Magnus P. Borres

Background: As a surrogate for eosinophilic activation, eosinophil‐derived neurotoxin (EDN) is a potential clinical biomarker. However, EDN levels and discriminatory ability in different asthma phenotypes are unknown. We quantified serum and nasal lavage fluid (NLF) EDN levels and assessed the potential to differentiate clinically defined asthma phenotypes in an adult‐representative sample. Methods: A total of 1499 serum and 386 NLF samples from individuals with current asthma obtained from the West Sweden Asthma Study were analyzed for EDN. Eosinophilic asthma was defined as blood eosinophil count of ≥ 300 cells/mm ³ , T2‐high asthma was defined as blood eosinophil count of ≥ 300 cells/mm ³ or fractional exhaled nitric oxide (FeNO) levels of ≥ 25 ppb. Other asthma phenotypes were defined based on presence of atopy, chronic rhinosinusitis (CRS), nasal polyposis, and obesity. Results: Subjects with eosinophilic asthma had higher serum and NLF EDN levels than those with non‐eosinophilic asthma. In ROC analyses, serum EDN provided excellent discrimination between eosinophilic and non‐eosinophilic asthma (area under curve [AUC] = 0.84, 95% CI = 0.82–0.86); the corresponding AUC for NLF EDN was 0.67 (95% CI = 0.62–0.73). Serum and NLF EDN were higher in atopic asthma, T2‐high asthma, and asthma with nasal polyposis compared to their counterparts, but not in asthma with CRS. The highest absolute values of serum and NLF EDN were observed in the high eosinophil + FeNO group, followed by the high‐eosinophil‐only and high‐FeNO‐only groups. Conclusion: Both serum and NLF EDN were higher in those with eosinophilic compared to non‐eosinophilic asthma. However, only serum EDN appears to distinguish eosinophilic asthma in ROC analyses.

Background: Allergic rhinitis (AR) is one of the most common chronic diseases worldwide. There are limited prospective long‐term data regarding persistency and remission of AR. The objective of this study was to investigate the natural course of pollen‐induced AR (pollen‐AR) over 20 years, from childhood into early adulthood.Methods: Data from 1137 subjects in the Barn/Children Allergi/Allergy Milieu Stockholm Epidemiologic birth cohort (BAMSE) with a completed questionnaire regarding symptoms, asthma, treatment with allergen immunotherapy (AIT) and results of allergen‐specific IgE for inhalant allergens at 4, 8, 16 and 24 years were analyzed. Pollen‐AR was defined as sneezing, runny, itchy or blocked nose; and itchy or watery eyes when exposed to birch and/or grass pollen in combination with allergen‐specific IgE ≥0.35kU_A/L to birch and/or grass.Results: Approximately 75% of children with pollen‐AR at 4 or 8 years had persistent disease up to 24 years, and 30% developed asthma. The probability of persistency was high already at low levels of pollen‐specific IgE. The highest rate of remission from pollen‐AR was seen between 16 and 24 years (21.5%); however, the majority remained sensitized. This period was also when pollen‐specific IgE‐levels stopped increasing and the average estimated annual incidence of pollen‐AR decreased from 1.5% to 0.8% per year.Conclusion: Children with pollen‐AR are at high risk of persistent disease for at least 20 years. Childhood up to adolescence seems to be the most dynamic period of AR progression. Our findings underline the close cross‐sectional and longitudinal relationship between sensitization, AR and asthma.

Sesame is a potentially potent allergen that can trigger skin, gastrointestinal, and respiratory tract symptoms, and anaphylaxis. Only 20% to 30% of sesame‐allergic children develop tolerance. The prevalence of sesame allergy depends on local diets and ranges from 0.1% to 0.9%. A high risk of accidental exposure to sesame has resulted in mandatory food labeling in many countries. More than half of patients with sesame allergy are also allergic to peanut/tree nuts. Serum‐specific IgE testing with a quantitative Ses i 1 component can be performed safely and has higher clinical specificity and better positive predictive value for oral food challenge (OFC) than whole sesame extract or skin prick testing (SPT). Compared with SPT or OFC, in vitro Ses i 1 testing requires no special techniques and carries no risk of reactions. Diagnosis of suspected sesame allergy begins with a thorough history and physical examination. A positive sesame extract test (≥0.1 kU_A/L) should prompt further testing. In patients with a high probability of reacting, results of component testing may facilitate a decision about performing an OFC. In a Japanese study of OFC and Ses i 1, there was a 5% probability of a positive OFC with Ses i 1 sIgE levels 32.0 kU_A/L. Most patients could safely consume sesame if sIgE levels were A/L. Ses i 1 testing can be used to guide appropriate management (avoidance, emergency medication, and oral immunotherapy).

Background Allergic rhinitis (AR) is one of the most common chronic diseases worldwide. There are limited prospective long-term data regarding persistency and remission of AR. The objective of this study was to investigate the natural course of pollen-induced AR (pollen-AR) over 20 years, from childhood into early adulthood. Methods Data from 1137 subjects in the Barn/Children Allergi/Allergy Milieu Stockholm Epidemiologic birth cohort (BAMSE) with a completed questionnaire regarding symptoms, asthma, treatment with allergen immunotherapy (AIT) and results of allergen-specific IgE for inhalant allergens at 4, 8, 16 and 24 years were analysed. Pollen-AR was defined as sneezing, runny, itchy, or blocked nose; and itchy or watery eyes when exposed to birch and/or grass pollen in combination with allergen-specific IgE ≥0.35kU _A /l to birch and/or grass. Results Approximately 75% of children with pollen-AR at 4 or 8 years had persistent disease up to 24 years, and 30% developed asthma. The probability of persistency was high already at low levels of pollen-specific IgE. The highest rate of remission from pollen-AR was seen between 16 and 24 years (21.5%), however the majority remained sensitized. This period was also when pollen-specific IgE-levels stopped increasing and the average estimated annual incidence of pollen-AR decreased from 1.5% to 0.8% per year. Conclusion Children with pollen-AR are at high risk of persistent disease for at least 20 years. Childhood up to adolescence seems to be the most dynamic period of AR progression. Our findings underline the close cross-sectional and longitudinal relationship between sensitization, AR, and asthma.

Sesame is a potentially potent allergen that can trigger skin, gastrointestinal, and respiratory tract symptoms, and anaphylaxis. Only 20% to 30% of sesame-allergic children develop tolerance. The prevalence of sesame allergy depends on local diets and ranges from 0.1% to 0.9%. A high risk of accidental exposure to sesame has resulted in mandatory food labeling in many countries. More than half of patients with sesame allergy are also allergic to peanut/tree nuts. Serum specific IgE testing with a quantitative Ses i 1 component can be performed safely and has higher clinical specificity and better positive predictive value for oral food challenge (OFC) than whole sesame extract or skin prick testing (SPT). Compared with SPT or OFC, in vitro Ses i 1 testing requires no special techniques and carries no risk of reactions. Diagnosis of suspected sesame allergy begins with a thorough history and physical examination. A positive sesame extract test (≥0.1 kU _A /L) should prompt further testing. In patients with a high probability of reacting, results of component testing may facilitate a decision about performing an OFC. In a Japanese study of OFC and Ses i 1, there was a 5% probability of a positive OFC with Ses i 1 sIgE levels 32.0 kU _A /L. Most patients could safely consume sesame if sIgE levels were A /L. Ses i 1 testing can be used to guide appropriate management (avoidance, emergency medication, and oral immunotherapy).

Sensitization to shrimp and house dust mites in a Swedish population-based study: Influence on allergic disorders and lung functionIda Waern1, Magnus Molin2, Robert Movérare2,3, Jonas Lidholm2, Andrei Malinovschi4, Magnus P. Borres2,5, Christer Janson3.1Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden2Thermo Fisher Scientific, Uppsala, Sweden3Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden4Department of Medical Sciences: Clinical Physiology, Uppsala University, Uppsala, Sweden5Department of Maternal and Child Health, Uppsala University, Uppsala, Sweden

Background: Tree nut allergy may cause anaphylaxis. There are limited population‐based studies on prevalence and early‐life risk factors.Methods: We evaluated the prevalence of reported symptoms and allergic sensitization to tree nuts at age 24 years in the BAMSE population‐based cohort study and assessed early‐life factors associated with the development of tree nut allergy.We estimated tree nut allergy prevalence, by analysing questionnaire data on tree nut ingestion and symptoms at age 12, 16 and 24 years, and IgE sensitization at age 24 years to hazelnut, walnut, pecan, cashew, pistachio, Brazil nut, almond extracts and allergen molecules Cor a 1, 9, 14 (hazelnut), Jug r 1 (walnut) and Ana o 3 (cashew). We evaluated eczema, asthma, food allergies, inherited risk of allergy and gender as potential early‐life risk factors.Results: Data were available for 2215/4089 (54%) BAMSE study participants, for estimation of the prevalence of tree nut sensitization (21.2%), tree nut allergy symptoms (9.8%) and combined sensitization and symptoms (7.9%, 2.1% for storage protein sensitization and symptoms, 4.3% for any sensitization and non‐mild symptoms). Sixty‐three per cent of sensitized individuals (295/470) were asymptomatic, but only 76/470 (16%) storage protein sensitized individuals. Egg allergy (OR_adj 8.50 95% CI 2.15–33.6), eczema (OR_adj 2.53 95% CI 1.21–5.32) and asthma (OR_adj 5.59 95% CI 2.35–13.3)) at pre‐school age were associated with future development of tree nut symptoms and storage protein sensitization. At age 24 years, tree nut allergy was associated with current eczema and with markers of current asthma severity. Sensitization to storage proteins was more strongly associated with symptoms than sensitization to whole extract for all tree nuts evaluated.Conclusions: In this Swedish cohort, we found tree nut whole extract sensitization is common but usually asymptomatic. Storage protein sensitization is a more reliable indicator of tree nut symptoms. Tree nut allergy is associated with early onset, persistent and severe atopic disease.