Serum markers of macrophage activation in pre-eclampsia: no predictive value of soluble CD163 and neopterin

Modulation of cell-mediated immunity during pregnancy in wild bonobos

During pregnancy, the mammalian immune system must simultaneously protect against pathogens while being accommodating to the foreign fetal tissues. Our current understanding of this immune modulation derives predominantly from industrialized human populations and laboratory animals. However, their environments differ considerably from the pathogen-rich, resource-scarce environments in which pregnancy and the immune system co-evolved. For a better understanding of immune modulation during pregnancy in challenging environments, we measured urinary neopterin, a biomarker of cell-mediated immune responses, in 10 wild female bonobos (Pan paniscus) before, during and after pregnancy. Bonobos, sharing evolutionary roots and pregnancy characteristics with humans, serve as an ideal model for such investigation. Despite distinct environments, we hypothesized that cell-mediated immune modulation during pregnancy is similar between bonobos and humans. As predicted, neopterin levels were higher during than outside of pregnancy, and highest in the third trimester, with a significant decline post-partum. Our findings suggest shared mechanisms of cell-mediated immune modulation during pregnancy in bonobos and humans that are robust despite distinct environmental conditions. We propose that these patterns indicate shared immunological processes during pregnancy among hominins, and possibly other primates. This finding enhances our understanding of reproductive immunology.

Reduction of serum-induced endothelial STAT3(Y705) activation is associated with preeclampsia

OBJECTIVES

Preeclampsia is associated with maternal morbidity and mortality during pregnancy, and also an increased cardiovascular disease (CVD) risk later in life. During preeclampsia, alterations in secreted placental factors leading to systemic maternal endothelial dysfunction are evident. However, little is known about the associated endothelial intracellular signaling. STAT3 is a latent cytoplasmic transcription factor involved in endothelial cell differentiation, survival, and angiogenesis. We aimed to test if preeclampsia and preeclampsia-related placental factors could alter serum-induced STAT3(Y705) activation in endothelial cells. Furthermore, if altered serum-induced endothelial STAT3 (Y705) activation is related to post-preeclamptic CVD risk.

STUDY DESIGN

HUVECs were used as a model of maternal endothelium. Experiments entailed addition of 20% human pregnancy serum as well as addition of recombinant PlGF, sFLT1 and VEGF-A_165a to the cells.

MAIN OUTCOME MEASURES

Levels of pSTAT3(Y705) related to STAT3 levels were evaluated by immunoblotting analysis.

RESULTS

Our results show that preeclamptic serum induces significantly lower STAT3(Y705) phosphorylation compared with uncomplicated pregnancy serum (P = 0.0089) in endothelial cells. Furthermore, STAT3(Y705) phosphorylation was not changed upon addition of PlGF, sFLT1, or VEGF-A_165a together with pregnancy sera compared with sera alone. Finally, sera from women with previous preeclampsia and current hypertension and carotid atherosclerotic plaques show significantly lower STAT3(Y705) phosphorylation capabilities compared with healthy women with previous uncomplicated pregnancies 8-18 years after deliveries (P = 0.029).

CONCLUSIONS

Reduction in serum-induced endothelial STAT3(Y705) activation may play an important role in the preeclampsia-associated endothelial dysfunction. Additionally, reduced endothelial STAT3(Y705) phosphorylation may contribute to increased post-preeclamptic CVD risk 8-18 years after delivery.

C-Reactive Protein for Prediction or Early Detection of Pre-Eclampsia: A Systematic Review

OBJECTIVE

Pre-eclampsia (PE) is a serious disease of pregnancy and one of the major causes of morbidity and mortality for both the mother and baby. This systematic review aims to detect the role of high-sensitivity C-reactive protein (CRP) in the detection of PE.

METHODS

Thirty-four articles published between 2001 and 2019 were included in this review. The articles were extracted from OVID Medline and Embase. The study designs of these articles are randomized controlled, cohort, case-control, and cross-sectional studies evaluating CRP as a marker to predict or early diagnose PE. The quality assessment of these articles is made by the modified Quality Assessment of Diagnostic Accuracy Studies 2 tool. Meta-analysis was not done because of clinical and statistical heterogeneity.

RESULTS

A positive association between CRP levels and the development of PE was confirmed in 18 studies. This positive effect was addressed in patients with normal BMI (<25 kg/m2) in 3 studies and in overweight patients in 2 studies. One study addressed this positive association in patients with a BMI ranging between 28 and 31 kg/m2. Three studies determined a cutoff level of CRP above which a significant risk of PE development should be suspected. These levels ranged between 7 and 15 mg/L.

CONCLUSION

CRP is a promising cost-effective biomarker that may be used in the prediction of PE. A CRP level higher than 15 mg/L may suggest initiation of low-dose aspirin in low-risk pregnancies.

Inflammatory Markers and Preeclampsia: A Systematic Review

BACKGROUND

Preeclampsia (PE), a serious and variable pregnancy complication affecting 5%-10% of the obstetric population, has an undetermined etiology, yet inflammation is concomitant with its development, particularly in relation to endothelial dysfunction.

OBJECTIVE

The purpose of this systematic review was to examine the published evidence concerning an association between PE and inflammatory markers for their usefulness in the prediction or early identification of women with PE in antepartum clinical settings.

METHODS

In this systematic review, we used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Cumulative Index for Nursing and Allied Health and MEDLINE/OVID were the electronic databases used for identifying published articles. We placed no time limit on the publication year.

RESULTS

The search generated 798 articles. After removing duplicates, screening abstracts, and conducting full-text reviews, we retained 73 articles and examined 57 unique markers. This review shows that C-reactive protein and the cytokines, specifically the proinflammatory markers IL-6, IL-8, and tumor necrosis factor alpha, garner the most support as potential inflammatory markers for clinical surveillance of PE, particularly during the second and third trimesters.

DISCUSSION

Based on this review, we cannot recommend any single inflammatory marker for routine clinical use to predict/identify PE onset or progression. Research is recommended to examine a combination panel of these four inflammatory markers both with and without clinical risk factors toward the goal of translation to practice.

Effect of THP-1 Cells on the Formation of Vascular Tubes by Endothelial EA.hy926 Cells in the Presence of Placenta Secretory Products

We studied the effect of THP-1 cells on the formation of vessel-like structures by endothelial cells in the presence of placenta-conditioned media. Addition of THP-1 cells to endothelial cells cultured in the presence of media conditioned by first-trimester placentas led to an increase in the length of cell tubes and reduced their number in comparison with endothelial cell monoculture. In the presence of media conditioned by third-trimester placentas, THP-1 cells did not affect the length and number of cell tubes formed by endothelial cells. When evaluating the formation of vessel-like structures by endothelial cells in co-culture, marked decrease in the length of cell tubes in the presence of media conditioned by first-trimester placentas vs. third-trimester placentas was noted. No differences in the length and number of cell tubes formed by endothelial cells co-cultured with THP-1 cells in the presence of placental factors from women with preeclampsia and uncomplicated pregnancy were found. These findings can reflect the peculiarities of the influence of macrophages on the formation of blood vessels by endothelial cells in the placenta.

C-reactive protein and later preeclampsia: systematic review and meta-analysis taking into account the weight status

OBJECTIVES

This study aims to determine whether high C-reactive protein (CRP) concentration during pregnancy is associated with later preeclampsia and whether weight status (BMI) is a potential modifier of the relation between CRP and preeclampsia.

METHODS

Twenty-three studies were included in a systematic literature review and a subset of 18 in a meta-analysis. Weighted mean difference (WMD) [with their 95% confidence intervals (CI)] of CRP in preeclampsia and control groups was the estimator. A quality assessment was carried out using a scale specifically developed for this study. Meta-regression with estimates for study characteristics and inter-arm differences and sensitivity and subgroup analysis was employed. Statistical heterogeneity was investigated using I(2) statistic.

RESULTS

The pooled estimated CRP between 727 women, who developed preeclampsia and 3538 controls was 2.30 mg/l (95% CI: 1.27-3.34). The heterogeneity among studies was high (I(2) = 92.8). The WMD was found to be lower in studies comprising preeclampsia and control groups with similar BMI [WMD = 0.85 (95% CI: 0.10-1.61); I(2) = 25.3%] compared with studies among which BMI was significantly elevated in the preeclampsia group [2.01 (95% CI: 1.23-2.78); I(2) = 0.0%], which may explain the high heterogeneity of pooled data. Meta-regression results confirmed that difference in BMI between groups modifies the association of CRP and preeclampsia. High quality studies represented 30%.

CONCLUSION

The pooled WMD suggest that women with higher levels of CRP may have an increased risk of developing preeclampsia. This association seems to be modified by confounders, such as BMI. Further studies of high methodological quality are needed.

Plasma levels of inflammatory markers neopterin, sialic acid, and C-reactive protein in pregnancy and preeclampsia

BACKGROUND

To determine whether the cellular inflammatory marker of activated macrophages and monocytes, neopterin (NEO), and the acute-phase inflammatory markers sialic acid (SA) and C-reactive protein (CRP) are elevated in pregnancy and further elevated in the pregnancy syndrome preeclampsia.

METHODS

Maternal plasma concentrations of NEO, SA, and CRP were measured by high-sensitivity enzyme-linked immunosorbent assay (ELISA) or high-performance liquid chromatography in 20 nonpregnant women, 40 women with uncomplicated pregnancies, 50 women with transient hypertension of pregnancy alone, 49 women with small for gestational age (SGA) infants without preeclampsia, and 47 women with preeclampsia.

RESULTS

The mean concentration of plasma NEO, SA, and CRP were all significantly elevated in all groups of pregnant women compared to nonpregnant women (P < 0.001 for all). In addition, maternal plasma NEO concentrations were further elevated in women with preeclampsia compared to the other groups of pregnant women (P < 0.01). As expected, the acute-phase inflammatory markers CRP and SA correlated positively with each other. However, CRP was also correlated with the activated macrophage and monocyte marker NEO in women with transient hypertension of pregnancy and with preeclampsia (P < 0.05).

CONCLUSIONS

The inflammatory markers NEO, SA, and CRP are all elevated during pregnancy. However, only NEO, a marker of macrophage and monocyte activation, was further elevated in women with preeclampsia. These data suggest that there is a striking increase in inflammation during pregnancy, and cellular immune activation is further elevated during preeclampsia.