Is Component-Specific Antibody Testing Sufficient to Replace the Oral Food Challenge in the Diagnostics of Peanut-Sensitized Children? A Proof-of-Concept Study.

(1) Peanut allergy is associated with high risk of anaphylaxis which could be prevented by oral immunotherapy. Patients eligible for immunotherapy are selected on the basis of a food challenge, although currently the assessment of antibodies against main peanut molecules (Ara h 1, 2, 3 and 6) is thought to be another option. (2) The current study assessed the relationship between the mentioned antibodies, challenge outcomes, skin tests and some other parameters in peanut-sensitized children. It involved 74 children, divided into two groups, based on their response to a food challenge. (3) Both groups differed in results of skin tests, levels of component-specific antibodies and peanut exposure history. The antibody levels were then used to calculate thresholds for prediction of challenge results or symptom severity. While the antibody-based challenge prediction revealed statistical significance, it failed in cases of severe symptoms. Furthermore, no significant correlation was observed between antibody levels, symptom-eliciting doses and the risk of severe anaphylaxis. Although in some patients it could result from interference with IgG4, the latter would not be a universal explanation of this phenomenon. (4) Despite some limitations, antibody-based screening may be an alternative to the food challenge, although its clinical relevance still requires further studies.

Sensitization to nut allergens in children with food allergy and other atopic diseases - just a coexistence?

Introduction: Allergy to nuts, the most common food allergy in childhood, is considered as a significant health problem. Aim: To investigate sensitization to selected nuts in children with or without atopic allergy. Material and methods: Retrospective analysis involved records of 598 children, diagnosed with food allergy. Laboratory data concerned screening for sensitization to major allergens of hazelnut, peanut and walnut. Results: Approximately 77.8% of children with food allergy presented at least one concomitant atopic disease: allergic rhinitis (52.9%), atopic dermatitis (48%) or asthma (31.4%). Nearly one-third experienced at least one episode of anaphylaxis. The nut-specific antibodies were found in 67% of children. Among them, 56% were sensitized to hazelnut, and 54% to peanut. Sensitization to other nuts was less frequent (< 30%). Only 27% of patients were mono-sensitized, the remaining 73% were co-sensitized to two or three of tested nuts. Noteworthy, the occurrence of sensitization varied among age-related groups, and also depended on clinical diagnosis. In patients with sole food allergy the frequency of sensitization was highest in youngest children, whereas, when accompanied by other atopic disease, it was highest in schoolchildren. In children without food allergy, but with another atopic disease, the prevalence of sensitization was relatively low, without any specific pattern. Conclusions: The analysis of sensitization patterns may help to identify patients with an increased risk, and gives the opportunity to introduce more effective prophylaxis. However, since even the first exposure to nuts may be sufficient to trigger the anaphylaxis, this risk should be considered as a serious issue at any age.

Prevalence of nut allergen sensitization among children in central Poland.

Introduction: The diagnostics of plant-derived food allergy may be challenging. However, the recognition of sensitization patterns in defined populations, especially in children, is clinically relevant as it enables the use of secondary prophylaxis to prevent life-threatening complications. Aim: To investigate the rates and sensitization patterns to nut allergens in children from central Poland. Material and methods: The retrospective assessment concerned data of 598 children diagnosed in a single centre due to suspected food allergy. The analysis included the results of component-based multiparametric assay Allergy Explorer2 (ALEX2). Results: The sensitization to particular nut allergens varied among patients, depending on their age and nut type. The sensitization to any nut was found in 67% of children, whereas sensitization to hazelnut and peanut was the most common (56% and 55% of all children, respectively). Hazelnut sensitization was predominant in every age, and its prevalence increased with age, while peanut sensitization was detected in more than half of individuals from all groups, except for teenagers (44% of cases). Among hazelnut molecules sensitization to Cor a 1.04 was the most prevalent (74% of sensitized children), and for peanut allergens - Ara h 1 (65% of sensitized patients). The simultaneous sensitization to hazelnut, peanut and walnut (two or all of them) was found in almost half of the entire group. Conclusions: Component-based diagnostics enables differentiation between primary and cross-reactive sensitization to nut allergens and detects co-sensitization. The clinical relevance of the latter observation is remarkable as co-sensitization increases the risk of life-threatening reactions even in trace nut contamination.