Immunotherapy Administered Under the Tongue to Treat Dust Mite Allergy

This study will investigate sublingual immunotherapy (SLIT), a treatment involving antigens placement under the tongue to help asthma sufferers build a tolerance to the allergy-causing substances. Specifically, this study will determine the effectiveness of SLIT at two different dosing regimens for patients with intermittent mild asthma caused by dust mites.

Asthma is a serious lung condition that is the leading cause of long-term illness in children. Many common household substances can trigger or worsen an asthma attack. It is important for people to reduce household allergens and learn effective treatments for specific types of asthma. Inhaled short-acting beta agonist such as albuterol is the standard treatment for mild, intermittent asthma. However, recent studies have shown that adding allergen-specific immunotherapy to your current asthma therapy can help to control asthma symptoms. This study will determine the safety and effectiveness of SLIT in two different dosing regimens in treating patients with house dust mite-induced allergic rhinitis/mild intermittent asthma. Participants will be randomly assigned to receive low dose SLIT, high dose SLIT, or placebo for at least 12 months. House dsut mite-induced allergy skin tests will be performed at study entry, at selected timepoints throughout the study, and at the end of the study. The tests will determine whether SLIT creates an immune tolerance state as well as whether SLIT acts via local or systemic immunological systems.

Antigen challenge was performed using the antigen house dust mite. Increasing doses of antigen were inhaled and then lung function (using the procedure Spirometry, measuring Forced Expiatory Volume in the 1st second FEV1) was measured after each dose. The challenge was stopped once the lung function (FEV1) was dropped by 20% of percent predicted. The dose of antigen that caused a 20% drop in lung function is considered the bronchial threshold. The higher the dose of antigen that causes the drop in lung function, the higher tolerance a participant has of inhaling house dust mite. This dose was measure at baseline and then again after 12-18 months of treatment with sublingual house dust mite antigen.Cumulative breath units is the unit of measure to indicate how much antigen is tolerated before the FEV1 is dropped by 20%. Cumulative breath units is also known as breath units.

Inclusion Criteria: House dust mite-induced allergic rhinitis/mild intermittent asthma Exclusion Criteria: Use of previous allergy immunotherapy for house dust mite asthma Pregnancy or breastfeeding

Bush RK, Swenson C, Fahlberg B, Evans MD, Esch R, Morris M, Busse WW. House dust mite sublingual immunotherapy: results of a US trial. J Allergy Clin Immunol. 2011 Apr;127(4):974-81.e1-7. doi: 10.1016/j.jaci.2010.11.045. Epub 2011 Feb 18. Erratum In: J Allergy Clin Immunol. 2011 Jun;127(6):1561. Morris, Mary [added].