Currently, patients with moderate to severe atopic dermatitis are treated with dupilumab if unresponsive to topical treatment. However, not all patients who suffer from atopic dermatitis respond similarly to this treatment. Pattern recognition of immune cells (PRI) is an efficient method to screen patients to allow a more personalized therapy.

The main aim of this scientific explorative study is to unravel the changes in peripheral blood immune cell compositions in patients with atopic eczema undergoing dupilumab treatment. This allows the identification of phenotypes of treatment responders and non-responders and possible approaches of treatment modifications for non-responders.

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 PRI is a new bioinformatic analysis strategy that allows in-depth data analysis from flow cytometry with multiple variables. This facilitates the identification of meaningful T cell subpopulations, which are differentially abundant between two groups to predict responders and non-responders prior to dupilumab treatment.

Peripheral blood will be collected before, 4 weeks, 8 weeks, and 16 weeks after initiating the systemic treatment with dupilumab to identify recognition patterns/markers on the T cells. Therefore, a predefined multicolor flow cytometry panel was developed to analyse lineage, differentiation and activation markers.

Patients will receive a systemic therapy (dupilumab 600 mg loading dose, followed by 300 mg in two weeks intervals). Follow up visits will be performed every 3 months starting from the second visit (2nd visit will take place 4 weeks after initiating Dupilumab treatment).

The blood samples that are taken as part of this scientific study are pseudonymized in the research laboratories and stored for a period of 5 years after the end of this study or the publication of the results and destroyed.

Inclusion Criteria:

• Age 18 and above
• Diagnosis of atopic dermatitis for ≥1 year
• Inadequate response to treatment with topical medications
• Confirmed dupilumab treatment

Exclusion Criteria:

• Age below 18
• Known or suspected allergy or reaction to any component of the dupilumab formulation
• Known active allergic or irritant contact dermatitis that is likely to interfere with the assessment of the severity of AD
• Severe conjunctivitis or blepharitis

Consecutive patients with moderate to severe atopic dermatitis presenting in the clinic of Dermatology, Charité - Universitätsmedizin Berlin, Germany