing tools for the early prediction of risk for preterm, preeclamptic, and other abnormal pregnancies.

Premature cardiovascular disease following a history of hypertensive disorder of pregnancy

BACKGROUND

Following an episode of hypertensive disorder of pregnancy (HDP) women have an increased risk of cardiovascular disease over their lifetime. At the time of acute coronary syndrome we compared clinical information between women with and without a history of hypertension in pregnancy to gain further insight into the pathophysiology of cardiovascular disease in this population.

METHODS

GENESIS-PRAXY (GENdEr and Sex determInantS of cardiovascular disease: from bench to beyond-PRemature Acute Coronary SYdrome) is a prospective multicenter study, with recruitment between January 2009 and April 2013, including 242 parous women with premature acute coronary syndrome.

RESULTS

The median age was 50years (IQR 6) and HDP was common; 43 (17.8%) women had prior gestational hypertension, 33 (13.6%) preeclampsia and 166 (68.6%) a prior normotensive pregnancy. Women with a history of HDP commonly had chronic hypertension and diabetes and those presenting with ST-elevation myocardial infarction were more likely to have a history of preeclampsia (aOR 3.12, 95% CI 1.22-8.01) than were women with prior normotensive pregnancies. Neither gestational hypertension (aOR 1.40, 95% CI 0.60-3.26) nor preeclampsia (aOR 0.63, 95% CI 0.23-1.74) was associated with a higher composite risk of three-vessel, left main or proximal left anterior descending coronary disease.

CONCLUSION

In this study of women with premature cardiovascular disease, ST-elevation myocardial infarction was associated with a history of preeclampsia possibly because of persistent endothelial dysfunction. High-risk coronary lesions on angiography did not appear to have an association with preeclampsia or gestational hypertension despite a high burden of traditional risk factors.

Acute atherosis in vacuum suction biopsies of decidua basalis: An evidence based research definition

BACKGROUND

Acute atherosis (AA) of the uteroplacental spiral arteries has been characterised by subendothelial lipid-laden foam cells, perivascular leukocyte infiltrates (PVI) and fibrinoid necrosis. Because precise diagnostic criteria are not available for comparative research studies we developed and tested new simplified criteria based on 237 cases.

METHODS

Decidual basalis samples were collected by vacuum suction at elective cesarean deliveries. Spiral arteries were evaluated in serial decidual tissue sections from women with normal pregnancy, preeclampsia, and diabetes. Features of AA were sought in parallel sections stained with H&E and immunostained for CD68, cytokeratin CK7 and desmin, and costained with Periodic Acid Schiff (PAS).

RESULTS

Foam cell lesions were defined as two or more adjacent, intramural, vacuolated CD68 positive cells, PVI as a focal perivascular lymphocyte accumulation, more dense than in the surrounding decidua. Increased fibrinoid (PAS positive) was identified if present in ≥75% of the arterial wall circumference. PVI and increased fibrinoid were significantly associated with preeclampsia but not specifically associated with the presence of foam cell lesions. Hence we diagnosed decidua basalis AA lesions solely by the presence of foam cell lesions, occurring in preeclampsia (37%), diabetes (10%) and healthy normotensive women (11%). The simplified criterion was reproducible by different investigators. Decidua basalis AA occurred most commonly and extensively in preeclampsia, but did not distinguish between preterm and term disease.

DISCUSSION

Our evidence based criterion for decidua basalis AA diagnosis in vacuum suction biopsies may not apply to myometrial or decidua parietalis arteries. In decidual basalis samples it should facilitate comparisons between research studies, to improve pathophysiological understanding of AA and preeclampsia.

Acute Atherosis of the Uterine Spiral Arteries: Clinicopathologic Implications

Acute atherosis is unique vascular changes of the placenta associated with poor placentation. It is characterized by subendothelial lipid-filled foam cells, fibrinoid necrosis of the arterial wall, perivascular lymphocytic infiltration, and it is histologically similar to early-stage atherosclerosis. Acute atherosis is rare in normal pregnancies, but is frequently observed in non- transformed spiral arteries in abnormal pregnancies, such as preeclampsia, small for gestational age (SGA), fetal death, spontaneous preterm labor and preterm premature rupture of membranes. In preeclampsia, spiral arteries fail to develop physiologic transformation and retain thick walls and a narrow lumen. Failure of physiologic transformation of spiral arteries is believed to be the main cause of uteroplacental ischemia, which can lead to the production of anti-angiogenic factors and induce endothelial dysfunction and eventually predispose the pregnancy to preeclampsia. Acute atherosis is more frequently observed in the spiral arteries of the decidua of the placenta (parietalis or basalis) than in the decidual or myometrial segments of the placental bed. The presence and deeper location of acute atherosis is associated with poorer pregnancy outcomes, more severe disease, earlier onset of preeclampsia, and a greater frequency of SGA neonates in patients with preeclampsia. Moreover, the idea that the presence of acute atherosis in the placenta may increase the risk of future cardiovascular disease in women with a history of preeclampsia is of growing concern. Therefore, placental examination is crucial for retrospective investigation of pregnancy complications and outcomes, and accurate placental pathology based on universal diagnostic criteria in patients with abnormal pregnancies is essential for clinicopathologic correlation.

Prevalence of hypertensive disorders in women after preeclamptic pregnancy associated with decidual vasculopathy

OBJECTIVE

A subgroup of preeclamptic women has spiral artery lesions termed decidual vasculopathy (DV) which relate to worse clinical outcome. We aimed to determine whether a history of preeclampsia (PE) with DV is associated with adverse overall and future pregnancy outcome, including increased recurrence risk of hypertensive diseases of pregnancy.

METHODS

Via posted survey women with PE and DV (DV positive) in the index pregnancy were compared to those without the lesions (DV negative) on overall and future pregnancy outcome.

RESULTS

DV positive cases showed a higher incidence of chronic hypertension both preconceptionally and at time of survey, adjusted odds ratio 4.8 (2.0-11.9). The DV positive group had a higher overall incidence of pregnancies with gestational hypertension (22% vs 13%, p = 0.04), preterm birth (59% vs 45%, p = 0.02) and a lower birth weight centile (30 vs 39, p = 0.02). There was no difference in outcome of future pregnancies, irrespective of the use of prophylactic aspirin.

CONCLUSION

Women with DV-associated PE have a higher overall incidence of adverse obstetric outcome and of chronic hypertension, indicating an underlying vascular pathology, putting them at risk for pregnancy and cardiovascular complications. These women constitute a target group for counseling, monitoring and possibly lifestyle or pharmacological interventions.

Chronic villitis of unknown etiology and massive chronic intervillositis have similar immune cell composition

INTRODUCTION

Chronic villitis of unknown etiology (CVUE) and massive chronic intervillositis (MCI) are placental lesions associated with infiltration of mononuclear cells in the chorionic villi and the intervillous spaces, respectively. It is not well known whether immune cells in CVUE and MCI have similar phenotypic characteristics.

METHODS

A cross-sectional study of third trimester placentas was conducted to identify immune cell subpopulations in CVUE and MCI (n = 17/group). CVUE was diagnosed with H&E staining and antibody to CD3 in serial sections; and MCI, by the presence of massive infiltration of mononuclear cells in the intervillous spaces. Immune cells, ICAM-1 expression and nuclear factor κB (NF-κB) activation were determined immunohistochemically.

RESULTS

CVUE and MCI showed similar infiltrates, mainly CD68+ and CD3+ cells. Most cells (>80%) were CD45RB+, and one third were CD45RO+ in both lesions. There were slightly more CD8+ than CD4+ cells in both CVUE and MCI. More than 90% of cells in CVUE and MCI were ICAM-1+ with NFκB nuclear localization. Syncytiotrophoblast ICAM-1 expression was significantly (p < 0.001) higher in MCI (mean of 81.0; range of 71.6-86.0) than in CVUE (52.4; 36.4-59.4) or normal placentas (0.2; 0.0-0.6). Both, failure of physiologic transformation of spiral arteries and placental atherosclerosis-like lesions of atherosis were significantly more frequent in MCI than in CVUE or normal placentas (p = 0.044 and p = 0.007, respectively).

DISCUSSION

These finding suggest that MCI and CVUE have very similar infiltration of immune cells although MCI has more severe placental lesions.

The frequency of acute atherosis in normal pregnancy and preterm labor, preeclampsia, small-for-gestational age, fetal death and midtrimester spontaneous abortion

OBJECTIVE

Acute atherosis is characterized by subendothelial lipid-filled foam cells, fibrinoid necrosis and perivascular lymphocytic infiltration. This lesion is generally confined to non-transformed spiral arteries and is frequently observed in patients with preeclampsia. However, the frequency of acute atherosis in the great obstetrical syndromes is unknown. The purpose of this study was to determine the frequency and topographic distribution of acute atherosis in placentas and placental bed biopsy samples obtained from women with normal pregnancy and those affected by the "great obstetrical syndromes". We also examined the relationship between acute atherosis and pregnancy outcome in patients with preeclampsia.

MATERIAL AND METHODS

A retrospective cohort study of pregnant women who delivered between July 1998 and July 2014 at Hutzel Women's Hospital/Detroit Medical Center was conducted to examine 16, 345 placentas. Patients were classified into the following groups: (1) uncomplicated pregnancy; (2) spontaneous preterm labor (sPTL) and preterm prelabor rupture of membranes (PPROM); (3) preeclampsia; (4) gestational hypertension; (5) small-for-gestational age (SGA); (6) chronic hypertension; (5) fetal death; (6) spontaneous abortion and (7) others. A subset of patients had placental bed biopsy. The incidence of acute atherosis was compared among the different groups.

RESULTS

(1) The prevalence of acute atherosis in uncomplicated pregnancies was 0.4% (29/6961) based upon examination of nearly 7000 placentas; (2) the frequency of acute atherosis was 10.2% (181/1779) in preeclampsia, 9% (26/292) in fetal death, 2.5% (3/120) in midtrimester spontaneous abortion, 1.7% (22/1,298) in SGA neonates and 1.2% (23/1,841) in sPTL and PPROM; (3) among patients with preeclampsia, those with acute atherosis than in those without the lesion had significantly more severe disease, earlier onset, and a greater frequency of SGA neonates (p < 0.05 all) and (4) the lesion was more frequently observed in the decidua (parietalis or basalis) than in the decidual segment of the spiral arteries in patients with placental bed biopsies.

CONCLUSIONS

Acute atherosis is rare in normal pregnancy, and occurs more frequently in patients with pregnancy complications, including preeclampsia, sPTL, preterm PROM, midtrimester spontaneous abortion, fetal death and SGA.

Placental lesions associated with acute atherosis

OBJECTIVE

Acute atherosis is a lesion of the spiral arteries characterized by fibrinoid necrosis of the vessel wall, an accumulation of fat-containing macrophages, and a mononuclear perivascular infiltrate, which can be found in patients with preeclampsia, fetal death, small-for-gestational age, spontaneous preterm labor/premature prelabor rupture of membrane, and spontaneous mid-trimester abortion. This lesion is thought to decrease blood flow to the intervillous space which may lead to other vascular lesions of the placenta. The objective of this study was to test whether there is an association between acute atherosis and placental lesions that are consistent with maternal vascular underperfusion (MVU), amniotic fluid infection (AFI), fetal vascular thrombo-occlusive disease (FVTOD) or chronic inflammation.

MATERIAL AND METHODS

A retrospective cohort study of pregnant women who delivered between July 1998 and July 2014 at Hutzel Women's Hospital/Detroit Medical Center was conducted examine 16 457 placentas. The frequency of placenta lesions (diagnosed using the criteria of the Perinatal Section of the Society for Pediatric Pathology) was compared between pregnancies with and without acute atherosis.

RESULTS

Among 16 457 women who were enrolled, 10.2% (1671/16 457) were excluded, leaving 14 786 women who contributed data for analysis. Among them, the prevalence of acute atherosis was 2.2% (326/14 786). Women with acute atherosis were more than six times as likely as those without to have placental lesions consistent with maternal underperfusion (adjusted odds ratio - aOR: 6.7; 95% CI 5.2-8.6). To a lesser degree, acute atherosis was also associated with greater risks of having either lesions consistent with FVTOD (aOR 1.7; 95% CI 1.2-2.3) or chronic chorioamnionitis (aOR 1.9; 95% CI 1.3-3), but not with other chronic inflammatory lesions, after adjusting for gestational age at delivery. In contrast, women with acute atherosis were 60% less likely to have lesions consistent with AFI, adjusting for gestational age at delivery (aOR 0.4; 95% CI 0.3-0.5).

CONCLUSIONS

Acute atherosis is associated with increased risks of having placental lesions consistent with MVU, and to a lesser extent, chronic chorioamnionitis and those consistent with FVTOD.

Pre-eclampsia part 1: current understanding of its pathophysiology

Pre-eclampsia is characterized by new-onset hypertension and proteinuria at ≥20 weeks of gestation. In the absence of proteinuria, hypertension together with evidence of systemic disease (such as thrombocytopenia or elevated levels of liver transaminases) is required for diagnosis. This multisystemic disorder targets several organs, including the kidneys, liver and brain, and is a leading cause of maternal and perinatal morbidity and mortality. Glomeruloendotheliosis is considered to be a characteristic lesion of pre-eclampsia, but can also occur in healthy pregnant women. The placenta has an essential role in development of this disorder. Pathogenetic mechanisms implicated in pre-eclampsia include defective deep placentation, oxidative and endoplasmic reticulum stress, autoantibodies to type-1 angiotensin II receptor, platelet and thrombin activation, intravascular inflammation, endothelial dysfunction and the presence of an antiangiogenic state, among which an imbalance of angiogenesis has emerged as one of the most important factors. However, this imbalance is not specific to pre-eclampsia, as it also occurs in intrauterine growth restriction, fetal death, spontaneous preterm labour and maternal floor infarction (massive perivillous fibrin deposition). The severity and timing of the angiogenic imbalance, together with maternal susceptibility, might determine the clinical presentation of pre-eclampsia. This Review discusses the diagnosis, classification, clinical manifestations and putative pathogenetic mechanisms of pre-eclampsia.

Histologic differences in placentas of preeclamptic/eclamptic gestations by birthweight, placental weight, and time of onset

With preeclampsia/eclampsia (PE/E), infants more often are either large or small for gestational age. We explored whether the differences in infant birthweight (BW), placental weights (PW), or time of onset are associated with histologic features of maternal vascular underperfusion. A retrospective chart identified 243 PE/E gestations between 2007 and 2010. Gestational age only was known at slide review. Investigated features included increased syncytial knots, villous agglutination, increased intervillous fibrin, distal villous hypoplasia, acute atherosis, mural hypertrophy of membrane arterioles, muscularized basal plate arteries, increased placental site giant cells, increased immature intermediate trophoblasts, infarcts, and villitis. The results were correlated with BW, PW, and onset time PE/E. One hundred thirty-eight PE/E gestations were identified with adequate slides and history. Increased BW placentas had decreased syncytial knots and increased mural hypertrophy of membrane arterioles. Decreased BW had increased placenta site giant cells. Increased PW had decreased distal villous hypoplasia. Decreased PW had increased syncytial knots, increased intervillous fibrin, and increased acute atherosis. Early-onset disease had increased syncytial knots, distal villous hypoplasia, villous agglutination, and infarcts. This suggests PE/E is not a single process resulting in a uniform distribution of lesions but, rather, is composed of several different processes manifesting a single clinical presentation.

Review: Preeclampsia, acute atherosis of the spiral arteries and future cardiovascular disease: two new hypotheses

Preeclampsia is a serious complication of pregnancy, potentially lethal for women and offspring. Affected women have an augmented risk of later cardiovascular disease and premature death and may have risk factors in common with older persons developing cardiovascular disease. In some cases of preeclampsia, lipid-filled foam cells accumulate in the walls of the spiral arteries of the uteroplacental circulation (acute atherosis). These lesions resemble the early stages of atherosclerosis and are thought to regress after delivery. The mechanisms that contribute to acute atherosis are largely unknown, but are related to defective vascular remodeling of the spiral arteries in the first half of pregnancy. Spiral artery lipid deposition may also occur in normal pregnancies, which suggests that it may not be confined exclusively to maladapted spiral arteries or caused by hypertension. Our first hypothesis is that there are several pathways to the development of acute atherosis, which converge at the point of excessive decidual inflammation in the final common pathway. Our second hypothesis is that acute atherosis, evolving during the short time of pregnancy, identifies a subset of women at augmented risk for atherosclerosis and later chronic arterial disease better than the diagnosis of preeclampsia itself. If confirmed, this may enable better preventive management for the affected women.

Beyond the placental bed: placental and systemic determinants of the uterine artery Doppler waveform

The uterine artery Doppler waveform has been extensively investigated, though its widespread clinical use as a predictor of adverse pregnancy outcome remains under debate. The determinants of the waveform have classically been ascribed to transformation of the spiral arteries and the development of a low resistance uteroplacental circulation, failure of which predisposes to pre-eclampsia, fetal growth restriction and other adverse outcomes. It has become increasingly evident that although spiral artery transformation determines in some part the characteristics of the Doppler waveform, factors pertaining to maternal vascular and endothelial function are also important.

Sex-specific basis of severe placental dysfunction leading to extreme preterm delivery

OBJECTIVES

Since pregnancies with a male fetus have higher perinatal complications attributed to placental dysfunction, including severe pre-eclampsia and intrauterine growth restriction, the objective of our study was to formally evaluate placental pathology for a placental origin of these sex-specific differences.

DESIGN

Retrospective study at Mount Sinai Hospital in Toronto, Canada. Identification of 262 singleton pregnancies affected by severe pre-eclampsia and/or intrauterine growth restriction who delivered between 22 and 32 weeks' gestation from 2000 to 2010. Detailed placental pathology was reviewed, and data from 140 pregnancies with male fetuses were compared with 122 pregnancies with female fetuses. A comparison group of 40 unaffected pregnancies who delivered in the same gestational range was used to determine baseline rates of placental pathology.

MAIN OUTCOME MEASURED

Detailed placental pathology, including placental development/differentiation, velamentous umbilical cord insertion, maternal-fetal interface pathology, villous infarction, hemorrhagic lesions, villous development, and fetal vascular under-perfusion.

RESULTS

Impaired placental development and differentiation was equally common amongst males (73/140, 52.1%) and females (69/122, 56.6%). Male placentas exhibited significantly higher rates of chronic deciduitis (17.9% vs. 9.0%; relative risk [RR] 1.98, 95% confidence interval [CI] 1.02-3.86) and velamentous umbilical cord insertion (9.5% vs. 1.7%; RR 5.66, 95% CI 1.30-24.6), and a significantly lower frequency of villous infarction (55.4% vs. 73.7%; RR 0.75, 95% CI 0.62-0.90) than female placentas. No significant differences were noted for other lesions.

CONCLUSIONS

Fetal sex exerts a differential effect on the placental pathology that mediates severe pre-eclampsia and/or IUGR. Placental pathology at birth may provide insight into the mechanisms linking adverse in utero events with long-term adult disease since, for example, a male tendency to an inflammatory pathology at the maternal-fetal interface may be linked to the excess risk of coronary artery disease.

Increased prevalence of peripheral blood granulysin-producing cytotoxic T lymphocytes in preeclampsia

Preeclampsia (PE) is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive arms of the immune system. Granulysin is a cytolytic and pro-inflammatory molecule expressed by activated human cytotoxic T lymphocytes and natural killer (NK) cells. Recent data show that serum granulysin levels are elevated in preeclampsia. The purpose of this study was to determine whether the proportion of peripheral blood cytotoxic T lymphocytes and NK cells that express intracellular granulysin is altered in PE. Twenty-two preeclamptic patients and 29 healthy pregnant women were involved in this case-control study. Intracellular granulysin expression of lymphocytes was determined with flow cytometric examination. In healthy pregnant women, the majority of NK cells and a small fraction of cytotoxic T cells expressed granulysin in their cytoplasma (median (25-75 percentile): 53.5 (45.6-68.0)% and 13.8 (8.5-23.1)%, respectively). In PE, the percentage of granulysin-positive cytotoxic T lymphocytes was markedly increased, while the proportion of granulysin-producing NK cells was unchanged as compared to healthy pregnant women (for cytotoxic T cells: 34.1 (19.3-45.6)%, p<0.001; for NK cells: 57.2 (42.9-74.9)%, p>0.05). Maternal age of healthy pregnant women showed a significant inverse correlation with the frequency of granulysin-expressing NK cells (Spearman R=-0.44, p<0.05), while their BMI correlated positively with the proportions of granulysin-positive cytotoxic T cells and NK cells (Spearman R=0.43, p<0.05 for both). In conclusion, the majority of circulating NK cells but only a small population of cytotoxic T cells shows intracellular granulysin expression in normal pregnancy. In preeclampsia, the proportion of granulysin-producing cytotoxic T cells in the peripheral blood is markedly increased, which might contribute to the development of the pro-inflammatory Th1-type immune responses characteristics of the maternal syndrome of the disease.

Von Willebrand factor and ADAMTS13: a candidate couple for preeclampsia pathophysiology

OBJECTIVE

The goal of this study was to search for an association between a desintegrin-like and metalloprotease thrombospondin type 1 motif, member 13 (ADAMTS13) levels and the occurrence of preeclampsia, its characteristics (time-onset and severity), and its consequences (occurrence of fetal growth restriction or preterm delivery).

METHODS AND RESULTS

We studied 140 pairs of women in a case-control study with 3 matching criteria: maternal age, gestational age, and ethnic origin. We measured ADAMTS13 activity using a fluorescence resonance energy transfer assay with the fluorescence resonance energy transfer-VWF73 peptide. ELISA was used to assess protein antigen levels: ADAMTS13, von Willebrand Factor (VWF), interleukin-6, C-reactive protein, P-selectin, and thrombospondin-1. The lowest levels of ADAMTS13 (activity ≤ 70% or antigen ≤ 592 ng/mL) were significantly associated with preeclampsia (odds ratios [OR] [95% confidence interval] of 4.2 [1.1 to 15] and 14.3 [1.7 to 123], respectively). This association was independent of VWF levels and preeclampsia risk factors but dependent on interleukin-6 and C-reactive protein levels for ADAMTS13 activity. Levels of ADAMTS13 activity (≤ 57%) were significantly associated with early-onset preeclampsia (OR = 2.5 [1.1 to 5.8]). Severe preeclampsia was associated with the highest levels of P-selectin (>57 ng/mL) (OR = 3.4 [1.2 to 9.7]).

CONCLUSIONS

Preeclampsia is associated with decreased levels of ADAMTS13, independently of VWF. This decrease is quantitative, occurs early, and seems to be dependent on inflammation. Our results suggest that ADAMTS13 could participate in the pathophysiology of preeclampsia.

Role of nutrition in the risk of preeclampsia

Preeclampsia (PE) accounts for about one-quarter of the cases of maternal mortality and ranks second among the causes of pregnancy-associated maternal deaths in Canada and worldwide. The identification of an effective strategy to prevent PE is a priority and a challenge for research in obstetrics. Progress has been hampered by inadequate understanding of the underlying etiology of the disease. The role of maternal diet in the etiology of PE has recently received increased attention. The objective of this paper is to provide an overview of the literature concerning 1) the current understanding of the pathogenesis of PE, 2) the biological plausibility and potential mechanisms underlying the associations between maternal dietary exposures, nutrition, and the risk of PE, and 3) the epidemiological findings of maternal nutrient intake in relation to the risk of PE.

The biology of preeclampsia

Preeclampsia is a systemic disease that results from placental defects and occurs in about 5-8% of pregnancies worldwide. Preeclampsia is a disease of many theories, wherein investigators put forward their favorite mechanistic ideas, each with a causal appeal for the pathogenesis of preeclampsia. In reality, the patho-mechanism of preeclampsia remains largely unknown. Preeclampsia, as diagnosed in patients today, is likely a heterogeneous collection of disease entities that share some common features but also show important differences. Therefore, one single mechanism may never be found to explain all the variants of preeclampsia. Current research must focus on evaluating such diverse mechanisms, as well as the possible common effector pathways. Here, we provide a discussion of several possible mechanisms and putative theories proposed for preeclampsia, with particular emphasis on the recent discovery of a new genetic mouse model offering new opportunities to explore experimental therapies.

Search for an association between V249I and T280M CX3CR1 genetic polymorphisms, endothelial injury and preeclampsia: the ECLAXIR study

BACKGROUND

Preeclampsia and coronary-artery disease share risk factors, suggesting common pathophysiological mechanisms. CX3CR1/CX3CL1 mediates leukocyte migration and adhesion and has been implicated in the pathophysiology of several inflammatory diseases. M280/I249 variants of CX3CR1 are associated with an atheroprotective effect and reduced endothelial dysfunction. The aim of this study was to search for an association between V249I and T280M polymorphisms of CX3CR1, preeclampsia and endothelial dysfunction.

METHODOLOGY/PRINCIPAL FINDINGS

We explored these polymorphisms with real-time polymerase chain reaction in a case-control study (184 white women with preeclampsia and 184 matched normotensive pregnant women). Endothelial dysfunction biomarkers including von Willebrand factor, VCAM-1 and thrombomodulin, as well as the soluble form of CX3CL1 were measured by enzyme-linked immunosorbent assays (ELISA). The I249 and M280 alleles were associated neither with preeclampsia, nor with its more severe form or with endothelial injury. In contrast, we found a trend toward increased CX3CL1 levels in preeclampsia patients, especially in early-onset- preeclampsia as compared to its level in later-onset- preeclampsia.

CONCLUSIONS/SIGNIFICANCE

This is the first study to characterize the CX3CR1 gene polymorphisms in patients with preeclampsia. We found no differences in genotype or haplotype frequencies between patients with PE and normal pregnancies, suggesting that maternal CX3CR1 V249I and T280M polymorphisms do not increase susceptibility to preeclampsia. Further studies should be performed to directly evaluate the pathophysiological role of CX3CL1, a molecule abundantly expressed in endometrium, which has been shown to stimulate human trophoblast migration.

Trophoblast invasion

The establishment of a pregnancy depends upon mechanisms of forming close contacts between embryonic/fetal and maternal tissues. The starting point is the attachment of the blastocyst to the uterine wall, and this critical step is followed by a series of different morphogenetic events leading to placentation. These processes depend on the invasive properties of extra-embryonic trophectoderm-derived cells that show their highest expression in species with haemochorial placentation, i.e. Insectivores, rodents, and primates including the human. In this review we will concentrate upon the human with occasional reference to other species.

Placental pathology in egg donor pregnancies

OBJECTIVE

To determine placental pathology and immune response at the maternal-fetal interface in pregnancies conceived by IVF via egg donation compared with nondonor IVF pregnancies.

DESIGN

Retrospective case-control study.

SETTING

Academic medical center.

PATIENT(S)

The study population included 20 egg donor and 33 nondonor IVF pregnancies of >24 weeks' gestation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Perinatal complications (gestational hypertension, abruption, preterm delivery, cesarean section), microscopic features indicating an immune response and trophoblast damage, and characterization of inflammatory cells using immunohistochemistry.

RESULT(S)

There was an increase in gestational hypertension and preterm delivery in egg donor pregnancies. Dense fibrinoid deposition in the basal plate with severe chronic deciduitis containing significantly increased numbers of T helper and natural killer cells were demonstrated in egg donor placentas. Trophoblast damage was also increased in the preterm egg donor group.

CONCLUSION(S)

There are significant histological and immunohistochemical differences between the placentas of egg donor and nondonor IVF pregnancies. The increased immune activity and fibrinoid deposition at the maternal-fetal interface of egg donor pregnancies could represent a host versus graft rejection-like phenomenon.

Hearing impairment in pregnancy toxemia

OBJECTIVE: Preeclampsia characterized by widespread endothelial damage and dysfunction, systemic toxicity, coagulation defects, and an increased systemic inflammatory response, poses some risk factors for hearing loss.

STUDY DESIGN: A case-control study.

SUBJECTS AND METHODS: Two groups with 37 pre-eclamptic and 38 healthy pregnant women were matched by age. Other factors that could possibly influence hearing were ruled out. Transient otoacoustic emission (TEOAE) was carried out for both groups before delivery and was repeated two weeks after delivery in cases of failure.

RESULTS: We could not find any abnormality in the healthy pregnant women who underwent the TEOAE test, but five of the preeclamptic women failed the initial test before delivery. This condition was recovered two weeks later. Statistical analysis showed significant difference (TEOAE disturbances) between the two groups ( P = 0.025).

CONCLUSIONS: This study showed that pregnancy toxemia might have effects on hearing abilities.