Problem of nonresponse to allergen immunotherapy

Abstract

Introduction: Allergen immunotherapy (AIT) is very important and effective and reduces medication use in patients with allergic rhinitis. However, some patients have no response to AIT. Aim: To explore the problem of nonresponding patients after AIT. Material and methods: This retrospective randomized observational study included 1056 patients with allergic rhinitis who underwent subcutaneous injection allergen immunotherapy (SCIT). Patients who received SCIT to one of the following allergens: grass pollen, birch, trees, mugwort, house dust mites, Alternaria or cat were analyzed according to the inclusion criterion of ≥ 20% improvement in all monitored parameters. There were symptoms and medication score, rhinitis symptom score and serum allergen-specific IgE and IgG4. Results: A total of 806 (76.3%) patients met the criterion of 20% or greater improvement after SCIT. The greatest effectiveness was obtained in patients receiving SCIT to grass pollen (293 participants; 83.2%), birch (82; 81.2%) and house dust mites (255; 76.4%). Statistically significant predictors of an improved AIT outcome in the multivariate analysis were SCIT to grass pollen (OR = 2.34, p = 0.035), SCIT to birch (OR = 2.25, p = 0.021) and the presence of only intermittent allergic rhinitis before SCIT (OR = 2.05, p = 0.039). Patients who received SCIT to mugwort, Alternaria or cat had weak response results especially in long-term observations. Conclusions: The best predictors to obtain good responsiveness to SCIT are the presence of intermittent allergic rhinitis to grass or birch pollen. Patients with allergies to mugwort, Alternaria and cat with a prolonged duration of persistent allergic rhinitis dominated in the group of nonresponders to SCIT.