Impact of Heat and Pressure Processing Treatments on the Digestibility of Peanut, Hazelnut, Pistachio and Cashew Allergens
Food processing can alter protein biochemical properties, impacting immunoreactivity and allergenicity. A key feature of food allergens is their resistance to enzymatic digestion, particularly by pepsin and trypsin. This study compares the digestomes of raw and heat- and/or pressure-treated peanuts, hazelnuts, pistachios and cashews using the INFOGEST harmonized digestion protocol and analyzing their IgE-binding capacity through in vitro methods. Protein patterns from controls and digestomes were resolved by SDS-PAGE and tested with sera from allergic patients, confirmed by competitive ELISA for hazelnuts and peanuts. The results indicate that processing methods differently affect the gastrointestinal (GI) digestion of these allergens. Simulated GI digestion caused a significant destruction of protein structures, reducing but not eliminating IgE reactivity for all four nuts. Boiling for 60 min did not change the SDS-PAGE profiles, but it did stimulate enzymatic activity, decreasing IgE binding capacity. In contrast, applying heat and pressure led to a nearly complete inhibition of allergenic potential during simulated digestion. These findings suggest that employing intense food processing techniques and investigating the gastrointestinal effects of highly allergenic nuts could be crucial steps toward developing new hypoallergenic formulations.
https://doi.org/10.3390/foods13223549
Tree Nut Allergy in Children—What Do We Know? —A Review
Food allergy represents a significant public health concern, with its prevalence increasing in recent decades. Tree nuts are among major allergenic foods, and allergies to them are frequently linked to severe and potentially life-threatening reactions. Data on the prevalence and natural history of tree nut allergy are limited. Primary nut allergy typically presents with rapid-onset IgE-mediated symptoms. Diagnosis can be confirmed by demonstrating a positive skin prick test (SPT), specific IgE (sIgE), or through an oral food challenge. Component-resolved diagnostics (CRD) can identify those with a high risk of anaphylaxis. The main management strategy involves avoiding the culprit allergen and treating symptoms after accidental exposure. New therapeutic options, such as sublingual immunotherapy, oral food immunotherapy, with or without omalizumab, and other monoclonal antibodies, are being investigated to modify tree nut allergy. Tree nut allergy is a lifelong disease with a low likelihood of resolution. The aim of this paper is to present the current data on the prevalence, diagnosis, natural history, and management options for tree nut allergy.
https://doi.org/10.3390/nu16233978
Comparing two Peanut Desensitization Protocols in pre-school children: a Real-World Clinical Practice
Background: Peanut allergy is the main food allergy in childhood and poses significant health concerns. Objective: This study aimed to critically evaluate the effectiveness and safety of Oral Immune Therapy (OIT) using crushed peanuts versus peanut puffs. Methods: Children with an allergist diagnosed peanut allergy based on a history of an IgE-mediated reaction and a positive skin prick test for peanuts were recruited at the Montreal Children's Hospital and the Children's Clinic located in Montreal. Based on age and personal preference, initial doses of peanut were given in either puff (Bamba) or crushed peanut form. Patients continued the same dose for 2-5 weeks at home, filled out a symptom diary, and returned to the clinic for up-dosing until maintenance was reached (2 teaspoons of peanut butter). A continuation ratio regression model was used to evaluate the effect of the allergen type on the severity of anaphylactic and allergic reactions during OIT while adjusting for potential confounders. Results: Between October 2020 and June 2023, 191 children (59.6% male; median age 1.95 years) were recruited. Most patients (75.1%) had eczema, and 12.7% had asthma. Oral desensitization was performed using one of two strategies according to the allergist: Crushed peanut (n=60 (31.4%)( and peanut puff (n=131 (68.6%)). Of the participants, the consumption of puff lowered reaction severity by a factor of 3.39 (95% CI, 1.4 to 8.22), in comparison to crushed peanuts. Older age markedly elevates the adjusted odds of reacting to a particular severity level as compared to a lower level by 1.19 (95% CI, 1.04 to 1.37). Conclusion: Modified peanut desensitization using peanut puffs has shown potential in reducing the severity of allergic reactions in younger children. Older children may experience a higher risk of severe reactions, indicating the need for age-specific approaches to desensitization protocols.
https://doi.org/10.1159/000542429
Safety and adherence of early oral immunotherapy for peanut allergy in a primary care setting: a retrospective cross-sectional study
Background: Peanut allergy is a common food allergy with potentially life-threatening implications. Early oral immunotherapy for peanut allergy (P-EOIT) has been shown to be effective and safe in research and specialty clinic settings. Provision of P-EOIT in primary care would make it available to more patients. We sought to assess the safety of P-EOIT in a primary care setting by documenting the rates of peanut-related allergic reactions leading to emergency department (ED) visits and use of epinephrine. We also examined adherence by assessing the percentage of patients reaching maintenance phase and continuing ingestion after one year of P-EOIT. Methods: This retrospective study included all patients aged less than 36 months who started P-EOIT at a primary care allergy clinic in New Brunswick, Canada, from 2016 to 2020. The population included patients who (1) had a history of an allergic reaction to peanuts with a positive skin prick test or positive peanut specific IgE level (ps-IgE) or (2) no history of ingestion and a baseline ps-IgE ≥5 kU/L. Patients had biweekly clinic visits with graded increases in peanut protein up to a maintenance dose of 300 mg of peanut protein daily. A blinded retrospective review of paper charts and electronic medical records was conducted along with phone interviews regarding ED visits and epinephrine use. Results: All 69 consented patients reached maintenance dose over a median of 29 weeks, and 66 patients (95.7%) were still regularly consuming peanut protein after 1 year of maintenance. One patient had a peanut ingestion-related ED visit requiring epinephrine during the escalation phase of peanut protein dosing (1.4%). During the first year of maintenance phase, no patients had peanut ingestion-related ED visits nor required epinephrine. Conclusion: Early oral immunotherapy for peanut allergy in a primary care setting appears to be safe and our findings suggest that it does not lead to an increased burden of emergency department visits. Our population had high adherence rates, with the majority achieving maintenance dose and staying on this dose for one year.
https://doi.org/10.1186/s13223-024-00916-5
Flying with nut and other food allergies: unravelling fact from fiction
There is a common perception that peanut/tree nut particles can be transmitted through aircraft ventilation systems and pose a significant risk to passengers with food allergies. In fact, food-induced allergic reactions are around 10-100 times less common during flights than 'on the ground', perhaps because of the multiple precautions food-allergic passengers take when flying. We review the evidence for strategies to help prevent accidental allergic reactions while travelling on commercial flights (review registered at PROSPERO, ref CRD42022384341). Research studies (including aircraft simulations) show no evidence to support airborne transmission of nut allergens as a likely phenomenon. Announcements requesting 'nut bans' are not therefore supported, and may instal a false sense of security. The most effective measure is for passengers to wipe down their seat area (including tray table and seat-back entertainment system). Food proteins are often 'sticky' and adhere to these surfaces, from where they are easily transferred to a person's hands and onto food that might be consumed. Airline companies can help to facilitate this through pre-boarding. Passengers at risk of anaphylaxis should be prescribed two adrenaline [epinephrine] autoinjector devices, to carry on their person at all times-including when flying. Airlines should consider including a separate supply of 'general use' adrenaline autoinjectors in the onboard medical kit for use in an emergency. All airlines should have clear policies relating to food allergies which are easily available from their websites or on request. These policies should be applied consistently by both ground staff and cabin crew, in order to provide reassurance to food-allergic passengers and their caregivers.
https://doi.org/10.1136/archdischild-2024-327848
Air pollution is associated with persistent peanut allergy in the first 10 years
Background: The role of air pollution in eczema and food allergy development remains understudied. Objective: We aimed to assess whether exposure to air pollution is associated with eczema and food allergies in the first 10 years of life. Methods: HealthNuts recruited a population-based sample of 1-year-old infants who were followed up at ages 4, 6, and 10 years. Annual average fine particulate matter (particulate matter with diameter of 2.5 μm or less, or PM2.5) and nitrogen dioxide (NO2) exposures were assigned to geocoded residential addresses. Eczema was defined by parent report. Oral food challenges to peanut, egg, and sesame were used to measure food allergy. Multilevel logistic regression models were fitted, and estimates were reported as adjusted odds ratios. Results: Those exposed to high concentration of NO2 (<10 ppb) at age 1 year had higher peanut allergy prevalence at ages 1 (adjusted odds ratio [95% confidence interval], 2.21 [1.40-3.48]) and 4 (2.29 [1.28-4.11]) years. High exposure to NO2 at 6 years old were associated with higher peanut allergy prevalence at age 6 (1.34 [1.00-1.82] per 2.7 ppb NO2 increase) years. Similarly, increased PM2.5 at age 1 year was associated with peanut allergy at ages 4, 6, and 10 years (respectively, 1.27 [1.01-1.60], 1.27 [1.01-1.56], and 1.46 [1.05-2.04] per 1.2 μg/m PM2.5 increase) years. We found that increased concentrations of NO2 or PM2.5 at age 1 year were associated with persistent peanut allergy at later ages. Little evidence of associations was observed with eczema or with egg allergy. Conclusions: Early-life exposure to PM2.5 and NO2 was associated with peanut allergy prevalence and persistence. Policies aiming at reducing air pollution could potentially reduce presence and persistence of peanut allergy.
https://doi.org/10.1016/j.jaci.2024.08.018
Oral Food Challenge in Children with Tree Nut and Peanut Allergy: The Predictive Value of Diagnostic Tests
Food allergy (FA) affects approximately 6-8% of young children, with a peak prevalence at approximately one year of age. Tree nut and peanut allergies are among the main causes of anaphylaxis in the world. The gold standard for the diagnosis of FAs is the oral food challenge (OFC). Other diagnostic tests used in the clinical practice are skin prick tests (SPTs) and laboratory tests to measure out the presence of serum specific IgE (sIgE). In this narrative review, we collect the current evidence of the predictive value (PV) of SPTs and sIgE for the outcome of the OFCs. In literature, data are conflicting as to whether increasing sIgE concentration and wheal size in SPTs correlate with OFC outcomes. Most studies included in our review have shown that in vivo and in vitro tests may predict OFC outcomes with variable PV, but data are not conclusive; therefore, the OFC currently remains the gold standard for FA diagnosis. https://doi.org/10.3390/diagnostics14182069
Peanut allergen characterization and allergenicity throughout development
Introduction: Peanut allergy (PA) in children is a major concern. There is a need for better biological material for both diagnosis and oral immunotherapy (OIT) treatments. The unique state of seeds at early reproductive stages may affect the allergenicity of storage proteins, and impact clinical diagnostic and OIT protocols. The objective of this study was to evaluate the major allergen content in sequential seed developmental stages and monitor allergenicity via specific IgE binding quantification and skin prick testing. Methods: Seeds were collected from peanut plants and sorted into five developmental stages: initial (S1), developing (S2), full-size without coloration (S3), full-size with coloration (S4), and fully mature (S5) seeds. Samples were characterized by RNA-Seq, ELISA, and immunohistochemistry. Lyophilized, ground preparations were used for evaluation of skin test responses in sixty challenge-proven PA children. Results: Gene expression, protein content, and specific IgE binding of allergenic proteins increased throughout seed maturation and development. An expression bias towards the less allergenic A-genome copy of the major allergen Ara h 2 was found in earlier stages, especially in stage S2. Immunohistochemical staining showed that Ara h 2 is more dispersed in the cell and less accumulated within organized bodies at stage S2 versus stage S4. Significant differences were found in mean wheal responses between the commercial peanut extract (equivalent to stage S5) and stages S1 and S2, but not with stage S4, upon skin prick testing in subjects with PA. Discussion: The observed decrease in peanut-specific IgE binding of immature peanut seeds may be a result not only of decreased amounts of allergenic proteins, but also of profound changes in seed composition and conformation. This may be significant for developing a safer and more effective peanut OIT protocol. https://doi.org/10.3389/falgy.2024.1395834
Epicutaneous immunotherapy for the treatment of peanut allergy
Peanut allergy treatment options remain limited, but novel approaches are being studied, including epicutaneous immunotherapy (EPIT). EPIT uses the cutaneous immune system to promote tolerance to food allergens. Viaskin™ Peanut, an approach to EPIT in late-stage clinical development uses an occlusive patch with a condensation chamber that enables natural epidermal water loss to solubilize dry antigen on the patch, which is then absorbed and captured by skin Langerhans cells. This form of EPIT does not require disruption of the skin barrier, thus avoiding a proinflammatory cytokine response by targeting the nonvascularized epidermis and limiting systemic allergen exposure. Extensive preclinical research suggests that Viaskin Peanut has a distinct mechanism of desensitization, including the potential for disease modification, driven by a unique population of regulatory T cells. Numerous clinical studies of Viaskin Peanut have demonstrated desensitization and reductions in reaction severity, particularly in children aged 1 through 11 years, as well as a favorable safety profile with mostly mild-to-moderate skin reactions that were observed to decrease over time. EPIT with Viaskin Peanut may be a potential therapeutic option for peanut allergy that is clinically practical with long-term efficacy and tolerability. https://doi.org/10.1111/all.16324
Safety and feasibility of peanut, tree nut, and sesame oral immunotherapy in infants and toddlers in a real-world setting
Background: Oral immunotherapy (OIT) for food allergy has been largely studied in older children within the context of clinical trials, and its availability has historically been limited for younger patients with food allergy. Data has shown that the most impact may actually be seen with the use of OIT in younger infants and toddlers. Objective: To evaluate the safety and feasibility of OIT in subjects younger than 24 months in a real-world setting using commercially available food products. Methods: This was a retrospective study of subjects 24 months and younger initiated on OIT for peanut, tree nut, or sesame allergy within the Scripps Clinic allergy department. Medical records were reviewed for data regarding initial oral food challenges (OFCs), OIT, and adverse outcomes. Results: Fifty-two subjects under 24 months of age were initiated on OIT. Most subjects (84.6%) were on single food OIT, some (15.4%) were on multi-food OIT. No increased adverse outcomes were observed on multi-food OIT. Of the 59 initial OFCs, objective reactions occurred during 42 challenges, the majority being low grade reactions. During initial OFCs, 86.1% of peanut allergic children tolerated 1/8 of one Bamba stick with no reaction. The majority (73.1%) of subjects up-dosed at home and most (51.9%) had no reactions while up-dosing. Some had low grade cutaneous reactions, none requiring epinephrine or emergency evaluation. Conclusion: OIT in infants is safe and feasible to perform in a real-world setting using commercially available food products with at home up-dosing, thus increasing the availability of OIT for patients. https://doi.org/10.1016/j.jaip.2024.09.025