Vagus Nerve Stimulation Shows Promise for RA

Researchers writing in the journal PNAS find that vagus nerve stimulation reduces inflammation in rheumatoid arthritis patients and say it could possibly one day offer patients a new viable treatment alternative.

Previous studies in immunology and neuroscience have shown that reflex circuits, such as the “inflammatory reflex,” is defined by signals that travel in the vagus nerve to inhibit monocyte and macrophage production of tumor necrosis factor (TNF) and other cytokines. These reflex circuits can apparently be enhanced by electrically stimulating the vagus nerve with an implantable device, thereby significantly reducing cytokine production and relieving disease severity in animal models of endotoxemia, sepsis and colitis.

In this study, researchers showed that an implantable vagus nerve-stimulating device in epilepsy patients inhibited peripheral blood production of TNF, IL-1β, and IL-6. But for 17 rheumatoid arthritis patients, vagus nerve stimulation of up to four times daily significantly inhibited TNF production for up to 84 days. Their disease severity improved “significantly,” the researchers wrote.

Several patients reported significant improvements, including some who had previously failed to respond to any other form of pharmaceutical treatment. In addition, no serious adverse side effects were reported.

“Together, these results establish that vagus nerve stimulation targeting the inflammatory reflex modulates TNF production and reduces inflammation in humans. These findings suggest that it is possible to use mechanism-based neuromodulating devices in the experimental therapy of RA and possibly other autoimmune and autoinflammatory diseases,” the authors wrote.

Electrical vagal nerve stimulation modulates the same inflammatory cytokines implicated in causing RA and a host of other rheumatologic diseases. Side effects are minimal and include transient hoarseness and intraoperative bradycardia. More large-scale research is warranted, but this study indicates that vagal nerve stimulation may alleviate symptoms of suffering for possibly many RA patients.

The research was done in conjunction with researchers from the Academic Medical Center/University of Amsterdam, the Feinstein Institute for Medical Research and SetPoint Medical.

Takeaways

• Vagal nerve stimulation is an established safe treatment for epilepsy with a long track record.
• People with epilepsy and rheumatoid arthritis who are treated with implanted vagal nerve stimulation see a reduction in symptoms of RA.
• Vagal stimulation appears to reduce the release of inflammatory cytokines.
• Vagal stimulation could be a promising new therapy for rheumatoid arthritis.

References:

Frieda A. Koopmana, Sangeeta S. Chavanb, et. al. "Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis," PNAS. July 19, 2016. www.pnas.org/lookup/suppl/doi:10.1073/pnas.1605635113/-/DCSupplemental