RESUMEN
Summary: Background. The effectiveness of pre-seasonal allergoid immunotherapy in polysensitized patients are not well-known. The aim of the present study was to compare the clinical efficacy and immunological changes of pre-seasonal allergoid immunotherapy in mono and polysensitized patients with grass pollen allergy. Methods. Fourty six patients with seasonal allergic rhinitis undergoing pre-seasonal grass pollen immunotherapy and 28 cases followed by conventional drug treatment were included. These groups were divided into monosensitized and polysensitized ones. All patients were followed between March-September with symptom-medication scores, and visual analogue scale (VAS). The quality of life was assessed using the Mini-RQLQ questionnaire. Phleum pratense (Phl p) specific IgE and IgG4 (UNI-CAP 100, Phadia) measurements were performed before and after 7 weeks of immunotherapy. Results. In the immunotherapy group, 15th weekly symptom-medication scores and VAS scores between May and August were found to be significantly lower than those in the control group (p < 0.05). Phl p specific IgE and IgG4 levels were significantly higher after immunotherapy compared to those before immunotherapy (p = 0.001). Furthermore, Phl p specific IgG4 levels after immunotherapy were also significantly higher than in the control group (p = 0.001). Improvements in activities-practical problems and non-nose/eye symptoms quality of life scores were significantly different between two groups (p < 0.05). There was no difference in terms of clinical and immunological parameters in mono- and polysensitized patients (p > 0.05). Conclusions. This study indicates that clinical improvement with pre-seasonal grass pollen immunotherapy is accompanied by important increase in specific IgG4 blocking antibodies. Furthermore, a single-allergen immunotherapy can lead to similar clinical efficacy and immunological changes in polysensitized as well as monosensitized patients with grass pollen allergy.