Marini-Rapoport, O., M. Bhowmik, S.U. Patil, 2025. Basophil activation test for the improved diagnosis of peanut and tree nut allergy. Curr Allergy Asthma Rep 25, 19. https://doi.org/10.1007/s11882-025-01200-1
Purpose of review: As an ex-vivo test of allergic effector cell activation, basophil activation testing (BAT) to allergen enables quantification of the in-vivo IgE-mediated allergic response. BAT thus holds promise in the diagnosis and monitoring of peanut and tree nut allergies. Recent systematic analyses and expert recommendations support a role for BAT in the diagnosis of peanut and tree nut allergy. Recent findings: Diagnostic cut-offs for BAT in peanut and tree nut allergy have been identified. Consistently, BAT can discriminate with high sensitivity and specificity between allergy and tolerance when measured against oral food challenges. Furthermore, the utilization of BAT has can increase the sensitivity and specificity of peanut allergy and tree nut allergy diagnosis, both alone and in conjunction with specific IgE testing and skin prick testing. Summary: BAT is a promising tool in the diagnosis of peanut and tree nut allergy.
Spolidoro, G.C.I., D. Lisik, S. Nyassi, A. Ioannidou, M.M. Ali, Y.T. Amera, G. Rovner, E. Khaleva, C. Venter, R. van Ree, M. Worm, B. Vlieg-Boerstra, A. Sheikh, A. Muraro, G. Roberts, B. I. Nwaru, 2024. Prevalence of tree nut allergy in Europe: A systematic review and meta-analysis. Allergy. 79: 302-323. doi:10.1111/all.15905
In 2014, the European Academy of Allergy and Clinical Immunology (EAACI) published the first systematic review that summarized the prevalence of food allergy (FA) and food sensitization in Europe for studies published 2000–2012. However, only summary estimates for tree nut allergy (TNA) were feasible in that work. In the current update of that systematic review, we summarized the prevalence of tree nut allergy/sensitization to individual tree nuts. Six databases were searched for relevant papers published 2012–2021 and 17 eligible studies were added to the 15 studies already identified between 2000 and 2012, giving a total of 32 studies. Of the investigated tree nuts, meta-analysis was possible for hazelnut, walnut, almond, and in few cases, for cashew, and Brazil nut. The lifetime self-reported prevalence was 0.8% (95% CI0.5–1.1) for hazelnut and 0.4% (0.2–0.9) for walnut. The point self-reported prevalence was 4.0% (2.9–5.2) for hazelnut, 3.4% (2.0–4.9) for Brazil nut, 2.0% (1.1–2.9) for almond, and 1.8% (1.1–2.5) for walnut. Point prevalence of food challenge- confirmed TNA was 0.04% (0.0–0.1) for hazelnut and 0.02% (0.01–0.1) for walnut. Due to paucity of data, we could not identify any meaningful and consistent differences across age groups and European regions.
Goldberg, M.R., M.Y. Appel, K. Tobi, M.B. Levy, N. Epstein-Rigbi, M. Holmqvist, J. Östling, L. Nachshon, J. Lidholm, A. Elizur, 2024. Validation of the NUT CRACKER diagnostic algorithm and prediction for cashew and pistachio co-allergy. J Allergy Clin Immunol Pract. 12(5):1273-1282.
Background: Because of the high cross-sensitization among tree nuts, the NUT CRACKER (Nut Co-reactivity-Acquiring Knowledge for Elimination Recommendations) study proposed a diagnostic algorithm to minimize the number of required oral food challenges (OFCs). Objective: To validate the algorithm for cashew and pistachio allergy and determine markers for allergic severity. Methods: Patients (n = 125) with a median age of 7.8 (interquartile range, 5.9-11.2) years with suspected tree nut allergy were evaluated prospectively with decision tree points on the basis of skin prick test (SPT), basophil activation test (BAT), and knowledge of the coincidence of allergies. Validation of allergic status was determined by OFC. Markers of clinical severity were evaluated using the combined original and prospective cohort (n = 187) in relationship to SPT, BAT, and Ana o 3-sIgE. Results: Reactivity to cashew in SPT, BAT, and Ana o 3-sIgE and the incidence of abdominal pain on challenge were significantly higher in dual-allergic cashew/pistachio patients (n = 82) versus single cashew allergic patients (n = 18) (P = .001). All 3 diagnostic tests showed significant inverse correlation with log10 reaction doses for positive cashew OFC. The algorithm reduced overall the total number of OFCs by 72.0%, with a positive predictive value and negative predictive value of 93.0% and 99.0%, respectively. Cashew false-positives were observed primarily in hazelnut-allergic patients (P = .026). In this population, Ana o 3-specific IgE could diagnose cashew allergy with a sensitivity of more than 90% and a specificity of more than 95%. Conclusions: The NUT CRACKER diagnostic algorithm was validated and reduced the number of diagnostic OFCs required. Markers for severity phenotypes may guide oral immunotherapy protocols, improving the risk/benefit ratio for patients.
Cuadrado, C., C. Arribas, A. Sanchiz, M.M. Pedrosa, P. Gamboa, D. Betancor, C. Blanco, B. Cabanillas, R. Linacero, 2024. Effects of enzymatic hydrolysis combined with pressured heating on tree nut allergenicity. Food Chem. 451:139433. https://doi.org/10.1016/j.foodchem.2024.139433
Hazelnut, pistachio and cashew are tree nuts with health benefits but also with allergenic properties being prevalent food allergens in Europe. The allergic characteristics of these tree nuts after processing combining heat, pressure and enzymatic digestion were analyzed through in vitro (Western blot and ELISA) and in vivo test (Prick-Prick). In the analyzed population, the patients sensitized to Cor a 8 (nsLTP) were predominant over those sensitized against hazelnut seed storage proteins (Sprot, Cor a 9 and 14), which displayed higher IgE reactivity. The protease E5 effectively hydrolyzed proteins from hazelnut and pistachio, while E7 was efficient for cashew protein hydrolysis. When combined with pressured heating (autoclave and Controlled Instantaneous Depressurization (DIC)), these proteases notably reduced the allergenic reactivity. The combination of DIC treatment before enzymatic digestion resulted in the most effective methodology to drastically reduce or indeed eliminate the allergenic capacity of tree nuts.
