The interrelationship of complement-activation fragments and angiogenesis-related factors in early pregnancy and their association with pre-eclampsia

Placenta-mediated pregnancy complications in women with a history of late fetal loss and placental infarction without thrombophilia: risk of recurrence and efficacy of pharmacological prophylactic interventions. A 10-year retrospective study

PURPOSE

To evaluate the risk of recurrence of severe placenta-mediated pregnancy complications and compare the efficacy of two different anti-thrombotic regimens in women with a history of late fetal loss without thrombophilia.

PATIENTS AND METHODS

We performed a 10-year retrospective observational study (2008-2018) analyzing a cohort of 128 women who suffered from pregnancy fetal loss (>20 weeks of gestational age) with histological evidence of placental infarction. All the women tested negative for congenital and/or acquired thrombophilia. In their subsequent pregnancies, 55 received prophylaxis with acetylsalicylic acid (ASA) only and 73 received ASA plus low molecular weight heparin (LMWH).

RESULTS

Overall, one-third of all pregnancies (31%) had adverse outcomes related to placental dysfunction: pre-term births (25% <37 weeks, 5.6% <34 weeks), newborns with birth weight <2500 g (17%), and newborns small for gestational age (5%). The prevalence of placental abruption, early and/or severe preeclampsia, and fetal loss >20 weeks were 6%, 5%, and 4% respectively. We found a risk reduction for combination therapy (ASA plus LMWH) compared with ASA alone for delivery <34 weeks (RR 0.11, 95% CI: 0.01-0.95 p = 0.045) and a trend for the prevention of early/severe preeclampsia (RR 0.14, 95% CI: 0.01-1.18, p = 0.0715), while no statistically significant difference was observed for composite outcomes (RR 0.51, 95%CI: 0.22-1.19, p = 0.1242). An absolute risk reduction of 5.31% was observed for the ASA plus LMWH group. Multivariate analysis confirmed a risk reduction for delivery <34 weeks (RR 0.32, 95% CI 0.16-0.96 p = 0.041).

CONCLUSION

In our study population, the risk of recurrence of placenta-mediated pregnancy complications is substantial, even in the absence of maternal thrombophilic conditions. A reduction of the risk of delivery <34 weeks was detected in the ASA plus LMWH group.

Diagnosis and treatment of lupus nephritis: a summary of the Consensus Document of the Spanish Group for the Study of Glomerular Diseases (GLOSEN)

Lupus nephritis (LN) is the most frequent serious manifestation of patients with systemic lupus erythematosus (SLE). Up to 60% of SLE patients develop LN, which has a significant impact on their quality of life and prognosis. Recent advances have improved the diagnostic approach to LN, and new drugs that block specific pathways and kidney damage progression have been developed. Several randomized and well-powered clinical trials have confirmed the efficacy of these agents in terms of proteinuria remission and preservation of kidney function in the medium and long term, with an acceptable safety profile and good tolerance. The combination of different therapies allows for reduction of the dose and duration of corticosteroids and other potentially toxic therapies and leads to an increase in the number of patients achieving complete remission of the disease. This consensus document carried out by the Spanish Group for the Study of Glomerular Diseases (GLOSEN) provides practical and updated recommendations, based on the best available evidence and clinical expertise of participating nephrologists.

Inhibiting B cell activating factor attenuates preeclamptic symptoms in placental ischemic rats

PROBLEM

Preeclampsia (PE), new-onset hypertension during pregnancy, is associated with a pro-inflammatory state with activated T cells, cytolytic natural killer (NK) cells, dysregulated complement proteins, and B cells secreting agonistic autoantibodies to the angiotensin II type-1 receptor (AT1-AA). The reduced uterine perfusion pressure (RUPP) model of placental ischemia recapitulates these features of PE. Blocking CD40L-CD40 communication between T and B cells or B cell depletion with Rituximab prevents hypertension and AT1-AA production in RUPP rats. This suggests that T cell-dependent B cell activation contributes to the hypertension and AT1-AA associated with PE. B2 cells maturing into antibody producing plasma cells are the product of T cell-dependent B cell-interactions and B cell Activating Factor (BAFF) is an integral cytokine in the development of B2 cells specifically. Thus, we hypothesize that BAFF blockade will selectively deplete B2 cells, therefore reducing blood pressure, AT1-AA, activated NK Cells, and complement in the RUPP rat model of PE.

METHOD OF STUDY

Gestational Day (GD) 14 pregnant rats underwent the RUPP procedure, and a subset were treated with 1 mg/kg Anti-BAFF antibodies via jugular catheters. On GD19, blood pressure was measured, B cells and NK cells were measured by flow cytometry, AT1-AA was measured by cardiomyocyte bioassay, and complement activation was measured by ELISA.

RESULTS

Anti-BAFF therapy attenuated hypertension, AT1-AA, NK cell activation, and APRIL levels in RUPP rats without negatively impacting fetal outcomes.

CONCLUSIONS

This study demonstrates that B2 cells contribute to hypertension, AT1-AA, and NK cell activation in response to placental ischemia during pregnancy.

Consensus document of the Spanish Group for the Study of the Glomerular Diseases (GLOSEN) for the diagnosis and treatment of lupus nephritis

A significant number of patients with systemic lupus erythematosus (between 20% and 60% according to different reported series) develop lupus nephritis in the course of its evolution, which directly influences their quality of life and vital prognosis. In recent years, the greater knowledge about the pathogenesis of systemic lupus and lupus nephritis has allowed relevant advances in the diagnostic approach and treatment of these patients, achieving the development of drugs specifically aimed at blocking key pathogenic pathways of the disease. Encouragingly, these immunomodulatory agents have shown in well-powered, randomized clinical trials good clinical efficacy in the medium-term, defined as proteinuria remission and preservation of kidney function, with an acceptable safety profile and good patient tolerability. All this has made it possible to reduce the use of corticosteroids and other potentially more toxic therapies, as well as to increase the use of combined therapies. The present consensus document carried out by the Glomerular Diseases Working Group of the Spanish Society of Nephrology (GLOSEN), collects in a practical and summarized, but rigorous way, the best currently available evidence about the diagnosis, treatment, and follow-up of lupus nephritis patients, including cases of special situations, with the main objective of providing updated information and well-founded clinical recommendations to treating physicians, to improve the diagnostic and therapeutic approach to our patients.

Alternative pathway activation in pregnancy, a measured amount "complements" a successful pregnancy, too much results in adverse events

During pregnancy, the maternal host must adapt in order to enable growth of the fetus. These changes affect all organ systems and are designed both to protect the fetus and to minimize risk to the mother. One of the most prominent adaptations involves the immune system. The semi-allogenic fetoplacental unit has non-self components and must be protected against attack from the host. This requires both attenuation of adaptive immunity and protection from innate immune defense mechanisms. One of the key innate immune players is complement, and it is important that the fetoplacental unit is not identified as non-self and subjected to complement attack. Adaptation of the complement response must, however, be managed in such a way that maternal protection against infection is not compromised. As the complement system also plays a significant facilitating role in many of the stages of a normal pregnancy, it is also important that any necessary adaptation to accommodate the semi-allogenic aspects of the fetoplacental unit does not compromise this. In this review, both the physiological role of the alternative pathway of complement in facilitating a normal pregnancy, and its detrimental participation in pregnancy-specific disorders, are discussed.

The evaluation of some serum immunochemical markers in early onset pre-eclamptic women from Algeria

PROBLEM

Progress in understanding the underlying mechanism responsible for the syndrome pre-eclampsia should reconfigure antenatal clinical care and minimize human and financial costs, yet at present there is no accurate theory that permits development of reliable predictive tests and prophylactic intervention to mitigate disease. To contribute to this ongoing effort, we aimed to assess various circulating markers pertaining to different theories.

METHOD OF STUDY

Serum samples from thirty-four women with established early onset preeclampsia (ePE) were assessed in terms of oxidative stress (malondialdehyde- MDA), angiogenic status (PlGF & sFLT-1), complement system (The alternative pathway -AP₅₀ & complement factor H- CFH) and circulating inflammatory markers (Interleukin 6- IL-6 & Procalcitonin- PCT). Control groups of gestational age matched patients included 20 gestational hypertensive (GH) and 6 normotensive pregnant women (NPW).

RESULTS

Our work shows that PlGF is the only serum marker who does exhibit a continued decrease from NPW to GH to ePE (r_pearson = -0.428, p = .002). The ePE group had a profound impairment in circulating PlGF (66.93 ± 20.62 pg/ml) compared to GH (142.67 ± 39.79 pg/ml; p = .069) and NPW (636.83 ± 392.66 pg/ml; p = .002). Then, PlGF >71.29 pg/ml pg/ml is the cut-off that has the highest negative predictive value enabling exclusion of ePE (Sp 78%, Se 70%, p = .000). No such interesting results could be obtained with the other markers.

CONCLUSION

Our data confirm that the angiogenic factor PlGF may be highly relevant in biological mechanisms underlying the development of ePE. This article is protected by copyright. All rights reserved.

High early pregnancy body mass index is associated with alterations in first- and second-trimester angiogenic biomarkers

BACKGROUND

Obesity is associated with various placenta-mediated adverse pregnancy outcomes, including preeclampsia, preterm birth, and stillbirth. Mechanisms linking obesity with placental dysfunction are not completely understood.

OBJECTIVE

This study aimed to examine the relationship between early pregnancy body mass index and placental angiogenic biomarkers soluble fms-like tyrosine kinase-1, placental growth factor, and the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio.

STUDY DESIGN

We conducted secondary analyses of an existing substudy within a multisite, prospective observational cohort study of nulliparous pregnant women in the United States. First- and second-trimester maternal blood samples, first-trimester body mass index, and demographic, lifestyle, and pregnancy outcomes data were collected. Soluble fms-like tyrosine kinase-1 and placental growth factor concentrations were measured at 6 to 13 and 16 to 22 weeks of gestation for women (cases) who experienced one of several adverse pregnancy outcomes (delivery at <37 weeks of gestation, preeclampsia or eclampsia, birthweight for gestational age <5th percentile, or stillbirth) and for those who had none of those outcomes (controls). We used multivariable mixed-effects linear regression models to estimate the association of body mass index with angiogenic biomarkers at both time points. We evaluated mean change between first- and second-trimester biomarker concentrations using multivariable linear regression models. Lastly, we used logistic regression models to estimate the risk of a high second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio, using clinically established cutoffs for risk prediction.

RESULTS

Angiogenic biomarker and early pregnancy body mass index data were available for 2363 women (1467 with adverse pregnancy outcomes and 896 controls). High early pregnancy body mass index was associated with consistently lower soluble fms-like tyrosine kinase-1 concentrations across the first and second trimesters of pregnancy. We found lower first-trimester placental growth factor concentrations in the group with class II or III obesity (P<.001) and lower second-trimester placental growth factor concentrations among groups who were overweight, with class I obesity, and class II or III obesity (P<.001). For every unit increase in early pregnancy body mass index, there was a -4.4 pg/mL (95% confidence interval, -3.6 to -5.2) smaller mean increase in placental growth factor concentrations between the first and second trimesters of pregnancy. These differences resulted in significantly lower mean first-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios among groups who were overweight, with class I obesity, and class II or III obesity (P<.05) and in a significantly higher second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio among the group with class II or III obesity (P<.001), compared with the group with normal body mass index. Each unit of increase in body mass index was associated with a 0.5 (95% confidence interval, 0.3-0.7) greater mean increase in the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio between the first and second trimesters of pregnancy. In stratified analyses, associations between body mass index and angiogenic biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor were similar in nonadverse pregnancy outcome and adverse pregnancy outcome subgroups, whereas associations between body mass index and the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio were attenuated in the subgroups. Participants in the group with class II or III obesity were 3.13 (95% confidence interval, 1.15-8.49) times more likely than participants with normal weight to have a second-trimester ratio of ≥38 in univariate analysis.

CONCLUSION

High early pregnancy body mass index was associated with lower soluble fms-like tyrosine kinase-1 and placental growth factor concentrations across early pregnancy. Maternal body mass was inversely associated with first-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios and positively associated with second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios, driven by a diminished rise in placental growth factor between the first and second trimesters of pregnancy. Women with class II or III obesity have an increased risk of a high second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio associated with placental dysfunction.

Complement activation and regulation in preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome

The complement system is critical to human health owing to its central role in host defense and innate immunity. During pregnancy, the complement system must be appropriately regulated to allow for immunologic tolerance to the developing fetus and placenta. Although some degree of complement activation can be seen in normal pregnancy, the fetus seems to be protected in part through the placental expression of complement regulatory proteins, which inhibit complement activation at different steps along the complement activation cascade. In women who develop preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, there is a shift toward increased complement activation and decreased complement regulation. There is an increase in placental deposition of C5b-9, which is the terminal effector of classical, lectin, and alternative complement pathways. C5b-9 deposition stimulates trophoblasts to secrete soluble fms-like tyrosine kinase-1, which sequesters vascular endothelial growth factor and placental growth factor. Pathogenic mutations or deletions in complement regulatory genes, which predispose to increased complement activation, have been detected in women with preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome. Before the disease, biomarkers of alternative complement pathway activation are increased; during active disease, biomarkers of terminal complement pathway activation are increased. Urinary excretion of C5b-9 is associated with preeclampsia with severe features and distinguishes it from other hypertensive disorders of pregnancy. Taken together, existing data link preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome with increased activation of the terminal complement pathway that, in some cases, may be influenced by genetic alterations in complement regulators. These findings suggest that the inhibition of the terminal complement pathway, possibly through C5 blockade, may be an effective strategy to treat preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, but this strategy warrants further evaluation in clinical trials.

Maternal C3 complement and C-reactive protein and pregnancy and fetal outcomes: A secondary analysis of the PEARS RCT-An mHealth-supported, lifestyle intervention among pregnant women with overweight and obesity

Objectives:

Elevated circulating levels of complement component 3 (C3) and C-reactive protein (CRP) have been linked with adverse pregnancy outcomes. Lifestyle interventions may hold potential to ameliorate these effects. We investigated the effect of an antenatal healthy lifestyle intervention on maternal C3 and CRP concentrations and assessed their relationship with maternal and fetal metabolic markers and outcomes.

Study design:

Secondary analysis of data from the Pregnancy Exercise And Nutrition Research Study (PEARS) randomized controlled trial.

Methods:

Women (n = 406) with C3 and CRP concentrations determined in early pregnancy (14–16 weeks) and/or late pregnancy (28-weeks) with corresponding fasting glucose, insulin, c-peptide, and lipid profiles were included in the analysis. Pregnancy outcomes included: diagnoses of gestational diabetes (GDM), pre-eclampsia (PET) or pregnancy induced hypertension (PIH), pre-term birth (delivery < 37 weeks), low birth weight (<2500 g), small-for-gestational age (SGA) defined using < 5th or 10th centile for birthweight and cord blood measures of glucose and lipid metabolism. T-tests investigated changes in C3 and CRP over time. Chi-square, Pearson’s’ correlations and multiple regression investigated relationships with outcomes.

Results:

The PEARS intervention did not influence maternal C3 or CRP concentrations in pregnancy. There was no relationship between CRP concentrations and any maternal or infant outcome. Women who developed GDM had higher C3 concentrations in early (p = 0.01) and late pregnancy (p = 0.02). Women who developed PIH/PET had lower C3 concentrations in early (p = 0.02), but not late (p = 0.10) pregnancy. Maternal C3 concentrations in early pregnancy were a small but significant predictor of maternal insulin concentrations in early (β = 0.40, 95% CI 0.27, 0.53; p < 0.001) and late (β = 0.30, 95% CI 0.17, 0.43p < 0.001) pregnancy, early total cholesterol (TC), and both early and late triglycerides, LDL and HDL Cholesterol concentrations (all p < 0.001). Women who delivered SGA babies (<10th centile) had lower C3 concentrations than women who did not in both early (p < 0.001) and late pregnancy (p = 0.01). No relationship between maternal C3 or CRP and fetal glucose concentrations or lipid profiles was observed.

Conclusion:

Maternal C3 may play a role in multiple adverse pregnancy outcomes including cardiometabolic ill-health. Further research on this, and strategies to reduce C3 in a pregnant population, are warranted.

Adipsin of the Alternative Complement Pathway Is a Potential Predictor for Preeclampsia in Early Pregnancy

Objective

The concentrations of complement proteins (adipsin, C3a, and C5a) and soluble endoglin (sENG) in the plasma were measured in this study, and their value as early-pregnancy predictors and potential diagnostic marker of preeclampsia was assessed, respectively.

Experimental Design

Plasma samples were obtained from healthy and preeclampsia pregnant women before delivery for a cross-sectional study. Plasma samples were collected from healthy and preeclampsia pregnant women throughout pregnancy and postpartum for a follow-up study. Enzyme-linked immunosorbent assays were used to detect plasma levels of several complement proteins (adipsin, C3a, and C5a) and sENG.

Results

The plasma levels of adipsin, C5a, and sENG were significantly increased before delivery in pregnant women with preeclampsia. During pregnancy, the plasma adipsin, C5a, and sENG levels were increased from the third trimester in healthy pregnant women; plasma adipsin levels remained stable after delivery, while C3a levels increased in the second trimester and remained stable afterward. Furthermore, levels of adipsin, C5a, and sENG were higher in preeclampsia patients at different stages of pregnancy; the C3a level presents a similar change and no difference was found in the third trimester. In the first trimester, receiver-operating curve (ROC) curve analysis showed that adipsin (AUC, 0.83 ± 0.06, P=0.001) and sENG (AUC, 0.74 ± 0.09, P=0.021) presented high value as predictors of early pregnancy.

Conclusions

Adipsin is likely a novel plasma biomarker to monitor the increased risk of preeclampsia in early pregnancy. Moreover, the increased plasma levels of adipsin, C5a, and sENG before delivery may be associated with preeclampsia.

Low Molecular Weight Heparins (LMWH) and Implications along Pregnancy: a Focus on the Placenta

Low molecular weight heparins (LMWH) have been largely studied for their use during pregnancy. The biology and the pharmacology of these molecules are well known and may be summarized in three main mechanisms of action: anti-coagulant, anti-inflammatory, and immunomodulant. The clinical implications of these drugs during pregnancy are mainly related to their action on the placenta, because of the presence of specific molecular and cellular targets, particularly at the trophoblast-endometrial interface. As well as for the prevention and treatment of thromboembolism, LMWH have been largely investigated for the improvement of embryo implantation and for the prevention of placenta-related complications such as preeclampsia, fetal growth restriction, and intrauterine fetal death. However, data on this topic are still unclear. The present review discusses the biological features, the mechanisms of action, and the possible contribution of LMWH to the success of placentation along pregnancy, pointing out the need for future basic science and clinical researches in this important field with the final aim to improve clinical practice in high-risk pregnancies.

Quantitative Alterations in Complement Alternative Pathway and Related Genetic Analysis in Severe Phenotype Preeclampsia

Background

Preeclampsia and hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome share many clinical and biologic features with thrombotic microangiopathy syndromes caused by complement abnormalities. Our hypothesis was that similar functional and genetic alterations in the complement alternative pathway (CAP) are present in these disorders of pregnancy.

Methods

We conducted quantitative analysis of proteins involved in CAP using ELISA and nephelometry on prospectively collected blood samples from patients with severe phenotype preeclampsia (defined as delivery ≤34 weeks due to preeclampsia), HELLP syndrome, or eclampsia, and matched normotensive controls (n=25 in each arm) between 2011 and 2016. Sequencing was performed to interrogate 14 genes encoding CAP components.

Results

Both groups were similar in age, gravidity, parity, marital status, and race. The study group had a higher BMI (mean±SD, 32±8 versus 25±4 kg/m²; P=0.002) and earlier gestational age at delivery (32.5±3.6 versus 40.3±1 weeks; P<0.001). Serologic studies demonstrated elevated Bb subunit (median [range], 1.2 [0.5-4.3] versus 0.6 [0.5-1] μg/ml; P<0.001), complement C5 concentration (28 [18-33] versus 24 [15-34] mg/dl; P=0.03), and sMAC (371 [167-761] versus 184 [112-249] ng/ml; P<0.001) concentrations in patients with preeclampsia. Two thirds of patients with preeclampsia had at least one nonsynonymous sequence variant in CAP genes.

Conclusion

Patients with severe phenotype preeclampsia manifest functional alterations in CAP activation. Genetic variants in the CAP genes were detected in several patients, but a larger population study is necessary to fully evaluate genetic risk. Genetic screening and complement-targeted treatment may be useful in risk stratification and novel therapeutic approaches.

Serum complement proteomics reveal biomarkers for hypertension disorder of pregnancy and the potential role of Clusterin

INTRODUCTION

Hypertension disorder of pregnancy (HDP) is one of the leading causes of maternal and foetal illness. The aim of the current study was to identify and verify novel serum markers for HDP.

METHODS

A label-free LC-MS/MS method was used to establish the serum proteomic profiles of 12 pre-HDP (before clinical diagnosis of HDP) pregnancies and verify prioritized candidates in the verification set of 48 pre-HDP pregnancies. These biomarkers were revalidated by ELISA in an independent cohort of 88 pre-HDP pregnancies. Subsequently, the candidate biomarkers were histologically analysed by immunohistochemistry, and function was evaluated in TEV-1 cells.

RESULTS

We identified 33 proteins with significantly increased abundance and 14 with decreased abundance (peptide FDR ≤ 1%, P < 0.05). Complement was one of the top enriched components in the pre-HDP group compared with the control group. Three complement factors (CLU, CFHR5, and CRP) were significantly increased in the three sets, of which CLU was a critical factor for the development of HDP (OR = 1.22, P < 0.001). When these three factors and body weight were combined, the AUC was 0.74, with a sensitivity of 0.67 and specificity of 0.68 for HDP prediction compared with normal pregnancy. In addition, inflammation-induced CLU could inhibit the invasion of TEV-1 cells.

CONCLUSIONS

Complement proteins may play an essential role in the occurrence of HDP by acting on trophoblast cells. CLU may be a high-risk factor for HDP, and the models combining candidates show reasonable screening efficiency of HDP in the first half of pregnancy.

Diseases and conditions that impact maternal and fetal health and the potential for nanomedicine therapies

Maternal mortality rates in the United States have steadily increased since 1987 to the current rate of over 16 deaths per 100,000 live births. Whereas most of these deaths are related to an underlying condition, such as cardiovascular disease, many pregnant women die from diseases that emerge as a consequence of pregnancy. Both pre-existing and emergent diseases and conditions are difficult to treat in pregnant women because of the potential harmful effects of the treatment on the developing fetus. Often the health of the woman and the health of the baby are at odds and must be weighed against each other when medical treatment is needed, frequently leading to iatrogenic preterm birth. However, the use of engineered nanomedicines has the potential to fill the treatment gap for pregnant women. This review describes several conditions that may afflict pregnant women and fetuses and introduces how engineered nanomedicines may be used to treat these illnesses. Although the field of maternal-fetal nanomedicine is in its infancy, with additional research and development, engineered nanotherapeutics may greatly improve outcomes for pregnant women and their offspring in the future.

Complement inhibitor Crry expression in mouse placenta is essential for maintaining normal blood pressure and fetal growth

Many circumstantial evidences from human and animal studies suggest that complement cascade dysregulation may play an important role in pregnancy associated complications including preeclampsia. Deletion of rodent specific complement inhibitor gene, Complement Receptor 1-related Gene/Protein y (Crry) produces embryonic lethal phenotype due to complement activation. It is not clear if decreased expression of Crry during pregnancy produces hypertensive phenotype. We downregulated Crry in placenta by injecting inducible lentivialshRNA vectors into uterine horn of pregnant C57BL/6 mice at the time of blastocyst hatching. Placenta specific downregulation of Crry without significant loss of embryos was achieved upon induction of shRNA using an optimal doxycycline dose at mid gestation. Crry downregulation resulted in placental complement deposition. Late-gestation measurements showed that fetal weights were reduced and blood pressure increased in pregnant mice upon downregulation of Crry suggesting a critical role for Crry in fetal growth and blood pressure regulation.

Dysregulation of complement system during pregnancy in patients with preeclampsia: A prospective study

Recent studies have shown that aberrant activation of the complement system plays an important role in the pathogenesis of preeclampsia. There is evidence to suggest that aberrant activation of the complement system may already be present during the first trimester. Here, we performed a prospective study in which peripheral blood samples were collected from 500 women during pregnancy. Twenty-one patients (41 specimens) suffering from preeclampsia later in pregnancy were classified into the study group, and sixty-three gravidas with normal pregnancies (136 specimens) were selected as the control group. The plasma concentrations of complement factor B (CFB), C1q, complement factor H (CFH), C3c, C4, C3a, C5a and soluble C5b-9 (sC5b-9) were measured. The levels of CFB (P = 0.004), CFH (P = 0.002), C1q (P = 0.044), C3c (P = 0.032) and C4 (P = 0.015) were significantly higher in preeclampsia than in normal pregnancy during the first trimester, and these levels became similar to those in normal pregnancy thereafter. Before the onset of preeclampsia, the levels of C3a, C5a and sC5b-9 in the preeclampsia group were similar to those in control group even in late pregnancy. C3a levels showed a significant positive correlation with C5a in normal pregnancy (r=0.658, P<0.01) but not in preeclampsia (r = 0.001, P = 1).Thus, we found that aberrant activation of the complement system in patients with preeclampsia was initiated during the first trimester but returned to normal pregnancy levels in the second trimester. At the same time, there is aberrant regulation of complement activation at the C3a-C5a level in preeclampsia during pregnancy.

Pregnancy and Systemic Lupus Erythematosus

As SLE onset is often in young adulthood, pregnancy is common and is usually successful. Pregnancy, though, is considered high-risk due to a combination of maternal (lupus flare, diabetes, pre-eclampsia) and fetal (miscarriage, intrauterine fetal demise, preterm birth, intrauterine growth restriction, congenital heart block) risks. Pregnancy should be planned for a time of good control of SLE (on allowable medications). The antimalarial hydroxychloroquine should be continued. The only permitted immunosuppressive drugs are azathioprine and tacrolimus. Of the antiphospholipid antibodies, only the lupus anticoagulant has been associated with adverse pregnancy outcomes in the largest prospective multicenter study, Predictors of Pregnancy Outcome: Biomarkers in Antiphospholipid Antibody Syndrome and Systemic Lupus Erythematosus (PROMISSE). Management of antiphospholipid syndrome in pregnancy is low molecular weight heparin and aspirin, although only 75% of pregnancies are successful.

Dysregulation of Complement Activation and Placental Dysfunction: A Potential Target to Treat Preeclampsia?

Preeclampsia is one of the leading causes of maternal and neonatal mortality and morbidity worldwide, affecting 2–8% of all pregnancies. Studies suggest a link between complement activation and preeclampsia. The complement system plays an essential role in the innate immunity, leading to opsonization, inflammation, and elimination of potential pathogens. The complement system also provides a link between innate and adaptive immunity and clearance of immune complexes and apoptotic cells. During pregnancy there is increased activity of the complement system systemically. However, locally at the placenta, complement inhibition is crucial for the maintenance of a normal pregnancy. Inappropriate or excessive activation of the complement system at the placenta is likely involved in placental dysfunction, and is in turn associated with pregnancy complications like preeclampsia. Therefore, modulation of the complement system could be a potential therapeutic target to prevent pregnancy complications such as preeclampsia. This review, based on a systematic literature search, gives an overview of the complement system and its activation locally in the placenta and systemically during healthy pregnancies and during complicated pregnancies, with a focus on preeclampsia. Furthermore, this review describes results of animal and human studies with a focus on the complement system in pregnancy, and the role of the complement system in placental dysfunction. Various clinical and animal studies provide evidence that dysregulation of the complement system is associated with placental dysfunction and therefore with preeclampsia. Several drugs are used for prevention and treatment of preeclampsia in humans and animal models, and some of these drugs work through complement modulation. Therefore, this review further discusses these studies examining pharmaceutical interventions as treatment for preeclampsia. These observations will help direct research to generate new target options for prevention and treatment of preeclampsia, which include direct and indirect modulation of the complement system.

The role of biomarkers in predicting pre-eclampsia in high-risk women

Background

There are limited data on performance of biomarkers to predict pre-eclampsia (PE) in high-risk women. This study investigated the ability of FABP4, PAPP-A, PlGF, sFlt-1 and sEng to predict PE in a high-risk group.

Methods

Non-fasting samples were analysed at 11 + 0–13 + 6 (V1) and 19 + 0–21 + 6 weeks (V2) ( n = 195). Logistic regression models were determined. Area under (AUC) the receiver operating characteristic (ROC) curve analysis was performed. The added value of biomarkers to clinical characteristics for PE prediction was quantified using integrated discrimination improvement (IDI) and net reclassification improvement (NRI) indices.

Results

Prevalence of PE was 12%. Lower concentrations of sFlt-1:PlGF (V1) and PlGF and PlGF:sEng (V2) were seen in women who developed PE. Controlling for baseline characteristics (V1), a doubling of sFlt-1 (pg/mL) (median 896.0, IQR 725.5–1097.0) and sFlt-1:PlGF (median 21.2, IQR 14.7–32.3) was associated with reduction in odds of PE (OR 0.20, 95% CI 0.06–0.65, P = 0.007 and OR 0.48, 95% CI 0.25–0.92, P = 0.04). Addition of sFlt-1 and sFlt-1:PlGF to baseline characteristics non-significantly improved AUC (0.74) (AUC 0.77, P = 0.40 and 0.76, P = 0.39). NRI and IDI analyses confirmed added clinical utility of sFlt-1 (NRI = 0.539, P = 0.01 and IDI = 0.052, P = 0.03). In V2, doubling of PlGF:sEng (median 71.9, IQR 47.0–102.8) was associated with reduction in the risk of PE (OR 0.56, 95% CI 0.35–0.98, P = 0.04). The addition of PlGF:sEng to baseline characteristics non-significantly improved AUC from 0.78 to 0.82 ( P = 0.25) and improved reclassification of cases (NRI = 0.682, P = 0.002).

Conclusions

Screening tests incorporating first trimester sFlt-1 and second trimester PlGF:sEng have potential to aid PE prediction in high-risk pregnancies.

Systemic activation of the complement system in patients with advanced age-related macular degeneration

Purpose:

To examine the role of systemic activation of the complement system (assessed by levels of circulating C3a, Ba, and sC5b-9) in patients (n = 122) with advanced age-related macular degeneration, geographic atrophy, and neovascular age-related macular degeneration, compared with cataract controls (n = 27).

Methods:

Plasma complement factors were measured using enzyme-linked immunosorbent assays. Statistical analysis included univariate and multivariate logistic regression (p < 0.05).

Results:

Adjusted for age, the odds ratios of C3a and sC5b-9 for any advanced age-related macular degeneration were 1.78 (95% confidence interval = 1.16–2.73, p < 0.01) and 1.20 (95% confidence interval = 1.04–1.39, p = 0.01), respectively. We found a significantly elevated adjusted odds ratio of C3a (adjusted odds ratio = 1.71, 95% confidence interval = 1.12–2.60, p = 0.01) and sC5b-9 (adjusted odds ratio = 1.22, 95% confidence interval = 1.04–1.43, p = 0.01) for neovascular age-related macular degeneration. Adjusted for age, neither C3a, sC5b-9, nor Ba were associated with geographic atrophy.

Conclusion:

We suggest a role for elevated plasma levels of C3a and sC5b-9 in patients with neovascular age-related macular degeneration. The study’s results reinforce the need for more investigation to assess the impact of therapeutic interventions targeted at the complement signaling pathways in age-related macular degeneration.

Biomarkers of glomerular dysfunction in pre-eclampsia - A systematic review

BACKGROUND

Early detection of pre-eclampsia remains one of the major focuses of antenatal obstetric care. There is often a delay in the diagnosis, mainly due to the non-specific nature of the condition. Podocytes which play a pivotal role in glomerular function become injured in pre-eclampsia leading to subsequent proteinuria. Our aim was to review available studies to determine the clinical utility of biomarkers of podocyte injury in pre-eclampsia.

METHODS

We used QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria to perform a systematic review of the literature to determine the clinical utility of podocyte injury biomarkers in predicting pre-eclampsia.

RESULTS

This study identified five potential renal biomarkers including podocytes, nephrin, synaptopodin, podocin and podocalyxin. The pooled sensitivity of all biomarkers was 0.78 (95% CI 0.74-0.82) with a specificity of 0.82 (95% CI 0.79-0.85). The area under the Summary of Receiver Operating Characteristics Curve (SROC) was 0.926 (SE 0.30). Urinary nephrin achieved the highest diagnostic values with a sensitivity of 0.81 (95% CI 0.72-0.88) and specificity of 0.84 (95% CI 0.79-0.84).

CONCLUSION

Biomarkers of glomerular injury show promise as diagnostic aids in pre-eclampsia. A large-scale prospective cohort study is warranted before these biomarkers can be recommended for routine clinical care.

Complement activation predicts adverse pregnancy outcome in patients with systemic lupus erythematosus and/or antiphospholipid antibodies

OBJECTIVE

Studies in mouse models implicate complement activation as a causative factor in adverse pregnancy outcomes (APOs). We investigated whether activation of complement early in pregnancy predicts APOs in women with systemic lupus erythematosus (SLE) and/or antiphospholipid (aPL) antibodies.

METHODS

The PROMISSE Study enrolled pregnant women with SLE and/or aPL antibodies (n=487) and pregnant healthy controls (n=204) at <12 weeks gestation and evaluated them monthly. APOs were: fetal/neonatal death, preterm delivery <36 weeks because of placental insufficiency or preeclampsia and/or growth restriction <5th percentile. Complement activation products were measured on serial blood samples obtained at each monthly visit.

RESULTS

APO occurred in 20.5% of SLE and/or aPL pregnancies. As early as 12-15 weeks, levels of Bb and sC5b-9 were significantly higher in patients with APOs and remained elevated through 31 weeks compared with those with normal outcomes. Moreover, Bb and sC5b-9 were significantly higher in patients with SLE and/or aPL without APOs compared with healthy controls. In logistic regression analyses, Bb and sC5b-9 at 12-15 weeks remained significantly associated with APO (OR_adj=1.41 per SD increase; 95% CI 1.06 to 1.89; P=0.019 and OR_adj=1.37 per SD increase; 95% CI 1.05 to 1.80; P=0.022, respectively) after controlling for demographic and clinical risk factors for APOs in PROMISSE. When analyses were restricted to patients with aPL (n=161), associations between Bb at 12-15 weeks and APOs became stronger (OR_adj=2.01 per SD increase; 95% CI 1.16 to 3.49; P=0.013).

CONCLUSION

In pregnant patients with SLE and/or aPL, increased Bb and sC5b-9 detectable early in pregnancy are strongly predictive of APOs and support activation of complement, particularly the alternative pathway, as a contributor to APOs.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Kidney Outcomes and Risk Factors for Nephritis (Flare/De Novo) in a Multiethnic Cohort of Pregnant Patients with Lupus

BACKGROUND AND OBJECTIVES

Kidney disease is a critical concern in counseling patients with lupus considering pregnancy. This study sought to assess the risk of renal flares during pregnancy in women with previous lupus nephritis in partial or complete remission, particularly in those with antidouble-stranded DNA antibodies and low complement levels, and the risk of new-onset nephritis in patients with stable/mildly active SLE.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We assessed active nephritis (renal flares and de novo kidney disease) and associated predictors during pregnancy in patients with lupus with urine protein ≤1000 mg and serum creatinine <1.2 mg/dl at baseline; 373 patients (52% ethnic/racial minorities) enrolled between 2003 and 2012 were prospectively followed in the Predictors of Pregnancy Outcome: Biomarkers in Antiphospholipid Syndrome and Systemic Lupus Erythematosus Study. Active nephritis was defined by proteinuria increase of >500 mg and/or red blood cell casts.

RESULTS

Of 118 patients with previous kidney disease, 13 renal flares (11%) occurred (seven of 89 in complete remission and six of 29 in partial remission) compared with four with de novo kidney involvement (2%) in 255 patients without past kidney disease (P<0.001). Active nephritis was not associated with ethnicity, race, age, creatinine, BP, or antihypertensive and other medications. In multivariable logistic regression analyses, patients with past kidney disease in complete or partial remission more often experienced active nephritis (adjusted odds ratio, 6.88; 95% confidence interval, 1.84 to 25.71; P=0.004 and adjusted odds ratio, 20.98; 95% confidence interval, 4.69 to 93.98; P<0.001, respectively) than those without past kidney disease. Low C4 was associated with renal flares/de novo disease (adjusted odds ratio, 5.59; 95% confidence interval, 1.64 to 19.13; P<0.01) but not low C3 or positive anti-dsDNA alone.

CONCLUSIONS

De novo kidney involvement in SLE, even in ethnic/racial minorities, is uncommon during pregnancy. Past kidney disease and low C4 at baseline independently associate with higher risk of developing active nephritis. Antibodies to dsDNA alone should not raise concern, even in patients with past kidney disease, if in remission.

An observational study of haemostatic changes, leptin and soluble endoglin during pregnancy in women with different BMIs

Obesity increases the risk of venous thromboembolism (VTE) in pregnancy. The pathogenesis is hypothesized to be because of multiple factors including prothrombotic changes, but there has been minimal haemostatic research looking at the combined state of obesity and pregnancy. We aimed to determine whether variation in BMI in the third trimester of pregnancy was associated with prothrombotic changes. We recruited 110 women into four groups depending on their BMI at first antenatal appointment: normal, overweight, obese and morbidly obese. Women with increased risk of VTE, and/or receiving thromboprophylaxis, and/or more than 35 years and those in labour were excluded. Thromboelastography, platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, prothrombin fragment 1 + 2, free and total protein S, plasminogen activator inhibitor type 1, tissue plasminogen activator antigen, D-dimers, soluble endoglin and leptin levels were measured. There were no significant differences in haemostatic measures with changing BMI. There was a positive correlation between BMI and both platelet count (correlation coefficient r = 0.214, P = 0.036) and leptin (r = 0.435, P < 0.001), but only leptin had a significant association with BMI once adjusted for age, gestation and parity. Despite recruitment into the morbidly obese group being suboptimal, these findings suggest that in pregnancy, the increased risk of VTE seen in obese mothers is not mediated through increased prothrombotic changes, and thus the increased risk of VTE in obese pregnant women may be because of other mechanisms, for example endothelial dysfunction, inflammation and venous stasis.

The Level of Serum and Urinary Nephrin in Normal Pregnancy and Pregnancy with Subsequent Preeclampsia

PURPOSE

The aim of this study was to evaluate serum and urinary nephrin levels of normal pregnancy to establish a standard reference value and to compare them with patients who subsequently developed preeclampsia (PE).

MATERIALS AND METHODS

In this prospective study, 117 healthy singleton pregnancies were enrolled between 6 to 20 weeks of gestation at 2 participating medical centers during October 2010 to March 2012. Urine and serum samples were collected at the time of enrollment, each trimester, and at 4 to 6 weeks postpartum. Enzyme-linked immunosorbent assay for nephrin was performed and samples from patients who subsequently developed PE were compared to the normal patients.

RESULTS

Of 117 patients initially enrolled, 99 patients delivered at the study centers and of those patients, 12 (12.1%) developed PE at a median gestational age of 34⁺⁴ weeks (range 29⁺⁵-36⁺⁶). In the normal patients (n=68), serum nephrin level decreased and urinary nephrin level increased during the latter of pregnancy. In 12 patients who subsequently developed PE, a significant rise in the 3rd trimester serum and urinary nephrin levels, compared to the controls, was observed (p<0.001), and this increase occurred 9 days prior to the onset of clinical disease.

CONCLUSION

As the onset of PE was preceded by the rise in the serum and urinary nephrin in comparison to normal pregnancy, serum and urinary nephrin may be a useful predictive marker of PE.

Innate Immune System at the Maternal-Fetal Interface: Mechanisms of Disease and Targets of Therapy in Pregnancy Syndromes

The maternal-fetal interface is an immunologically unique site that allows the tolerance to the allogenic fetus and maintains host defense against possible pathogens. Balanced immune responses are required for the maintenance of successful pregnancy. It has been demonstrated that innate immune disturbances may be responsible for some adverse pregnancy outcomes such as preeclampsia (PE); hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome; intrauterine growth restriction (IUGR); and recurrent spontaneous abortion (RSA). Observational studies suggest that immunomodulatory treatments in pregnancy-specific complications may improve both the hematological/biochemical features in the mother and the perinatal outcomes. The following review will discuss how recent and relevant findings in the field of the innate immunity have advanced our understanding of the role of inflammation and innate immune system in the pathogenesis of pregnancy failure and will discuss the therapeutic outcomes of the existing studies and clinical trials in light of these new insights.

The Relationship of Longitudinal Levels of Complement Bb During Pregnancy with Preeclampsia

PROBLEM

To determine the understudied relationship between complement Bb during pregnancy in subjects with preeclampsia compared with normotensive controls.

METHOD OF STUDY

Nested case-control study.

RESULTS

Average Bb levels significantly decreased over time in pregnancy [weekly slope (S.E.): -0.0094 (0.0005), P < 0.01]. Cross-sectionally, at less than 10 weeks, Bb levels decreased with increasing gestational age in women who remained normotensive [weekly slope (S.E.): -0.007 (0.02) and for women who developed preeclampsia (weekly slope (S.E.): -0.059 (0.03) P = 0.12]. Among women who developed preeclampsia, Bb levels were greatest when samples were drawn in the gestational window of 15-20 weeks [(weekly slope (S.E.): 0.06 (0.02)], while levels among normotensive women were inversely related with gestational age [weekly slope (S.E.): -0.02 (0.01)]. The differences in slopes between cases and controls between 10 and 21 weeks' gestation were statistically significant (P = 0.003).

CONCLUSIONS

We suggest dysregulation of Bb activation between 10 and 20 weeks' gestation in women who develop preeclampsia.

Complement Split Products in Amniotic Fluid in Pregnancies Subsequently Developing Early-Onset Preeclampsia

Objective. To determine the second-trimester amniotic fluid concentrations of complement split products in pregnancies subsequently affected by early-onset preeclampsia. Study Design. Cohort of 731 women with singleton pregnancies undergoing second-trimester genetic amniocentesis followed up to delivery and analyzed as a nested case-control study. Cases of preeclampsia developing before 34 weeks' gestation (n = 15) were compared with 47 uncomplicated term controls. Amniotic fluid collected at amniocentesis was tested for complement split products Bb, C4a, C3a, and C5a. Results. Women who developed early-onset preeclampsia as compared with the term pregnant controls had significantly higher (P = 0.04) median amniotic fluid C3a levels (318.7 ng/mL versus 254.5 ng/mL). Median amniotic fluid Bb levels were also significantly higher (P = 0.03) in preeclamptic women than in normal pregnant women (1127 ng/mL versus 749 ng/mL). Median levels of C4a and C5a were not significantly different between the groups. Conclusion. Our data suggest that complement activation in early pregnancy is associated with early-onset preeclampsia. We believe this to be the first prospective study to link complement activation in amniotic fluid in early pregnancy and later development of preeclampsia. Our findings provide evidence that immune dysregulation may precede the clinical manifestations of preeclampsia and that the alternative complement pathway is principally involved.

Complement factor B activation in patients with preeclampsia

Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. Bb, the active fragment of complement factor B (fB), has been reported to be a predictor of preeclampsia. However, conflicting results have been found by some investigators. We hypothesized that the disagreement in findings may be due to the racial/ethnic differences among various study groups, and that fB activation is significant in women of an ethnic minority with preeclampsia. We investigated the maternal and fetal levels of Bb (the activated fB fragment) in pregnant women of an ethnic minority with or without preeclampsia. We enrolled 291 pregnant women (96% of an ethnic minority, including 78% African-American). Thirteen percent of these were diagnosed with preeclampsia. Maternal venous blood was collected from all participants together with fetal umbilical cord blood samples from 154 deliveries in the 291 women. The results were analyzed using the Mann-Whitney U test and multivariate analyses. Maternal Bb levels were significantly higher in the preeclamptic group than in the nonpreeclamptic group. Levels of Bb in fetal cord blood were similar in both groups. Subgroup analyses of African-American patients' results confirmed the study hypothesis that there would be a significant increase in Bb in the maternal blood of the preeclamptic group and no increase in Bb in the fetal cord blood of this group. These results suggest that a maternal immune response through complement fB might play a role in the development of preeclampsia, particularly in African-American patients.

State of the art: Reproduction and pregnancy in rheumatic diseases

Throughout the last decade, increasing awareness has been raised on issues related to reproduction in rheumatic diseases including basic research to clarify the important role of estrogens in the etiology and pathophysiology of immune/inflammatory diseases. Sub- or infertility is a heterogeneous condition that can be related to immunological mechanisms, to pregnancy loss, to disease burden, to therapy, and to choices in regard to family size. Progress in reproductive medicine has made it possible for more patients with rheumatic disease to have children. Active disease in women with rheumatoid arthritis (RA) affects their children's birth weight and may have long-term effects on their future health status. Pregnancy complications as preeclampsia and intrauterine growth restriction are still increased in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS), however, biomarkers can monitor adverse events, and several new therapies may improve outcomes. Pregnancies in women with APS remain a challenge, and better therapies for the obstetric APS are needed. New prospective studies indicate improved outcomes for pregnancies in women with rare diseases like systemic sclerosis and vasculitis. TNF inhibitors hold promise for maintaining remission in rheumatological patients and may be continued at least in the first half of pregnancy. Pre-conceptional counseling and interdisciplinary management of pregnancies are essential for ensuring optimal pregnancy outcomes.

Relationship between maternal immunological response during pregnancy and onset of preeclampsia

Maternofetal immune tolerance is essential to maintain pregnancy. The maternal immunological tolerance to the semiallogeneic fetus becomes greater in egg donation pregnancies with unrelated donors as the complete fetal genome is allogeneic to the mother. Instead of being rejected, the allogeneic fetus is tolerated by the pregnant woman in egg donation pregnancies. It has been reported that maternal morbidity during egg donation pregnancies is higher as compared with spontaneous or in vitro fertilization pregnancies. Particularly, egg donation pregnancies are associated with a higher incidence of pregnancy-induced hypertension and placental pathology. Preeclampsia, a pregnancy-specific disease characterized by the development of both hypertension and proteinuria, remains the leading cause of maternal and perinatal mortality and morbidity. The aim of this review is to characterize and relate the maternofetal immunological tolerance phenomenon during pregnancies with a semiallogenic fetus, which are the spontaneously conceived pregnancies and in vitro fertilization pregnancies, and those with an allogeneic fetus or egg donation pregnancies. Maternofetal immune tolerance in uncomplicated pregnancies and pathological pregnancies, such as those with preeclampsia, has also been assessed. Moreover, whether an inadequate maternal immunological response to the allogenic fetus could lead to a higher prevalence of preeclampsia in egg donation pregnancies has been addressed.

Early elevations of the complement activation fragment C3a and adverse pregnancy outcomes

OBJECTIVE

To estimate whether elevations of complement C3a early in pregnancy are predictive of the subsequent development of adverse pregnancy outcomes.

METHODS

A plasma sample was obtained from each enrolled pregnant woman before 20 weeks of gestation. The cohort (n=1,002) was evaluated for the development of adverse pregnancy outcomes defined as hypertensive diseases of pregnancy (gestational hypertension or preeclampsia), preterm birth (before 37 weeks of gestation), premature rupture of the membranes, pregnancy loss (during the embryonic and fetal period), intrauterine growth restriction, and the composite outcome of any adverse outcome.

RESULTS

One or more adverse pregnancy outcomes occurred in 211 (21%) of the cohort. The mean levels (ng/mL) of C3a in early pregnancy were significantly (P=<.001) higher among women with one or more adverse outcomes (858±435) compared with women with an uncomplicated pregnancy (741±407). Adjusted for parity and prepregnancy body mass index, women with levels of C3a in the upper quartile in early pregnancy were three times more likely to have an adverse outcome later in pregnancy compared with women in the lowest quartile (95% confidence interval, 1.8-4.8; P<.001). The link between early elevated C3a levels and adverse pregnancy outcomes was driven primarily by individual significant (P<.05) associations of C3a with hypertensive diseases of pregnancy, preterm birth, and premature rupture of the membranes.

CONCLUSION

Elevated C3a as early as the first trimester of pregnancy is an independent predictive factor for adverse pregnancy outcomes, suggesting that complement-related inflammatory events in pregnancy contribute to the subsequent development of poor outcomes at later stages of pregnancy.

LEVEL OF EVIDENCE

II.

Gestational diabetes and hypertensive disorders of pregnancy as vascular risk signals: an overview and grading of the evidence

The occurrence of common pregnancy-related medical disorders identifies women at high risk of developing future vascular disease. Systematic reviews of cohort studies demonstrate that gestational diabetes confers a 7-fold risk increase for type 2 diabetes, and preeclampsia confers a 1.8-fold risk increase for type 2 diabetes and 3.4-fold risk increase for hypertension. Gestational diabetes and hypertensive disorders of pregnancy (HDP) increase the risk of premature vascular disease, but the 2-fold risk increase associated with preeclampsia is only partially explained by the development of traditional vascular risk factors. Despite the compelling evidence for gestational diabetes and HDP as vascular risk indicators, there are no published Canadian vascular prevention guidelines that recognize these postpartum women. In contrast, the 2011 American Heart Association guidelines on cardiovascular disease in women include gestational diabetes and HDP in their vascular risk assessment. Studies indicate that the importance surveillance of vascular risk factors in these women after pregnancy is underappreciated by the women themselves and their physicians. Although a prudent diet and physically active lifestyle were demonstrated to reduce diabetes risk in women with a gestational diabetes history in the American Diabetes Prevention Program trial, adoption of these health behaviours is low; qualitative studies confirm a need for tailored strategies that address barriers and provide social support. Further research is also needed on approaches to reduce vascular risk in women with a history of gestational diabetes and HDP. Otherwise, an early window of opportunity for chronic disease prevention in young, high-risk women will be missed.

Maternal and fetal alternative complement pathway activation in early severe preeclampsia

PROBLEM

We sought to determine whether alternative complement activation fragment Bb (Bb) levels are elevated in the maternal, fetal, and placental blood in cases of severe preeclampsia (PE) compared with normotensive controls.

METHOD OF STUDY

This was a cross-sectional study of women admitted at ≥24 weeks gestation with or without severe PE. Maternal plasma was collected at the time of enrollment. Umbilical venous cord and intervillous space blood were collected at delivery. Plasma Bb levels were assessed using ELISA. Bb levels were compared between cases and controls.

RESULTS

Median Bb levels were higher in the maternal plasma of severe PE subjects (n = 24) than in controls (n = 20), 1.45 ± 1.03 versus 0.65 ± 0.23 μg/mL, P < 0.001. In umbilical venous plasma, Bb levels were higher in severe PE subjects (n = 15) compared with controls (n = 15), 2.48 ± 1.40 versus 1.01 ± 0.57 μg/mL, P = 0.01.

CONCLUSION

Activation fragment Bb is increased in the maternal and umbilical venous blood of cases of severe PE when compared with normotensive controls. These data provide support for alternative complement pathway involvement in the pathogenesis of severe PE and demonstrate that alternative complement activation occurs not only in the maternal but also in the fetal compartment.

Gestational angiogenic biomarker patterns in high risk preeclampsia groups

OBJECTIVE

Several conditions are associated with increased preeclampsia (PE) risk. Whether altered maternal angiogenic factor levels contribute to risk in these conditions is unknown. Our objective was to compare angiogenic biomarker patterns in high-risk pregnancies and low-risk controls.

STUDY DESIGN

We conducted a planned secondary analysis of a 2-center observational study of angiogenic biomarkers in high-risk women. A total of 156 pregnant women with a PE risk factor and 59 low-risk controls were studied. Serial maternal serum samples were collected during 3 gestational windows: 23-27 weeks, 28-31 weeks, and 32-35 weeks. Soluble fms-like tyrosine kinase 1 (sFlt1), soluble endoglin (sEng), and placental growth factor (PlGF) were measured by enzyme-linked immunosorbent assay. Geometric mean angiogenic biomarker levels and angiogenic ratio (sFlt1 + sEng):PlGF were compared with low-risk controls for each risk group, at each gestational window.

RESULTS

Gestational biomarker patterns differed in PE risk groups as compared with low-risk controls. Women with multiple gestations had markedly higher sFlt1 and sEng at all gestational windows. Women with prior PE had higher sFlt1 and angiogenic ratio, and lower PlGF, from 28 weeks onward. Women with chronic hypertension had significantly higher angiogenic ratio for all 3 gestational windows, but differences disappeared when women with PE were excluded. Obese and nulliparous women had significantly lower PlGF, but no differences in the angiogenic ratio.

CONCLUSION

High-risk groups have altered angiogenic biomarker patterns compared with controls, suggesting that altered production or metabolism of these factors may contribute to PE risk, particularly in women with multiple gestations and prior PE.

Preeclampsia 2012

Preeclampsia is a common complication of pregnancy associated with high maternal morbidity and mortality and intrauterine fetal growth restriction. There is extensive evidence that the reduction of uteroplacental blood flow in this syndrome results from the toxic combination of hypoxia, imbalance of angiogenic and antiangiogenic factors, inflammation, and deranged immunity. Women treated for preeclampsia also have an increased risk for cardiovascular and renal disease. At present it is unclear if the increased cardiovascular and renal disease risks are due to residual and or progressive effects of endothelial damage from the preeclampsia or from shared risk factors between preeclampsia and cardiac disease. Moreover, it appears that endothelin-1 signaling may play a central role in the hypertension associated with preeclampsia. In this paper, we discuss emerging data on the pathogenesis of preeclampsia and review therapeutic options.

Circulating ficolin-2 and ficolin-3 in normal pregnancy and pre-eclampsia

Ficolins are soluble molecules of the innate immune system that recognize carbohydrate molecules on microbial pathogens, apoptotic and necrotic cells. They act through two distinct routes: initiating the lectin pathway of complement activation and mediating a primitive opsonophagocytosis. In this study, we measured plasma levels of ficolin-2 and ficolin-3 in 60 pre-eclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women by enzyme-linked immunosorbent assay (ELISA). Circulating levels of complement activation products (C4d, C3a, SC5b9), angiogenic factors (soluble fms-like tyrosine kinase-1, placental growth factor) and markers of endothelial activation (von Willebrand factor antigen), endothelial injury (fibronectin) and trophoblast debris (cell-free fetal DNA) were also determined. Plasma levels of ficolin-2 were significantly lower in healthy pregnant than in healthy non-pregnant women, while ficolin-3 levels did not differ significantly between the two groups. Furthermore, pre-eclamptic patients had significantly lower ficolin-2 and ficolin-3 concentrations than healthy non-pregnant and pregnant women. In the pre-eclamptic group, plasma ficolin-2 levels showed a significant positive correlation with serum placental growth factor (PlGF) concentrations and significant inverse correlations with serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1), blood urea nitrogen and creatinine, serum lactate dehydrogenase activities, as well as with plasma VWF:antigen, fibronectin and cell-free fetal DNA concentrations. In conclusion, circulating levels of ficolin-2 are decreased in the third trimester of normal pregnancy. There is a further decrease in plasma ficolin-2 concentrations in pre-eclampsia, which might contribute to the development of the maternal syndrome of the disease through impaired removal of the trophoblast-derived material released into the maternal circulation by the hypoxic and oxidatively stressed pre-eclamptic placenta.

Late-onset preeclampsia is associated with an imbalance of angiogenic and anti-angiogenic factors in patients with and without placental lesions consistent with maternal underperfusion

OBJECTIVE

An imbalance between maternal angiogenic/anti-angiogenic factors concentrations has been observed in preeclampsia (PE) and other obstetrical syndromes. However, the frequency of pathologic findings in the placenta and the changes in maternal plasma angiogenic/anti-angiogenic factor concentrations differ between late- and early-onset PE. The aim of this study was to determine if the maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 and 2 (sVEGFR-1 and sVEGFR-2) are different in late-onset PE with and without placental pathologic findings consistent with maternal underperfusion.

STUDY DESIGN

A cross-sectional study was conducted including 64 uncomplicated women and 66 women with late-onset PE (>34 weeks) who had blood samples and placenta available for pathologic examination. Patients with late-onset PE were divided into those with and without placental histologic findings consistent with maternal underperfusion as proposed by the Society for Pediatric Pathology. Maternal plasma concentrations of PlGF, sEng, sVEGFR-1 and sVEGRF-2 were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

1) the prevalence of placental histological findings consistent with maternal underperfusion among women with late-onset PE was higher than that of those with an uncomplicated pregnancy (47% (31/66) vs. 7.8% (5/64), respectively; p < 0.01); 2) patients with late-onset PE and histological findings consistent with maternal underperfusion had a significantly lower median plasma concentration of PlGF, plasma PlGF/sVEGFR-1 ratio and plasma PlGF/sEng ratio than those with late-onset PE without placental underperfusion lesions (each p < 0.05); 3) the most common pathological findings in the placenta of patient with PE were lesions consistent with villous changes (77%, 24/31); and 4) isolated vascular lesions in the placenta were found only in 2 cases (6.5%), and the rest had a combination of villous and vascular lesions.

CONCLUSIONS

Nearly half of the patients with late-onset PE have placental lesions consistent with maternal underperfusion. These lesions are associated with an imbalance in the maternal concentration of angiogenic/anti-angiogenic factors. We propose that there is a link between maternal underperfusion and an anti-angiogenic state characterized by the changes in the concentrations of angiogenic and anti-angiogenic factors in women with late onset PE.

Prepregnancy obesity and complement system activation in early pregnancy and the subsequent development of preeclampsia

OBJECTIVE

We hypothesized that women who are obese before they become pregnant and also have elevations of complement Bb and C3a in the top quartile in early pregnancy would have the highest risk of preeclampsia compared with a referent group of women who were not obese and had levels of complement less than the top quartile.

STUDY DESIGN

This was a prospective study of 1013 women recruited at less than 20 weeks' gestation. An EDTA-plasma sample was obtained, and complement fragments were measured using enzyme-linked immunosorbent assays. The data were analyzed using univariable and multivariable logistic regression analysis.

RESULTS

Women who were obese with levels of Bb or C3a in the top quartile were 10.0 (95% confidence interval, 3.3-30) and 8.8 (95% confidence interval, 3-24) times, respectively, more likely to develop preeclampsia compared with the referent group.

CONCLUSION

We demonstrate a combined impact of obesity and elevated complement on the development of preeclampsia.