Evaluation of the use of biomarker levels in dried blood spots as a measurement tool for disease severity in patients with atopic dermatitis and psoriasis.

Atopic dermatitis (AD) and psoriasis are common chronic inflammatory skin
diseases with a relapsing and remitting pattern. Promising new treatments for
atopic dermatitis and psoriasis are currently investigated. An important
question will be whether they are more effective than established treatments
such as cyclosporin A. However, comparing the results of (different) clinical
trials is often difficult because of the large number of clinical outcome
measures that are being used.
Many severity measurement tools that are used in clinical trials have not been
validated. A recent review concluded that the Eczema Area and Severity Index
(EASI), the SCORing Atopic Dermatitis (SCORAD) and the Patient Oriented Eczema
Measure (POEM) are currently the best validated instruments to assess the
severity of AD. The Psoriasis Area and Severity Index (PASI) and the
self-assesed PASI (SA-PASI) are the most widely used clinical trial efficacy
end points for psoriasis. However, the use of these instruments is time
consuming and the ultimate goal from the perspective of evidence-based
medicine is to achieve worldwide consensus to consistently apply a single
valid, reliable, and feasible instrument to measure disease severity of AD and
psoriasis in all future clinical trials. Therefore, there is an urgent need for
a valid, reliable and objective severity measurement tool.
The discovery of novel cytokines and chemokines generated new potential
biomarkers. A large number of these serum biomarkers have been found to
correlateto disease severity in AD. The most frequently reported serum
biomarkers for AD include serum ECP, serum IgE, serum IL-2R, and serum
TARC/CCL17 levels. Currently, no biomarkers are used for monitoring disease
severity in psoriasis.
A disadvantage of the use of serum biomarkers is the need for a venipuncture,
that can only be performed by trained personnel. We therefore want to
investigate the correlation of the levels of a panel of biomarkers determined
in dried blood spots (DBS) with disease severity. Collection of a DBS is a
relatively simple and minimally invasive, nearly painless procedure that can be
done by the patients themselves, at home. We suggest that biomarkers determined
in DBS can replace the assessment of disease severity by clinical severity
measurement tools. This will have great advantages for both daily practice and
clinical trials. It offers an objective measurement tool for disease severity
in AD and psoriasis, which will improve monitoring of patients and make outcome
measures in clinical trials more comparable. Moreover it will decrease the
burden of disease, because less visits to the hospital are necessary. Also in
daily practice this will give us an objective tool to monitor the effects of
treatments/interventions.

To investigate whether the levels of a panel of biomarkers in dried blood spots
can be used as a disease severity measurement tool in patients with AD or
psoriasis.

Time point 1: visit to the outpatient clinic.
-the researcher explains how to obtain a DBS,
-DBS sampling,
-disease severity measurement by the patient using POEM/SA-PASI,
-disease severity measurement by the clinician using EASI/PASI,
-the DBS is brought to the laboratory by the research-physician.

Time point 2: visit to the outpatient clinic, 3 weeks after visit 1.
-DBS sampling,
-disease severity measurement by the patient using POEM/SA-PASI,
-disease severity measurement by the clinician using EASI/PASI,
-the DBS is brought to the laboratory by the research-physician.

Time point 3: visit to the outpatient clinic, 6 weeks after visit 1.
-DBS sampling,
-disease severity measurement by the patient using POEM/SA-PASI,
-disease severity measurement by the clinician using EASI/PASI,
-the DBS is brought to the laboratory by the research-physician.

Participants will undergo a finger prick in three sessions. Performing a
fingerprick entails a slight risk of haemorrhage and infection. The fingerprick
is comparable to the routinely obtained fingerpricks by diabetic patients at
home.