Wearable sweat sensing device can signal IBD flare-ups

A wearable device that continuously measures inflammatory bowel disease (IBD) biomarkers, such as calprotectin and C-reactive protein (CRP), from sweat can distinguish between healthy and IBD patients and, as such, be used to monitor patients in real-time to flag an impending flare-up, as shown in a study.

Called SWEATSENSER, the device consists of a replaceable sweat-sensing strip mounted onto a wearable electronic reader that is worn around the wrist. It features a two-electrode system that facilitates detection and quantification of the target biomarkers from small volumes of perspired sweat during normal periods of activity.

Sweat contains a range of analytes—from ions, metabolites, and small molecules to a variety of proteins—and is thus suitable for noninvasive health monitoring platforms, according to principal investigator Dr Badrinath Jagannath of the University of Texas at Dallas, US, who presented their study at the at the virtual Crohn's and Colitis Congress (CCC 2022).

Already, Jagannath and his team previously established that SWEATSENSER can indeed detect inflammatory biomarkers in a continuous manner. In a preclinical assessment, the stable measurements for more than 30 hours demonstrated the ability and efficiency of the device for reliable real-time, continuous monitoring. [Inflamm Bowel Dis 2020;26:1533-1542]

In the current study, the investigators tested the device in 10 healthy individuals and one IBD patient. All participants were asked to wear SWEATSENSER for up to 24 hours over multiple days in order to measure CRP and calprotectin continuously for a minimum of 6 hours.

The participants contributed a total of 151 data points with the SWEATSENSER (healthy individuals, n=108; IBD patient, n=43). Results showed a significant difference in the biomarker levels between the healthy and IBD groups.

Specifically, CRP levels in sweat, computed as a time-average of every 2 hours, were much higher in the IBD patient vs healthy individuals (p<0.0001). The same was true for calprotectin levels, which were found to be 620 and 379 ng/mL (p<0.001), respectively. [CCC 2022, abstract P033]

“This is the first in-human demonstration of a wearable technology for tracking and stratification between healthy and IBD participants,” according to Jagannath, adding that the data confirm the first proof-of-feasibility of real-time monitoring of IBD markers from sweat for detecting elevated levels and a subsequent flare-up.

Calprotectin and CRP are upregulated during an IBD flare, so they serve as key markers for flare-up and inflammation in IBD. Jagannath noted that these two proteins can be picked up in sweat and that this expression correlates well with the expression in blood plasma. [Biol Psychiatry 2008;64:907-911; J Immunol Methods 2006;315:99-109]

Current testing methods and practices rely on samples such as blood and faeces and, thus, lack the ability for real-time tracking of flares, he said. “Therefore, continuous monitoring of [calprotectin and CRP] in real-time can aid in providing active feedback and decision support on the health state for better IBD patient management.”