Multiple pollen sensitization: A molecular approach to the diagnosis

Background: Sensitization to multiple pollen species is a frequent diagnost ic event. Several allergenic molecules with a high level of homology have b een identified in divergent pollen families and named panallergens. Methods : We sought to define the criteria to evaluate the prevalence of the multip le pollen sensitization, to identify specific markers of this condition, an d to correlate them with the underlying allergic disease. Patients presenti ng an allergic respiratory disease underwent skin testing with 23 pollens. Patients fulfilling predefined selection criteria were grouped and classifi ed as having multiple pollen sensitization. Patients in each subgroup were tested for IgE to rBet v 2, rJun o 2, rBet v 1, rPhl p 5 and bromelain. Dem ographical, allergological and clinical data were recorded in the subgroup of patients with multiple pollen sensitization. Results: Seventeen percent of the pollen-sensitized patients formed the multiple pollen-sensitized sub group. These subjects were positive for most of the pollen species tested r egardless of known exposure to them. None of the subjects sensitized to les s than six pollen species were positive to panallergens, whereas 55% of the sera of the multiple pollen-sensitized group were positive to rBet v 2, an d 15% to rJun o 2. IgE to rBet v 1 and rPhl p 5 were found positive in all the subgroups. Age, gender, bronchial asthma, oral allergy syndrome, skin t est reactivity and previous specific immunotherapy differed significantly w hen these two subsets were considered. Conclusions: Allergy diagnosis based on allergenic molecules is crucial in the patient with multiple pollen sen sitization. This condition appears to be determined by the sensitization to defined allergenic components (panallergens) rather than by pollen of mult iple species as such. Detection of IgE to nonpanallergenic molecules allows to identify more relevant allergenic sources. Clinical aspects of the unde rlying allergic disease (e.g. asthma and oral allergy syndrome) seem to be differently related to IgE reactivity to panallergens. Ccpyright (C) 2001 S . Karger AG, Basel