Patients with allergic rhinitis show an allergen-specific interferon-gamma defect

Allergic rhinitis (AR) is characterized by Th2 polarized immune response. Consequently, allergic patients have a defect in IFN-gamma production. So far, however, all the experimental studies have investigated only the IFN-gamma production induced by the causal allergen. The aim of this study is to investigate whether there is a difference in the in vitro IFN-gamma production, using different allergens as stimuli, in patients presenting with rhinitis due to pollen allergy. Forty-one AR patients with pollen allergy were enrolled. IFN-gamma-specific producing cells were stimulated with PHA, causal pollen, and House Dust Mite (HDM). IFIN-gamma production was assessed by cytokine ELISPOT. IFN-gamma production of peripheral blood mononuclear cells (PBMC) stimulated by specific pollen was significantly lower than IFN-gamma production of PBMC stimulated by HDM (p<0.001). IFN-gamma production of PBMC stimulated by specitic pollen was significantly lower than IFN-gamma production of PBMC stimulated by PHA (p<0.001). Moreover, in the HDM-sensitized patients, there seems to be a trend for a different defect. The present study highlights that the defective IFN-gamma production is allergen specific and that HDM sensitization may also affects this parameter.