Wearable perspiration sensor for continuous inflammation tracking in inflammatory bowel disease.

BACKGROUND: Wearable sensors present an opportunity to monitor inflammation via noninvasive media such as perspiration, which may be sampled continuously to track biomarkers in inflammatory bowel disease (IBD). Here we demonstrate the use of a perspiration sensor for C-reactive protein (CRP) and calprotectin and their clinical significance. METHODS: Thirty-three patients with IBD were enrolled in a cross-sectional study of CRP and calprotectin perspiration expression compared to expression in serum and stool, respectively. Perspiration on-body measurements were obtained every minute using a wearable sensor worn for 40-130 minutes during standard of care assessment. Synchronously collected serum levels were measured, as was fecal calprotectin from a subcohort. RESULTS: Principal component analysis of demographic data identified age, disease activity, and diagnosis as the major contributors to variance in the dataset. When endoscopic scores were incorporated into the PCA, both disease activity and endoscopy score were identified as contributing most strongly to the primary variance. In perspiration and serum, median CRP was observed to be elevated in patients with Crohn's disease (CD) compared to ulcerative colitis, while median calprotectin was elevated in UC compared to CD. Median calprotectin across perspiration, serum, and stool was observed to be elevated in IBD of the colon over isolated ileal IBD. Furthermore, median perspiration and serum CRP were elevated in patients under 40 years of age compared to those 40 and older, whereas median perspiration, serum, and fecal calprotectin were elevated in patients 40 and older compared to the younger cohort. CONCLUSIONS: We report the use of a noninvasive perspiration sensor for tracking inflammatory markers in patients with IBD and demonstrate consistency of perspiration CRP and calprotectin measurements with corresponding serum and stool measurements.