3-years' long-term effect of subcutaneous immunotherapy (SCIT) with a high-dose hypoallergenic 6-grass pollen preparation in adults.

Background: Most clinical trials investigating preventive and disease-modifying effects of SCIT were performed in children for only a few allergen products. In this study we observed adult patients 3 years after the completion of treatment with a high-dose hypoallergenic 6-grass pollen preparation.

Methods: A double-blind, placebo-controlled (DBPC) trial had proven efficacy and safety of a high-dose hypoallergenic 6-grass pollen preparation in adults. 3 years after termination of a 3-years' pre-seasonal SCIT symptom and medication scores, quality of life, and the development of new sensitizations were investigated Patients who fulfilled the same inclusion and exclusion criteria at start of the DBPC study and who had not received SCIT in the meantime served as a control group.

Results: Symptom-medication score and symptom score were significantly reduced in the Ex-SCIT group in comparison to the control group (p = 0.000). Quality of life (RQLQ) was significantly better in the Ex-SCIT group (p = 0.000). 20 (77%) subjects of the Ex-SCIT group did not show any new sensitizations against a defined allergen panel in comparison to 3 (23%) patients of the control group.

Conclusion: This 3-years' controlled follow-up study in adults demonstrates long-term improvements in symptom-medication score and quality of life and reduced onset of new sensitizations after completion of SCIT.