Molecules in Blood Foretell Development of Preeclampsia
High levels of two proteins in the blood of pregnant women appear to signal the subsequent development of preeclampsia, a life-threatening complication of pregnancy.
Preeclampsia is a leading cause of maternal death and often occurs without warning. The condition results in high blood pressure and protein in the urine. Preeclampsia may begin with mild symptoms, but progress to severe preeclampsia and then to eclampsia — dangerously high blood pressure and convulsions — which can result in disability or death. When preeclampsia is not severe, the high blood pressure it causes can usually be treated in the short term. Unfortunately, the only cure for preeclampsia is delivery of the baby.
Alterations in two proteins circulating in the blood — fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) — appear to be involved in the development of preeclampsia. Since endoglin, another protein, acts together with sFlt1 to induce a severe preeclampsia-like syndrome in pregnant rats, a research team led by Dr. Richard Levine at NIH's National Institute of Child Health and Human Development and Dr. S. Ananth Karumanchi at the Beth Israel Deaconess Medical Center and Harvard Medical School set out to examine whether it's also associated with preeclampsia in women. Funding for their study was provided by several NIH components.
In the September 7 issue of the New England Journal of Medicine, the researchers report that levels of endoglin were significantly higher in those women who, two to three months later, went on to develop preeclampsia. An increased level of endoglin was usually accompanied by increased levels of sFlt1. The risk of preeclampsia was greater for those women with the highest levels of both, but not for either alone.
Detecting high levels of both endoglin and sFlt1 early in pregnancy might prove helpful in predicting the development of preeclampsia. Detecting high levels of these molecules might also help to distinguish preeclampsia from chronic high blood pressure, kidney disease and other conditions that can produce symptoms similar to preeclampsia.
"We've found specific molecules that appear to be causing the clinical signs of preeclampsia and so we now have an idea which molecules we would need to interfere with to treat the disease," Dr. Levine said. However, attempts to develop a drug treatment will need to proceed carefully, he cautioned. Restoring normal blood pressure and blood flow to the mother might deprive the fetus of blood.
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