Grass Pollen Immunotherapy Using a Cluster Regime for Seasonal Rhinitis and Asthma

This was a single centre, randomized, double-blind, placebo-controlled, parallel group study. The main aim of this study was to assess the effects of grass pollen immunotherapy on symptoms, bronchial hyperresponsiveness, and quality of life in seasonal rhinitis and asthma. Forty-four patients with severe summer hay fever (of whom 36 reported seasonal chest symptoms and 28 had seasonal bronchial hyperresponsiveness) participated in a randomised double-blind, placebo-controlled, parallel group study. After symptom monitoring for one summer, participants matched placebo injections (n=22) in a rapid up-dosing cluster regimen for 4 weeks, followed by monthly injections for 2 years. Outcome measures included hay fever symptoms and medication use, health-related quality of life, and measurements of non-specific bronchial responsiveness. Results: Significant reductions were observed in immunotherapy group compared with the placebo group in hay fever symptoms (49%, 15%: P = 0.1), medication scores (80%, 18%; P=.007), and seasonal chest symptoms (90%, 11%; P \< .05). Impairment of overall quality of life (mean score of 7 domains) during the pollen season was less in the immunotherapy group than in the placebo group (median difference \[95% CI\], 0.8 \[0.18-1.5\]; P=.05=2\]. During the pollen season, there was no change in airway methacholine PC20 (provocation concentration producing a 20% fall in FEV1) in the immunotherapy-treated group (P=5), compared with an almost 3 doubling-dose decrease in the placebo-treated group (P=.5), compared with an almost 3 doubling dose decrease in the placebo-treated group (P=.01, between-group difference). There were no significant local or systemic side effects during the study. Conclusion: Grass pollen immunotherapy improves quality of life in seasonal allergic rhinitis and reduces seasonal asthma symptoms and bronchial hyperresponsiveness. Note: Ongoing mechanistic studies and nasal biopsies studies until 2008