R Asero1. 1. Ambulatorio di Allergologia, Clinica San Carlo, Paderno Dugnano, MI, Italy. r.asero@libero.it
Abstract
BACKGROUND: Some studies have suggested that specific immunotherapy (SIT) may cause de novo sensitization to allergenic proteins to which patients were not previously allergic. This event might theoretically involve cross-reacting pollen allergens, such as profilin or polcalcins, posing a risk of SIT-induced polysensitization to pollens in patients who were originally monosensitized. OBJECTIVES: The aim of this study was to assess whether injection SIT with commercial pollen extract represents a risk factor for the de novo development of sensitization to different pollens in monosensitized patients. METHODS: The study involved 142 subjects diagnosed as being monosensitized to a single pollen: 64 patients who were administered a 3-year course of injection SIT and 78 controls. Subjects underwent control skin prick tests (SPT) with a series of 8 seasonal airborne allergens at least 3 years after the first visit. Patients with 5 or more new sensitivities on SPT were considered to be de novo polysensitized. RESULTS: At the end of the 3-year follow-up period, the proportion of polysensitized subjects was identical in previously monosensitized patients who underwent SIT and control individuals (11% and 10%, respectively). Individuals who were polysensitized were significantly younger than those who were not (mean age +/- SD, 21.6 +/- 11.0 years vs. 31.6 +/- 15.6 years; P < .05). CONCLUSION: SIT does not represent a risk factor for progression towards multiple pollen sensitization in monosensitized pollen-allergic patients.
BACKGROUND: Some studies have suggested that specific immunotherapy (SIT) may cause de novo sensitization to allergenic proteins to which patients were not previously allergic. This event might theoretically involve cross-reacting pollen allergens, such as profilin or polcalcins, posing a risk of SIT-induced polysensitization to pollens in patients who were originally monosensitized. OBJECTIVES: The aim of this study was to assess whether injection SIT with commercial pollen extract represents a risk factor for the de novo development of sensitization to different pollens in monosensitized patients. METHODS: The study involved 142 subjects diagnosed as being monosensitized to a single pollen: 64 patients who were administered a 3-year course of injection SIT and 78 controls. Subjects underwent control skin prick tests (SPT) with a series of 8 seasonal airborne allergens at least 3 years after the first visit. Patients with 5 or more new sensitivities on SPT were considered to be de novo polysensitized. RESULTS: At the end of the 3-year follow-up period, the proportion of polysensitized subjects was identical in previously monosensitized patients who underwent SIT and control individuals (11% and 10%, respectively). Individuals who were polysensitized were significantly younger than those who were not (mean age +/- SD, 21.6 +/- 11.0 years vs. 31.6 +/- 15.6 years; P < .05). CONCLUSION: SIT does not represent a risk factor for progression towards multiple pollen sensitization in monosensitized pollen-allergicpatients.