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Inflammatory bowel disease (IBD) can be treated effectively by anti-tumour necrosis factor (TNF) therapy. We set out to investigate the unclear immunoregulatory mechanisms of the treatment. Thirty-four patients with IBD treated with anti-TNF were included. Lymphocytes from peripheral blood and intestinal biopsies were analysed by flow cytometry. Regulation of antigen-stimulated proliferation was analysed by blocking of interleukin (IL)-10, transforming growth factor (TGF)-β or depletion of CD25+ cells in peripheral blood mononuclear cell cultures. No changes in CD4+CD25+, CD25+TNF-RII+ or CD4+CD25+forkhead box protein 3 (FoxP3+) T cells could be observed in peripheral blood after, in comparison to before, 6 weeks of treatment. The suppressive ability of CD4+CD25+ cells did not change. There was an initial decrease of CD4+CD25+ cells in intestinal mucosa after 2 weeks of treatment, followed by an increase of these cells from weeks 2 to 6 of treatment ( P < 0·05). This was accompanied by an increased percentage of CD69+ cells among these cells after 6 weeks of treatment compared to before treatment ( P < 0·01). There was also an increase of mucosal T helper type1 cells from weeks 2 to 6 ( P < 0·05). In addition, CD25+TNF-RII+ cells in the mucosa were decreased after 6 weeks of treatment compared to before treatment ( P < 0·05). Before treatment, peripheral blood mononuclear cell baseline proliferation was increased when IL-10 was blocked ( P < 0·01), but not after. In CD25+ cell-depleted cultures proliferation increased after treatment ( P < 0·05). Our data indicate that anti-TNF treatment leads to an induction of effector T cells. Anti-TNF therapy has no significant impact on regulatory T cells in IBD, although the composition of regulatory T cell subsets may change during treatment. [ABSTRACT FROM AUTHOR]

Background Allergy to the domestic dog ( C anis familiaris) affects 5-10% of the population in affluent countries. Three of four patients are allergic to more than one pet, which can only partially be explained by cross-reactivity between serum albumins. The lipocalin protein family harbours allergens in mammalian species. Methods We set out to clone and characterize a novel dog allergen, and investigate its potential role in cross-sensitization between dog, cat and horse. The gene encoding Can f 6 was amplified from dog skin and bladder cDNA libraries. The corresponding allergen was produced and purified by recombinant techniques and evaluated by SDS-PAGE, size exclusion chromatography, circular dichroism spectra, ELISA and basophil activation test. Results Ig E antibodies to Can f 6 were found in serum from 38% of dog-sensitized subjects. Sequence similarities between the lipocalin allergens Can f 6, Fel d 4 (cat) and Equ c 1 (horse) suggested a probability for cross-reactivity, which was demonstrated by competitive ELISA. The biological relevance of Can f 6 was confirmed by basophil activation test in dog-allergic patients. Conclusion Can f 6 is a new lipocalin dog allergen that cross-reacts with lipocalins from horse and cat. Can f 6 and homologous allergens may contribute to multisensitization and symptoms in individuals allergic to mammals. [ABSTRACT FROM AUTHOR]

Background: Allergy to laboratory animals is a well-known occupational hazard. The aim was to investigate the frequency of allergic sensitization and respiratory symptoms among pet shop staff and to document their work environment. Methods: Subjects (n = 59) from 24 pet shops were investigated with a questionnaire and lung function tests and skin prick tests against a panel of common inhalant and pet shop allergens. Blood samples were taken for immunoglobulin E (IgE) and IgE antibodies against Phadiatop and specific pet shop allergens. Personal airborne rodent allergen (n = 40) and endotoxin exposure (n = 40) was measured during work. Airborne rodent allergens were also collected using petri dishes at work (n = 40) and at home (n = 45). Results: Fifty-three percent reported nasal symptoms, 34% eye symptoms, and 22% had experienced symptoms indicating asthma. However, only four workers (7%) were previously diagnosed with asthma. One-third reported respiratory symptoms at work, mostly against rodents, birds, insects, and hay, and 29% were sensitized to work-related allergens, mainly rodents and fodder insects, e.g., Zophobas. Atopy and total IgE > 100 kU/l increased prevalence of pet shop sensitization [prevalence ratio (PR) 17 and 5.5, respectively], and atopy increased work-related symptoms (PR 3.2). Endotoxin levels were similar between shops with and without rodents. Exposure to animals outside of work was extensive. Conclusions: A third of the pet shop workers reported airway symptoms at work or were sensitized, sometimes to unusual pet shop allergens, especially among atopics. The findings stress the importance of improving the knowledge of health risks and allergen avoidance measures among pet shop staff. [ABSTRACT FROM AUTHOR]

Background: A hypoallergen of the major cat allergen Fel d 1, recombinant (r) Fel d 1 (DTE III), was previously shown to have retained T-cell reactivity and strongly reduced IgE-binding capacity compared to unmodified rFel d 1. Here, we evaluated the therapeutic capacity of rFel d 1 (DTE III) in a mouse model for cat allergy. Methods: Mice were subcutaneously (s.c.) sensitized with rFel d 1 and subsequently treated (s.c.) with 50 or 200 μg rFel d 1 (DTE III), or 50 lg rFel d 1, prior to intranasal challenge with cat dander extract. Airway hyperreactivity (AHR), cells and cytokines in bronchoalveolar lavage fluid, splenocyte in vitro response, and serum immunoglobulins were analyzed. Seven cat-allergic patients and ten healthy controls were tested for skin prick test (SPT) reactivity to rFel d 1 (DTE III) and rFel d 1. Results: Mice treated with 50 and 200 lg rFel d 1 (DTE III), and 50 lg rFel d 1, produced increased serum levels of rFel d 1-specific IgG1 and IgG2a compared to sham-treated mice. IgG from all treatment groups could block binding of patients' IgE to rFel d 1. The 200 lg rFel d 1 (DTE III) treatment tended to reduce AHR. All mice tolerated treatment with rFel d 1 (DTE III), in contrast to only four of ten treated with rFel d 1. Compared to rFel d 1, the hypoallergen showed a tendency of reduced SPT reactivity. Conclusion: The rFel d 1 (DTE III) hypoallergen might be a promising candidate for application in immunotherapy of cat allergy with improved safety and efficacy. [ABSTRACT FROM AUTHOR]

To cite this article: Asarnoj A, Movérare R, Östblom E, Poorafshar M, Lilja G, Hedlin G, van Hage M, Ahlstedt S, Wickman M. IgE to peanut allergen components: relation to peanut symptoms and pollen sensitization in 8-year-olds. Allergy 2010; 65: 1189–1195. Background: Allergen-specific IgE testing is often performed with crude peanut extract, but the results may be difficult to interpret because of cross-reactions between peanut and other plant allergens. The aim was to investigate IgE reactivity to peanut allergen components in children from a birch-rich region in relation to pollen sensitization and peanut symptoms. Methods: From a birth cohort, clinical parameters were obtained through questionnaires and IgE antibody levels to peanut and birch pollen were measured. Different peanut/birch sensitization phenotypes were defined among 200 selected children. IgE reactivity to peanut and pollen allergen components was analysed using microarray technique. Results: Peanut symptoms were reported in 87% of the children with IgE reactivity to any of the peanut allergens Ara h 1, 2 or 3 but not to Ara h 8 ( n = 46) vs 17% of children with IgE reactivity to Ara h 8 but not to Ara h 1, 2 or 3 ( n = 23), P < 0.001. Furthermore, symptoms were more severe in children with Ara h 1, 2 or 3 reactivity. Children with IgE reactivity both to Ara h 2 and to Ara h 1 or 3 more often reported peanut symptoms than children with IgE only to Ara h 2 (97% vs 70%, P = 0.016), particularly respiratory symptoms (50% vs 9%, P = 0.002). Conclusions: IgE analysis to peanut allergen components may be used to distinguish between peanut-sensitized individuals at risk of severe symptoms and those likely to have milder or no symptoms to peanut if sensitized to pollen allergens and their peanut homologue allergens. [ABSTRACT FROM AUTHOR]

To cite this article: Weinmayr G, Genuneit J, Nagel G, Björkstén B, van Hage M, Priftanji A, Cooper P, Rijkjärv M-A, von Mutius E, Tsanakas J, Forastiere F, Doekes G, Garrido JB, Suarez-Varela MM, Bråbäck L, Strachan DP, the ISAAC Phase Two Study Group. International variations in associations of allergic markers and diseases in children: ISAAC Phase Two. Allergy 2010; 65: 766–775. Background: Circulating allergen-specific IgE (sIgE) and skin prick tests (SPT) are used to define atopy. Downregulation of local inflammatory responsiveness has been proposed to explain a low prevalence of positive SPTs in less affluent countries. We analysed the association between SPTs, total and allergen-specific IgE and their relationships to allergic symptoms in centres with diverse living conditions. Methods: Cross-sectional studies of stratified random samples of 8 to 12-year-old children ( n = 7461) used the standardized methodology of Phase Two of the International Study of Asthma and Allergies in Childhood (ISAAC). Symptoms of asthma, rhinitis and eczema were ascertained by parental questionnaires. Skin examination, hypertonic saline bronchial challenge, six aeroallergen SPTs and measurements of serum total IgE and sIgE were performed. Results: In nonaffluent countries, a higher proportion of children with positive SPT had no detectable sIgE (range 37–61%) than in affluent countries (0–37%). Total serum IgE was associated with all disease outcomes among children with both positive SPT and sIgE ( P < 0.001), but only with self-reported eczema in children with negative SPTs and negative sIgE. Conclusions: The international pattern of discordance between SPT and sIgE results did not support the downregulation hypothesis. Among children with no evidence of sensitization to common aeroallergens, increased total IgE contributes little to the risk of wheeze and rhinitis in the general population but may play a role in eczema. [ABSTRACT FROM AUTHOR]

To cite this article: Thunberg S, Gafvelin G, Nord M, Grönneberg R, Grunewald J, Eklund A, van Hage M. Allergen provocation increases TH2-cytokines and FOXP3 expression in the asthmatic lung. Allergy 2010; 65: 311–318. Background: Allergic asthma is caused by allergen-specific IgE and T-helper cell (Th) type 2 responses towards airborne allergens. The objective of this study was to investigate local and systemic regulatory mechanisms in the early asthmatic response to bronchial allergen provocation. Methods: Birch pollen-allergic patients with mild asthma ( n = 13) and healthy nonallergic controls ( n = 14) were subjected to bronchoalveolar lavage (BAL) and blood sampling. On patients BAL was performed twice: without preceding provocation (‘before samples’) and 24 h after bronchial provocation with birch pollen allergen. Lymphocytes in BAL and peripheral blood mononuclear cells (PBMCs) were phenotyped by multi-colour flow cytometry and cytokines measured by cytometric bead array. Proliferation and secreted cytokines were analysed in allergen-stimulated PBMCs, CD25+ depleted PBMCs and PBMCs with IL-10 neutralizing antibodies. Results: The numbers of CD69+ and FOXP3+ lymphocytes were higher in BAL after compared with before allergen provocation in asthmatic patients. Moreover, allergen provocation increased expression of FOXP3 in CD4+CD25bright cells. The cytokine profile in BAL fluid from asthmatics revealed higher levels of IL-5, compared with the controls, and an increase in IL-5, IL-6, IL-9 and IL-10 after allergen provocation. Pollen allergen stimulated PBMC cultures from asthmatic patients produced elevated levels of IL-5 and IL-13 compared with the controls, which were not affected by depletion of CD25+ cells or IL-10 neutralization. Conclusion: Despite an increase in CD4+CD25bright cells expressing high levels of FOXP3 in response to bronchial allergen provocation, asthmatic patients exhibit enhanced levels of Th2 cytokines in the lung, which may indicate an inability among infiltrating cells to suppress Th2 responses. [ABSTRACT FROM AUTHOR]

To cite this article: Asarnoj A, Östblom E, Ahlstedt S, Hedlin G, Lilja G, van Hage M, Wickman M. Reported symptoms to peanut between 4 and 8 years among children sensitized to peanut and birch pollen – results from the BAMSE birth cohort. Allergy 2010; 65: 213–219. Background: Specific IgE tests are sometimes difficult to interpret due to structural similarities between certain food and pollen allergens. This may be the reason why concomitant sensitization to peanut and birch pollen is frequently seen. The aim of this study was to investigate reported symptoms to peanut- and birch pollen in relation to sensitization. Methods: The data originate from 1928 children in the BAMSE birth cohort. Background factors and clinical parameters were obtained and the levels of IgE antibodies to peanut and birch pollen measured at 4 and 8 years. Results: IgE antibodies to peanut were found in 5.5% and 7.4% of the children at 4 and 8 years, respectively. The IgE antibody levels to peanut were higher in children sensitized to peanut but not birch than in children sensitized to peanut and birch among both 4- and 8-year-olds ( P = 0.093 and P = 0.003, respectively). Eight-year-olds sensitized to peanut but not birch, more often reported symptoms to peanut than children sensitized to both peanut and birch pollen (76% vs 46%, P = 0.002). The probability of reported symptoms to peanut increased significantly with increasing IgE levels to peanut, especially in 8-year-olds not sensitized to birch. Conclusions: Children sensitized to both peanut and birch pollen are less likely to report symptoms to peanut than children sensitized to peanut but not to birch pollen at 8 years. This is likely due to cross reactions between birch pollen and peanut and can explain the high sensitization rate to peanut in areas where birch trees are common. [ABSTRACT FROM AUTHOR]

Background: Defined particles carrying tightly bound allergens at high density have been suggested as alternatives in allergy vaccination. Carbohydrate based particles (CBP), sized 2 μm, provide a platform for covalent coupling of allergens. Objective: To investigate the mechanisms of antigen presentation by CBP, as well as cellular and humoral responses after vaccination with the major cat allergen Fel d 1, covalently coupled to CBP. Methods: Mice ( n = 10/group) were subcutaneously vaccinated with CBP-rFel d 1, CBP or phosphate buffer saline (PBS) before sensitization with rFel d 1 and challenged with cat dander extract. Fluorescent and 75Se-radiolabeled tracking of allergens and particles were performed with flow cytometry and whole-body autoradiography. Humoral, cellular and regulatory immune responses were analyzed by ELISA and flow cytometry. Cytokines were measured in bronchoalveolar lavage fluid and splenocyte cultures. Results: CBP-rFel d 1 prevented induction of airway inflammation and induced allergen-specific T-cell anergy. CBP-rFel d 1 also induced rapid IgM and IgG1-responses compared with soluble rFel d 1. Particles were phagocytosed by antigen-presenting cells and transported to draining lymph nodes and spleen. Moreover, antigen coupled to CBP remained longer at the injection site compared with alum. Conclusions: Covalent coupling of rFel d 1 to CBP induces rapid antibody production, prevents induction of allergic immune responses and systemic allergen spreading. Thus, CBP comprise several attractive adjuvant features for use in allergy vaccination. Clinical Implications: Prolonged allergen exposure through covalent coupling to particles suitable for phagocytosis, provides an adjuvant for safer and efficient allergy vaccination. [ABSTRACT FROM AUTHOR]

Background Treating allergies with modified allergens is an approach to make the treatment safer and more efficient. Art v 1 is the most prominent allergen of mugwort pollen and a significant cause of hayfever around Europe. The aim of this study was to reduce the allergenicity of Art v 1 by acetylation, and to investigate the capacity of the modified protein to generate blocking antibodies. Methods The reduction of allergenicity of Art v 1 following acetylation was monitored by immunoblot, ELISA inhibition using a pool of sera from mugwort pollen allergic patients, basophil activation assay and by skin prick testing of mugwort-allergic patients. Rabbits were immunized against Art v 1 and acetylated Art v 1 (acArt v 1) and the rabbit antisera were tested for their capacity to block human IgE binding in ELISA. Human T cell proliferation against Art v 1 and acArt v 1 was examined in peripheral blood mononuclear cells (PBMCs) of mugwort pollen allergic patients and cytokine release in PBMC cultures was monitored. Results Acetylation of Art v 1 gave a derivative of reduced allergenicity in the in vitro and ex vivo tests applied. The skin test reactivity to acArt v 1 was significantly reduced in 19 patients when compared with the reactivity to Art v 1. Rabbit antibodies to acArt v 1 and Art v 1 showed similar capacity to block human IgE binding to Art v 1 in inhibition ELISA. Both proteins were able to induce proliferation of PBMCs and CD3/CD4+ cells of mugwort-allergic patients. Release of IL-5 was significantly reduced in cultures stimulated with acArt v 1. Conclusions Art v 1 modified by acetylation had a significantly reduced allergenicity in vitro and in vivo, while its immunogenicity was retained. Modification of allergens by acetylation could be a new strategy for allergen-specific immunotherapy. [ABSTRACT FROM AUTHOR]

Background House dust mites (HDM) Dermatophagoides pteronyssinus are a frequent indoor allergen source. Our aim was to determine the frequencies of IgE reactivity to purified HDM allergen molecules in mite allergic patients from different parts of Europe in order to establish an allergen panel for diagnosis of HDM allergy. Materials and methods Populations of D. pteronyssinus-allergic patients from Austria ( n = 56), France ( n = 55), Italy ( n = 67) and Sweden ( n = 65) and storage mite allergic patients from Sweden ( n = 31) were analysed for IgE reactivity to eight purified natural (n) and recombinant (r) D. pteronyssinus allergens (nDer p 1, rDer p 2, nDer p 4, rDer p 5, rDer p 7, rDer p 8, rDer p 10 and rDer p 14) in RAST-based dot blot assays. Results Using a combination of Der p 1 and Der p 2, at least 97% of the D. pteronyssinus-allergic patients could be diagnosed in each of the HDM allergic populations. However, more than 50% of the patients also reacted with other allergens and significant variabilities regarding the frequencies of IgE reactivity to individual allergen molecules were found. Patients with a predominant storage mite allergy showed none or only very weak IgE reactivity to purified D. pteronyssinus allergens. Conclusions Purified Der p 1 and Der p 2 are sufficient for the diagnosis of ≥ 97% of D. pteronyssinus allergic patients in Europe, but other allergens may also play an important role for the diagnosis and treatment of HDM allergy. [ABSTRACT FROM AUTHOR]

Background Several studies have consistently reported inverse associations between exposure to endotoxin in house dust and atopy. With regard to the association between house dust endotoxin and asthma, the results are inconsistent. Objectives To study the association between house dust endotoxin levels and respiratory symptoms and atopy in populations from largely different countries. Methods Data were collected within the International Study on Asthma and Allergies in Childhood Phase Two, a multi-centre cross-sectional study of 840 children aged 9–12 years from six centres in the five countries of Albania, Italy, New Zealand, Sweden and the United Kingdom. Living room floor dust was collected and analysed for endotoxin. Health end-points and demographics were assessed by standardized questionnaires. Atopy was assessed by measurements of allergen-specific IgE against a panel of inhalant allergens. Associations between house dust endotoxin and health outcomes were analysed by logistic regression. Odds ratios (ORs) were presented for an overall interquartile range increase in exposure. Results Many associations between house dust endotoxin in living room floor dust and health outcomes varied between countries. Combined across countries, endotoxin levels were inversely associated with asthma ever [adjusted OR (95% confidence interval (CI)) 0.53 (0.29–0.96) for endotoxin levels per m2 of living room floor] and current wheeze [adjusted OR (95% CI) 0.77 (0.64–0.93) for endotoxin levels per gram of living room floor dust]. There were inverse associations between endotoxin concentrations and atopy, which were statistically significant in unadjusted analyses, but not after adjustment for gender, parental allergies, cat and house dust mite allergens. No associations were found with dust quantity and between endotoxin exposure and hayfever. Conclusion These findings suggest an inverse association between endotoxin levels in living room floor dust and asthma in children. [ABSTRACT FROM AUTHOR]

Background: The predictive value of reported early symptoms to pollen or fruits on later allergic disease is unclear. Our aim is to evaluate if symptoms to pollen and/or to fruits early in life are associated with allergic disease and sensitization to pollen at 4 years. Methods: The study included 3619 children from the Barn (Children), Allergy, Milieu, Stockholm, Epidemiology project (BAMSE) birth cohort. Reported symptoms of wheeze, sneeze or rash to birch, grass or weed, symptoms (vomiting, diarrhea, rash, facial edema, sneeze, or wheeze) to fruits including tree-nuts at 1 or 2 years of age, and definitions of asthma, rhinitis and eczema at 4 years were derived from questionnaire data. Sensitization to pollen allergens was defined as allergen-specific IgE-antibodies to any pollen (birch/timothy/mugwort) ≥0.35 kUA/l. Results: At 1 or 2 years of age, 6% of the children were reported to have pollen-related symptoms, 6% had symptoms to fruits, and 1.4% to both pollen and fruits. Children with symptoms to both pollen and fruits at 1 or 2 years of age had an increased risk for sensitization to any pollen allergen at age 4 (ORadj = 4.4, 95% CI = 2.1–9.2). This group of children also had a substantially elevated risk for developing any allergic disease (asthma, rhinitis, or eczema) at 4 years irrespective of sensitization to pollen (ORadj = 8.6, 95% CI = 4.5–16.4). Conclusions: The prevalence of reported symptoms to pollen and fruits is very low in early childhood. However, children with early symptoms to both pollen and fruits appear to have a markedly elevated risk for allergic disease. [ABSTRACT FROM AUTHOR]

Background Birch pollen and pollen from related trees of the Fagales order are a major cause of allergic rhinitis, conjunctivitis, and asthma through the spring season in northern and central Europe. Objective To investigate the clinical effects of injection immunotherapy with genetically modified derivatives of major birch pollen allergen Bet v 1 on pollen-induced allergic symptoms. Methods A three-arm double-blind placebo-controlled immunotherapy study was conducted with one pre-seasonal course of treatment using two derivatives of Bet v 1, namely a recombinant Bet v 1 trimer and an equimolar mixture of two recombinant Bet v 1 fragments together representing the whole protein sequence. Analysis of local and systemic adverse events was performed for 124 patients who had received at least one dose of medication. Clinical efficacy was monitored by symptom medication scores and interval scoring in the per protocol-treated population ( n=84). In addition, skin and nasal provocation responses and allergen-specific antibodies were assessed. Results There were trends towards improvement in the subjects' well-being and clinical symptoms (nasal scores), although comparisons with a placebo group did not show statistical significance in the main end-point, the combined symptom medication score. Reductions in skin and nasal sensitivity were observed for some subjects with a trend for the Bet v 1 trimer to be more effective than the fragments. Treatment induced strong IgG1 and IgG4 allergen-specific antibody responses. Local injection-site reactions were most frequent in the trimer group affecting 59.5% of patients as opposed to 37.8% and 30.6% in the fragment and placebo groups, respectively. Systemic reactions were elicited more frequently by fragments. A large proportion of adverse side-effects appeared hours following injections, and might be attributable to concurrent exposure to related pollens. Conclusion Single courses of injection immunotherapy with Bet v 1 allergen derivatives showed trends towards improved well-being and reduced reactivity to specific allergen provocation, but did not yield significant improvement in the combined symptom medication score in this study. [ABSTRACT FROM AUTHOR]

Background There is limited knowledge of the development of IgE-antibody levels over time in childhood, with respect to persistency and co-sensitization to specific inhalant allergens. Methods Data from 2033 children participating in the BAMSE birth cohort was used. Background factors and clinical parameters were obtained and IgE antibody (ab) levels to eight common airborne allergens were measured (⩾0.35 kUA/L) when the children were 4 and 8 years of age. Results Between 4 and 8 years the proportion of children sensitized to any of the inhalant allergens tested increased from 15% to 25%. At 4 years IgE-ab to birch and cat dominated, whereas at the age of 8, there was a considerable increase in the proportion of sensitization to timothy and dog. Except for mites and moulds, IgE-ab levels to all aeroallergens increased significantly between 4 and 8 years among those already sensitized at 4. Transient sensitization to inhalant allergen was uncommon. Furthermore, sensitization to birch pollen at 4 years increased the risk for becoming sensitized to timothy, cat and dog later in life. Such an association was not observed among those sensitized primarily to animal dander. Conclusions There is a prominent process of sensitization at pre-school age to inhalant allergens, and in Northern Europe sensitization to birch pollen early in life seems to be important for this process. Such a process has a probable impact on the development of allergic disease in the growing child. [ABSTRACT FROM AUTHOR]

Background Longitudinal data from population-based studies on the development and persistence of food hypersensitivity (FHS) during childhood are almost absent. Methods A population-based birth cohort was established, and information on various exposures and symptoms of allergic disease were obtained from questionnaires when the children were 2 months, 1, 2, 4 and 8 years of age. Complete data were available on 3104 children. Children with reported FHS and doctor's diagnosis of food allergy (RDFA) were identified and allocated into transient, intermittent, late-onset and persistent phenotypes. Food allergen-specific IgE-antibodies (abs) to a mix of six common food allergens (fx5®) were analysed at 4 and 8 years of age in 1857 children. Results The overall prevalence of reported FHS in combination with RDFA should be 3.1% at 1 year to 7.6% at 8 years of age. However, reactions to milk, egg, fish and wheat decreased, whereas an increase was seen for peanuts and tree nuts. Reported reactions to egg, peanuts or tree nuts early in life, as well as IgE-abs to food allergens at the age of 4, increased the risk of FHS at 8 years of age. Furthermore, FHS at young ages increased the risk for asthma, eczema and allergic rhinitis at 8 years of age, even when adjustments were made for children with these symptoms during the first 2 years of life. Conclusion The increasing prevalence of FHS up to the age of 8 years probably reflects an increasing prevalence of allergy to birch pollen and pollen-related reactions to foods. Reactions to egg, peanuts and tree nuts early in life increase the risk of FHS at 8 years. Furthermore, reported FHS at young ages, even though transient, seems to increase the risk for other allergic diseases at 8 years of age. [ABSTRACT FROM AUTHOR]

Background Current diagnosis of allergy and asthma to cat is confirmed using cat dander extract (CDE). We have previously engineered a recombinant major cat allergen, rFel d 1, with properties identical to the natural molecule. Objective The aim of the study was to evaluate IgE and IgG4 antibodies to rFel d 1 among sera from cat-allergic children and adults suffering from asthma and/or rhinoconjunctivitis (RC) in populations from Sweden and Austria. Methods Cat-allergic children and adults from Sweden ( n=27 and 31, respectively) and Austria ( n=41 and 41) with RC and/or asthma were selected. Sera were tested for IgE and IgG4 antibodies to CDE and rFel d 1 by CAP, and IgE to rFel d 1 by ELISA. Healthy subjects and non-cat-allergic patients ( n=75) were included as controls. Results There was a high correlation between IgE responses to rFel d 1 and CDE among the 140 patients ( rs=0.85, P<0.001); however, measured levels to rFel d 1 were on average 30% higher ( P<0.0001). Ninety-eight percent of patients and none of the controls showed IgE to rFel d 1 and there was a threefold increased risk of asthma for half of the children with the highest IgE levels [odds ratio 3.23; 95% confidence interval (CI), 1.19–8.79] by ELISA. IgE responses to rFel d 1 among children with asthma were higher (median 19.4 kU/L) compared with children with RC (median 6.6 kU/L, P<0.05) and adults with asthma (median 3.0 kU/L, P<0.01). Furthermore, children with asthma displayed higher IgG4 levels than the asthmatic adults. Conclusion A single recombinant molecule, rFel d 1, is at least as sensitive for in vitro diagnostics of cat allergy as the current extract-based test. Elevated IgE antibody levels to Fel d 1 are suggested to be a risk factor for asthma in cat-allergic children. [ABSTRACT FROM AUTHOR]

Background: Diagnosis of food hypersensitivity (FHS) is difficult and interpretation of food allergy tests is complicated. Objective: To investigate the probability of reported FHS in relation to levels of food-specific IgE-antibodies (AB) in a population-based setting of 4-year-old children ( n = 2336). Methods: Information on FHS was obtained from a questionnaire and specific IgE-AB to milk, egg, fish, peanut, soy and wheat were analysed. Results: Thirty-one per cent of the children with reported FHS ( n = 284) were sensitized (≥0.35 kUA/l) to at least one of the tested foods compared with 11% of children without FHS ( n = 2052). Furthermore, the probability of reported symptoms to milk, egg and fish increased with increasing levels of food-specific IgE-AB to the same food allergens. A similar trend was seen for peanut and wheat, but not for soy. Increasing levels of specific IgE-AB to milk or egg were also associated with an increasing risk of reported symptoms caused by other foods. Conclusions: Quantitative measurements of IgE-AB to milk, egg and fish are useful to evaluate IgE-associated FHS in preschool children also in a population based sample. Such measurements appear to be of limited value for soy bean and wheat, in particular as a screening method. [ABSTRACT FROM AUTHOR]