Clinical-Grade Patches as a Medium for Enrichment of Sweat-Extracellular Vesicles and Facilitating Their Metabolic Analysis

Cell-secreted extracellular vesicles (EVs), carrying components such as RNA, DNA, proteins, and metabolites, serve as candidates for developing non-invasive solutions for monitoring health and disease, owing to their capacity to cross various biological barriers and to become integrated into human sweat. However, the evidence for sweat-associated EVs providing clinically relevant information to use in disease diagnostics has not been reported. Developing cost-effective, easy, and reliable methodologies to investigate EVs' molecular load and composition in the sweat may help to validate their relevance in clinical diagnosis. We used clinical-grade dressing patches, with the aim being to accumulate, purify and characterize sweat EVs from healthy participants exposed to transient heat. The skin patch-based protocol described in this paper enables the enrichment of sweat EVs that express EV markers, such as CD63. A targeted metabolomics study of the sweat EVs identified 24 components. These are associated with amino acids, glutamate, glutathione, fatty acids, TCA, and glycolysis pathways. Furthermore, as a proof-of-concept, when comparing the metabolites' levels in sweat EVs isolated from healthy individuals with those of participants with Type 2 diabetes following heat exposure, our findings revealed that the metabolic patterns of sweat EVs may be linked with metabolic changes. Moreover, the concentration of these metabolites may reflect correlations with blood glucose and BMI. Together our data revealed that sweat EVs can be purified using routinely used clinical patches, setting the foundations for larger-scale clinical cohort work. Furthermore, the metabolites identified in sweat EVs also offer a realistic means to identify relevant disease biomarkers. This study thus provides a proof-of-concept towards a novel methodology that will focus on the use of the sweat EVs and their metabolites as a non-invasive approach, in order to monitor wellbeing and changes in diseases.

Residential Exposure to Dampness Is Related to Reduced Level of Asthma Control among Adults

We assessed potential relations between indicators of indoor dampness and mold exposures at home and the level of asthma control among adults. The present population-based cross-sectional study, the Northern Finnish Asthma Study (NoFAS), included 1995 adult subjects with bronchial asthma who replied to study questionnaires (response rate: 40.4%). The Asthma Control Test (ACT) was used as the measure of asthma control. We calculated the mean difference in ACT score (ACT_difference) and the risk ratio (RR) of poor asthma control (ACT ≤ 19) for the exposure and reference groups and applied Poisson regression to adjust for potential confounding. Exposure to indoor dampness at home was related to a significantly reduced level of asthma control (ACT_difference: -0.83, 95% CI: -1.60 to -0.07), especially among men (ACT_difference: -2.68, 95% CI: -4.00 to -1.37). Water damage (aRR = 1.29, 95% CI: 1.01, 1.65) and indoor dampness, especially among men (aRR = 1.92, 95% CI: 1.15, 3.20), increased the risk of poor asthma control. We provide evidence that exposure to indoor dampness at home reduces asthma control among adults, especially in men. Indoor visible mold and mold odor were not significantly related to asthma control. Advice on how to prevent indoor dampness at home should be an important part of asthma management.

Cold weather increases respiratory symptoms and functional disability especially among patients with asthma and allergic rhinitis

Cold weather affects the respiratory epithelium and induces bronchial hyperresponsiveness. We hypothesized that individuals with allergic rhinitis or/and asthma experience cold weather-related functional disability (FD) and exacerbation of health problems (EH) more commonly than individuals without these. This was a population-based study of 7330 adults aged 25–74 years. The determinants of interest, including doctor-diagnosed asthma and allergic rhinitis, and the outcomes, including cold weather-related FD and EH, were measured using a self-administered questionnaire. The prevalences of cold-related FD and EH were 20.3% and 10.3%, respectively. In Poisson regression, the risk of FD increased in relation to both allergic rhinitis (adjusted prevalence ratio (PR) 1.19, 95% CI 1.04–1.37 among men; 1.26, 95% CI 1.08–1.46 among women), asthma (1.29, 0.93–1.80; 1.36, 0.92–2.02, respectively) and their combination (1.16, 0.90–1.50; 1.40, 1.12–1.76, respectively). Also the risk of cold weather-related EH was related to both allergic rhinitis (1.53, 1.15,−2.04 among men; 1.78, 1.43–2.21 among women), asthma (4.28, 2.88–6.36; 3.77, 2.67–5.34, respectively) and their combination (4.02, 2.89–5.59; 4.60, 3.69–5.73, respectively). We provide new evidence that subjects with allergic rhinitis or/and asthma are more susceptible to cold weather-related FD and EH than those without pre-existing respiratory diseases.