Insufficient immune tolerance during pregnancy is associated with pathological conditions such as preeclampsia (PE). Soluble fms-like tyrosine kinase-1 (sFLT1), which exerts a role in the late... Show moreInsufficient immune tolerance during pregnancy is associated with pathological conditions such as preeclampsia (PE). Soluble fms-like tyrosine kinase-1 (sFLT1), which exerts a role in the late stage of PE, has shown its beneficial anti-inflammatory effects in inflammation-associated diseases. Macrophage migration inhibitory factor (MIF) was reported to upregulate sFLT1 production in experimental congenital diaphragmatic hernia. However, the placental sFLT1 expression in early uncomplicated pregnancy and whether MIF can regulate sFLT1 expression in uncomplicated and preeclamptic pregnancy are unclear. We collected first-trimester placentas and term placentas from uncomplicated and preeclamptic pregnancies to investigate sFLT1 and MIF expression in vivo. Primary cytotrophoblasts (CTBs) and a human trophoblast cell line (Bewo) were used to study the regulation of MIF on sFLT1 expression in vitro. In placentas from first-trimester pregnancy, we observed a high expression of sFLT1, specifically in extravillous trophoblasts (EVTs) and syncytiotrophoblast (STB) cells. MIF mRNA levels strongly correlated with sFLT1 expression in term placentas from preeclamptic pregnancies. In in vitro experiments, sFLT1 and MIF levels increased significantly in CTBs during their differentiation to EVTs and STBs, and MIF inhibitor (ISO-1) significantly reduced sFLT1 expression in a dose-dependent manner during this process. sFLT1 showed significant upregulation with increasing doses of MIF in Bewo cells. Our results show that sFLT1 is highly expressed at the maternal-fetal interface during early pregnancy and that MIF can increase sFLT1 expression in early uncomplicated pregnancy and PE, which suggests that sFLT1 plays an essential role in the modulation of inflammation in pregnancy. Show less
Eikmans, M.; Morales-Prieto, D.M.M.; Hoorn, M.L. van der; Markert, U.R.R. 2022
Preeclampsia (PE) generally manifests in the second half of pregnancy with hypertension and proteinuria. The understanding of the origin and mechanism behind PE is incomplete, although there is... Show morePreeclampsia (PE) generally manifests in the second half of pregnancy with hypertension and proteinuria. The understanding of the origin and mechanism behind PE is incomplete, although there is clearly an immune component to this disorder. The placenta constitutes a complicated immune interface between fetal and maternal cells, where regulation and tolerance are key. Stress factors from placental dysfunction in PE are released to the maternal circulation evoking the maternal response. Several complement factors play a role within this intricate landscape, including C1q in vascular remodeling and Factor H (FH) as the key regulator of alternative pathway complement activation. We hypothesize that decreased levels of C1q or FH, or disturbance of their function by autoantibodies, may be associated with PE. Autoantibodies against C1q and FH and the concentrations of C1q and FH were measured by ELISA in maternal sera from women with preeclamptic and normal pregnancies. Samples originated from cohorts collected in the Netherlands (n=63 PE; n=174 control pregnancies, n=51 nonpregnant), Finland (n=181 PE; n=63 control pregnancies) and Norway (n=59 PE; n=27 control pregnancies). Serum C1q and FH concentrations were higher in control pregnancy than in nonpregnant women. No significant differences were observed for serum C1q between preeclamptic and control pregnancy in any of the three cohorts. Serum levels of FH were lower in preeclamptic pregnancies compared to control pregnancies in two of the cohorts, this effect was driven by the early onset PE cases. Neither anti-C1q autoantibodies nor anti-FH autoantibodies levels differed between women with PE and normal pregnancies. In conclusion, levels of anti-C1q and anti-FH autoantibodies are not increased in PE. C1q and FH are increased in pregnancy, but importantly, a decrease in FH concentration is associated with PE. Show less
Obstetrical complications, often referred to as the "great obstetrical syndromes," are among the most common global causes of mortality and morbidity in young women and their infants. However,... Show moreObstetrical complications, often referred to as the "great obstetrical syndromes," are among the most common global causes of mortality and morbidity in young women and their infants. However, treatments for these syndromes are underdeveloped compared with other fields of medicine and are urgently needed. This current paucity of treatments for obstetrical complications is a reflection of the challenges of drug development in pregnancy. The appetite of pharmaceutical companies to invest in research for obstetrical syndromes is generally reduced by concerns for maternal, fetal, and infant safety, poor definition, and high-risk regulatory paths toward product approval. Notably, drug candidates require large investments for development with an unguaranteed return on investment. Furthermore, the discovery of promising drug candidates is hampered by a poor understanding of the pathophysiology of obstetrical syndromes and their uniqueness to human pregnancies. This limits translational extrapolation and de-risking strategies in preclinical studies, as available for other medical areas, compounded with limited fetal safety monitoring to capture early prenatal adverse reactions. In addition, the ethical review committees are reluctant to approve the inclusion of pregnant women in trials, and in the absence of regulatory guidance in obstetrics, clinical development programs are subject to unpredictable regulatory paths. To develop effective and safe drugs for pregnancy complications, substantial commitment, and investment in research for innovative therapies are needed in parallel with the creation of an enabling ethical, legislative, and guidance framework. Solutions are proposed to enable stakeholders to work with a common set of expectations to facilitate progress in this medical discipline. Addressing this significant unmet need to advance maternal and possibly perinatal health requires the involvement of all stakeholders and specifically patients, couples, and cli-nicians facing pregnancy complications in the dearth of appropriate therapies. This paper focused on the key pharmaceutical research and development challenges to achieve effective and safe treatments for obstetrical syndromes. Show less
van't Hof, L.J.; Schotvanger, N.; Haasnoot, G.W.; Keur, C. van der; Roelen, D.L.; Lashley, L.E.E.L.O.; ... ; Hoorn, M.L.P. van der 2021
IntroductionIn pregnancy, the mother and fetus differ in HLA antigens, and yet the maternal immune system generally tolerates the fetus. KIR receptors expressed by maternal uterine NK cells at the... Show moreIntroductionIn pregnancy, the mother and fetus differ in HLA antigens, and yet the maternal immune system generally tolerates the fetus. KIR receptors expressed by maternal uterine NK cells at the maternal-fetal interface directly interact with HLA-C on extravillous trophoblast cells for optimal placental development. In this study, we aimed to determine whether there is a preferential selection for HLA compatibility and specific KIR/HLA-C combinations in uncomplicated and preeclamptic naturally conceived pregnancies compared to what would be expected by chance.MethodsGenotyping for maternal and fetal HLA-A, -B, -C, -DR, and -DQ, and maternal KIR was performed for 451 uncomplicated pregnancies and 77 pregnancies complicated with preeclampsia. The number of HLA antigen (mis)matches between mother and fetus was calculated and compared to expected values obtained by randomization of the HLA haplotype, inherited from the father, over the existing maternal haplotype of the fetuses. A similar methodology was executed for analysis of the KIR/HLA-C data (n=309).ResultsIn uncomplicated pregnancies, the degree of maternal-fetal HLA matching was not different than expected-by-chance values. In preeclamptic pregnancies, the degree of maternal-fetal HLA matching was different in observed compared to expected-by-chance values (p=0.012). More specifically, the degree of maternal-fetal matching of HLA-C was higher in the actual preeclamptic pregnancies than was expected-by-chance (p=0.007). Preeclamptic pregnancies showed an overall tendency towards higher maternal-fetal HLA compatibility, for total HLA matches (p=0.021), HLA class I (p=0.038) and HLA-C (p=0.025) compared to uncomplicated pregnancies.ConclusionThe data suggest that there is no preferential selection of maternal-fetal HLA compatibility in uncomplicated pregnancies. In contrast, increased total HLA, HLA class I and, especially, HLA-C compatibility is associated with preeclampsia, suggestive for a role of HLA mismatches in immune regulation leading to uncomplicated pregnancy. Show less
Krop, J.; Heidt, S.; Claas, F.H.J.; Eikmans, M. 2020
In pregnancy, the semi-allogeneic fetus needs to be tolerated by the mother's immune system. Regulatory T cells (Tregs) play a prominent role in this process. Novel technologies allow for in-depth... Show moreIn pregnancy, the semi-allogeneic fetus needs to be tolerated by the mother's immune system. Regulatory T cells (Tregs) play a prominent role in this process. Novel technologies allow for in-depth phenotyping of previously unidentified immune cell subsets, which has resulted in the appreciation of a vast heterogeneity of Treg subsets. Similar to other immunological events, there appears to be great diversity within the Treg population during pregnancy, both at the maternal-fetal interface as in the peripheral blood. Different Treg subsets have distinct phenotypes and various ways of functioning. Furthermore, the frequency of individual Treg subsets varies throughout gestation and is altered in aberrant pregnancies. This suggests that distinct Treg subsets play a role at different time points of gestation and that their role in maintaining healthy pregnancy is crucial, as reflected for instance by their reduced frequency in women with recurrent pregnancy loss. Since pregnancy is essential for the existence of mankind, multiple immune regulatory mechanisms and cell types are likely at play to assure successful pregnancy. Therefore, it is important to understand the complete microenvironment of the decidua, preferably in the context of the whole immune cell repertoire of the pregnant woman. So far, most studies have focused on a single mechanism or cell type, which often is the FoxP3 positive regulatory T cell when studying immune regulation. In this review, we instead focus on the contribution of FoxP3 negative Treg subsets to the decidual microenvironment and their possible role in pregnancy complications. Their phenotype, function, and effect in pregnancy are discussed. Show less
Hypertension during pregnancy and preeclampsia are associated with increased arterial thrombotic risk in later life. Whether these complications are associated with risk of venous thromboembolism ... Show moreHypertension during pregnancy and preeclampsia are associated with increased arterial thrombotic risk in later life. Whether these complications are associated with risk of venous thromboembolism (VTE) on the short term after pregnancy and on the long term, that is, outside pregnancy, is largely unknown. We conducted a nationwide cohort study in women with at least 1 pregnancy and their first VTE risk by linking the Dutch perinatal registry (Perined) to anticoagulation clinics. We used Cox proportional hazard models to estimate hazard ratios (HRs) and corresponding 95% CI for VTE risk in women with hypertension during pregnancy, women with preeclampsia, compared with women with uncomplicated pregnancies (reference). A total of 1 919 918 women were followed for a median of 13.7 (interquartile range, 7.6-19.2) years for a total of 24 531 118 person-years in which 5759 first VTEs occurred; incidence rate: 2.3 (95% CI, 2.3-2.4) per 10 000 person-years. In the first pregnancy and 3-month postpartum period, VTE risk was higher in women with hypertension, HR, 2.0 (95% CI, 1.7-2.4), and highest among women with preeclampsia, HR, 7.8 (95% CI, 5.4-11.3), versus the reference group. On the long term, women with hypertension during pregnancy and preeclampsia had a higher VTE risk: HR, 1.5 (95% CI, 1.4-1.6) and HR, 2.1 (95% CI, 1.8-2.4), respectively, versus the reference group. When excluding events during pregnancy and postpartum, these HRs were 1.4 (95% CI, 1.3-1.5) and 1.6 (95% CI, 1.4-2.0), respectively. In conclusion, hypertension during pregnancy and preeclampsia are associated with an increased VTE risk during pregnancy and postpartum period and in the 13 years after. Show less
Lopes, S.M.C.D.; Alexdottir, M.S.; Valdimarsdottir, G. 2020
Emerging data suggest that a trophoblast stem cell (TSC) population exists in the early human placenta. However, in vitro stem cell culture models are still in development and it remains under... Show moreEmerging data suggest that a trophoblast stem cell (TSC) population exists in the early human placenta. However, in vitro stem cell culture models are still in development and it remains under debate how well they reflect primary trophoblast (TB) cells. The absence of robust protocols to generate TSCs from humans has resulted in limited knowledge of the molecular mechanisms that regulate human placental development and TB lineage specification when compared to other human embryonic stem cells (hESCs). As placentation in mouse and human differ considerably, it is only with the development of human-based disease models using TSCs that we will be able to understand the various diseases caused by abnormal placentation in humans, such as preeclampsia. In this review, we summarize the knowledge on normal human placental development, the placental disease preeclampsia, and current stem cell model systems used to mimic TB differentiation. A special focus is given to the transforming growth factor-beta (TGF beta) family as it has been shown that the TGF beta family has an important role in human placental development and disease. Show less
BackgroundPreeclampsia is a female-specific risk factor for the development of future cardiovascular disease. Whether early preventive cardiovascular disease risk screenings combined with risk... Show moreBackgroundPreeclampsia is a female-specific risk factor for the development of future cardiovascular disease. Whether early preventive cardiovascular disease risk screenings combined with risk-based lifestyle interventions in women with previous preeclampsia are beneficial and cost-effective is unknown.MethodsA micro-simulation model was developed to assess the life-long impact of preventive cardiovascular screening strategies initiated after women experienced preeclampsia during pregnancy. Screening was started at the age of 30 or 40 years and repeated every five years. Data (initial and follow-up) from women with a history of preeclampsia was used to calculate 10-year cardiovascular disease risk estimates according to Framingham Risk Score. An absolute risk threshold of 2% was evaluated for treatment selection, i.e. lifestyle interventions (e.g. increasing physical activity). Screening benefits were assessed in terms of costs and quality-adjusted-life-years, and incremental cost-effectiveness ratios compared with no screening.ResultsExpected health outcomes for no screening are 27.35 quality-adjusted-life-years and increase to 27.43 quality-adjusted-life-years (screening at 30 years with 2% threshold). The expected costs for no screening are euro9426 and around euro13,881 for screening at 30 years (for a 2% threshold). Preventive screening at 40 years with a 2% threshold has the most favourable incremental cost-effectiveness ratio, i.e. euro34,996/quality-adjusted-life-year, compared with other screening scenarios and no screening.ConclusionsEarly cardiovascular disease risk screening followed by risk-based lifestyle interventions may lead to small long-term health benefits in women with a history of preeclampsia. However, the cost-effectiveness of a lifelong cardiovascular prevention programme starting early after preeclampsia with risk-based lifestyle advice alone is relatively unfavourable. A combination of risk-based lifestyle advice plus medical therapy may be more beneficial. Show less
Lawera, A.; Tong, Z.; Thorikay, M.; Redgrave, R.E.; Cai, J.; Dinther, M. van; ... ; Li, W. 2019
