Preeclampsia risk predicted with liquid biopsy test

Preeclampsia is a very dangerous pregnancy disorder for both the woman and her future baby, and early detection is essential to avoid serious complications. Now, a group of Belgian scientists from the University of KU Leuven have created a liquid biopsy method that measures DNA methylation levels in the blood to identify pregnant women at risk of developing preeclampsia early in pregnancy.

Preeclampsia affects one in 40 pregnant women and is characterized by high levels of blood pressure and the presence of protein in the urine. Without proper treatment it can damage the organs, and even cause the death of the mother or the fetus. Inducing labor is sometimes necessary to prevent this and lower blood pressure, but in one in eight cases preeclampsia develops between 20 and 34 weeks of pregnancy, and babies born before 34 weeks can develop serious complications. .

The exact causes of preeclampsia are unknown, so it is not easy to know which women are most at risk of developing it. However, it is known that the placenta plays a key role and for this reason the researchers from the KU Leuven, led by Professor Bernard Thienpont, decided to compare placental DNA in 498 women with and without early preeclampsia.

“A big advantage of our test is that it can be done with DNA obtained from a simple blood sample taken around the 12th week of pregnancy.”

“It is normal for the DNA structure of the placenta to change during pregnancy, a process driven by DNA methylation,” explained Professor Thienpont. “But we see a different pattern of DNA methylation in women who develop early preeclampsia. The cause of this difference is currently unknown, but it allows us to identify women who are at higher risk and treat them even before symptoms appear.”

A non-invasive and effective technique to predict preeclampsia

Liquid biopsy is a non-invasive diagnostic test that is increasingly being used to detect disease and monitor its progression and patient response to treatment. Oncology is one of the specialties in which it is most used to look for signs of tumors in the bloodstream.

He new methylome blood test proposed by the researchers uses cell-free DNA methylation information combined with maternal characteristics. The researchers used DNA methylation data in the blood of the participants – nearly a third of whom developed preeclampsia – to design a model that allowed risk stratification not only when preeclampsia was diagnosed, but also before symptoms developed. around 12 weeks of gestation.

The results of a new analysis involving 197 of these pregnant women demonstrated that this model, in combination with clinical and demographic risk factors already used in the clinic, generated a risk score that correctly predicted 72% of patients. with early-onset preeclampsia. The findings have been published in Nature Medicine.

“A big advantage of our test is that it can be done with DNA obtained from a simple blood sample taken around the 12th week of pregnancy. In Belgium, that blood sample is often taken anyway for the NIPT test to detect fetal chromosomal abnormalities. Therefore, we do not need to take additional samples, nor cells from the placenta itself”explica Thienpont.

“Over time, our analysis will be able to run concurrently with the NIPT test. But first, we’ll focus on implementing our new method on a larger scale, optimizing it, and validating it. We also want to investigate whether certain women would benefit more from a preventive examination, for example, in the case of a first pregnancy”, concludes the researcher.


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