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Pregnancy Disorder Linked to Alzheimer’s Disease Protein

  • Jessica Berman

Researchers have identified a potential cause of a pregnancy disorder called preeclampsia, which is a leading cause of mother and newborn mortality around the world. An international team of scientists has linked the condition to a protein that’s been implicated in the development of Alzheimer’s disease.

An estimated 75,000 women in the industrialized world die each year as a result of preeclampsia, a poorly understood pregnancy complication. Many more women and babies die in the developing world, where the condition is difficult to spot in women who are not getting routine prenatal care.

That is because the initial symptoms can be subtle, a silent rise in blood pressure being the most common. Untreated, the condition can lead to seizures, stroke, liver failure and death of both mother and child. To treat preeclampsia, doctors will deliver the babies early.

Researchers have identified a potential cause - misfolded proteins, including amyloid precursor protein and beta-amyloid - which are also found in the brains of people with Alzheimer’s disease.

Investigators, led by Center for Perinatal Research Director Irina Buhimschi of Nationwide Children’s Hospital in Columbus Ohio, discovered the malformed proteins clogging the placentas, or birth sacs, of women who developed preeclampsia.

“A lot of proteins need to be placed in different places," she said. "There are many proteins that are made de novo - by the placenta, by the baby that need to be excreted. So the organism of the mother has an extra load to take care of."

Buhimschi says preeclampsia usually strikes women during their first pregnancy, possibly because their bodies have not adapted to carrying a child.

She says if they are abnormal, the misfolded proteins cannot travel easily between mother and child and they back up in the placenta.

Buhimschi and colleagues got the idea to use a dye called Congo Red to look for the presence of the proteins in the urine of pregnant women. The dye binds to abnormal protein material and was used for many years to detect amyloid plaques in the brains of deceased Alzheimer’s patients.

“If we think these women spill these misfolded proteins in urine, can we test the dye, which otherwise has never been used with the urine of women with preeclampsia, to see if those proteins also bind [to] Congo Red? So we found that, yes, we could use it and transform it pretty much to [a] diagnostic test," she said.

Buhimshi says the Congo Red Dot urine test is highly accurate in detecting preeclampsia. It is being tested in a number of countries, including South Africa and India.

Researchers report their findings in the journal Science Translational Medicine.