In a study of pregnant women in the United States, Cedars-Sinai researchers found that a specific imbalance of two placental proteins could predict which women were at risk of developing a severe form of preeclampsia, a life-threatening blood pressure disorder. .
The study is published in the journal NEJM records.
“We found that a blood test measuring the ratio of two proteins involved in the development of blood vessels in the placenta could identify which of the women would develop premature preeclampsia with severe features,” said the co-lead author of the Study, Sarah Kilpatrick, MD, PhD, Chair. from the Department of Obstetrics and Gynecology at Cedars-Sinai. “This test was significantly better than all standard of care markers for preeclampsia with severe features. It predicted with over 90% accuracy whether the patient would develop preeclampsia with severe features or not, whereas the usual markers were accurate less than 75% of the time.”
The blinded prospective study of women initially hospitalized with premature hypertension involved 1,014 patients from 18 hospitals across the country.
“This multicenter investigation is one of the few large studies of the risk of developing preeclampsia with severe features in the United States. The women represented a more racially diverse cohort than previous studies and included patients from small community hospitals and large academic medical centers in both cases. cities and rural areas,” Kilpatrick said.
Preeclampsia is the most common hypertensive disorder associated with pregnancy. The severe form of the disease can lead to dangerous high blood pressure, organ failure, vision loss, or even stroke. It affects about 5% of pregnant women and is one of the main causes of death and serious illness in the mother and the fetus.
Investigators found that a specific protein imbalance revealed in blood tests of hospitalized pregnant women provided a way to quantify their risk of developing severe preeclampsia. This involves levels of soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PIGF) in the bloodstream.
“An sFlt-1 to PIGF ratio of 40 or greater predicts the development of severe preeclampsia, adverse outcomes, and early delivery within two weeks, two-thirds of the time,” said S. Ananth Karumanchi, MD, co -study lead author, Medallion Chair in Vascular Biology.
“Conversely, if the critical ratio between the two proteins was less than 40, we found that the risk of the patient progressing to preeclampsia with severe features within two weeks of the blood test was less than 5%,” said Karumanchi, also director. of Nephrology at Cedars-Sinai.
Currently, the only cure for preeclampsia is childbirth. A test indicating that a premature patient, a woman who has completed less than 37 weeks of pregnancy, is at risk of developing serious illness could help optimize care.
“We anticipate that this blood test could eventually lead to better health outcomes for mothers and their babies,” Kilpatrick said. “It is well known that preeclampsia progresses in virtually all patients until delivery. But it can be very difficult to predict the optimal time for delivery. Having an accurate test would help us make sure the mother was in the right hospital to support her care and that of her premature baby.”
Rates of preeclampsia have been steadily rising, largely due to the rise in obesity and hypertension in the country. Black, Native American and Alaska Native women have significantly higher rates of disease than white women and a higher risk of death.
Investigators also hope the findings may point the way to potential drug therapies for at-risk women.
“We know that sFlt-1 is the protein that goes up even before any symptoms of preeclampsia appear, and that the ratio of sFlt-1 to PlGF predicts worsening of the disease,” Karumanchi said. “Further research may identify a drug mechanism that could reduce sFlt-1 levels and be used to safely prolong pregnancy; this would be a game-changer for very premature patients with preeclampsia.”
While the study involved a single blood test of two proteins, the researchers are encouraged that more research, involving large numbers of subjects, will provide better tools to thwart preeclampsia before it can seriously harm patients and their babies.
“We performed this study to identify a simple and accurate biomarker that clinicians can use to determine who is most at risk for preeclampsia with severe features and who would be an appropriate candidate for treatments we might develop for this devastating disease” , said the co-study. senior author Ravi Thadhani, MD, MPH, professor of medicine at Harvard Medical School, director of studies at Mass General Brigham, Boston, Massachusetts, and visiting scholar at Cedars-Sinai. “I believe we have achieved that goal.”