Imunoalergologia, Área de Pediatria Médica, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE, Lisboa
- 6th International Symposium on Molecular Allergology, 17-21 Novembro 2015, Lisboa, Portugal
Introduction: In the south of Portugal, grass and olive tree are the most common pollen allergens. In a previous study in pollen polysensitized patients, when comparing the results of SPT (skin prick tests) and ISAC (ImmunoCAP-ISAC) we observed an excellent concordance between the two tests for grass but not for olive pollen. The aim of this study was to characterize the pattern of sensitization to mollecular allergens in patients with positive SPT to olive and pollen polysensitization.
Method: We did a retrospective analysis on a sample of 42 patients with asthma and/or rhinitis, with positive SPT to olive and at least one more pollen, who had specific IgE detection by ISAC. We analized the results of ISAC, focusing on olive pollen specific allergens (Ole e 1, Ole e 7 and Ole e 9) and crossreactive allergens
Results: Mean age was 22 years (ranging from 4 to 52 years) and 52% were females. Besides olive, SPT was positive to grass in 95,2%, plantain in 45,2%, birch in 35,9%, plane tree in 35,9% and to other pollens in less than 30% each. In ISAC, 50% (n=21) were positive to Ole e 1 and 7% (n=3) reacted to Ole e 7, corresponding to 22 olive positive patients (Olea+). No patient reacted to Ole e 9. Overall, 48% (n=20) had no detectable IgE to the olive pollen allergens present in ISAC (Olea-). We found co-sensitization to grass allergens in the majority of our sample: 82% of Olea+ patients and 100% of Olea- patients. Olea+ patients were sensitized to profillins and/or polcalcins in 36% of cases; Olea- patients in 50% of cases. We found no sensitization to any crossreactive allergen (profillins, polcalcins, PR-10 or LTP) in 41% of Olea+ and in 45% of Olea-patients. In this sample of 42 patients with positive SPT to olive pollen, ISAC detected no IgE, neither to olive species specific nor to crossreactive molecules in 21% (n=9).
Conclusion: In polysensitized patients, positive SPT in the absence of species specific molecules is attributed to the presence of sensitization to panallergens and not to the allergen source. In our sample of patients apparently sensitized to olive the percentage of sensitization to olive species specific allergens was low and in almost half of these there was also no reactivity to panallergens which could explain the positive SPT. These results suggest that we might be missing, in ISAC, an olive species specific allergen rellevant to our population.
Palavras Chave: Olive Pollen, Mollecular Allergens, Panallergens, Diagcnosis