Specific IgE to Jug r 1 has no additional value compared with extract-based testing in diagnosing walnut allergy in adults

The relevance of sIgE to 2S albumins was previously established for peanut and hazelnut allergy in children and adults,1,3,4 as well as for cashew, pistachio, and Brazil nut, mostly in children.5,6 The fact that sIgE to the walnut 2S albumin Jug r 1 was not superior compared with sIgE to walnut extract on CAP or SPT is in contrast to previous results in peanut and hazelnut allergy.1,2,7 Other walnut allergens, like the 11S globulin Jug r 4 or a not yet identified Bet v 1-like (pathogenesis-related class 10 [PR-10]) protein, might play a role in some subjects not sensitized to the currently available components.8 In hazelnut, 11S globulin Cor a 9, homologous to Jug r 4, was an important marker for severe allergy.1 Although pollen-related allergens have been identified in hazelnut and almond, none has been officially recognized in walnut so far.