Genomic Findings May Lead to Blood Test for Preeclampsia

A genomics-based study revealed a panel of microRNAs that may eventually be used to diagnose preeclampsia, a dangerous complication occurring during pregnancy.

MicroRNAs (miRNAs) and short interfering RNAs (siRNA) comprise a class of about 20 nucleotides-long RNA fragments that block gene expression by attaching to molecules of messenger RNA in a fashion that prevents them from transmitting the protein synthesizing instructions they had received from the DNA. With their capacity to fine-tune protein expression via sequence-specific interactions, miRNAs help regulate cell maintenance and differentiation.

Preeclampsia is one of the most dangerous pregnancy complications, and the leading cause of maternal and perinatal mortality and morbidity. Although the clinical symptoms appear late, its origin is early, and hence detection is feasible already at the first trimester.

In the current study, investigators at Tel Aviv University (Israel) and King's College, London (United Kingdom) evaluated the abundance of circulating miRNAs in the plasma of pregnant women in their first trimester, seeking transcripts that best separated the preeclampsia samples from those of healthy pregnant women. To this end, they performed miRNA sequencing of 75 preeclampsia and control samples, and identified 25 transcripts that were differentially expressed between preeclampsia and the control groups.

Based on these 25 miRNA transcripts, the investigators developed a model for the classification of preeclampsia samples. Results obtained using this model suggested that there was significant predictive value of circulating small RNA molecules in the first trimester, and laid the foundation for producing a novel early non-invasive diagnostic tool for preeclampsia, which could reduce the life-threatening risk for both the mother and fetus.

"Up to 8% of pregnant women may contract preeclampsia during their second or third trimester," said senior author Dr. Noam Shomron, professor of cell and developmental biology at Tel Aviv University. "This is a serious disease that endangers the health, sometimes even the lives, of the mother and the fetus. We do not know what causes it, but preeclampsia, if caught in time, has a simple and proven remedy: low doses of aspirin administered from the 16th week until the end of pregnancy."

"But we sought a definitive biomarker that appears in a patient's blood as early as the first trimester, before any symptoms appear," said Dr, Shomron. "Our findings form the basis for a simple blood test that would predict preeclampsia and, in turn, allow doctors to provide treatment that would prevent the very onset of the disease."

The study was published in the February 21, 2018, online edition of the journal Scientific Reports.

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Tel Aviv University
King's College, London