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Evaluation of Oral Food Challenges With Hazelnut And Actual Reintroduction Of Hazelnut In The Diet After Negative OFC
AB24 Abstracts
SATURDAY
90
Evaluation of Oral Food Challenges With Hazelnut And Actual Reintroduction Of Hazelnut In The Diet After Negative OFC N. W. De Jong1, N. Tirzikhan1, H. F. J. Savelkoul2, R. Gerth van Wijk1; 1 ErasmusMC, Rotterdam, NETHERLANDS, 2Wageningen University, Wageningen, NETHERLANDS. RATIONALE: Hazelnut (Hn) allergy is quite common in Europe. This study aimed to evaluate the outcome of Oral Food Challenges (OFC) in patients with a suspected Hn allergy, and to assess the actual reintroduction of hazelnuts in the diet of patients with a negative OFC. METHODS: A retrospective study was performed in the period dec. 2009- dec.2010 at the outpatient allergy clinic ‘‘Kinderhaven’’ and the Department of Allergology, ErasmusMC in Rotterdam, the Netherlands. Patients, with negative Hn OFC, were contacted by telephone (> 5 months later) for additional information about the reintroduction of Hn in the diet after a negative OFC. RESULTS: In total 801 patients with a suspected Hn allergy underwent a SPT with Hn extract. 375/801 had a positive SPT with Hn extract. 47 patients underwent an additional OFC with Hn. The outcome of the OFC was negative for 40/47 patients and no severe reactions were reported during the OFCs. Follow up by telephone resulted in 7/40 (17.5%) patients who still avoided hazelnuts: 5 for reasons like fear and aversion and 2 did not trust the outcome of the OFC. 27/40 patients stated to eat only hazelnut products and 5 tried pure hazelnuts. CONCLUSIONS: No severe reactions were reported during and after the OFC, which indicates the safety of the OFC procedures. Secondly, Hn reintroduction failed for a substantial amount of patients, which emphasizes the need for post OFC consultations, supported with psychological and dietary advices.
91
Milk And Egg Allergy In Adulthood G. Marco, E. Rodriguez, T. Nunez, P. Martinez, C. Pinto, R. Pineda, D. Perez, J. Zubeldia, M. L. Baeza; Hospital General Universitario Gregorio Maranon, Madrid, SPAIN. RATIONALE: Milk and egg allergy in the adulthood is very rare. Yet, the allergy workup confirms only a small percentage of the suspected patients. METHODS: An observational, retrospective study was carried out in patients older than 15 years old attended in our Allergy Service during 2010. A total of 7211 patients were attended, 1133 referred food related symptoms. Among them, 19 and 22 reactions were associated to egg or milk, respectively. RESULTS: Allergic diagnosis, based on anamnesis, prick-test, sIgE or oral challenge, was confirmed in 68.4% of egg (46.1% bird-egg syndrome) and 22.7% of the milk cases. Mean age of symptom’s onset was lower in allergic groups [37.8614.1 years (egg), 24.666.1 (milk)] than in nonallergic patients (45.3613.2 and 36.1615.6 years, respectively). Cutaneous symptoms were mainly reffered by both allergic groups (53.8% of egg and 60% of milk cases) compared to non-allergic groups (16.7% and 17.6%, respectively). Gastrointestinal symptoms were more frequently present in non-allergic patients (83% and 76%, respectively), compared to allergic group (61% of egg and 60% of milk cases). Atopic dermatitis was observed in 38.5% of egg group. Other antecedents; food allergies, rhinoconjunctivitis-asthma, urticaria or drug allergy, were similar in all groups. CONCLUSIONS: Milk and egg allergy in adulthood is rare and symptoms of the allergic population do not differ significantly from the nonallergic groups. The presence of egg allergy is frequently associated with atopic dermatitis.
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
92
Cellular and Serologic Profiling of Adults with Peanut Allergen Sensitization E. C. McGowan, J. H. Savage, J. P. Courneya, P. M. Sterba, A. S. Parihar, R. A. Wood, R. G. Hamilton, S. S. Saini; Johns Hopkins Hospital, Baltimore, MD. RATIONALE: We compared the expression of basophil and serologic measures in peanut-allergen (PA) sensitized adults with varying clinical manifestations. METHODS: Adult subjects were evaluated by history, total IgE, peanutspecific IgE, IgE anti-Ara-h 1,2,3, and 8 (ISAC and ImmunoCAP), basophil spontaneous histamine release (SHR), PA-mediated basophil histamine release (BHR), and baseline basophil CD203c expression. RESULTS: Adults with confirmed peanut allergy (Group B, n514) were compared to peanut-sensitized, but tolerant, adults(Group C, n54). Peanut-specific IgE (median 15.2 vs. 1.03 kUa/L, p 5 0.009) and specific to total IgE ratios (7.11% vs. 0.39%, p 5 0.022) were increased in Group B compared to Group C, but not total IgE levels. Group B subjects demonstrated broader IgE reactivity to +Ara-h 1,2,3, and 8 by ISAC (28.11 ISU vs 0 ISU, p 5 0.05) and ImmunoCAP (34.11 vs. 0.34 kUa/L, p 5 0.019). Group B had markedly increased Arah-2 (15.4 vs. 0.055 kUa/ L, p 5 0.007) and similar Arah-h 8 ImmunoCAP reactivity (p50.95). Basophil SHR was higher in Group B (6.3% v. 2.65%, p 5 0.015), but not baseline surface CD203c expression. PA concentrations eliciting threshold and maximum BHR were several logs lower in Group B (p 5 <0.01). CONCLUSIONS: Adults with peanut allergy were found to have broader PA-specific IgE expression and heightened measures of basophil reactivity compared to subjects with asymptomatic sensitization.
93
The Effects of CCR9+ and CD103+ Dendritic Cells on Regulatory T-cells in Food Allergy M. A. Garcia, K. Nadeau; Stanford University, Stanford, CA. RATIONALE: We have previously implicated CD103+ DCs (dendritic cells) and CCR9+ pDCs (plasmacytoid DCs) in food allergy. We coincubated dendritic cells with T-cells in food allergy and healthy patients and measured the degree to which regulatory T-cells (Tregs) could be induced. We hypothesized that food allergy patients, having fewer numbers of tolerogenic DCs, would have reduced induction of Tregs. METHODS: To model the gut environment, PBMCs (peripheral blood mononuclear cells) from healthy (HC) or food allergic (FA) subjects were coincubated with the Caco2 (epithelial gut cells, ATCC) cell line for 18 hours either with or without stimulation by the allergen. To model the periphery, DCs and T-cells isolated from whole blood were coincubated for up to 72 hours. In both cases, the change in number of Tregs was evaluated. RESULTS: In the gut model studies, we saw an increase of Tregs in HC subjects compared to a decrease in FA patients (+1.3 vs. -1.0%, n53, p<0.05), following incubation with Caco2 cell after food allergen stimulation. In the peripheral blood incubations, Tregs increased the most after 24 hours when adding both anti-CCR9 and 1MT*. *inhibitor of indoleamine 2,3-deoxygenase (IDO) in DCs CONCLUSIONS: These findings are the first to implicate CD103 gut DCs with human food allergy. Additionally, we have shown that DCs can be altered in their Treg induction ability when blocking specific chemokine receptors (CCR9) and tolerogenic enzymes (IDO) in DCs. Continuing to identify important dendritic cell biomarkers will better enable us to diagnose and treat food allergy patients in the future.
SATURDAY
90
Evaluation of Oral Food Challenges With Hazelnut And Actual Reintroduction Of Hazelnut In The Diet After Negative OFC N. W. De Jong1, N. Tirzikhan1, H. F. J. Savelkoul2, R. Gerth van Wijk1; 1 ErasmusMC, Rotterdam, NETHERLANDS, 2Wageningen University, Wageningen, NETHERLANDS. RATIONALE: Hazelnut (Hn) allergy is quite common in Europe. This study aimed to evaluate the outcome of Oral Food Challenges (OFC) in patients with a suspected Hn allergy, and to assess the actual reintroduction of hazelnuts in the diet of patients with a negative OFC. METHODS: A retrospective study was performed in the period dec. 2009- dec.2010 at the outpatient allergy clinic ‘‘Kinderhaven’’ and the Department of Allergology, ErasmusMC in Rotterdam, the Netherlands. Patients, with negative Hn OFC, were contacted by telephone (> 5 months later) for additional information about the reintroduction of Hn in the diet after a negative OFC. RESULTS: In total 801 patients with a suspected Hn allergy underwent a SPT with Hn extract. 375/801 had a positive SPT with Hn extract. 47 patients underwent an additional OFC with Hn. The outcome of the OFC was negative for 40/47 patients and no severe reactions were reported during the OFCs. Follow up by telephone resulted in 7/40 (17.5%) patients who still avoided hazelnuts: 5 for reasons like fear and aversion and 2 did not trust the outcome of the OFC. 27/40 patients stated to eat only hazelnut products and 5 tried pure hazelnuts. CONCLUSIONS: No severe reactions were reported during and after the OFC, which indicates the safety of the OFC procedures. Secondly, Hn reintroduction failed for a substantial amount of patients, which emphasizes the need for post OFC consultations, supported with psychological and dietary advices.
91
Milk And Egg Allergy In Adulthood G. Marco, E. Rodriguez, T. Nunez, P. Martinez, C. Pinto, R. Pineda, D. Perez, J. Zubeldia, M. L. Baeza; Hospital General Universitario Gregorio Maranon, Madrid, SPAIN. RATIONALE: Milk and egg allergy in the adulthood is very rare. Yet, the allergy workup confirms only a small percentage of the suspected patients. METHODS: An observational, retrospective study was carried out in patients older than 15 years old attended in our Allergy Service during 2010. A total of 7211 patients were attended, 1133 referred food related symptoms. Among them, 19 and 22 reactions were associated to egg or milk, respectively. RESULTS: Allergic diagnosis, based on anamnesis, prick-test, sIgE or oral challenge, was confirmed in 68.4% of egg (46.1% bird-egg syndrome) and 22.7% of the milk cases. Mean age of symptom’s onset was lower in allergic groups [37.8614.1 years (egg), 24.666.1 (milk)] than in nonallergic patients (45.3613.2 and 36.1615.6 years, respectively). Cutaneous symptoms were mainly reffered by both allergic groups (53.8% of egg and 60% of milk cases) compared to non-allergic groups (16.7% and 17.6%, respectively). Gastrointestinal symptoms were more frequently present in non-allergic patients (83% and 76%, respectively), compared to allergic group (61% of egg and 60% of milk cases). Atopic dermatitis was observed in 38.5% of egg group. Other antecedents; food allergies, rhinoconjunctivitis-asthma, urticaria or drug allergy, were similar in all groups. CONCLUSIONS: Milk and egg allergy in adulthood is rare and symptoms of the allergic population do not differ significantly from the nonallergic groups. The presence of egg allergy is frequently associated with atopic dermatitis.
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
92
Cellular and Serologic Profiling of Adults with Peanut Allergen Sensitization E. C. McGowan, J. H. Savage, J. P. Courneya, P. M. Sterba, A. S. Parihar, R. A. Wood, R. G. Hamilton, S. S. Saini; Johns Hopkins Hospital, Baltimore, MD. RATIONALE: We compared the expression of basophil and serologic measures in peanut-allergen (PA) sensitized adults with varying clinical manifestations. METHODS: Adult subjects were evaluated by history, total IgE, peanutspecific IgE, IgE anti-Ara-h 1,2,3, and 8 (ISAC and ImmunoCAP), basophil spontaneous histamine release (SHR), PA-mediated basophil histamine release (BHR), and baseline basophil CD203c expression. RESULTS: Adults with confirmed peanut allergy (Group B, n514) were compared to peanut-sensitized, but tolerant, adults(Group C, n54). Peanut-specific IgE (median 15.2 vs. 1.03 kUa/L, p 5 0.009) and specific to total IgE ratios (7.11% vs. 0.39%, p 5 0.022) were increased in Group B compared to Group C, but not total IgE levels. Group B subjects demonstrated broader IgE reactivity to +Ara-h 1,2,3, and 8 by ISAC (28.11 ISU vs 0 ISU, p 5 0.05) and ImmunoCAP (34.11 vs. 0.34 kUa/L, p 5 0.019). Group B had markedly increased Arah-2 (15.4 vs. 0.055 kUa/ L, p 5 0.007) and similar Arah-h 8 ImmunoCAP reactivity (p50.95). Basophil SHR was higher in Group B (6.3% v. 2.65%, p 5 0.015), but not baseline surface CD203c expression. PA concentrations eliciting threshold and maximum BHR were several logs lower in Group B (p 5 <0.01). CONCLUSIONS: Adults with peanut allergy were found to have broader PA-specific IgE expression and heightened measures of basophil reactivity compared to subjects with asymptomatic sensitization.
93
The Effects of CCR9+ and CD103+ Dendritic Cells on Regulatory T-cells in Food Allergy M. A. Garcia, K. Nadeau; Stanford University, Stanford, CA. RATIONALE: We have previously implicated CD103+ DCs (dendritic cells) and CCR9+ pDCs (plasmacytoid DCs) in food allergy. We coincubated dendritic cells with T-cells in food allergy and healthy patients and measured the degree to which regulatory T-cells (Tregs) could be induced. We hypothesized that food allergy patients, having fewer numbers of tolerogenic DCs, would have reduced induction of Tregs. METHODS: To model the gut environment, PBMCs (peripheral blood mononuclear cells) from healthy (HC) or food allergic (FA) subjects were coincubated with the Caco2 (epithelial gut cells, ATCC) cell line for 18 hours either with or without stimulation by the allergen. To model the periphery, DCs and T-cells isolated from whole blood were coincubated for up to 72 hours. In both cases, the change in number of Tregs was evaluated. RESULTS: In the gut model studies, we saw an increase of Tregs in HC subjects compared to a decrease in FA patients (+1.3 vs. -1.0%, n53, p<0.05), following incubation with Caco2 cell after food allergen stimulation. In the peripheral blood incubations, Tregs increased the most after 24 hours when adding both anti-CCR9 and 1MT*. *inhibitor of indoleamine 2,3-deoxygenase (IDO) in DCs CONCLUSIONS: These findings are the first to implicate CD103 gut DCs with human food allergy. Additionally, we have shown that DCs can be altered in their Treg induction ability when blocking specific chemokine receptors (CCR9) and tolerogenic enzymes (IDO) in DCs. Continuing to identify important dendritic cell biomarkers will better enable us to diagnose and treat food allergy patients in the future.