Gutiérrez-Díaz, G., D. Betancor, J. Parrón-Ballesteros, R.G. Gordo, E.S. Castromil-Benito, E. Haroun, M. Vázquez de la Torre, J. Turnay, M. Villalba, J. Cuesta-Herranz, C. Pastor-Vargas, 2024. Identification of new allergens in macadamia nut and cross-reactivity with other tree nuts in a Spanish cohort. Nutrients. 16(7):947. https://doi.org/10.3390/nu16070947
The consumption of macadamia nuts has increased due to their cardioprotective and antioxidant properties. However, this rise is consistent with an increase in the cases of macadamia nut allergy, leading to severe reactions. Although two Macadamia integrifolia allergens (Mac i 1 and Mac i 2) have been identified in Australian and Japanese patients, the allergenic sensitization patterns in Western European populations, particularly in Spain, remain unclear. For this purpose, seven patients with macadamia nut allergy were recruited in Spain. Macadamia nut protein extracts were prepared and, together with hazelnut and walnut extracts, were used in Western blot and inhibition assays. IgE-reactive proteins were identified using MALDI-TOF/TOF mass spectrometry (MS). Immunoblotting assays revealed various IgE-binding proteins in macadamia nut extracts. Mass spectrometry identified three new allergens: an oleosin, a pectin acetylesterase, and an aspartyl protease. Cross-reactivity studies showed that hazelnut extract, but not walnut extract, inhibited macadamia nut oleosin-specific IgE binding. This suggests that oleosin could be used as marker for macadamia-hazelnut cross-reactivity. The results show an allergenic profile in the Spanish cohort different from that previously detected in Australian and Japanese populations. The distinct sensitization profiles observed highlight the potential influence of dietary habits and environmental factors exposure on allergenicity.
Pasioti, M., P. Xepapadaki, A.G. Mathioudakis, J. Lakoumentas, E. Efstathiou, N.G. Papadopoulos, 2024. Current options in the management of tree nut allergy: A systematic review and narrative synthesis. Pediatr Allergy Immunol. 35(5):e14132. doi: 10.1111/pai.14132.
Tree nut allergy is a lifelong and potentially life-threatening condition. The standard of care is strictly avoiding the culprit nut and treating accidental reactions symptomatically. To evaluate potential therapeutic options for desensitizing patients with IgE-mediated tree nut allergy, we systematically searched three bibliographic databases for studies published until January 2024. We looked for active treatments of IgE-mediated allergy to tree nuts (walnut, hazelnut, pistachio, cashew, almond, pecan, macadamia nut, and brazil nut). We focused on allergen-specific immunotherapy (AIT) using oral (OIT), sublingual (SLIT), epicutaneous (EPIT), or subcutaneous (SCIT) delivery, or other disease-modifying treatments. We found 19 studies that met our criteria: 3 studies investigated sublingual immunotherapy, 5 studied oral immunotherapy to a single tree nut, and 6 used multi-food oral immunotherapy with or without omalizumab. The remaining studies investigated the effectiveness of monoclonal antibodies or IgE-immunoadsorption in multi-food allergic patients, including patients with tree nut allergy. The heterogeneity of the studies prevented pooling and meta-analysis. Oral immunotherapy, single or multi-nut, with or without omalizumab, was the most studied approach and appears effective in conferring protection from accidental exposures. Omalizumab monotherapy is the only approved alternative management for reducing allergic reactions that may occur with accidental exposure.
Goh, S.H., G.C. Yap, H.Y. Cheng, W.C. Chiang, J.Y. Soh, K.W. Chong, A. Goh, E.H. Tham, A. Tyebally, S. Ganapathy, I. Ibrahim, B.W. Lee, 2024. Trends in Childhood Anaphylaxis in Singapore: 2015-2022. Clin Exp Allergy. 54(8):585-595. doi: 10.1111/cea.14528.
Background: There has been limited data regarding the incidence of anaphylaxis in Asia. We aim to describe patterns in patient characteristics, triggers and clinical presentation of childhood anaphylaxis in Singapore. Methods: This was a retrospective review of emergency electronic medical records of children with anaphylaxis. Patients with the allergy-related diagnoses of anaphylaxis, angioedema, allergy and urticaria based on ICD-9 codes were screened. Cases fulfilling the World Allergy Organization criteria for anaphylaxis were included. Results: A total of 1188 cases of anaphylaxis were identified with a median age of 6.3 years. Extrapolating data from the study sites, from 2015 to 2022, the incidence rate of childhood anaphylaxis emergency visits in Singapore doubled from 18.9 to 38.8 per 100,000 person-years, with an incidence rate ratio (IRR) of 2.06 (95% confidence interval [CI] 1.70-2.49). In 2022, the incidence rate of food anaphylaxis was 30.1 per 100,000 person-years, IRR 2.39 (95% CI 1.90-3.01) and drug anaphylaxis was 4.6 per 100,000 person-years, IRR 1.89 (95% CI 1.11-3.25). The incidence rate in children aged 0-4 years quadrupled during the study period. Common triggers were egg (10.4%), peanut (9.3%), tree nut (8.8%), milk (8%), shellfish (7.8%) and non-steroidal anti-inflammatory drug (4.4%). The majority (88.6%) of patients were treated with intramuscular adrenaline. Total number of allergy-related visits did not increase over time between 2015 and 2019. Rates of severe anaphylaxis, namely anaphylactic shock and admission to high-dependency and intensive care, did not increase over time, with a mean incidence of 1.6, IRR 0.85 (95% CI 0.40-1.83) and 0.7, IRR 1.77 (95% CI 0.54-5.76) per 100,000 person-years, respectively. Conclusion: While the number of emergency visits due to childhood anaphylaxis has increased, the number of cases of allergy-related visits, anaphylactic shock and anaphylaxis requiring high-dependency and intensive care did not rise.
De Agrela-Mendes, I., M. Pedrosa, C. Gómez-Traseira, E. Phillips-Anglés, M. Rodríguez-Álvarez, S. Quirce, 2024. Tolerance of peanuts and tree nuts in Spanish children with exclusive sensitization to lipid transfer proteins. Pediatr Allergy Immunol. 35(7):e14204. doi: 10.1111/pai.14204.
Background: Allergy to peanuts and tree nuts is a common cause of food allergy in Spain, with lipid transfer proteins (LTP) being the most frequently recognized panallergen. LTP sensitization often leads to multiple food group sensitivities, resulting in overly restrictive diets that hinder patient’s quality of life. This study aimed to assess the tolerance of peanuts and tree nuts (hazelnuts and walnuts) in children sensitized to LTP, potentially mitigating the need for such diets. Methods: This prospective study enrolled individuals diagnosed with allergy to peanuts, hazelnuts, or walnuts. Data were collected from medical records, including demographics and clinical history. Allergological assessment comprised skin prick tests using commercial extracts and the nuts in question, alongside measurements of total and specific IgE to nuts and their primary molecular components. Participants showing positive LTP sensitization without sensitization to seed storage proteins underwent open oral nut challenges. Results: A total of 75 individuals labeled as allergic to peanuts, 44 to hazelnuts, and 51 to walnuts were included. All of them underwent an open oral provocation test with the incriminated nut, showing a high tolerance rate. Peanut was tolerated by 98.6% of patients, 97.72% tolerated hazelnut, and 84.3% tolerated walnut. Conclusion: The findings suggest that the majority of patients allergic to peanuts, hazelnuts, or walnuts, due to LTP sensitization and lacking IgE reactivity to seed storage proteins, can tolerate these nuts. This supports the need for personalized nut tolerance assessments to avoid unnecessary dietary restrictions.
