by Summary: Higher concentrations of immune proteins are present in the blood both before and after an epileptic seizure. Researchers say the biomarkers can be identified via a simple blood test.
Source: Lund University
Researchers at Lund University in Sweden have discovered elevated levels of immune proteins in the blood before and after an epileptic seizure. The possible biomarkers can be identified with a simple blood test.
Diagnosing epilepsy is currently resource-intensive, and distinguishing it from other disorders can be challenging. Better diagnostic methods are therefore urgently needed as soon as the patient seeks medical help after a suspected seizure.
Epilepsy is the collective term for abnormal activity in the brain that causes a temporary loss of control over behavior and movement. The condition can be congenital, caused by a tumor, stroke, or an infection in the brain, and cause very different symptoms depending on which part of the brain the episode begins or spreads. Inflammatory processes that begin as an immune response in the body can also trigger an attack.
Therefore, the researchers began to search for possible biomarkers for epilepsy within the immune system. There are previous studies, but the results so far have been mixed and difficult to interpret:
“In our study we have a carefully selected group of participants and we have a lot of background information on each person. We also considered a number of confounders that can compromise the immune system, such as other neurological and immunological disorders, infections, and various psychiatric conditions,” says Christine Ekdahl Clementson.
She is a group leader and associate professor at Lund University and consultant in clinical neurophysiology at Skåne University Hospital. Her focus is on advanced epilepsy investigations and she led the research study. The research team also compared epileptic seizures with so-called psychogenic non-epileptic seizures.
Psychogenic seizure is a psychiatric diagnosis manifested by clinical symptoms that can easily be confused with epilepsy. It is a chronic condition that is believed to be underdiagnosed and as such is often mistakenly treated with epilepsy drugs. Therefore, there is a great demand to be able to distinguish the states more easily.
“Determining whether someone has epilepsy or is affected by psychogenic seizures is resource-intensive. It may be necessary to hospitalize the patient for several days with constant video and EEG monitoring, with medical staff available 24 hours a day. It’s tough for the patient that it takes time to make a diagnosis,” says Marie Taylor, MD and PhD student on the research team.
The researchers discovered that levels of five inflammatory markers – proteins – were acutely elevated in people who had had an epileptic seizure.
“We call these markers ‘fingerprints’ because they are multiple inflammation-relevant proteins with different reaction patterns. The patients with epilepsy already showed elevated levels of one of the five proteins – IL-6 – before their seizures, a level that transiently increased even further immediately after the seizure,” says Marie Taylor.
In contrast, there were no changes in the biomarkers in patients with psychogenic seizures. This could mean that a simple blood test in a patient who comes to the emergency room after a seizure can show if the immunological response is elevated. If this is not the case, there is a greater chance that it is a psychogenic seizure, which gives a first indication of how to assess the patient further.
“The next step is to replicate our studies in a broader and less homogeneous patient population in which we examine the ‘fingerprint’ in adults with epilepsy. We also want to see if the biomarkers respond in the same way in children, where the causes of epilepsy are more likely to be genetic.
“We are doing this through an ongoing study in Lund in collaboration with Child and Adolescent Psychiatry and Pediatric Neurology,” concludes Christine Ekdahl Clementson.
About this news from epilepsy research
Author: press office
Source: Lund University
Contact: Press Office – Lund University
Picture: The image is in the public domain
Original research: Open access.
“Immune response in the blood before and after epileptic and psychogenic non-epileptic seizures” by Matilda Ahl et al. helioon
Abstract
Immune response in the blood before and after epileptic and psychogenic non-epileptic seizures
highlights
- Elevated serum IL-6 levels in patients with temporal and frontal lobe epilepsy
- Altered postictal-interictal ratio of serum immune factors after temporal but not frontal lobe seizures
- No change in serum IL-6 levels in patients with psychogenic non-epileptic seizures
Abstract
Inflammatory processes can cause epileptic seizures and seizures can promote an immune response. Therefore, the systemic immune response is a compelling diagnostic and prognostic marker in epilepsy.
We examined the immune response before and after epileptic and psychogenic non-epileptic seizures (PNES). Serum samples from patients with videoEEG-verified temporal or frontal lobe epilepsy (TLE or FLE) or TLE + PNES showed increased interleukin-6 (IL-6) levels between seizures (interictal) compared to controls.
Patients with PNES had no increase in IL-6. IL-6 levels transiently increased further within hours of an attack (postictal) in TLE patients but not in FLE patients. The postictal to interictal ratio of additional five immune factors was also increased only in TLE patients.
We conclude that immune factors have the potential to be future biomarkers for epileptic seizures and that heterogeneity between different epileptic and non-epileptic seizures can be revealed in peripheral blood sampling independent of comorbidities.
