Sweat-based wearable opens doors to real-time IBD monitoring

A novel, noninvasive, multiplexed device, called SWEATSENSER, can detect inflammatory markers interleukin-1β (IL-1β) and C-reactive protein (CRP) in the sweat of healthy people, according to a study.

“This work signifies a promising noninvasive technology that allows for continuous monitoring of inflammatory markers that may be implicated in the IBD aetiology,” the researchers said. “The next steps for the technology will focus on testing the device on IBD patients so as to continuously monitor inflammatory markers associated with the disease.”

To first test whether the device could detect changes in biomarker levels, the researchers first tested buffers spiked with IL-1β and CRP. They found that the SWEATSENSER could reliably identify spikes in marker levels. The dynamic ranges for detection of the respective biomarkers were 0.2–200 pg/mL and 1 pg/mL to 10ng/mL, respectively. [Inflamm Bowel Dis 2020;doi:10.1093/ibd/izaa191]

The researchers then tested the device on sweat samples, which they collected from 26 healthy volunteers using FDA-approved patches placed on either arm. One patch was removed 24 hours after placement and the other was removed at 72 hours. SWEATSENSER measurements were compared against an ELISA* reference.

The mean IL-1β and CRP sweat levels were 2 and 11.6 pg/mL, respectively. Pearson correlation analysis showed that SWEATSENSER shared a very good association with ELISA for both IL-1β (r, 0.99) and CRP (r, 0.95).

Bland-Altman plots confirmed the good agreement between both measurement methods. IL-1β showed a tiny mean bias of –0.25 pg/mL toward zero, which was of no significant impact. CRP measurements had a bigger mean bias of –3.9 pg/mL, though this is also unlikely to be substantially consequential. For both biomarkers, most of the measurements fell within ±2 standard deviations of the mean bias, further indicating good between-method agreement.

SWEATSENSER was then tested as a wearable device in 20 healthy volunteers, who wore the sensor for at least 1 hour. The device measured a mean IL-1β concentration of 28 pg/mL. Although measurements varied considerably, ranging from 6–58 pg/mL, errors overlapped, suggesting that IL-1β levels were in a similar range across the volunteers.

“[W]e demonstrate a wearable, noninvasive, multiplexed SWEATSENSER that can detect the study inflammatory biomarkers in a continuous manner,” the researchers said. “This work can be extended to encompass several inflammatory biomarkers through the antibody affinity capture mechanism.”

“Our next step is to test the device on IBD patients to further evaluate if the levels of the markers can be differentiated between healthy and IBD patient cohorts. The device is envisioned to serve IBD patients for reporting a flare-up in real-time for better IBD management,” they added.

*Enzyme-linked immunosorbent assay