Detection of Skin Epithelial Barrier in Patients With Allergic Skin Disorders

Study Overview
=================
Brief Summary
-----------------
The primary function of epithelial tissues is to form a barrier between the body and the external environment, in order to protect the internal tissues from environmental stresses, by minimizing water loss and preventing the entry of pathogens, pollutants and allergens. Allergic disorders, such as atopic dermatitis, have been associated to an impaired epithelial barrier function. Indeed, defects in the epithelial barriers allow tissue-damaging factors to enter the tissue and thus activate the immune response. This study aims to establish a method to assess the epithelial barrier function in vivo by electrical impedance (EI) spectroscopy, a new technique for the characterisation of epithelial tissue. By this technique, a harmless electrical signal is sent through the skin and the response of the tissue is analysed, which is influenced by several cellular properties, such as shape, orientation and size. In order to validate this technique, skin of mice was treated with some molecules able to destroy the epithelial barrier. The investigators observed that, after damaging the barrier, a decrease of the EI can be detected, consistent with the type and degree of the damage. Based on this result, the investigators believe that this technique is a good candidate as an in vivo method to determine skin barrier defects, which might be used in the future as an early diagnostic tool for the prediction of the risk to develop atopic dermatitis in young subjects, allowing the possibility to apply in time possible preventive measures. In addition, this technique might be suitable for the evaluation of a given therapy during the hospitalisation. To confirm this hypothesis, in the present study patients with atopic dermatitis will be recruited. EI measurements will be performed in both lesional and non-lesional skin and values will be compared in order to detect any difference in the electrical response due to the inflammatory state. In addition, in order to evaluate whether these patients have an appreciable defect in their skin electrical behaviour, the investigators will compare non-lesional and lesional skin of patients with skin of healthy volunteers. Peripheral venous blood and skin biopsies will be collected, in oder to characterise several immune cell populations, to detect specific skin barrier mutations and to measure serum cytokines and immunoglobulins. These and some other parameters and will be analysed in order to identify a possible correlation with the EI.

Official Title
-----------------
Assessment of Skin Epithelial Barrier Defects in Patients With Allergic Skin Disorders by Electrical Impedance Spectroscopy

Conditions
-----------------
Atopic Dermatitis, Skin Inflammation

Intervention / Treatment
-----------------
* Device: Nevisense


Participation Criteria
=================
Eligibility Criteria
-----------------
The inclusion criteria for patients in this study are as follows: Age 0 - 85 years Diagnosis of atopic dermatitis and/or another disease of the atopic group The inclusion of patients in this study is independent from the current therapy. During the study all patients will be kept on a therapy that is medically indicated The inclusion criteria for healthy controls in this study are as follows: Age 0 - 85 years No diagnosis or history of allergic disease The inclusion of patients in this study is independent from the current therapy. During the study all patients will be kept on a therapy that is medically indicated Written consent will be obtained after detailed information of the study was given to the participant. Exclusion criteria: Unable to give consent or refusal to participate in the study

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Subjects with atopic dermatitis<br> | Device: Nevisense<br>* Measurement of electrical impedance<br>|
| Controls<br> | Device: Nevisense<br>* Measurement of electrical impedance<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of electrical impedance values between lesional and non-lesional skin in patients with atopic dermatitis | In patients with atopic dermatitis electrical impedance will be measured. Measurements will be performed in both lesional skin and non-lesional skin and values will be compared in order to detect any difference in skin permeability and electrical response due to the inflammatory state. | At Day 0 on hospital admission | 
| Comparison of electrical impedance values in healthy controls and patients with atopic dermatitis | In order to evaluate whether patients have an appreciable defect in their skin electrical behaviour, we will compare the skin of patients with the skin of healthy volunteers. | At Day 0 on hospital admission | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between electrical impedance measurements and innate and adaptive immune responses | 50 ml of peripheral venous blood will be taken in lithium heparin 7 ml tubes and one 7 ml tube without anticoagulant for serum collection. Peripheral blood mononuclear cells (PBMC) will be purified by ficoll density gradient from venous blood and then analysed by multicolor flow cytometry, to characterize T cells, B cells, Natural Killer cells and other immune cell populations. Possible correlations between EI values and these cell subsets will be described. | At Day 0 on hospital admission; at Day 10; at Day 20 on completion of treatment. | 
| Correlation between electrical impedance measurements and genes associated with epidermal barrier defects | From venous blood, DNA will be isolated to detect specific skin barrier mutations, such as filaggrin defects. Possible correlations between EI values and these defects will be identified. | At Day 0 on hospital admission; at Day 10; at Day 20 on completion of treatment. | 
| Correlation between electrical impedance measurements and immune biomarkers in serum | From serum, cytokines and immunoglobulins will be measured, by using protein analysis methods (immunoblotting, ELISA), in order to identify a possible correlation between EI values and specific serum biomarkers. | At Day 0 on hospital admission; at Day 10; at Day 20 on completion of treatment. | 
| Correlation between electrical impedance measurements and the expression profile of relevant proteins at skin tissue level | Skin biopsies will be collected, Real Time Polymerase Chain Reaction (PCR) and immunohistochemistry will be performed to analyse relevant skin molecules, such epidermal barrier proteins and tight junction proteins. Possible correlations between EI values and the expression of these proteins will be described. | At Day 0 on hospital admission; at Day 10; at Day 20 on completion of treatment. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Epithelial barrier, Atopic dermatis, Electrical impedance spectroscopy, Allergy