Carry-over effect on IFN-gamma production induced by allergen-specific immunotherapy

Background: Allergic rhinitis is characterized by Th2 polarization and defective IFN-gamma production. Specific immunotherapy determines an allergen-specific clinical improvement. Aim of the study: It was to evaluate whether a course of pre-seasonal SLIT with pollen allergen extract might affect the in vitro IFN-gamma production using Dermatophagoides farinae (Do allergen as stimulus, in patients presenting with rhinitis due to pollen allergy. Methods: Thirty-nine AR patients with pollen allergy were included in the study. They assumed pre-seasonal SLIT for 3 months. IFN-gamma-specific producing cells were assessed by cytokine ELISPOT before and 3 months after the SLIT course end. Results: SLIT provided a significant increase of both pollen-induced and Df-induced IFN-gamma production (p<0.001). Conclusions: The present study provides evidence that though the defective IFN-gamma production is allergen-specific in allergic subjects, the SLIT increasing effects on IFN-gamma may be non-specific. (c) 2008 Elsevier B.V. All rights reserved.