1 - Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE, Lisboa
- European Academy of Allergy and Clinical Immunology Congress 2015, Barcelona, Espanha; 6 a 10 de Junho de 2015 - POSTER
Background and Aim: ImmunoCap ISAC® (ISAC) is a diagnostic method which allows the detection of specific IgE to a high number of allergens. Different patterns of sensitization to PTS have been identified. We aimed to analyse these patterns and clinical correlation in a sample of patients studied with ISAC.
Methods: A transversal study was carried out, including all the patients who performed ISAC between 2012 and 2014 (n=80). Cases with positive results for components of peanut, tree nuts and seeds (PTS) were evaluated. Clinical manifestations of PTS allergy (PTSA) and the pattern of sensitisation were assessed.
Results:In 40% (n=32) of patients who performed ISAC a positive allergen component for PTS was detected. Mean age was 25 years (5-60); 56% male; 78% sensitized to pollen. Only half (n=16) had PTSA; the reactions ranged from mucocutaneous symptoms to anaphylaxis. 28 were sensitised to walnut, 19 to peanut, 12 to hazelnut, 4 to soybean, 2 to sesame seed, 1 to cashew and 0 to Brasil nut. Regarding the patterns of sensitisation to molecular components of PTS, most patients were sensitized to LTP (n=21; 66%) or to storage proteins (SP; n=14; 44%); only 3 patients were positive to PR-10 and only 6 had concomitant sensitization to more than one protein family. PTSA was reported by 71% (10/14) of patients sensitized to SP (3 cases of anaphylaxis) and 38% (8/21) of patients sensitized to LTP (2 cases of anaphylaxis). Among the asymptomatic ones, 78% were sensitized to LTP and 21% to SP. Only the sensitization to SP had a statistically significant association with the presence of PTSA (p=0,04).
Conclusions: In our sample, almost half of the patients tested by ISAC during a period of 3 years presented sensitisation to PTS. However, only half of these reported PTSA. In agreement with other studies, the frequency of symptomatic sensitisation is highest and significant when storage proteins are involved. Sensitization to LTP was common but not significantly associated with symptoms and sensitization to PR-10 proteins was rare. A limitation to our study is the fact that oral food challenges were not performed to confirm the diagnosis of PTSA.
Palavras Chave: Food allegy, tree nuts, peanut, ImmunoCapISAC®