Atopic Dermatitis: Sub-Saharan Africa vs. Central Europe

Study Overview
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Brief Summary
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Many people are affected by atopic dermatitis (AD) worldwide. However, clinical studies on AD in Sub-Saharan Africa are rare and there is a lack of knowledge about possible differences in pathogenesis between European and African AD. This study will collect clinical and laboratory data with the aim to compare clinical characteristics and immune responses in AD patients in Sub-Saharan Africa and Central Europe. Furthermore, relevant allergens as well as the nasal, skin and gut micro- and mycobiome will be investigated.

Detailed Description
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Objectives of the project: Compare the following aspects in patients suffering from atopic dermatitis (AD) and healthy control (HC) participants in Central Europe (CE) vs. Sub-Saharan Africa (SsA): Clinical characteristics, life quality, treatments, and family history Immune mapping and barrier characterization of lesional and non-lesional skin Exploration of the serological and cutaneous immune signatures Investigation of the skin, nasal and gut microbiome (including bacteria and fungi) Comparison of the sensitization patterns and putting it into clinical context (food questionnaire, anamnesis about allergic symptoms, analysis of IgE and IgG levels)

Official Title
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Environmental Impact and Immune Responses in Atopic Dermatitis Patients in Central Europe and Sub-Saharan Africa: A Prospective Study

Conditions
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Atopic Dermatitis

Intervention / Treatment
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* Other: Observation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: AD patients: Age: ≥18 years Written informed consent given after information about the research project Suffering from active atopic dermatitis No active skin disease other than atopic dermatitis No known active inflammatory disease other than atopic dermatitis/atopic diseases HC participants: Age: ≥18 years Written informed consent given after information about the research project No active skin disease No known atopic disease (atopic dermatitis, asthma, allergy, allergic rhinoconjuncitivitis) No known active inflammatory disease Exclusion Criteria: Known or suspected systemic immunosuppression because of disease Systemic immunomodulatory/-suppressive treatment Glucocorticoids or immunosuppressants (last 4 weeks) or JAK inhibitors (last week) or Omalizumab (last 4 weeks) or Other biologicals e.g. dupilumab (last 2 months) Clinical signs of active bacterial, fungal or viral infection Systemic antibiotic, antimycotic or antiviral treatment 4 weeks prior to start Phototherapy 4 weeks prior to start Active neoplasia Undergoing surgery in the last 2 months Infarction (e.g. stroke), embolism, or thrombosis in the last 2 months Inability to follow the study procedures e.g. due to language problems, dementia etc. of the participant

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Atopic Dermatitis (Europe)<br> | Other: Observation<br>* Questionnaires, Clinical Scores, Biomaterial Sampling<br>|
| Healthy Controls (Europe)<br> | Other: Observation<br>* Questionnaires, Clinical Scores, Biomaterial Sampling<br>|
| Atopic Dermatitis (Tanzania)<br> | Other: Observation<br>* Questionnaires, Clinical Scores, Biomaterial Sampling<br>|
| Healthy Controls (Tanzania)<br> | Other: Observation<br>* Questionnaires, Clinical Scores, Biomaterial Sampling<br>|
| Atopic Dermatitis (Madagascar)<br> | Other: Observation<br>* Questionnaires, Clinical Scores, Biomaterial Sampling<br>|
| Healthy Controls (Madagascar)<br> | Other: Observation<br>* Questionnaires, Clinical Scores, Biomaterial Sampling<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total and specific IgE and IgG levels | Will be put into clinical context with a questionnaire about food intake and allergic symptoms | Day 0 | 
| Questionnaire about food intake | Information about how often the participants are consuming certain foods | Day 0 | 
| Questionnaire about the presence of allergic symptoms | Information about symptoms upon allergen exposure | Day 0 | 
| Description of clinical appearance of AD on black vs. white skin | Appearance, severity and distribution of the skin lesions | Day 0 | 
| Stigmata of atopic constitution | The presence of atopic stigmata will be clinically assessed by study doctors by using a structured form | Day 0 | 
| Skin microbiome (microbial colonization of the skin) | Skin swabs will be taken at the following localizations: Antecubital crease, glabella, vertex, dorsal neck and lesional skin site Analysis by isolation and sequencing of the microbial DNA | Day 0 | 
| Change of the skin microbiome components over time | Skin swabs will be taken at the following localizations: Antecubital crease, glabella, vertex, dorsal neck and lesional skin site Analysis by isolation and sequencing of the microbial DNA | Day 0 and day 28 | 
| Nasal microbiome (microbial colonization of the nasal vestibule) | A nasal swab will be taken upon day 0 It will be used to grow cultures and analyse the microbial DNA | Day 0 | 
| Gut microbiome (microbial colonization of the gut) | Analysis by isolation and sequencing of the microbial DNA | Day 0 | 
| Cutaneous immune response | Skin biopsies are optional and will be taken from lesional and non-lesional skin They will be analyzed by imaging mass cytometry and spatial gene expression analysis | Day 0 | 
| Systemic immune response | Olink multiplex proteomics analyses and characterization of PBMCs will be performed | Day 0 | 
| Change of molecular and cellular mediators of the systemic immune response over time | Olink multiplex proteomics analyses and characterization of PBMCs will be performed | Day 0 and day 28 | 
| Barrier dysfunction of the skin (Imaging Mass Cytometry) | Skin biopsies are optional and will be taken from lesional and non-lesional skin | Day 0 | 
| Barrier dysfunction of the skin (Spatial gene expression analysis) | Skin biopsies are optional and will be taken from lesional and non-lesional skin | Day 0 | 
| Family history of atopic diseases | - Assessment of whether parents, siblings or other family members suffer from atopic diseases | Day 0 | 
| Questionnaire about current treatments | Participants will be asked about their intake of medication and their use of topical treatments | Day 0 | 
| Life Quality measured by Dermatology Life Quality Index (DLQI) | Min. 0, max. 30 points Higher scores indicate a lower quality of life | Day 0 |