House dust mite sublingual immunotherapy: a double-blind, placebo-controlled study in elderly patients with allergic rhinitis.

Background: Immunotherapy in elderly patients is controversial, and there is still no evidence supporting this treatment's safety and efficacy in this population. This study was performed to evaluate the safety and efficacy of specific sublingual immunotherapy for house dust mite (HDM) allergens in patients over 60 years of age with allergic rhinitis and a confirmed allergy to HDM.

Objective: This study sought to assess nasal symptoms during HDM season, reduce medication use and monitor for adverse reactions during immunotherapy.

Methods: One hundred and eleven 60- to 75-year-old patients with allergic rhinitis and a confirmed Dermatophagoides pteronyssinus and Dermatophagoides farinae allergy were included in the study. The patients were individually randomized to active or placebo groups using a double-blind method (NCTO01605760 ClinicalTrials.gov). A total of 51 subjects in the sublingual allergen-specific immunotherapy (SLIT) group (Staloral 300R, Stallergenes, France) and 57 subjects in the placebo group were monitored for 3 years.

Results: Forty-seven patients completed 3 years of SLIT, and 48 subjects finished the placebo treatment in the same time period. The total nasal symptom score decreased by 44% in the active group and 6% in the placebo group after 3 years of SLIT. This difference was only significant in the active group (P < 0.05). At the end of therapy, the total medication score of the active group decreased significantly by a maximum of 51% (P < 0.05), whereas the total medication score of the placebo control group showed an insignificant decrease (P = 0.56). There were no systemic adverse reactions during the study.

Conclusions & Clinical Relevance: Sublingual allergen-specific immunotherapy in elderly patients with a HDM allergy to D. pteronyssinus and D. farinae generated a significant clinical improvement in the active group compared with the placebo group, particularly during the heating season. This therapy was well tolerated.