Nav: Home

Autoantibodies in pregnancy: A cause of behavioral disorders in the child?

September 18, 2019

Dysfunctions in the maternal immune system that occur during pregnancy could possibly lead to impaired brain development in the unborn child. This is suggested by studies by the German Center for Neurodegenerative Diseases (DZNE) and Charite - Universitaetsmedizin Berlin, which are based on laboratory experiments and additional findings in humans. According to these studies, embryonic damage due to so-called autoantibodies could be a previously unnoticed cause of behavioral disorders that occur in diseases such as autism, schizophrenia and ADHD. The research results are published in the journal Annals of Neurology.

During pregnancy, antibodies from the mother's blood constantly enter the embryonic circulation via the umbilical cord to protect the developing child from infection. However, not all maternal antibodies are directed against foreign substances and serve to defend from pathogens. Some antibodies - known as autoantibodies - attack the body's own tissues. They may thus cause damage that can manifest, for example, as autoimmune diseases. Just like the beneficial antibodies, a pregnant woman passes on potentially harmful autoantibodies to her unborn child. This could promote the development of behavioral disorders in the child, as recent studies in animal models suggest. Initial data from studies in humans support these findings.

Dangerous Antibodies

The current study, led by Dr. Harald Pruess from the DZNE's Berlin site and the Department of Neurology with Experimental Neurology at the Charite, focused on an autoantibody that targets a specific protein on the surface of brain cells. This molecule, known as 'NMDA receptor', is essential for the interconnection of neurons and normal brain development. "The NMDA receptor antibody is a relatively common autoantibody. Data from blood donations suggest that up to one percent of the general population may carry this particular autoantibody in their blood. The reasons for this are largely unclear," said Pruess. If this autoantibody reaches the brain, serious inflammations can arise. However, most carriers are free of such symptoms because the blood-brain barrier - a filtering tissue that surrounds the brain's blood vessels - is usually hardly penetrable for antibodies. Unless this barrier is damaged or, as with an embryo in early pregnancy, not yet fully developed.

"We investigated the hypothesis that NMDA receptor antibodies reach the brain of the embryo and cause subtle but lasting impairments during this important phase of brain development," explained Pruess. Indeed, in mice, large quantities of maternal autoantibodies were found to reach the brain of the embryo. This resulted in a reduction of NMDA receptors, altered physiological functions and impaired neuronal development. The offspring showed abnormalities in behavior and some areas of their brains were smaller compared to healthy animals. "This hitherto unknown form of pregnancy-associated brain diseases is reminiscent of psychiatric disorders caused by rubella or chickenpox pathogens. These types of infections also have a temporary effect on the brain that can have lifelong consequences," said Pruess.

Findings in humans

In humans, initial analyses of data from a group of 225 mothers suggest that these autoantibodies occur more frequently in women who have a child with a neurodevelopmental disorder or psychiatric disease. The mothers seem to be protected by the blood-brain barrier. "Further studies will be needed in order to confirm the link between maternal NMDA receptor antibodies and human psychiatric disorders in humans," Pruess emphasized. "However, should future research results confirm our hypothesis, tests for such antibodies in pregnant women would have to be included in prenatal screenings. Where necessary, this would allow to initiate treatments to remove the autoantibodies in order to prevent the child from suffering potentially life-long adverse health effects."

The current results may explain why previous studies have failed to demonstrate a clear link between NMDA receptor antibodies and psychiatric diseases such as schizophrenia. In newborns, the antibodies transferred by the mother are broken down within a matter of weeks. Most patients in existing studies were young adults. Therefore, when the testing for these autoantibodies took place, they had long since disappeared.
-end-
Original publication

Human gestational NMDAR autoantibodies impair neonatal murine brain function, Betty Jurek, Mariya Chayka et al., Annals of Neurology (2019), DOI: 10.1002/ana.25552

DZNE - German Center for Neurodegenerative Diseases

Related Pregnancy Articles:

Going to sleep on your back in late pregnancy
This study looked at whether going to sleep on your back in the third trimester of pregnancy was associated with average lower birth weights.
Opioid use disorder in pregnancy: 5 things to know
Opioid use is increasing in pregnancy as well as the general population.
Medical imaging rates during pregnancy
Researchers looked at rates of medical imaging (CT, MRI, conventional x-rays, angiography, fluoroscopy and nuclear medicine) during pregnancy in this observational study that included nearly 3.5 million pregnant women in the United States and Canada from 1996 to 2016.
New research on diet and supplements during pregnancy and beyond
The foods and nutrients a woman consumes while pregnant have important health implications for her and her baby.
Obesity in early pregnancy linked to pregnancy complications
In a prospective study published in Obesity of 18,481 pregnant women in China who had never given birth before, obesity in early pregnancy was linked to higher risks of spontaneous abortion, preterm birth, and large birth weight in newborns.
Possible link between autism and antidepressants use during pregnancy
An international team led by Duke-NUS Medical School has found a potential link between autistic-like behaviour in adult mice and exposure to a common antidepressant in the womb.
Immigrant women more likely to be overweight during pregnancy
A new study in the Journal of Public Health finds that women in Norway from immigrant backgrounds are more likely to be overweight during pregnancy.
Stillbirths more likely if diabetes in pregnancy not diagnosed
Women who develop diabetes in pregnancy but are not diagnosed are much more likely to experience stillbirth than women without the condition, according to new research.
Do economic conditions affect pregnancy outcomes?
Economic downturn during early pregnancy was linked with modest increases in preterm birth in a Paediatric and Perinatal Epidemiology analysis.
Birthweight and early pregnancy body mass index may risk pregnancy complications
Women who were born with a low birthweight are at increased risk of pregnancy complications, according to a new Obesity study.
More Pregnancy News and Pregnancy Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.