Prolonged effect of allergen sublingual immunotherapy for house dust mites in elderly patients

The prolonged effect of allergen immunotherapy is unknown, especially in older patients.

To analyze the 3-year effect of sublingual allergen-specific immunotherapy (SLIT) to house dust mites in elderly patients with allergic rhinitis.

Forty-seven elderly patients (65.78 ± 4.89 years old) underwent SLIT to house dust mites and were monitored for 3 years and compared with a placebo group. SLIT was performed with the use of oral Staloral 300 SR Der p and Der f 50/50% extract (Stallergens Greer, London, United Kingdom) or placebo. Symptoms and medication score, represented by the average adjusted symptom score (AAdSS), serum level of immunoglobulin (Ig) G4 to Dermatophagoides pteronyssinus, Dermatophagoides farinae, Der p 1, and Der p 2, and quality of life, were assessed immediately after SLIT and 3 years later.

The AAdSS was significantly decreased after SLIT, and the level remained low during the 3 years after SLIT compared with placebo. Serum-specific IgG4 against D pteronyssinus, D farinae, Der p 1, and Der p 2 increased during the SLIT trial in the study group. For the 3 years of observation after SLIT, there were no significant changes of specific IgG4 levels against the analyzed allergens compared with results just after SLIT. Quality of life based on the Rhinoconjunctivitis Quality of Life Questionnaire score was significantly decreased in patients who received SLIT, from 1.48 (95% confidence interval 1.33-1.79) to 0.98 (95% confidence interval 0.67-1.07; P < .05) compared with 0.94 (95% confidence interval 0.55-1.04) 3 years after SLIT.

The prolonged positive effect after SLIT to house dust mites was observed in elderly patients with allergic rhinitis. Further trials are needed to confirm this effect.

ClinicalTrials.gov Identifier: NCT01605760.