Long-term efficacy of injected allergen immunotherapy for treatment of grass pollen allergy in elderly patients with allergic rhinitis.

Background: The effect of prolonged allergen immunotherapy is still insufficiently known, especially in elderly patients. Objective: The effect after a 3-year course of injected allergen-specific immunotherapy (AIT) for grass pollen allergy in elderly patients with allergic rhinitis was observed. Methods: Thirty-eight elderly patients (mean ± standard deviation, 66.2 ± 2.7 years old) who received preseasonal injected AIT or placebo for grass pollen allergy were monitored for 3 years and compared with a placebo group. The combined symptom medication score (CSMS), serum level of immunoglobulin G4 (IgG4) to phleum pratense 5 (Phl p5) and quality of life were assessed immediately after AIT and 3 years later. Results: After AIT, the CSMS was significantly decreased from 2.15 (range, 1.27-3.00) to 1.13 (range, 0.79-1.36) (p = 0.03) and remained lower (1.41 ± 0.72 versus 2.41 ± 1.11) than that in the placebo group during the 3 years after AIT. Serum-specific IgG4 against increased during the course of AIT and remained at a high level during further observation. Quality of life, based on the Rhinoconjunctivitis Quality of Life Questionnaire, was significantly decreased in the patients who received AIT from 1.51 (95% confidence interval [CI], 1.21-1.84) to 1.01 (95% CI, 0.93-1.87) (p < 0.05) and was decreased to 0.97-1.26 (95% CI, 0.88-1.82) during the 3 years after discontinuation of AIT. Conclusion: A prolonged positive effect after AIT for grass pollen allergy was observed in elderly patients with allergic rhinitis. Further trials are needed to confirm this effect.Clinical trial MC56871/12, <ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.clinicaltrials.gov">www.clinicaltrials.gov</ext-link>.