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

Summary

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. The first year will be followed by an optional open label extension period. 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.

Timeline

Start

2005-11

Primary completion

2008-12

Completion

2008-12

Publications

• Background Fanta C, Bohle B, Hirt W, Siemann U, Horak F, Kraft D, Ebner H, Ebner C. Systemic immunological changes induced by administration of grass pollen allergens via the oral mucosa during sublingual immunotherapy. Int Arch Allergy Immunol. 1999 Nov;120(3):218-24. doi: 10.1159/000024270.
• Background Gardner LM, Thien FC, Douglass JA, Rolland JM, O'Hehir RE. Induction of T 'regulatory' cells by standardized house dust mite immunotherapy: an increase in CD4+ CD25+ interleukin-10+ T cells expressing peripheral tissue trafficking markers. Clin Exp Allergy. 2004 Aug;34(8):1209-19. doi: 10.1111/j.1365-2222.2004.02009.x.
• Background Rolland JM, Douglass J, O'Hehir RE. Allergen immunotherapy: current and new therapeutic strategies. Expert Opin Investig Drugs. 2000 Mar;9(3):515-27. doi: 10.1517/13543784.9.3.515.
• O'Hehir RE, Gardner LM, de Leon MP, Hales BJ, Biondo M, Douglass JA, Rolland JM, Sandrini A. House dust mite sublingual immunotherapy: the role for transforming growth factor-beta and functional regulatory T cells. Am J Respir Crit Care Med. 2009 Nov 15;180(10):936-47. doi: 10.1164/rccm.200905-0686OC. Epub 2009 Aug 20.

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