Skin Testing With Recombinant Bet v 1 and Hypoallergenic Recombinant Bet v 1 Fragments

Aim of this study is to use the major allergen 1 of birch-tree pollen (Bet v 1, Betula verrucosa, synonymous Betula pendula), to investigate the contribution of immunoglobulin E (IgE)- versus non-IgE-mediated mechanisms to chronic skin inflammation in atopic dermatitis patients.

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Key information

Conditions

Atopic Dermatitis Congenital, Hereditary, and Neonatal Diseases and Abnormalities Dermatitis Dermatitis, Atopic Genetic Diseases, Inborn Hypersensitivity Hypersensitivity, Immediate Immune System Diseases Skin Diseases Skin Diseases, Eczematous Skin Diseases, Genetic Skin and Connective Tissue Diseases

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Medical University of Vienna

Vienna, 1090, Austria

About this study

In this study non-IgE-reactive recombinant Bet v 1 (rBet v 1) fragments (F1: aa 1-74; F2: aa 75-160) and the fully IgE-reactive recombinant Bet v 1 (aa 1-160)will be used for skin prick testing and atopy patch testing in birch pollen allergic patients with birch pollen induced exacerbation of atopic dermatitis. For control purposes birch pollen allergic patients without birch pollen-induced atopic eczema, persons with allergies other than to birch and non-allergic people will be tested.

The individuals will be subjected to in vivo skin prick and atopy patch testing with rBet v 1, rBet v 1 fragment 1, rBet v 1 fragment 2 and an equimolar mix of the rBet v 1 fragments. In parallel, the IgE reactivity, and in vitro T cell proliferation, and cytokine production will be studied. Those analyses should help to determine the relevance of IgE mediated mechanisms to chronic skin inflammation and T cell proliferation in AD patients.

A staining for the surface markers chemokine receptor (CCR4)+ and cutaneous lymphocyte antigen (CLA)+ which reportedly are enriched in inflamed skin will further allow to investigate whether patients with high numbers of T lymphocytes expressing CCR4 and CLA tend to exhibit stronger skin inflammation. Moreover, allergen-specific antibody and T cell responses will be analyzed 6-8 weeks after the epicutaneous allergen application.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Age between 18 and 75 years
They will be available to complete the study

Exclusion criteria

Severe general maladies
Severe skin inflammation in the test area
Risk of non-controllable general reaction
Pregnancy and breast-feeding
Autoimmune diseases, immune-defects including immuno-suppression, immune-complex-induced immunopathies
Contra-indication for adrenaline
Patients under long-term treatment with systemic corticosteroids immunosuppressive drugs, tranquilizers or psychoactive drugs
Positive IgE reaction on hypoallergenic Bet v 1 derivatives
The subject is currently participating in another clinical study in which the subject is or will be exposed to an investigational or a non-investigational drug.
The subject is at risk of non-compliance with the study procedures/restrictions

Treatment and study plan

SPT and APT

Other

All patients will be tested by skin prick testing (SPT: Histamine, buffer, commercial birch pollen extract, rBet v 1 (20 and 40 μg/ml), rBet v 1 fragment 1 (20 and 40 μg/ml), rBet v 1 fragment 2 (20 and 40 μg/ml), equimolar rBet v 1 fragment mix (20 and 40 μg/ml) in duplets.

Atopy patch testing (APT: birch pollen extract, rBet v 1:160 μg/application, rBet v 1 fragment 1: 160 μg/application, rBet v 1 fragment 2: 160 μg/ml, equimolar mix of rBet v 1 fragments: 160 μg/application; negative control with vaseline alone.

Primary outcomes

Number of Participants with Positive Atopy Patch Testing Reactions of Each Grade on the European Task Force on Atopic Dermatitis Scale

Time frame: 6 months

Birch pollen extract (BPE), as well as rBet v 1 (160mg), rBet v 1 fragment 1 (160mg), rBet v 1 fragment 2 (160mg), and an equimolar rBet v 1 fragment mix (80mg of each rBet v 1 fragment), were applied for 48h in patch test chambers onto nonlesional skin on the backs of the subjects. After 48h, patches were removed, and reactions were analyzed and photodocumented. Grading of positive APT reactions (i.e., reactions of more than 4 mm in diameter) was done according the European Task Force on Atopic Dermatitis by a blinded investigator: -, negative result; ?, only erythema, questionable; +, erythema, infiltration; ++, erythema, few papules (<3); +++, erythema, papules from 4 to less than many; ++++, erythema, many or spreading papules; or +++++, erythema, vesicles.

Sponsors and collaborators

Lead sponsor

Stefan Woehrl

Other

Collaborators

Medical University of Vienna

Registry information

Official study title

Skin Testing With Recombinant Bet v 1 and Hypoallergenic Recombinant Bet v 1 Fragments to Dissect the Contribution of IgE to Chronic Allergic Skin Inflammation

Important dates

Study start: 2011
Primary completion: 2011
Study completion: 2013
First posted: Mar 28, 2014
Registry last updated: Dec 8, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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