Microbiome in Atopic Dermatitis Under Systemic Therapy

Study Overview
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Brief Summary
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The skin microbiome plays a role in the pathogenesis of atopic dermatitis. However, it is unclear whether the range of microbiota on the skin is the cause or consequence of atopic skin inflammation. The influence of new systemic therapies for the treatment of moderate to severe atopic dermatitis (such as biologics or Janus kinase inhibitors) on the skin microbiome is largely unknown. The main aim of this scientific exploratory study is to investigate whether and how the skin microbiome changes in patients with moderate to severe atopic dermatitis during systemic therapy. This not only allows new hypotheses to be generated on the pathogenesis of atopic dermatitis, but also new objective scales for the severity of atopic dermatitis can be developed.

Detailed Description
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A better understanding of the pathology of atopic dermatitis could lead to the development of new therapeutic strategies for this disease and contribute to better and more targeted disease management - an advantage for all patients with atopic dermatitis. The routine examinations are carried out every quarter with routine visits over two years. The dates before, 6, 12, and 24 months after the initiation of systemic therapy are relevant for this study. Deviations from normal practice are not intended. Patients in whom a new initiation of systemic therapy is planned will be invited for a follow-up 6 weeks after initiation and quarterly follow-up visits. Blood samples must be obtained for the examination. The blood is taken to determine the systemic level of inflammatory mediators (serological biomarkers, PBMCs) and for genetic examinations (e.g. filaggrin gene mutation - FLG) as well as mRNA / lncRNA profile. The skin physiological examinations are not invasive or pain-related procedures. Microbiome sampling will be conducted by a skin swab of the inter-scapular region. The blood / skin samples taken as part of this scientific study are pseudonymized in the research laboratories. The samples are stored in the laboratories for a period of 5 years after the end of the study and then destroyed.

Official Title
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Identification of Skin-associated Microbiota in Atopic Dermatitis Patients Undergoing Systemic Therapy

Conditions
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Atopic Dermatitis

Intervention / Treatment
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* Other: not applicable, observational study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with moderate to severe atopic dermatitis Indication for systemic therapy Exclusion Criteria: Patients under 18 years of age upon introducing systemic therapy Pregnant and lactating women

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Dupilumab treated Patients (observational)<br>Patients with atopic dermatitis with indication for dupilumab treatment will be observed. | Other: not applicable, observational study<br>* Patients undergoing systemic therapy according to international accepted guidelines for the therapy of atopic dermatitis, observational study<br>|
| Cyclosporine treated Patients (observational)<br>Patients with atopic dermatitis with indication for cyclosporine treatment will be observed. | Other: not applicable, observational study<br>* Patients undergoing systemic therapy according to international accepted guidelines for the therapy of atopic dermatitis, observational study<br>|
| Baricitinib treated Patients (observational)<br>Patients with atopic dermatitis with indication for baricitinib treatment will be observed. | Other: not applicable, observational study<br>* Patients undergoing systemic therapy according to international accepted guidelines for the therapy of atopic dermatitis, observational study<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of the microbial composition | Comparison of the microbial composition of the skin before, 6 and 12 months after the initiation of systemic therapy. | 1 year | 
| Comparison of microbial composition of the skin with serological biomarkers | Comparison of microbial composition of the skin with serological biomarkers (z.B.TARC, TSLP, CCL27). | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microbial composition and skin barrier function | Comparison of the microbial composition of the skin with the skin physiology (including transepidermal water loss, sebumetry) | 1 year | 
| Correlation of main microbial representants of skin microbiome | Correlation of the S. aureus to the P. acnes ratio | 1 year | 
| Correlation of microbiome and severity of atopic dermatitis EASI | Correlation of the microbiome with the Eczema Area and Severity Index (EASI). EASI ranges from 0-72, increasing severity with increasing score. | 2 years | 
| Correlation of microbiome and severity of atopic dermatitis SCORAD | Correlation of the microbiome with Scoring of Atopic Dermatitis (SCORAD). SCORAD ranges from 0-103, increasing severity with increasing score. | 2 years | 
| Association of the skin microbiome with the mRNA EASI | Correlation of the main representants of skin microbiota and the Eczema Area and Severity Index (EASI). EASI ranges from 0-72, increasing severity with increasing score. | 2 years | 
| Association of the skin microbiome with the mRNA SCORAD | Correlation of the main representants of skin microbiota and Scoring of Atopic Dermatitis (SCORAD). SCORAD ranges from 0-103, increasing severity with increasing score. | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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dupilumab, cyclosporine, skin microbiome, baricitinib