Anna Winberg

A population-based study of animal component sensitization, asthma, and rhinitis in schoolchildren

Animal sensitization is a major determinant of asthma in children. Component‐resolved studies of unselected pediatric populations are lacking. The aim was to describe sensitization to animal components and the association with asthma and rhinitis in animal‐sensitized schoolchildren.

Vitamin D deficiency at the Arctic Circle – a study in food-allergic adolescents and controls

At the extremes of latitude, UVB intensity is insufficient for adequate vitamin D synthesis in winter. Fatty fish, vitamin D enriched milk, margarine and eggs are main dietary sources of vitamin D. Their elimination may increase the risk of vitamin D deficiency. The aim was to assess vitamin D status in food‐allergic adolescents eliminating milk, egg and/or fish compared with adolescents on normal diets.

Food hypersensitivity is common in Swedish schoolchildren, especially oral reactions to fruit and gastrointestinal reactions to milk

This study examined the prevalence, symptom expression and risk factors for food hypersensitivity among Swedish schoolchildren.

Assessment of Allergy to Milk, Egg, Cod, and Wheat in Swedish Schoolchildren: A Population Based Cohort Study.

Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is incomplete. The purpose of this study was to investigate the prevalence of allergies to milk, egg, cod, and wheat using reported data, clinical examinations, and double-blind placebo-controlled food challenges, and to describe the phenotypes of reported food hypersensitivity in a cohort of Swedish schoolchildren. Methods In a population-based cohort of 12-year-old children, the parents of 2612 (96% of invited) completed a questionnaire. Specific IgE antibodies to foods were analyzed in a random sample (n=695). Children reporting complete avoidance of milk, egg, cod, or wheat due to perceived hypersensitivity and without physician-diagnosed celiac disease were invited to undergo clinical examination that included specific IgE testing, a celiac screening test, and categorization into phenotypes of food hypersensitivity according to preset criteria. Children with possible food allergy were further evaluated with double-blind challenges. Results In this cohort, the prevalence of reported food allergy to milk, egg, cod, or wheat was 4.8%. Food allergy was diagnosed in 1.4% of the children after clinical evaluation and in 0.6% following double-blind placebo-controlled food challenge. After clinical examination, children who completely avoided one or more essential foods due to perceived food hypersensitivity were categorized with the following phenotypes: allergy (29%), outgrown allergy (19%), lactose intolerance (40%), and unclear (12%). Conclusions There was a high discrepancy in the prevalence of allergy to milk, egg, cod and wheat as assessed by reported data, clinical evaluation, and double-blind food challenges. Food hypersensitivity phenotyping according to preset criteria was helpful for identifying children with food allergy.

Milk allergy is a minor cause of milk avoidance due to perceived hypersensitivity among schoolchildren in Northern Sweden.

We investigated phenotypes of milk hypersensitivity among schoolchildren aged 11–12 in Northern Sweden.

New validated recipes for double-blind placebo-controlled low-dose food challenges

Double‐blind placebo‐controlled food challenges are considered the most reliable method to diagnose or rule out food allergy. Despite this, there are few validated challenge recipes available. The present study aimed to validate new recipes for low‐dose double‐blind placebo‐controlled food challenges in school children, by investigating whether there were any sensory differences between the active materials containing cows milk, hens egg, soy, wheat or cod, and the placebo materials. The challenge materials contained the same hypoallergenic amino acid–based product, with or without added food allergens. The test panels consisted of 275 school children, aged 8–10 and 14–15 yr, respectively, from five Swedish schools. Each participant tested at least one recipe. Standardized blinded triangle tests were performed to investigate whether any sensory differences could be detected between the active and placebo materials. In our final recipes, no significant differences could be detected between the active and placebo materials for any challenge food (p > 0.05). These results remained after stratification for age and gender. The taste of challenge materials was acceptable, and no unfavourable side effects related to test materials were observed. In summary, these new validated recipes for low‐dose double‐blinded food challenges contain common allergenic foods in childhood; cows milk, hens egg, soy, wheat and cod. All test materials contain the same liquid vehicle, which facilitates preparation and dosing. Our validated recipes increase the range of available recipes, and as they are easily prepared and dosed, they may facilitate the use of double‐blind placebo‐controlled food challenges in daily clinical practice.

Dynamics of cytokine mRNA expression and fecal biomarkers in school-children undergoing a double-blind placebo-controlled food challenge series

BACKGROUND There is need for prognostic markers for symptomatic food allergy since current diagnostic methods are insufficient and/or time and labor consuming. OBJECTIVE To estimate the cytokine mRNA profiles in peripheral blood mononuclear cells (PBMC) before and after a double-blind placebo-controlled food challenge series in schoolchildren with suspected allergy to milk, egg or cod and in healthy controls. Analyses of fecal inflammatory biomarkers before and after the challenge were included. METHODS Twelve-year-old children from a population-based cohort reporting complete avoidance of milk, egg, cod or wheat due to perceived hypersensitivity were clinically examined and those with suspected food allergy were evaluated with a 3-session double-blind placebo-controlled food challenge (n=18). Seven healthy controls participated in a double-blind challenge with egg. Before and after the challenge series, the cytokine mRNA expression was quantified for 13 cytokines discriminating between humoral Th2-, cytotoxic Th1-, regulatory Th3/Tr1- and inflammatory responses. Fecal calprotectin and eosinophil-derived neurotoxin (EDN) were also analyzed in children with suspected food allergy before and after the challenge series. RESULTS Pre challenge, children with suspected food allergy had higher IL-13andTNF-α expression and lower IFN-γ and IL-15 expression compared to healthy controls (all p<0.05). Children with challenge-proven food allergy had increased IL13andIL-10 expression compared to the levels seen in negative challenges (p<0.05). Post challenge, IL-1β and IL-6 mRNA levels were elevated in the food allergic children compared to controls (p<0.05). Fecal calprotectin and EDN levels were higher in challenge-proven food allergy compared to a negative challenge although not statistically significantly. CONCLUSION & CLINICAL RELEVANCE Increased baseline mRNA levels of the Th2-related cytokine IL-13 and the regulatory cytokine IL-10 predicted a positive food challenge outcome. These cytokines in combination with fecal calprotectin and EDN might serve as future prognostic markers for symptomatic, IgE-mediated food allergy but need further validation in a larger patient cohort.

Lung function after extremely preterm birth—A population‐based cohort study (EXPRESS)

Follow‐up studies of children and young adults born very‐to‐moderately preterm show persistent and significant lung function deficits. The aim of the study was to determine lung function and airway mechanics in school‐aged children born in 2004 to 2007 and extremely preterm (after 22‐26 weeks of gestation).

To face fear : a qualitative study of adolescents' experiences of double-blind, placebo-controlled food challenges

Kokkinou, D; Georgountzou, A; Maggina, P; Taka, S; Roumbedaki, E; Douladiris, N; Papaevangelou, V; Xepapadaki, P; Papadopoulos, NG Allergy Dpt, 2nd Pediatric Clinic, University of Athens, Athens, Greece; 3rd department of Pediatrics, ‘ATTIKON’ General University Hospital, Athens, Greece; Center for Pediatrics and Child Health Institute of Human Development, University of Manchester, Manchester, United Kingdom

Food hypersensitivity phenotypes among Swedish schoolchildren reporting partial avoidance of milk

Food hypersensitivity phenotypes among Swedish schoolchildren reporting partial avoidance of milkBackground: The insecticidal activity of plant lectins against a large array of insect species has been well documented. Insecticidal activities were found to be associated mostly with the two main groups of plant lectins: monocot mannose-binding and chitin binding lectin groups. Known as natural defense agents, plant lectins have been implicated as antibiosis factors against insects and considered as promising candidates for biological pesticides. Mistletoe (Viscum album) fruit lectin MChbL belongs to chitin-binding lectin group and is considered to expose toxic lesions on human. In vitro, plant lectins effect lymphocyte mitogenesis, aggregate immunoglobulins, induce histamine release from basophiles and mast cells. We have studied MChbL cytotoxicity towards human peripheral blood lymphocytes (PBL) in humans. Method: Human PBL culture was used to study MChbL cytotoxicity by mitogen stimulated MTT assay. PB from 15 volunteers were examined during this study and control group was compound from 12 healthy donors. The optical densities was measured on spectrophotometer Multiscan MCC at 570 nm wavelength. Results: Our study showed that any dose of mitogen ConA have stimulated the human PBL (1 lg/mL OD 0.198, 10 lg/mL OD 0.467, 100 lg/mL OD 0.344), whereas MChbL has inhibited the proliferation of PBL MChbL in both concentration (10 lg/ mL, 500 lg/mL) decreasing the amount of the cells and their viability. Particularly, this was obvious at higher concentration of MChbL 500 lg/mL applied (OD 0.60). Conclusion: MChbL expose cytotoxical effects to human peripheral blood lymphocytes (PBL), when administrated at high concentration 500 lg/mL. However, low concentrations of MChbL were less cytotoxic to PBL and exhibit similar results as ConA at the concentration of 1 lg/mL. Most likely, approaches to use MChbL as natural bio-pesticide must be considered at dose-dependent manner and administrated in the nontoxic range.