Atopic Dermatitis: Sub-Saharan Africa vs. Central Europe

Recruiting

• Conditions: Atopic Dermatitis
• Interventions: Other: Observation

• Registration Number: NCT05363904
• Lead Sponsor: University of Zurich

Brief Summary

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

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)

Study Timeline

• Study First Submitted: 2022-03-04
• Study Start: 2022-03-30
• Study First Submitted QC: 2022-05-02
• Study First Posted: 2022-05-06
• Status Verified: 2024-03
• Last Update Submitted: 2024-03-14
• Last Update Posted: 2024-03-15
• Primary Completion: 2024-12-31
• Study Completion: 2024-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 240

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Atopic Dermatitis (Tanzania)	Observation	-
Healthy Controls (Madagascar)	Observation	-
Healthy Controls (Europe)	Observation	-
Atopic Dermatitis (Madagascar)	Observation	-
Atopic Dermatitis (Europe)	Observation	-
Healthy Controls (Tanzania)	Observation	-

Primary Outcome Measures

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

Trial Locations

Locations (3)

Regional Dermatology Training Centre (RDTC); 🇹🇿 Moshi, Tanzania

University Hospital Joseph Raseta Befelatanana; 🇲🇬 Antananarivo, Madagascar

University Hospital Zurich; 🇨🇭 Zürich, Switzerland