BackgroundThe skin proteome contains valuable information on skin condition, but also on how skin may evolve in time and may respond to treatments. Despite the potential of measuring regulatory-, effector- and structural proteins in the skin for biomarker applications in clinical dermatology and skin care, convenient diagnostic tools are lacking. The aim of the present study was to develop a highly versatile and non-invasive diagnostic tool for multiplex measurements of protein biomarkers from the surface of skin.ResultsThe Transdermal Analyses Patch (TAP) is a novel molecular diagnostic tool that has been developed to capture biomarkers directly from skin, which are quantitatively analyzed in spot-ELISA assays. Optimisation of protocols for TAP production and biomarker analyses makes TAP measurements highly specific and reproducible. In measurements of interleukin-1α (IL-1α), IL-1 receptor antagonist (IL-1RA) and human β-defensin (hBD-1) from healthy skin, TAP appears far more sensitive than skin lavage-based methods using ELISA. No side-effects were observed using TAP on human skin.ConclusionTAP is a practical and valuable new skin diagnostic tool for measuring protein-based biomarkers from skin, which is convenient to use for operators, with minimal burden for patients.

Several potential clinical applications of stem cells rely on their capacity to migrate into sites of inflammation where they contribute to tissue regeneration processes. Inflammatory signals are partially mediated by chemokines acting via their receptors expressed on the target cells. Data concerning the repertoire and biological activities of chemokine receptors in human adipose tissue derived stromal cells (ADSCs) are limited. Here we show that CCR1 is one of the few chemokine receptors expressed in ADSCs at a high level. CCR1 expression varies in ADSCs derived from different donors. It sharply decreases in the early phase of ADSCs in vitro propagation, but further demonstrates relative stability. Expression of CCR1 positively correlates with expression of SOX2, OCT4 and NANOG, transcription factors responsible for maintenance of the stemness properties of the cells. We demonstrate that signaling via CCL5/CCR1 axis triggers migration of ADSCs, activates ERK and AKT kinases, stimulates NFκB transcriptional activity and culminates in increased proliferation of CCR1(+) cells accompanied with up-regulation of SOX2, OCT4 and NANOG expression. Our data suggest that chemokine signaling via CCR1 may be involved in regulation of stemness of ADSCs.

<b><i>Introduction:</i></b> Transdermal analysis patches (TAPs) noninvasively measure soluble proteins in the stratum corneum. Ultimately, such local protein profiles could benefit the search for biomarkers to improve personalized treatment in psoriasis. This study aimed to explore the patient friendliness and protein detection by TAP in pediatric psoriasis in daily clinical practice. <b><i>Methods:</i></b> In this observational study, TAPs measuring CXC chemokine ligand (CXCL)-1/2, CC chemokine ligand (CCL)-27, interleukin (IL)-1RA, IL-23, IL-1α, IL-8, IL-4, IL-22, IL-17A, vascular endothelial growth factor (VEGF), human beta-defensin (hBD)-2, hBD-1, and kallikrein-related peptidase (KLK)-5 were applied on lesional, peri-lesional, and non-lesional skin sites of psoriasis patients aged &#x3e;5 to &#x3c;18 years. Discomfort during TAP removal as an indicator for patient friendliness was assessed by visual analogue scale (VAS; range 0–10). <b><i>Results:</i></b> Thirty-two patients (median age 14.0 years) were included, of which 19 were treated with solely topical agents and 13 with systemic treatment. The median VAS of discomfort during TAP removal was 1.0 (interquartile range 1.0). Significantly higher levels in lesional versus non-lesional skin were found for IL-1RA, VEGF, CXCL-1/2, hBD-2, and IL-8, whereas lower levels were found for IL-1α. Skin surface proteins were measured in both treatment groups, with significant higher lesional levels of KLK-5, IL-1RA, hBD-2, IL-1α, IL-23, and CCL-27 in the systemic treatment group. <b><i>Conclusion:</i></b> The TAP platform holds the potential for patient-friendly and noninvasive monitoring of skin-derived proteins in pediatric psoriasis patients in daily clinical practice.

Introduction: Skin surface proteins are potential biomarkers in psoriasis and can be measured noninvasively with the Transdermal Analysis Patch (TAP). This study aims to assess markers measured by TAP over time in daily clinical practice, explore their correlation with disease severity in pediatric psoriasis, and compare the TAP and tape stripping detection capability. Methods: In this prospective observational daily clinical practice study, pediatric psoriasis patients (aged >5 to <18 years) were followed during one year. At each visit, TAPs were applied on lesional (n=2), peri-lesional (n=2), and non-lesional (n=1) sites. Post-lesional skin was sampled if all lesions on the arms, legs, or trunk cleared. Treatment and psoriasis severity data were collected. IL-1RA, hBD-2, IL-1α, IL-8, VEGF, CXCL-1/2, CCL-27, IL-23, hBD-1, IL-22, IL-17A, KLK-5, and IL-4 levels were quantified by spot-ELISA. For the statistical analysis Wilcoxon signed rank tests, Mann-Whitney U tests, and Spearman correlations were used. Detection capability of the TAP was compared to tape stripping in a separate cohort of adult psoriasis patients. Results: 32 patients (median age 15.0 years, median PASI 5.2) were followed for a mean of 11.3 (±3.4) months with a total of 104 visits. In lesional skin (n=197), significantly higher IL-1RA, hBD-2, IL-8, VEGF, CXCL-1/2, IL-23, hBD-1, IL-22, CCL-27, and IL-17A levels were found compared to non-lesional skin (n=104), while IL-1α was higher in non-lesional skin. Marker levels were highly variable over time and did not correlate with disease severity measured by PASI or SUM scores. Comparison of the TAP and tape strip detection capability in adult psoriasis patients (n=10) showed that lesional hBD-2, IL1-α, IL-8, and VEGF, and non-lesional IL-1RA, hBD-2, IL-8, and VEGF were more frequently detected in tape extracts than TAPs. Conclusion: Due to the lack of correlation with clinical disease severity and the current detection capability of the markers measured by TAP in psoriasis, its use in regular practice is still a bridge too far.