Every year, pregnant women around the world develop preeclampsia, a serious complication that can put both mother and child at risk. Blood pressure rises, organs can become damaged and, in severe cases, doctors are left with only one option: delivering the baby early to protect both lives.
Pre-eclampsia usually occurs after the 20th week of pregnancy. Typical signs include high blood pressure and protein in the urine. Despite decades of research, there is still no treatment that directly targets the cause of the disease.
A filter designed to remove a harmful protein
About 20 years ago, researchers in the United States identified a protein believed to play a central role in pre-eclampsia. It is called sFlt-1, short for “soluble fms-like tyrosine kinase 1”. High levels of the protein can damage blood vessels in the placenta and impair the baby’s development.
An international research team has now tested a way to remove the protein from the blood of pregnant patients. The method uses a special form of blood filtration known as apheresis. During the procedure, the patient’s blood passes through a specially developed filter that binds and removes the protein. A key role in the project was played by Holger Stepan, head of obstetrics at Leipzig University Hospital.
Small study, encouraging results
The procedure was tested in pregnant women for the first time in a pilot study involving nine patients — seven treated in Leipzig and two in Cologne. “The results are promising: we were able to reduce the concentration of the disease-causing protein in the blood. At the same time, the patients’ clinical condition stabilized and several pregnancies could be prolonged,” says Stepan. “This is an important step toward a causal therapy for preeclampsia.”
The findings were published in the journal Nature Medicine. The project builds on around 15 years of research. The filter technology was developed by the German biotechnology company Miltenyi Biotec. The researchers now plan to test the procedure in larger studies involving significantly more patients. Only then will it become clear whether the method could eventually develop into a standard treatment for pre-eclampsia.
Original publication:
Thadhani, R., Hiemstra, T.F., Vatish, M. et al. Targeted removal of soluble Fms-like tyrosine kinase 1 in very preterm preeclampsia: a pilot trial. Nat Med (2026).
