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Background: In birch‐dominated areas, allergies to pollen from trees of the order Fagales are considered to be initiated by the major birch pollen allergen Bet v 1. However, the sensitizing activity of Bet v 1‐homologs in Fagales pollen might be underestimated. Allergen‐specific T‐cells are crucial in the sensitization process. The T‐cell response to major allergens from alder, hazel, oak, hornbeam, chestnut, beech, and chestnut pollen has not yet been analyzed. Here, we characterized the cellular cross‐reactivity of major allergens in Fagales pollen with Bet v 1. Methods: T‐cell‐lines (TCL) were established from allergic individuals with Aln g 1, Car b 1, Ost c 1, Cor a 1, Fag s 1, Cas s 1, and Que a 1, and tested for reactivity with Bet v 1 and synthetic overlapping 12‐mer peptides representing its primary sequence. Aln g 1‐specific TCL was additionally tested with Aln g 1‐derived peptides and all allergens. IgE‐competition experiments with Aln g 1 and Bet v 1 were performed. Results: T‐cell‐lines initiated with Fagales pollen allergens varied strongly in their reactivity with Bet v 1 and by the majority responded stronger to the original stimulus. Cross‐reactivity was mostly restricted to the epitope Bet v 1142–153. No distinct cross‐reactivity of Aln g 1‐specific T‐cells with Bet v 1 was detected. Among 22 T‐cell epitopes, Aln g 1 contained two immunodominant epitopes. Bet v 1 inhibited IgE‐binding to Aln g 1 less potently than Aln g 1 itself. Conclusion: The cellular cross‐reactivity of major Fagales pollen allergens with Bet v 1 was unincisive, particularly for Aln g 1, most akin to Bet v 1. Our results indicate that humoral and cellular responses to these allergens are not predominantly based on cross‐reactivity with the major birch pollen allergen but suggest a Bet v 1‐independent sensitization in individuals from birch tree‐dominated areas. [ABSTRACT FROM AUTHOR]

According to ENDA; 6 (5.6%) patients were classified as NERD, 16 (15%) patients were classified as NECD, 28 (26.2%) patients were classified as NIUA, 49 (45.8%) patients were classified as SNIUAA, 1 (0.9%) patient was classified as SNIDR. The commonest test substance was beta lactam antibiotics (in 19 patients this was the primary agent), followed by general anaesthetic reactions (14 patients), local anaesthetics (5 patients), multiple antibiotics in cystic fibrosis patients (4 patients), insulins (3 patients) and aspirin (3 patients). While in the >2 years of age group, the histamine enduration became negative in 7 (1.8%) patients at 15 SP th sp minutes and in 33 (8.7%) patients at 20 SP th sp minutes, in the <= 2 years of age group the histamine enduration was negative in 6 (6.3%) patients at 15 SP th sp minute and in 26 (27.6%) patients a 20 SP th sp minutes ( I P i = 0.016, I P i < 0.001 respectively). Major trigger of reactions was I Hymenoptera venom i (98 patients), followed by medications (62 patients), other or unknown (35 patients) and food (23 patients). We included 13 patients with Mueller grade I, 19 patients with grade II, 15 patients with grade III and 16 patients with grade IV systemic reaction and 7 patients with large local reaction (LLR). [Extracted from the article]