Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A ticking time bomb: Circulating anti-NMDA receptor autoantibodies

23.09.2013
Scientists of the CNMPB and of the Max Planck Institute of Experimental Medicine find NMDAR autoantibodies in 10% of all tested individuals, which can cause neuropsychiatric dysfunctions in case of blood brain barrier disturbance. The study has been recently published in the journal Molecular Psychiatry.

“Anti-NMDA receptor encephalitis” was the name given to an acute brain disease, whose potential cause and treatment has been described in a number of recent publications. On the molecular level, this acute form of encephalitis is attended by a reduced function of glutamate receptors (NMDAR), which is caused by autoantibodies against these receptors in the brain.

Symptoms of the disease can be psychosis, movement disorders, epileptic seizures or reduction of cognitive performance in various shapes. However, as most studies are based on a generally fairly small number of patients, they neither cast a light on the relevance of NMDAR autoantibodies in the blood for the pathogenesis of the disease, nor do they yield data about their prevalence in healthy individuals.

Notable new findings are now provided by a new study conducted by Prof. Hannelore Ehrenreich and her team in cooperation with the Göttingen DFG Research Center and Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB).

The study demonstrates for the first time that NMDAR autoantibodies can be found in the serum of more than 10% of a total of nearly 3000 tested individuals, irrespective of whether they are patients or healthy individuals. Surprisingly, comparable autoantibody titers, antibody classes and functionalities were detected in healthy subjects and patients with a neuropsychiatric disease.

This insight led the authors of the study to the following central question: If, in fact, these autoantibodies play some pathological role, why do healthy individuals bearing them stay healthy?

In a series of animal experiments the scientists could demonstrate that the prerequisite for a triggering of symptoms by these autoantibodies, and thus for the pathogenesis of a disease process, is a dysfunction of the blood-brain barrier. This physiological barrier in a healthy organism delimits the central nervous system like a filter from the general blood stream and thus protects it from circulating pathogenic agents and toxins. A disruption of its natural barrier function enables the NMDAR autoantibodies circulating in the blood to enter the brain. This way, they reach the NMDA receptors located in the brain and can cause an impairment of function resulting in psychosis-similar symptoms, epileptic seizures or cognitive dysfunctions.

"In other words, more than 10% of all individuals carry a 'ticking time bomb', the disease relevance of which is only suppressed by an intact blood-brain barrier“, remarks Prof. Ehrenreich. An impaired blood brain barrier can be caused by a stroke, a brain trauma or by a viral infection, amongst others. In this context, the scientists performed an additional retrospective evaluation based on a large cohort of patients. They demonstrate an increase in the severity of neurological symptoms in subjects with a temporary or persisting blood-brain barrier dysfunction who carry NMDAR autoantibodies in their serum.

The authors of the study for the first time examined the question which factors are, in the end, responsible for triggering the generation of these NMDA autoantibodies. They found, on the one hand, an association of past influenza A or B infections with the appearance of these autoantibodies; on the other hand they identified by means of a genome-wide association study a genetic risk factor related to NMDAR biology.

The study published by first author Christian Hammer and coworkers is not only conceptually novel, it also yields considerable insight into a pathophysiological mechanism that is of crucial importance for neuropsychiatry and also for other clinical disciplines. The scientists commend that “patients with acute or chronic impairment of the blood-brain-barrier, e.g. after a brain injury, a stroke, any kind of encephalitis, epilepsy and also multiple sclerosis should be screened for the presence of NMDAR autoantibodies”. This might contribute to improve the course of disease by appropriate therapeutic methods and prevent long-term complications.

(cnmpb/mpiem)

Contact:
Max Planck Institute of Experimental Medicine
Clinical Neuroscience
Prof. Dr. Hannelore Ehrenreich (ehrenreich@em.mpg.de)
Phone 0551 / 39-3899 615
Hermann-Rein-Str. 3., 37075 Göttingen, Germany
Weitere Informationen:
http://www.ncbi.nlm.nih.gov/pubmed/23999527
- Original Publication
http://www.em.mpg.de/index.php
- Max Planck Institute of Experimental Medicine
http://www.cnmpb.de
- Cluster of Excellence and DFG-Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)

Dr. Heike Benecke | idw
Further information:
http://www.em.mpg.de/index.php

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>