Electrostimulation of the vagus nerve may help reduce the symptoms of rheumatoid arthritis.
This research gives hope that there may be a new way to help treat this autoimmune condition.
The vagus nerve, which is a very long nerve that runs between the brain and the neck, chest, and abdomen, is a complex structure.
Previous research has found an inflammatory reflex in the vagus nerve that reduces the production of cytokines, including certain molecules that are a component of autoimmune conditions. These molecules are called tumornecrosis factor (TNF).
The immune systems of healthy people block TNF, but in those with certain autoimmune conditions, excess TNF makes its way into the bloodstream and causes inflammation and a higher rate of symptoms associated with the conditions.
TNF is a target in many rheumatoid arthritis (RA) drugs, such as infliximab (Remicade) or etanercept(Enbrel). Many people call these drugs TNF-blockers.
The researchers thought that if they could boost this naturally occurring reflex in the vagus nerve, it might have a similar result — or one that was even better, as drugs that aim for TNF also suppress the immune system and have other unwelcome side effects.
“This is a really exciting development,” says Prof. Thomas Dörner, Chairperson of the Scientific Programme Committee at the Annual European Congress of Rheumatology, which this year takes place in Madrid, Spain.
“For many [people living with] RA, current treatments don’t work, or aren’t tolerated. These results open the door to a novel approach to treating not only RA but other chronic inflammatory diseases. This is certainly an area for further study,” adds Prof. Dörner.
Small neurostimulator led to big findings
The researchers implanted a small neurostimulator, called a MicrioRegulator, into 14 people with RA. To qualify for the study, each person had tried at least two medications that worked in different ways but that hadn’t helped reduce their symptoms.
The scientists then divided the participants into three groups: a placebo group, a group that had vagus stimulation once per day, and a group that had vagus stimulation four times per day.
The study, which took place over 12 weeks, revealed that those in the once-per-day group had a much better result, symptom-wise, than those in the other two groups — including those that had stimulation four times each day.
Both stimulation groups also had a distinct reduction of more than 30% in their cytokine levels during the course of the study.