Background-Targeted therapies to stabilize the clinical manifestations and prolong pregnancy in preeclampsia do not exist. Soluble fms-like tyrosine kinase 1 (sFlt-1), an alternatively spliced variant of the vascular endothelial growth factor receptor 1, induces a preeclampsia-like phenotype in experimental models and circulates at elevated levels in human preeclampsia. Removing sFlt-1 may benefit women with very preterm (Ͻ32 weeks) preeclampsia. Methods and Results-We first show that negatively charged dextran sulfate cellulose columns adsorb sFlt-1 in vitro. In 5 women with very preterm preeclampsia and elevated circulating sFlt-1 levels, we next demonstrate that a single dextran sulfate cellulose apheresis treatment reduces circulating sFlt-1 levels in a dose-dependent fashion. Finally, we performed multiple apheresis treatments in 3 additional women with very preterm (gestational age at admission 28, 30, and 27ϩ4 weeks) preeclampsia and elevated circulating sFlt-1 levels. Dextran sulfate apheresis lowered circulating sFlt-1, reduced proteinuria, and stabilized blood pressure without apparent adverse events to mother and fetus. Pregnancy lasted for 15 and 19 days in women treated twice and 23 days in a woman treated 4 times. In each, there was evidence of fetal growth. Conclusions-This pilot study supports the hypothesis that extracorporeal apheresis can lower circulating sFlt-1 in very preterm preeclampsia. Further studies are warranted to determine whether this intervention safely and effectively prolongs pregnancy and improves maternal and fetal outcomes in this setting. (Circulation. 2011;124:940-950.)Key Words: angiogenic factor Ⅲ apheresis Ⅲ preeclampsia P reeclampsia is a devastating medical complication of pregnancy associated with significant maternal and fetal morbidity and mortality. 1 The risk is highest in very preterm (Ͻ32 weeks) preeclampsia when the infant mortality rate is 70 times higher than at term. 2,3 Delivery of the placenta remains the only effective means to treat preeclampsia. Randomized trials have tested nonspecific interventions including antihypertensive agents; however, the ability of these and other interventions to prevent or stabilize the clinical manifestations and prolong pregnancy in preterm preeclampsia is limited. 4 -6 The underlying pathogenesis of preeclampsia has remained elusive, hampering successful development of targeted interventions for the condition. Clinical Perspective on p 950The prevailing hypothesis suggests that preeclampsia involves a placental factor that circulates to distal organs and causes damage to the vasculature. 7 We and others have suggested that excess placental derived soluble fms-like tyrosine kinase 1 (sFlt-1) or the soluble vascular endothelial growth factor (VEGF) receptor 1, an alternatively spliced variant of VEGF receptor 1, mediates the signs and symptoms of preeclampsia, and elevated circulating levels are associated with clinical preeclampsia. 8 -11 Circulating sFlt-1 levels in very preterm preeclampsia are among the highest obs...
RationalePreeclampsia is a devastating medical complication of pregnancy which leads to maternal and fetal morbidity and mortality. While the etiology of preeclampsia is unclear, human and animal studies suggest that excessive circulating levels of soluble fms-like tyrosine-kinase-1 (sFlt-1), an alternatively spliced variant of VEGF-receptor1, contribute to the signs and symptoms of preeclampsia. Since sFlt-1 binds to heparin and heparan sulfate proteoglycans, we hypothesized that the anticoagulant heparin, which is often used in pregnancy, may interfere with the levels, distribution and elimination of sFlt-1 in vivo.ObjectiveWe systematically determined serum and urine levels of angiogenic factors in preeclamptic women before and after administration of low molecular weight heparin and further characterized the interaction with heparin in biochemical studies.Methods and ResultsSerum and urine samples were used to measure sFlt-1 levels before and after heparin administration. Serum levels of sFlt-1 increased by 25% after heparin administration in pregnant women. The magnitude of the increase in circulating sFlt-1 correlated with initial sFlt-1 serum levels. Urinary sFlt-1 levels were also elevated following heparin administration and levels of elimination were dependent on the underlying integrity of the glomerular filtration barrier. Biochemical binding studies employing cation exchange chromatography revealed that heparin bound sFlt-1 had decreased affinity to negatively charged surfaces when compared to sFlt-1 alone.ConclusionLow molecular weight heparin administration increased circulating sFlt1 levels and enhanced renal elimination. We provide evidence that both effects may be due to heparin binding to sFlt1 and masking the positive charges on sFlt1 protein.
During pregnancy, maternal endocrine signals drive fetal development and program the offspring's physiology. A disruption of maternal glucocorticoid (GC) homeostasis increases the child's risk of developing psychiatric disorders later in life. We here show in mice, that the time of day of antenatal GC exposure predicts the behavioral phenotype of the adult offspring. Offspring of mothers receiving GCs out-of-phase compared to their endogenous circadian GC rhythm show elevated anxiety, impaired stress coping, and dysfunctional stressaxis regulation. The fetal circadian clock determines the vulnerability of the stress axis to GC treatment by controlling GC receptor (GR) availability in the hypothalamus. Similarly, a retrospective observational study indicates poorer stress compensatory capacity in 5-year old preterm infants whose mothers received antenatal GCs towards the evening. Our findings offer insights into the circadian physiology of feto-maternal crosstalk and assign a role to the fetal clock as a temporal gatekeeper of GC sensitivity.
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