Short-term immunotherapy: A prospective, randomized, double-blind, placebo-controlled multicenter study of molecular standardized grass and rye allergens in patients with grass pollen-induced allergic rhinitis

Background: Short-term immunotherapy (STI) can be beneficial for patients who are noncompliant with long-term specific immunotherapy. Objective: The efficacy and tolerance of STI with seven preseasonal injections of molecular standardized allergens from grass and rye pollen has been investigated in a double-blind, placebo-controlled multicenter study with 87 patients at 12 German University hospitals. Methods: Symptoms of the eyes, nose, and bronchi and use of symptomatic drugs were documented daily in diaries by patients with allergic rhinitis to grass and/or rye pollen and without bronchial asthma. Patients were monitored by skin prick test titration and measurement of levels of specific IgE and IgG4. Results: The median nasal score for the 10 weeks with the strongest symptoms during the grass pollen season was significantly lower (p = 0.014) with 35.0 for STI (n = 41) versus 69.0 for placebo (n = 40); the overall symptom score was 54.0 for STI versus 97.5 for placebo (p = 0.020). Only STI-treated patients exposed to less than 40 pollen grains per cubic meter per week showed a significantly lower nasal symptom score of 39.0 versus 75.0 for placebo (p = 0.006); these patients also had fewer nasal symptoms and less use of topical nasal drugs (p < 0.001). The threshold dose in skin prick tests was significantly higher, being 9.06 histamine equivalent for skin prick test (HEP) for STI-treated patients who received the maximum dose (n = 22) versus 4.33 HEP for placebo (p = 0.005). Specific IgE levels were significantly higher, being 55.9 SU/ml for STI versus 39.2 SU/ml for placebo after seven injections (p = 0.006) and level of specific IgG4 was 5.36% for STI versus 1.28% for placebo (p < 0.001). No severe systemic reactions were observed. Conclusion: STI with seven preseasonal injections with molecular standardized allergens is effective and well tolerated.