Non-invasive assessment of soluble skin surface biomarkers in atopic dermatitis patients-Effect of treatment

BACKGROUND

Skin biomarkers are important tools for characterizing specific disease processes in atopic dermatitis (AD) patients and can be used for monitoring and potentially predicting treatment response. Recent developments of minimally invasive skin sampling methods have made sampling easier and less inconvenient for patients. The objective of this study was to evaluate the non-invasive patch technique developed by FibroTx for skin biomarker analysis.

MATERIALS AND METHODS

Ten adult patients with AD were included in the study and treated with topical corticosteroid (diprosone 0.05%) for 2 weeks. Skin surface biomarkers were assessed in three lesional and non-lesional sites before and during treatment using the FibroTx Patch method. Skin tape strips were also collected from the subjects for comparison.

RESULTS

The results showed expression of IL-1 cytokine family members, chemokines, and defensins on lesional and non-lesional skin. Several of these markers were strongly reduced by topical treatment. The biomarker expression in skin surface eluates correlated strongly with those seen in skin tape strips from the same subjects.

CONCLUSION

These data further support the usefulness of non-invasive sampling methods for assessing inflammatory processes in AD skin and demonstrate that the patch sampling method is a good alternative to skin tape strips.

In vivo characterization of structural changes after topical application of glucocorticoids in healthy human skin

Topical glucocorticoids (GC) are known to induce changes in human skin with the potential to develop skin atrophy. Here, atrophogenic effects and subsequent structural changes in the skin after topical application of GC were investigated in vivo. Sixteen healthy volunteers were topically treated daily on the forearms with clobetasol propionate, betamethasone dipropionate, and the petrolatum vehicle for 4 weeks. All treated skin areas and a nontreated control area were examined by ultrasound, optical coherence tomography, confocal laser scanning microscopy, multiphoton tomography (MPT), and resonance Raman spectroscopy at baseline 1 day after last application and 1 week after last application. Investigated parameters included stratum corneum thickness, epidermal, and full skin thickness, keratinocyte size and density, keratinocyte nucleus-to-cytoplasm ratio, skin surface classification, relative collagen and elastin signal intensity, second-harmonic generation-to-autofluorescence aging index of dermis (SAAID), and the antioxidant status of the skin. A reduction in epidermal and dermal skin thickness was observed in GC treated as well as in vehicle-treated and untreated skin areas on the volar forearm. MPT analysis showed an increased epidermal cell density and reduced cell size and nucleus-to-cytoplasm ratio and a significant increase of SAAID after GC treatment indicating a restructuring or compression of collagen fibers clinically being observed as atrophic changes.

MicroRNA expression in early mycosis fungoides is distinctly different from atopic dermatitis and advanced cutaneous T-cell lymphoma

Mycosis fungoides (MF) is the most common variant of cutaneous T-cell lymphoma (CTCL). MF is characterized by chronic inflammation dominated by cluster of differentiation 4-positive (CD4(+)) T-cells and T helper 2 cytokines, and as the malignant T-cell clone is initially elusive, early diagnosis is often impossible. MF usually takes an indolent course, but for unknown reasons may turn into an aggressive disease with a poor prognosis. Herein, we used a global quantitative real-time polymerase chain reaction platform to study microRNA (miR) expression in patients with early MF (n=13), more advanced CTCL (n=42), and atopic dermatitis (AD, n=20). Thirty-eight miRs were differentially expressed (≥2-fold) in early MF vs. AD and 36 in early MF vs. more advanced disease. miRs that distinguish early MF from AD included both up-regulated (miR-155, miR-146a, 146b-5p, miR-342-3p, let-7i*) and down-regulated (miR-203, miR-205) miRs previously implicated in advanced CTCL. When comparing early MF to more advanced CTCL, additional miRs were significantly up-regulated including miRs which are part of the oncogenic miR-17/92, 106b/25 and 106a/363 clusters. In 16 patients for whom detailed follow-up data were available, 72 miRs were found differentially expressed between patients with progressive vs. those with non-progressive disease, again including miRs with a known relevance for lymphomagenesis, e.g. miR-155, miR-21, let-7i, miR-16, miR-142-3p, miR-146b-5p, miR-92a, miR-93 and miR-106a. In conclusion, we showed that early MF and AD display very different miR profiles despite their clinical, histological, and immunological similarities. During progression, an additional set of miRs becomes deregulated, suggesting their role in disease progression. These data suggest that miR profiling in CTCL may be a key to improving both diagnosis and risk prediction.