Severity and threshold of peanut reactivity during hospital-based open oral food challenges: an international multi-center survey (original) (raw)
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High-dose oral immunotherapy in children with anaphylaxis to peanut
2019
Background: Peanut allergy necessitates dietary restrictions, preferably individualized by determining reactivity threshold through an oral food challenge (OFC). However, risk of systemic reactions often precludes OFC in children with severe peanut allergy. Objective: We aimed to determine whether clinical and/or immunological characteristics were associated with reactivity threshold in children with anaphylaxis to peanut and secondarily, to investigate whether these characteristics were associated with severity of the allergic reaction during OFC. Methods: A double-blinded placebo-controlled food challenge (DBPCFC) with peanut was performed in 96 5-to 15-year-old children with a history of severe allergic reactions to peanut and/or sensitization to peanut (skin prick test [SPT] ≥3 mm or specific immunoglobulin E [s-IgE] ≥0.35 kUA/L). Investigations preceding the DBPCFC included a structured interview, SPT, lung function measurements, serological immunology assessment (IgE, IgG and IgG 4), basophil activation test (BAT) and conjunctival allergen provocation test (CAPT). International standards were used to define anaphylaxis and grade the allergic reaction during OFC. Results: During DBPCFC, all 96 children (median age 9.3, range 5.1-15.2) reacted with anaphylaxis (moderate objective symptoms from at least two organ systems). Basophil activation (CD63 + basophils ≥15%), peanut SPT and the ratio of peanut s-IgE/total IgE were significantly associated with reactivity threshold and lowest observed adverse events level (LOAEL) (all P < .04). Basophil activation best predicted very low threshold level (<3 mg of peanut protein), with an optimal cutoff of 75.8% giving a 93.5% negative predictive value. None of the characteristics were significantly associated with the severity of allergic reaction. Conclusion and Clinical Relevance: In children with anaphylaxis to peanut, basophil activation, peanut SPT and the ratio of peanut s-IgE/total IgE were associated with reactivity threshold and LOAEL, but not with allergy reaction severity. K E Y W O R D S anaphylaxis, basophil, double-blinded placebo-controlled food challenge, food allergy, immunoglobulin E, immunologic tests, peanut allergy, threshold levels The study was performed within the ORAACLE (Oslo Research group of Asthma and Allergy in Children; the Lung and Environment),
Predicting reactivity threshold in children with anaphylaxis to peanut
Clinical & Experimental Allergy, 2018
Background: Peanut allergy necessitates dietary restrictions, preferably individualized by determining reactivity threshold through an oral food challenge (OFC). However, risk of systemic reactions often precludes OFC in children with severe peanut allergy. Objective: We aimed to determine whether clinical and/or immunological characteristics were associated with reactivity threshold in children with anaphylaxis to peanut and secondarily, to investigate whether these characteristics were associated with severity of the allergic reaction during OFC. Methods: A double-blinded placebo-controlled food challenge (DBPCFC) with peanut was performed in 96 5-to 15-year-old children with a history of severe allergic reactions to peanut and/or sensitization to peanut (skin prick test [SPT] ≥3 mm or specific immunoglobulin E [s-IgE] ≥0.35 kUA/L). Investigations preceding the DBPCFC included a structured interview, SPT, lung function measurements, serological immunology assessment (IgE, IgG and IgG 4), basophil activation test (BAT) and conjunctival allergen provocation test (CAPT). International standards were used to define anaphylaxis and grade the allergic reaction during OFC. Results: During DBPCFC, all 96 children (median age 9.3, range 5.1-15.2) reacted with anaphylaxis (moderate objective symptoms from at least two organ systems). Basophil activation (CD63 + basophils ≥15%), peanut SPT and the ratio of peanut s-IgE/total IgE were significantly associated with reactivity threshold and lowest observed adverse events level (LOAEL) (all P < .04). Basophil activation best predicted very low threshold level (<3 mg of peanut protein), with an optimal cutoff of 75.8% giving a 93.5% negative predictive value. None of the characteristics were significantly associated with the severity of allergic reaction. Conclusion and Clinical Relevance: In children with anaphylaxis to peanut, basophil activation, peanut SPT and the ratio of peanut s-IgE/total IgE were associated with reactivity threshold and LOAEL, but not with allergy reaction severity. K E Y W O R D S anaphylaxis, basophil, double-blinded placebo-controlled food challenge, food allergy, immunoglobulin E, immunologic tests, peanut allergy, threshold levels The study was performed within the ORAACLE (Oslo Research group of Asthma and Allergy in Children; the Lung and Environment),
Rising prevalence of allergy to peanut in children: Data from 2 sequential cohorts
Journal of Allergy and Clinical Immunology, 2002
Background: Allergy to peanut is common. However, it is not known whether the prevalence of sensitization and clinical allergy to peanut is increasing. Objective: We sought to determine any change in the prevalence of peanut sensitization and reactivity in early childhood in 2 sequential cohorts in the same geographic area 6 years apart. Methods: Of 2878 children born between September 1, 1994, and August 31, 1996, living on the Isle of Wight, 1273 completed questionnaires, and 1246 had skin prick tests at the age of 3 to 4 years. Those with positive skin prick test responses to peanut were subjected to oral peanut challenges, unless there was a history of immediate systemic reaction. These data were compared with information on sensitization and clinical allergy to peanut available from a previous cohort born in 1989 in the same geographic area. Results: There was a 2-fold increase in reported peanut allergy (0.5% [6/1218] to 1.0% [13/1273]), but the difference was nonsignificant (P = .2). Peanut sensitization increased 3-fold, with 41 (3.3%) of 1246 children sensitized in 1994 to 1996 compared with 11 (1.1%) of 981 sensitized 6 years ago (P = .001). Of 41 sensitized children in the current study, 10 reported a convincing clinical reaction to peanut, and 8 had positive oral challenge results, giving an overall estimate of peanut allergy of 1.5% (18/1246). Conclusions: Sensitization to peanut had increased between 1989 and 1994 to 1996. There was a strong but statistically nonsignificant trend for increase in reported peanut allergy. (J Allergy Clin Immunol 2002;110:784-9.)
Risk Factors for Anaphylaxis in Children Allergic to Peanuts
Background and Objectives: Peanut allergy is the most common single cause of anaphylaxis in children. The risk factors for anaphylaxis in children with peanut allergy are not well defined. Therefore, we aimed to identify epidemiological, clinical and laboratory characteristics of children with peanut allergy that may predict the severity of allergic reaction and anaphylaxis. Materials and Methods: We conducted a cross-sectional study and included 94 children with peanut allergy. Allergy testing was performed, including skin prick testing and determination of specific IgE levels to peanut and its Ara h2 component. In case of discordance between patient history and allergy testing, an oral food challenge with peanut was performed. Results: Anaphylaxis, moderate and mild reactions to peanuts occurred in 33 (35.1%), 30 (31.9%) and 31 (33.0%) patients, respectively. The severity of the allergic reaction only weakly correlated (p = 0.04) with the amount of peanuts consumed. The median num...
Clinical & Experimental Allergy, 2016
Background The MIRABEL survey is an observational study on peanut allergy in France, Belgium and Luxemburg. The objectives are to provide data on a large population, to analyse the consumer behaviour, to study the presence of peanut traces in pre-packed foods with/without precautionary allergen labelling (PAL), and to combine these data to quantify allergic risk and produce a cost/benefit analysis. This paper reports a real-life observatory of 785 patients (< 16y: 86%): medical characteristics, eliciting doses (ED) in real life and in oral food challenges (OFC), factors associated with severe reactions, allergist dietary advice and patients' anxiety regarding their allergy. Methods Age and symptoms at diagnosis, route of exposure, comorbidities, allergy tests, ED (OFC/real life; mg peanut protein), dietary advice about PAL, and anxiety score were recorded. Results Median age was 3 years; 85% were declared allergic. Severe/potentially severe reactions were reported in 30% of the allergic patients: serious systemic reaction (15%), laryngeal angioedema (8%), shock (4%) and acute asthma (3%); 66% had atopic dermatitis, 58% asthma. Median ara h 2 sIgE level was 11.5 kUA/L. Of the 278 OFCs, 225 were positive (median ED: 67.3 mg). Real-life ED was < 100 mg in 44.3%. Severe reactions were significantly more frequent in teenagers and adults (P = 0.004), asthmatic patients (P = 0.033), and patients who reacted to inhalation (P < 0.001). No significant association was found for OFC ED or ara h 2 sIgE. Factors associated with strict avoidance advice including PAL were OFC ED < 100 mg (P < 0.001), but not severe reaction history (P = 0.051) or asthma (P = 0.34). Anxiety was significantly associated with strict avoidance (P < 0.001). Conclusion and clinical relevance Severe/potentially severe reactions, allergic comorbidities, and low EDs in real life are frequent in peanut-allergic patients. Asthma, teenage/ adulthood and reaction to inhalation are associated with severe symptoms. PAL and criteria guiding dietary advice need to be improved.
The Journal of allergy and clinical immunology, 2014
Threshold levels for peanut allergy determined by using oral challenges are important for the food industry with regard to allergen labeling. Moreover, the utility of biological markers in predicting threshold levels is uncertain. We sought to use a modified oral food challenge regimen that might determine threshold levels for peanut allergy mimicking a more real-life exposure and to correlate the eliciting dose (ED) and severity of clinical reaction in children with peanut allergy with B-cell, T-cell, and effector cell markers. A modified food challenge procedure with doses scheduled 2 hours apart was used in 63 children with peanut allergy. All children received a maximum of 8 semi-log increasing titration steps of roasted peanuts ranging from 3 to 4500 mg of peanut protein until objective allergic reactions occurred. Severity of symptoms was graded from I to V. Biological markers were measured before challenge. Forty-five of 63 patients showed objective symptoms after greater tha...