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Flying with nut and other food allergies: unravelling fact from fiction.

Turner, P., N. Dowdall, 2024. Flying with nut and other food allergies: unravelling fact from fiction. Arch Dis Child. 2024-327848. https://doi.org/10.1136/archdischild-2024-327848

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 install 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.

Development of cashew and pistachio ladders through a food-processing approach. 

Shwe Yee, N., H.K. Ng, J. Zeng, J. Bao, D.E. Campbell, P.J. Turner, N.A. Lee, 2024. Development of cashew and pistachio ladders through a food-processing approach. Foods. 13(21):3440. https://doi.org/10.3390/foods13213440

Following successful oral immunotherapy (OIT) for peanut allergy using boiled peanuts (BOPI trial), this study investigated the potential of wet-thermal-processing-induced allergen modifi cation, specifically soaking and boiling (1–4 h) to reduce the allergenicity of cashew and pistachio allergens. In addition, this study provides a foundation of understanding for developing safer forms of cashew/pistachio administration for application in OIT by gradual exposure to increasing doses of modified allergens with reduced potency as an “allergen ladder”. An SDS-PAGE analysis and an intrinsic-fluorescence spectroscopy revealed altered tertiary structures of the allergens, leading to their denaturation and even degradation. Notably, the reduction in both allergen-specific polyclonal IgG and human-specific IgE (sIgE) binding correlated with the treatment time, with the most significant decrease observed after 4 h of boiling. In contrast, shorter soaking treatments showed negligible effects on the IgE-binding capacity of these nuts, therefore indicating a further need for optimization. These findings indicate that extended boiling effectively reduced the amounts of the highly potent allergenic component Ana o 3 in cashew and Pis v 1 in pistachio, as confirmed by ELISA using polyclonal anti-Ana o 3 antibodies, and an immunoblot showed decreased IgE epitope binding in cashew and pistachio allergens, which further modified their allergenic profiles. This approach shows promise as a viable method for offering a safer therapeutic option for cashew/pistachio allergy.

Safety of oral immunotherapy for cashew nut and peanut allergy in children – a retrospective single-centre study.

Breiding, M., M. Soomann, M. Roth, J. Trück, F. Bellutti Enders, 2024. Safety of oral immunotherapy for cashew nut and peanut allergy in children – a retrospective single-centre study. Swiss Med Wkly. 154(11):3691. https://smw.ch/index.php/smw/article/view/3691

AIM OF THE STUDY: Oral immunotherapy (OIT) is increasingly used for the treatment of childhood food allergies, with limited data available on cashew nut OIT. This real-life study investigated the safety and feasibility of cashew nut OIT, comparing it with peanut OIT, with a focus on the up-dosing process. METHODS: We analyzed cashew nut (n = 24) and peanut (n = 38) OIT cases with treatment initiated between 2018 and 2022 at the University Children’s Hospital Basel. All patients who commenced therapy within this time frame were enrolled without prior selection. Two different starting protocols were used. Within the up-dosing protocol, the nut intake was incrementally increased by 20–30% every 2 weeks until reaching a maintenance dose of 1g of nut protein. After consuming the maintenance dose regularly for 18–24 months, a second oral food challenge was performed. Patients who passed this challenge were considered desensitized. The safety of the therapy was evaluated based on the severity of adverse reactions during the up-dosing phase. Symptom severity was evaluated using the validated ordinal food allergy severity scale (o-FASS-5). RESULTS: Over the study period, 33% of cashew nut-allergic and 63% of peanut-allergic patients experienced mild to moderate allergic reactions. Severe allergic reactions occurred in five peanut-allergic children with high baseline allergen-specific IgE levels. Six patients with peanut, and none with cashew nut OIT, discontinued the therapy due to adverse reactions. The mean duration to reach the maintenance phase was longer for children with asthma or another food allergy. Among children who already underwent the second oral food challenge, desensitization was achieved in 91% (11 out of 12) of cashew nut- and 73% (11 out of 15) of peanut-allergic patients. CONCLUSION: Cashew nut OIT had a low severity of adverse reactions and was generally well-tolerated. However, patient characteristics influenced side effect risk and treatment duration, emphasizing the need for individualized OIT strategies.

Impact of heat and pressure processing treatments on the digestibility of peanut, hazelnut, pistachio and cashew allergens.

Arribas, C., A. Sanchiz, M.M. Pedrosa, S. Perez-Garcia, R. Linacero, C. Cuadrado, 2024. Impact of heat and pressure processing treatments on the digestibility of peanut, hazelnut, pistachio and cashew allergens. Foods. 13(22):3549. https://doi.org/10.3390/foods13223549

Abstract: 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.