Immunoallergy Department, Dona Estefânia Hospital, Centro Hospitalar de Lisboa Central, E.P.E., Lisbon, Portugal
- Reunião internacional, apresentação sob a forma de Póster em EAACI Congress 2018, Munique, Alemanha
Background: Bet v 1, a major allergen found in birch pollen, belongs to the PR-10 protein group. In our practice, some Bet v 1 sensitized patients have been identified, residing in areas without this tree genus in its flora. Our aim was to characterize a Portuguese patient population with PR10 sensitization.
Method: A group of patients in whom ImmunoCap ISAC® (ISAC) study was performed, between January 2009 and June 2017, were analyzed. All subjects with one or more PR-10 sensitizations were selected, and their clinical records reviewed. A sequential sample of the last subjects (n=80) who underwent ISAC study, was then used for comparison.
Results: Out of 234 ISAC studies performed, only 16 were positive for PR-10 protein group. Median age was 18.3 years, 68% (n=11) were male. PR-10 sensitized individuals were more likely to live in Portalegre district compared to the control group (7/16 vs 1/80; p<0,001). 15 patients were positive for PR-10 family pollens (93,7%), frequently Bet v 1 (n=13), followed by Aln g 1 (n=10) and Cor a 1 (n=8). 14 out of the 16 patients were sensitized to PR-10 foods, mostly Cor a 1.0401 (n=13) and Mal d 1 (n=12). Skin prick tests revealed birch as the main sensitizing pollen as well (14/16). Moreover, only four patients were skin prick tested for Fagaceae trees which were positive for oak (4), chestnut tree (3) and cork tree (1). All patients were co-sensitized to other pollens, namely grass and all had respiratory allergy. Nine patients were food allergic, although seven of them were co-sensitized to other cross reactive LTP/profillin) or species specific proteins.
Conclusion: Although PR-10 sensitization is known to be rare in our population, mostly Alto Alentejo inhabitants showed sensitization to this protein family in our sample, either by in vitro and/or in vivo methods. This phenomenon is consistent with the native plant species of this region, which should be taken into account when studying the allergic profile of these patients. In our sample, all PR-10 sensitized patients had respiratory allergy while this protein didn’t seem to be relevant when it comes to food allergy. Further studies are needed to characterize which plant species belonging to this protein family are more significant for our country’s aerobiology context and to determine its clinical relevance.