A Trial of Immunological Outcomes of Sublingual Immunotherapy for House Dust Mite (D. Pteronyssinus) Allergy

Allergic diseases represent a major health issue worldwide. Mainstay treatment is allergen avoidance and pharmacotherapy for symptom relief. Allergen immunotherapy offers the advantages of specific treatment with long lasting efficacy, and can modify the course of disease. However, use of this treatment is restricted by the high risk of adverse events especially in asthmatics. Other, better tolerated, routes of allergen administration than the current conventional subcutaneous route (SCIT) have been investigated including sublingual (SLIT). However, the immune parameters of SLIT have not been examined. We propose conducting a randomised, placebo-controlled study of a commercially-available SLIT for house dust mite (HDM) allergy to investigate induction of relevant T cell regulatory immune mechanisms. Immunoregulatory cytokine synthesis and T cell phenotype and function (real time PCR and flow cytometry) will be examined. This project will provide important fundamental knowledge on which to base improved and greater application of this potentially curative treatment for allergy. SLIT has the potential advantage of home administration and suitability for patients with asthma who are currently unable to access many of the allergen desensitising regimens.

Official Title

A Trial of Immunological Outcomes of Sublingual Immunotherapy for House Dust Mite (D. Pteronyssinus) Allergy

Conditions

• Allergic Rhinitis
• Asthma

Study Type

Interventional

Study Design

Treatment, Randomized, Double-Blind, Placebo Control, Parallel Assignment

Further Details

• Primary Outcomes: Immunological mechanisms of SLIT by phenotyping different subsets of cytokine positive T cells, regulatory T cells, and memory T cells in peripheral blood of subjects before, during and after immunotherapy.; -Expression of “immunoregulatory” cytokines by CD4+ T; cells; – Helper, regulatory and memory T cell subsets; (a) Helper T cells; (b) Regulatory T cells; b1- Regulatory T cell phenotype; b2- Regulatory T cell function
• Secondary Outcomes: Symptom diary, medication use, visual analogue score, disease-specific rhinoconjunctivitis Quality of Life Questionnaire

Study Start

November 2005

Eligibility & Criteria

• Ages Eligible for Study: 18 Years – 70 Years
• Genders Eligible for Study: Both

Inclusion Criteria:

• allergic rhinitis and/or
• mild stable asthma
• house dust mite allergic
• positive HDM-specific IgE as determined by skin prick test (wheal diameter >6 mm to D. pteronyssinus) or CAP-Pharmacia score > 2

Exclusion Criteria:

• Immunodeficiency diseases
• Severe or uncontrolled asthma
• Previous immunotherapy with House dust mite (HDM) extract within the last five years or ongoing immunotherapy with HDM or other allergens
• Continuous oral corticosteroids
• Subjects on treatment with beta-blockers
• Pregnant women

Total Enrolment

30 (expected)

Contact Details

• Alessandra Sandrini, MD, PhD +61 3 9276 2000 Ext. 2350 a.sandrini@alfred.org.au
• Kirsten Deckert +61 3 9276 2000 Ext. 3710