Clinical Profiles of Peanut-Allergic Patients and their Sensitization Profiles to Tree Nuts by IgE ImmunoCAP Testing Table 1 summarizes the clinical reactivity profiles of the peanut-allergic childrens results of their skin-prick assessments for peanut, as well as their sensitization profiles to tree nuts. selected tree nuts using an adjusted and representative serum pool of the nine allergic patients. The results showed that this prepared peanut and tree nut protein extracts allowed for the detection of the majority of peanut and selected tree nut known allergens. The reciprocal inhibition ELISA experiments showed limited sIgE cross-reactivities between peanut and the analyzed tree nuts, with peanut being most likely the sensitizing allergen and tree nuts the cross-reactive ones. In the case of hazelnut and pistachio, a coexisting main sensitization to hazelnut and pistachio was also exhibited in the serum pool. Reciprocal inhibition immunoblotting further revealed that storage proteins (2S albumin, 7S vicilin and 11S legumin) could possibly account for the observed IgE-cross-reactions between peanut and the analyzed tree nuts in this cohort of allergic individuals. It also exhibited the importance of conformational epitopes in the exhibited cross-reactions. 0.05) were performed to detect significant differences. 3. Results and Discussion 3.1. Clinical Profiles of Peanut-Allergic Patients and their Sensitization Profiles to Tree Nuts by IgE ImmunoCAP Screening Table 1 summarizes the clinical reactivity profiles of the peanut-allergic childrens results of their skin-prick assessments for peanut, as well as 4-HQN their sensitization profiles to tree nuts. The ImmunoCAP system (CAP) was used in the evaluation of specific IgE (sIgEs) levels for peanut, almond, hazelnut and pistachio in patients sera. Allergen-specific IgE titers above 0.35 kUA/L were considered positive. Table 1 Clinical and sensitization profiles of the peanut-allergic children. 0.05) differences in the intensity of the responses among the tested sera. The binding response of sera from patients 2 and 6 to the 4-HQN peanut protein extract was less pronounced, while sera from patients 5 and 7 revealed the strongest sIgE binding. Open in a separate window Physique 2 Indirect ELISA analysis of specific immunoglobulin E (IgE)-binding to the natural peanut extract for each individual patient. Different letters represent statistical 4-HQN differences according to Tukeys test, with a confidence level of 95%. Values symbolize means SD (= 3). The differences in the sIgE ELISA-binding response of the sera was used to establish a representative pool of sera. The volume contributed by each patients serum to the pool was adjusted according to the observed intensity of sIgE binding. The contributing volume of the less-intense serum was higher in the pool than the one with a higher response. This adjustment avoids that this pool behaves like a dilution of the strongest serum, thereby hiding protein binding to the low sIgE titers from your other sera . The pattern of IgE-binding of the pool (PO) and the nine individual sera to the peanut protein extract was determined by immunoblotting. As shown in Physique 3, clear differences were observed in the resolved protein IgE-binding profiles among the tested sera. The majority of children presented intense bands primarily reacting in the regions of 12-19 kDa, 20-25 kDa, 30 to 40 kDa and 45 to 250 kDa, corresponding to a majority of the resolved proteins (P1-P19) in Physique 1 and Table 2. Of these, the protein bands compatible to Ara h 1, Ara h 2, Ara h 3, Ara h 6, Ara h 7 and Ara h 10 appear to be the most sensitizing peanut allergens for all those nine allergic children (Physique 3). A strong reactivity to Ara h 2 and Ara h 6 was observed for all those nine allergic patients, confirming once more the importance of sIgE against Ara h 2 and Ara h 6 as the highest predictors of clinical reactivity to peanut . Patients 1, 6, 7 and 8 showed, however, no or very little reactivity toward the Ara h 3/4 glycinin subunits around 22C24 kDa. In addition, an IgE-binding band named P2, which was not apparent around the SDS-PAGE Coomassie blue coloration (Physique 1), was detected in the immunoblots of all patients, except patients 6 and 7, who lacked reactivity to this band (Physique 3). This protein band (P2) could possibly be attributed to Ara h 4-HQN 5 (profilin, 12-15 kDa ) and to Ara h 11 (oleosin, 14 kDa ) (Table 2). Moreover, patient 6 experienced a different sensitization pattern, since he only showed IgE-binding in the 15-20 kDa region corresponding herein to P4-P7, which was associated to Ara h PPP1R12A 7, Ara h 10, and Ara h 2 (Table 2). Finally, sera of seven allergic patients (except patients 1 and 6) showed IgE binding to protein bands above 100 kDa (Physique 3). These bands could correspond to reported dimeric and.