Sweat-Based Wearable Device Monitors Key Markers of IBD Activity

A sweat-based wearable device can feasibly evaluate key markers of inflammatory bowel disease (IBD), including tumor necrosis factor-alpha (TNF-α) levels, according to new data presented at Digestive Disease Week (DDW) 2024.¹

Current monitoring for IBD relies primarily on patient-reported symptoms, or the cross-sectional evaluation of blood, stool, imaging, or endoscopy. A novel wearable device could offer the ability to monitor real-time disease activity, in both a remote and passive manner.

“TNF-α levels in the sweat of subjects with IBD correlate with serum values, suggesting feasibility in non-invasive disease monitoring,” wrote the investigative team, led by Shalini Prasad, PhD, The University of Texas at Dallas.

Across many disease states, wearable technology has been implemented in managing chronic disease, with the ability to measure continuously non-invasive physiologic variables.² Traditional markers of wearable devices include heart rate, physical activity, and sleep.

Sweat has been identified as a promising and easily accessible biofluid to monitor using wearable devices, as it can be assessed non-invasively for continuous sampling of sweat analytes with their serum concentrations.³ In particular, sweat contains biomarkers that play a notable role in the monitoring and pathophysiology of IBD, including inflammatory proteins, such as C-reactive protein, and cytokines, including TNF-α, interleukin-1, and interleukin-625.⁴

Previously, the most common way to evaluate sweat was by an adhesive patch, which can offer an effective assessment of biomarkers, but is offset by a limited duration of time and non-continuous measurement.⁵

To address these limitations, the investigative team developed a sweat-based wearable device to advantage from the ability to measure physiologically meaningful analytes in the sweat.¹ The device allowed for sedentary sweat sampling for up to 5 days, with real-time assessment of analyte concentrations sent to a custom smartphone application via Bluetooth.

Participants with an IBD-related hospital admission and C-reactive protein >5µg/L wore the sweat-based wearable device for up to 5 days. The device continuously assessed TNF-α levels in the sweat and the sensor response was measured by non-faradaic electrochemical impedance spectroscopy. Serum samples were collected daily to assess TNF-α levels in the blood.

A total of 28 participants were enrolled in the study, including 16 with IBD and 12 healthy controls. The sweat-sensing device measured sweat TNF-α in individuals with IBD between 0.31 and 4.1 pg/mL and between 0.09 to 1.23 pg/mL in healthy controls.

Among the IBD population, Prasad and colleagues identified a moderate, linear relationship between serum and sweat TNF-α levels (r2, 0.72). Individuals with IBD demonstrated a mean sweat TNF-α level of 2.11 pg/mL, compared with a mean value of 0.19 pg/mL in the healthy controls (P <.0001).

Overall, the sweat TNF-α measurements differentiated the active IBD cohort from healthy controls with an area under the curve (AUC) of 0.962 (95% CI, 0.894 to 1.000). The device demonstrated a sensitivity and specificity of 90.9% and 91.7% at a TNF-α cutoff of 0.98 pg/mL.

Based on these data, Prasad and colleagues indicated the sweat-sensing wearable device could provide a novel way to monitor key markers of IBD disease activity remotely, and further study may be warranted.

“This work suggests the feasibility of using a non-invasive sweat-sending wearable device to monitor IBD disease activity,” they wrote.

References

1. _{Hirten R, Lin K, Whang J, Shahub S, Helmus D, Muthukumar S, Sands B, Prasad S. Longitudinal Assessment of Sweat-Based TNF-Alpha in Inflammatory Bowel Disease Using a Wearable Device. Lecture presented at Digestive Disease Week 2024, May 18 - 21, 2024.}
2. _{Hirten RP, Stanley S, Danieletto M, et al. Wearable Devices Are Well Accepted by Patients in the Study and Management of Inflammatory Bowel Disease: A Survey Study. Dig Dis Sci. 2021;66(6):1836-1844. doi:10.1007/s10620-020-06493-y}
3. _{Emaminejad S, Gao W, Wu E, et al. Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform. Proc Natl Acad Sci U S A. 2017;114(18):4625-4630. doi:10.1073/pnas.1701740114}
4. _{Jagannath B, Lin KC, Pali M, Sankhala D, Muthukumar S, Prasad S. A Sweat-based Wearable Enabling Technology for Real-time Monitoring of IL-1β and CRP as Potential Markers for Inflammatory Bowel Disease. Inflamm Bowel Dis. 2020;26(10):1533-1542. doi:10.1093/ibd/izaa191}
5. _{Marques-Deak A, Cizza G, Eskandari F, et al. Measurement of cytokines in sweat patches and plasma in healthy women: validation in a controlled study. J Immunol Methods. 2006;315(1-2):99-109. doi:10.1016/j.jim.2006.07.011}