Pre-eclampsia, also known as toxemia, is a serious complication of pregnancy, characterized by high blood pressure, protein in the urine, and retention of fluid. Those affected need rest and close monitoring by their doctor or, in severe cases, admission to the hospital. The condition usually resolves soon after delivery, but early delivery increases the risk of complications to the baby. This has to be balanced against delay, which increases the risk that full eclampsia will develop in the mother, with seizures and organ damage threatening the lives of both mother and baby.

Pregnant women are currently screened for this condition during regular prenatal visits. During these visits, blood pressure is checked and a random urine sample is tested for the presence of protein. A high blood pressure reading may be due to pre-eclampsia but may also have other causes, such as chronic or gestational hypertension. Protein in the urine may indicate pre-eclampsia or may be caused by a urinary tract infection. Distinguishing pre-eclampsia from the other causes of abnormal screening results would aid doctors in the diagnosis and prompt treatment of their expectant patients.

Recently, Professor Thomas Rademacher and colleagues from University College London found that biologically active P-type inositol phosphoglycan (P-IPG), a small water-soluble molecule, was increased in the placenta, amniotic fluid, and urine of women with pre-eclampsia. Now, the urine findings have been confirmed and extended following their development of an enzyme-linked immunosorbent assay (ELISA) for P-IPG in urine. The collaborative study, carried out at University College London and John Radcliffe Hospital Oxford, was published in the January 2007 issue of the journal Hypertension.

The average P-IPG content of urine specimens collected during the first week after the diagnosis of pre-eclampsia in 27 women was 30 times greater than that in 47 matched healthy controls, with no overlap of values. Urine P-IPG increased after diagnosis and decreased steeply after delivery. Three of the women who developed pre-eclampsia had had multiple urine specimens collected earlier in their pregnancies as part of another research project. These specimens showed a time-related increase in P-IPG, values becoming abnormal three, five, and six weeks before clinical diagnosis.

Further research is underway to assess the potential of P-IPG as an early marker of pre-eclampsia, possibly together with other independent biomarkers to better help physicians identify women at risk of developing serious complications of pre-eclampsia.

Sources

S1
Williams PJ, Gumaa K, Scioscia M, Redman CW, Rademacher TW. Inositol phosphoglycan P-type in preeclampsia: a novel marker? Hypertension. 2007 Jan;49(1):84-9. (Accessed April 2007) Available online: http://www.medscape.com/medline/abstract/17116762

S2
Kasper D, et al. Eds. (2005). Harrison’s Principles of Internal Medicine, 16th edition, McGraw-Hill.