Vagus nerve stimulation may improve disease activity in patients with RA
Electrical stimulation of the vagus nerve may inhibit cytokine production and reduce disease severity in patients with rheumatoid arthritis, according to recently published research.
In addition to a group of seven patients with epilepsy, researchers enrolled 17 patients with rheumatoid arthritis (RA) with at least four tender or swollen joints despite the use of a stable dose of methotrexate for at least 3 months. Patients were categorized into a group of seven patients naïve to biologics and a group of 10 patients who had failed a variety of biologic treatment types.
The stimulation devices were implanted surgically and were inactive for 14 days after surgery, but the vagus nerve was stimulated prior to surgery to measure impedance and to verify function of the device. Following the recovery period, the first treatment day included a single 60-second stimulation with an electric current of 250-µs duration at 10 Hz with an output current of 0.25 to 2.0 mA. Through day 28, this process was repeated on a weekly basis and adjusted based on patient tolerance. On day 28, current output was similar between the two cohorts.
The production of tumor necrosis factor (TNF) and disease activity measurements were reduced and disease activity in peripheral blood at day 42 compared to baseline. The vagus nerve stimulator was turned off on day 42 for a 14-day hiatus, during which TNF production and measurements of disease activity increased by day 56. Following reactivation, TNF production was reduced when tested at day 84.
Using American College of Rheumatology criteria, 71.4% of patients had a 20% improvement in disease activity; 57.1% of patients had a 50% improvement; and 28.6% of patients had a 70% response. Laboratory cytokine measurements were significantly reduced during treatment, and measurement at day 21 showed a correlation between the reduction of interleukin-6 and lower disease activity.
“This first-in-class study supports a conceptual framework for further studies of electronic medical devices in diseases currently treated with drugs, an approach termed ‘bioelectronic medicine,’” the researchers wrote. “Larger clinical trials in RA can be designed and powered to
assess clinical efficacy, but our findings encourage pursuing this strategy in RA and in other cytokine-mediated autoimmune and auto-inflammatory disorders.”
Disclosures: Koopman reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.