A team of scientists from the Federal State Budget Institution "Research Center for Obstetrics, Gynecology and Perinatology", Moscow Institute of Physics and Technology, the Emanuel Institute for Biochemical Physics, and the Talrose Institute for Energy Problems of Chemical Physics have developed an approach for a method of non-invasive testing for pregnant women with a serious and complex condition called preeclampsia. In simpler terms, the scientists have found potential biomarkers in the urine of pregnant women. In the future, this urine-based diagnostic method will enable specialists to detect the disease in its early stages. A paper detailing the results has been published in the Journal of Proteomics.

Preeclampsia and why it is dangerous

Preeclampsia is a multisystem disorder that occurs in the second half of pregnancy and is characterized by high blood pressure and proteinuria (a significant increase in the normal level of protein in the urine). Women with the condition suffer headaches, swelling, fainting, and other unpleasant and often dangerous symptoms. Ultimately, preeclampsia puts the health and life of an expectant mother and her baby at serious risk. The symptoms of the condition are ambiguous, so doctors rarely diagnose "pure" preeclampsia. However, even if this diagnosis is made, a new problem arises - it is still not known what causes the disorder, therefore it is not possible to control it effectively.

This means that doctors are only able to prescribe supportive care and treat the symptoms, while trying to delay the birth of the child - a balance has to be made between allowing enough time for full fetal growth (although the baby is also affected by improper development of the placenta as a result of the condition) and preserving the mother's health.

Clues from the body and a discovery for the medicine of the future

If something is wrong with all the systems in the body, it is logical to assume that the "fault" is at molecular level. Protein is found even in the urine of an absolutely healthy person, although only in very small concentrations. From a doctor's point of view, one of the main symptoms of preeclampsia is a marked increase in this concentration (from the normal 0.03 g/l to the critical 0.3 g/l and above). The scientists wondered whether peptides (pieces of proteins) that are produced by women with preeclampsia could carry information about the disease. This approach is very much in line with the current focus on non-invasive testing, i.e. analysing available biomaterials such as urine, saliva, or exhaled air.

To identify potential peptide biomarkers, the researchers compared samples of three groups of ten women from the Research Center for Obstetrics, Gynecology and Perinatology: women with a normal pregnancy, and with mild and severe preeclampsia. The researchers were not only interested in comparing healthy women and patients with preeclampsia; they also wanted to examine how certain biomarkers are associated with the severity of the condition. Following the experiments, 35 potential peptide biomarkers of preeclampsia were identified. They included fragments of alpha-1-antitrypsin (14 peptides), collagen alpha-1(I) and alpha-1(III) chains (6 peptides), and uromodulin (7 peptides).

"In the Research Center for Obstetrics, Gynecology and Perinatology we were able to confirm a number of markers previously proposed by our colleagues abroad, and also identify some new ones. We will obviously need to verify and confirm their significance. What is important is that this non-invasive method has proven effective - it can be used as a basis to develop a clinical method," said Evgeniy Nikolaev, one of the authors of the study, professor and head of MIPT's Laboratory of Ionic and Molecular Physics.

Article: An untargeted approach for the analysis of the urine peptidome of women with preeclampsia, Evgeniy Nikolaev et al., Journal of Proteomics, doi:10.1016/j.jprot.2016.04.024, published online 21 April 2016.