Serum levels of neopterin and interleukin-2 receptor in women with severe preeclampsia

Urinary neopterin of wild chimpanzees indicates that cell-mediated immune activity varies by age, sex, and female reproductive status

The study of free-living animal populations is necessary to understand life history trade-offs associated with immune investment. To investigate the role of life history strategies in shaping proinflammatory cell-mediated immune function, we analyzed age, sex, and reproductive status as predictors of urinary neopterin in 70 sexually mature chimpanzees (Pan troglodytes) at Ngogo, Kibale National Park, Uganda. In the absence of clinical signs of acute infectious disease, neopterin levels significantly increased with age in both male and female chimpanzees, as observed in humans and several other vertebrate species. Furthermore, males exhibited higher neopterin levels than females across adulthood. Finally, females with full sexual swellings, pregnant females, and post-reproductive females, the oldest individuals in our sample, exhibited higher neopterin levels than lactating females and cycling females without full swellings. Variation in females' neopterin levels by reproductive status is consistent with post-ovulatory and pregnancy-related immune patterns documented in humans. Together, our results provide evidence of ample variation in chimpanzee immune activity corresponding to biodemographic and physiological variation. Future studies comparing immune activity across ecological conditions and social systems are essential for understanding the life histories of primates and other mammals.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

Upregulated unique long 16 binding protein 1 detected in preeclamptic placenta affects human extravillous trophoblast cell line (HTR-8/SVneo) invasion by modulating the function of uterine natural killer cells

Well-controlled trophoblast invasion at the maternal-fetal interface is crucial for normal placentation and successful pregnancy, otherwise pathological conditions of pregnancy occur, such as preeclampsia. In previous studies, it has been demonstrated that unique long 16 binding protein (ULBP)1, a ligand for the natural-killer group (NKG)2D receptor on uterine natural killer (uNK) cells, is upregulated in the placenta in patients with preeclampsia. As they are present on the majority of the decidua, uNK have an important role in pregnancy. The aim of the present study was to determine the role of ULBP1 in trophoblast cell invasion, which is closely associated with the occurrence of preeclampsia. In the present study, ULBP1 expression levels in placentas collected after cesarean section from women with preeclampsia and normal pregnant women were determined by immunohistochemistry, reverse transcription-quantitative polymerase chain reaction and western blotting. The effects of ULBP1 on extravillous trophoblast cell line (HTR-8/SVneo) invasion mediated via uNK cells and the underlying mechanisms were investigated. mRNA and protein expression levels of ULBP1 were significantly upregulated (P<0.05) in preeclamptic placentas compared with normal controls. ULBP1 inhibited HTR-8/SVneo cells via the regulation of biological functions of uNK cells, including the downregulation of NKG2D expression on uNK cells and the stimulation of production of cytokines and chemokines that affect extravillous cytotrophoblast invasion by uNK cells. ULBP1 may have an important role in the pathophysiology of preeclampsia through the modification of biological functions of uNK cells, which may affect trophoblast invasion.

HIF-1 Alpha and Placental Growth Factor in Pregnancies Complicated With Preeclampsia: A Qualitative and Quantitative Analysis

BACKGROUND

The pathophysiology of preeclampsia is not clearly understood worldwide. Hypoxia inducible factor 1α (HIF-1α) is thought to be the preliminary factor for the hypoxic conditions prevailing in preeclampsia, which causes imbalance in the expression of angiogenic proteins. A proangiogenic protein, placental growth factor (PIGF), is reported to be dysregulated in preeclampsia. Therefore, this study focuses on the investigation of HIF-1α and PIGF in preeclamptic conditions and a possible molecular association between them.

METHODS

Placental tissue (n = 45 + 45) and serum samples (n = 80 + 80) of preeclamptic patients and healthy control were collected and processed for the analysis of HIF-1α and PIGF by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA).

RESULTS

In preeclamptic group, the significant nuclear and cytoplasmic expression of HIF-1α was noticed in syncytiotrophoblast (P = 0.0001) but in control placenta, it was localized to cytoplasm (P = 0.0001). The intensity of PIGF expression was lower in syncytiotrophoblast cytoplasm (P = 0.0001) in preeclamptic cases as compared with control. Also, the significant upregulated concentration of HIF-1α and downregulated PIGF was observed in serum samples of preeclamptic woman (P = 0.0001). Thus, there was a significant direct negative correlation between HIF-1α and PIGF both at tissue and serum level (P < 0.01).

CONCLUSION

The direct inverse association between HIF-1α and PIGF in serum and placental tissues may be responsible for the low oxidative stress and endothelial dysfunction, leading to the pathogenesis of preeclampsia.

Immune mechanisms and the role of oxidative stress in intrahepatic cholestasis of pregnancy

INTRODUCTION

The purpose of this study was to investigate levels of inflammatory cytokines such as interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and neopterin and oxidative stress status in patients with intrahepatic cholestasis of pregnancy (ICP) as well as their potential role in the pathophysiology.

MATERIAL AND METHODS

Thirty patients with ICP (Group 1) and 30 healthy pregnant women (Group 2) were included in this prospective case-control study. Levels of IL-6, TNF-α and neopterin were determined in both of the groups. Total anti-oxidant status (TAS) and total oxidative stress (TOS) levels were determined by means of a fully automated Erel method. Oxidative stress index (OSI) was calculated as the ratio of TOS to TAS.

RESULTS

There was no significant difference between the groups in IL-6 and TNF-α levels (p = 0.105 and p = 0.722, respectively). The mean neopterin level was significantly higher in Group 1 compared to Group 2 (2.34 ±0.77 and 1.57 ±0.38, respectively, p = 0.001). In addition, TAS, TOS and OSI levels were significantly higher in Group 1 (p = 0.004, p = 0.001 and p = 0.001, respectively) compared to Group 2.

DISCUSSION

Intrahepatic cholestasis of pregnancy is an inflammatory disorder in which maternal immune reaction may play a role. Interleukin 6 and TNF-α, which are some of the markers of humoral reaction, act as an indicator of abnormal reaction rather than acute-phase reaction in ICP. Further clinical trials and supportive placental findings are needed on the role of cytokines in cellular and humoral immune reactions during the symptomatic period and delivery to better understand the role of immune mechanisms in the aetiology of ICP.

Is inflammation the cause of pre-eclampsia?

It has been proposed that either excessive inflammation or an imbalance in angiogenic factors cause pre-eclampsia. In the present review, the arguments for and against the role of inflammation and/or angiogenic imbalance as the cause of pre-eclampsia are discussed on the basis of the Bradford–Hill criteria for disease causation. Although both angiogenic imbalance and systemic inflammation are implicated in pre-eclampsia, the absence of temporality of inflammatory markers with pre-eclampsia challenges the concept that excessive inflammation is the cause of pre-eclampsia. In contrast, the elevation of anti-angiogenic factors that precede the clinical signs of pre-eclampsia fulfils the criterion of temporality. The second most important criterion is the dose–response relationship. Although such a relationship has not been proven between pro-inflammatory cytokines and pre-eclampsia, high levels of anti-angiogenic factors have been shown to correlate with increased incidence and disease severity, hence satisfying this condition. Finally, as the removal of circulating sFlt-1 (soluble Fms-like tyrosine kinase receptor-1) from pre-eclamptic patients significantly improves the clinical outcome, it fulfils the Hill's experiment principle, which states that removal of the cause by an appropriate experimental regimen should ameliorate the condition. In contrast, treatment with high doses of corticosteroid fails to improve maternal outcome in pre-eclampsia, despite suppressing inflammation. Inflammation may enhance the pathology induced by the imbalance in the angiogenic factors, but does not by itself cause pre-eclampsia. Development of therapies based on the angiogenic and cytoprotective mechanisms seems more promising.

Can we use neopterin as marker of viral infections in pregnant women with symptoms of imminent spontaneous abortion?

PURPOSE

To find out if determination of neopterin can be used for the detection of viral infections in pregnant women with symptoms of imminent spontaneous abortion.

METHODS

Eighty-eight pregnant women with symptoms of imminent spontaneous abortion (investigated group) and 88 healthy pregnant women were evaluated (control group). Neopterin level and IgM and IgG antibodies for eight viruses in the blood were determined.

RESULTS

Parvo B19 virus and elevated neopterin values were found in significantly higher number in investigated group than in control. There was no correlation between women with acute ParvoB19 infection and elevated neopterin level.

CONCLUSIONS

The determination of neopterin in the sera cannot be used for screening of viral infections in pregnancy.

Interleukin-10 reduces inflammation, endothelial dysfunction, and blood pressure in hypertensive pregnant rats

Hypertensive disorders of pregnancy are characterized by systemic and placental inflammation; however, treatment for these conditions has remained elusive. We tested whether administration of the anti-inflammatory cytokine interleukin-10 (IL-10) during pregnancy would attenuate the hypertension, endothelial dysfunction, proteinuria, and inflammation seen in pregnant DOCA/saline-treated (PDS) rats. Normal pregnant (NP) rats and PDS were given daily intraperitoneal injections of recombinant IL-10 from gestational day 13 until death on day 20. Systolic blood pressure, aortic endothelium-dependent relaxation responses, and urinary protein excretion were measured on days 13 and 20 of gestation. Fetal number and development, plasma endothelin-1 levels, serum and placental levels of IFNgamma and IL-10, and aortic and placental levels of platelet endothelial cell adhesion molecule (PECAM) were assessed on gestational day 20. Systolic blood pressure, aortic endothelial dysfunction, and urinary protein excretion were significantly increased at gestational day 13 in PDS rats. However, all of these were restored to NP levels following IL-10 treatment in PDS rats. IL-10 treatment also significantly increased the number of pups per litter in PDS rats and did not further affect fetal development. The beneficial effects of IL-10 in PDS rats were likely mediated by the decreased plasma levels of endothelin-1, decreased levels of circulating and placental IFNgamma, as well as decreased aortic and placental expression of PECAM. These data demonstrate that exogenous IL-10 can normalize blood pressure and endothelial function in pregnancy-induced hypertensive rats and may be beneficial in women with hypertensive disorders of pregnancy.

Immunosuppression improves blood pressure and endothelial function in a rat model of pregnancy-induced hypertension

BACKGROUND

Hypertensive disorders of pregnancy, including preeclampsia (PE), affect approximately 7-10% of pregnancies in the US. Clinical and experimental studies strongly suggest that the maternal immune system plays a role in the development of these disorders; however, few therapeutic options exist aside from delivery.

METHODS

Using a deoxycorticosterone acetate (DOCA)/salt-low renin rat model, which exhibits hypertension, proteinuria, endothelial dysfunction, and intrauterine growth restriction (IUGR), we measured serum cytokine levels as an indication of immune system activation. In addition, we suppressed the immune system with either azathioprine (Aza) or mycophenolate mofetil (MMF) during the second half of pregnancy to determine whether the these symptoms could be ameliorated.

RESULTS

Our results demonstrate that serum T helper-1 (Th1)-type inflammatory cytokines interleukin (IL)-2, IL-12, interferon-gamma (IFNgamma), and RANTES were significantly elevated in hypertensive pregnant rats while the Th2-type cytokine IL-4 was elevated in normal pregnant animals. Either Aza or MMF significantly attenuated the hypertension, proteinuria, and endothelial dysfunction as well as the increased proinflammatory Th1 cytokine profile in pregnant rats treated with DOCA/salt, and had no effect on these parameters in normal pregnant rats.

CONCLUSION

These data strongly suggest that maternal immune system activation plays a role in the development of pregnancy-induced hypertension (PIH).

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.