Showing papers in "Clinical & Experimental Allergy in 2003"

Long-lasting effect of sublingual immunotherapy in children with asthma due to house dust mite: a 10-year prospective study.

Abstract: Summary Background Subcutaneous immunotherapy for respiratory allergy has shown a long-lasting efficacy after its discontinuation, whereas this evidence is still lacking for sublingual immunotherapy, despite the fact that it is widely used. Objective We aimed to evaluate whether a long-lasting effect of SLIT occurs, in a prospective parallel group controlled study. Methods Sixty children (mean age 8.5 years) suffering from allergic asthma/rhinitis due to mites were subdivided into two matched groups: 35 underwent a 4- to 5-year course of SLIT with standardized extract and 25 received only drug therapy. The patients were evaluated at three time points (baseline, end of SLIT and 4 to 5 years after SLIT discontinuation) regarding presence of asthma, use of anti-asthma drugs, skin prick tests and specific IgE. Results We found that in the SLIT group there was a significant difference vs. baseline for the presence of asthma (P ≤ 0.001) and the use of asthma medications (P ≤ 0.01), whereas no difference was observed in the control group. The mean peak expiratory flow result was significantly higher in the active group than in the control group after 10 years. No change was seen as far as new sensitizations were concerned. Specific IgE showed a near-significant increase (baseline vs. 10 years, P = 0.06) only in the control group. Conclusion Our study demonstrates that sublingual immunotherapy is effective in children and that it maintains the clinical efficacy for 4 to 5 years after discontinuation.

Allergen-specific immunotherapy with a monophosphoryl lipid A-adjuvanted vaccine: reduced seasonally boosted immunoglobulin E production and inhibition of basophil histamine release by therapy-induced blocking antibodies.

Abstract: Summary Background Allergen-specific immunotherapy represents a causal form of treatment for IgE-mediated allergies. The allergen extract-based analyses of immunotherapy-induced effects yielded highly controversial results regarding a beneficial role of therapy-induced IgG antibodies. Objective We analysed allergen-specific IgE, IgG subclass, and IgM responses in patients treated with a grass pollen allergy vaccine adjuvanted with monophosphoryl lipid A (MPL), a Th1-inducing agent, and in a placebo group using recombinant timothy grass pollen allergen molecules (rPhl p 1, rPhl p 2, rPhl p 5). Results The strong induction of allergen-specific IgG1 and IgG4 antibodies observed only in the actively treated group was associated with significant clinical improvement. Therapy-induced allergen-specific IgM and IgG2 responses were also noted in several actively treated patients. An inhibition of allergen-dependent basophil histamine release was only obtained with sera containing therapy-induced allergen-specific IgG, but not with sera obtained before therapy or from placebo-treated patients. Moreover, patients with therapy-induced allergen-specific IgG antibodies showed a reduced induction of allergen-specific IgE responses during seasonal grass pollen exposure. Conclusion Successful immunotherapy with the MPL-adjuvanted grass pollen allergy vaccine is associated with the production of allergen-specific IgG antibodies. These blocking antibodies may have protective effects by inhibiting immediate-type reactions and systemic increases of IgE responses caused by seasonal allergen exposure.

Anaphylaxis: risk factors for recurrence.

Abstract: Background There are few studies on the incidence or recurrence of anaphylaxis. Objective To examine the incidence of anaphylaxis and risk factors for recurrence. Methods A prospective study of 432 patients referred to a community-based specialist practice in the Australian Capital Territory with anaphylaxis, followed by a survey to obtain information on recurrence. Results Of 432 patients (48% male, 73% atopic, mean 27.4 years, SD 19.5, median 26) with anaphylaxis, 260 patients were seen after their first episode; 172 experienced 584 previous reactions. fifty-four percent of index episodes were treated in hospital. Aetiology was identified in 91.6% patients: food (61%), stinging insects (20.4%) or medication (8.3%). The minimum occurrence and incidence of new cases of anaphylaxis was estimated at 12.6 and 9.9 episodes/100,000 patient-years, respectively. Follow-up data were obtained from 304 patients (674 patient-years). One hundred and thirty experienced further symptoms (45 serious), 35 required hospitalization and 19 administered adrenaline. Accidental ingestion of peanut/tree nut caused the largest number of relapses, but the highest risk of recurrence was associated with sensitivity to wheat and/or exercise. Rates of overall and serious recurrence were 57 and 10 episodes/100 patient-years, respectively. Of those prescribed adrenaline, 3/4 carried it, 2/3 were in date, and only 1/2 patients faced with serious symptoms administered adrenaline. Five patients each developed new triggers for anaphylaxis, or re-presented with significant psychiatric symptoms. Conclusion In any 1 year, 1/12 patients who have suffered anaphylaxis will experience recurrence, and 1/50 will require hospital treatment or use adrenaline. Compliance with carrying and using adrenaline is poor. Occasional patients develop new triggers or suffer psychiatric morbidity.

Maternal fish oil supplementation in pregnancy reduces interleukin‐13 levels in cord blood of infants at high risk of atopy

Abstract: Summary Background and objectives The epidemiological association between higher dietary n-3 polyunsaturated fatty acids (PUFA) and lower prevalence of asthma, has led to interest in the role of early dietary modification in allergic disease prevention. In this study we examined the effects of maternal n-3 (PUFA)-rich fish oil supplementation on cord blood (CB) IgE and cytokine levels in neonates at risk of developing allergic disease. Methods In a randomized double-blind, placebo-controlled trial, 83 atopic pregnant women received either fish oil capsules (n = 40) containing 3.7 g n-3 PUFA/day or placebo capsules (n = 43) from 20 weeks gestation until delivery. CB cytokine levels (IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, TNF-α and IFN-γ) and total IgE levels were measured and compared between the two groups. Fatty acid composition of red cell membranes was analysed by gas chromatography and the relationships among PUFA, cytokine and IgE levels were examined. Results Maternal fish oil supplementation resulted in a significant increase in n-3 PUFA levels (P < 0.001) in neonatal erythrocyte membranes. Neonates whose mothers had fish oil supplementation had significantly lower plasma IL-13 (P < 0.05) compared to the control group. There was also a significant inverse relationship between levels of n-3 PUFA in neonatal cell membranes and plasma IL-13. There was no difference in levels of IgE and the other cytokines measured. Conclusions This study provides preliminary evidence that increasing neonatal n-3 PUFA levels with maternal dietary supplementation can achieve subtle modification of neonatal cytokine levels. Further assessment of immune function and clinical follow-up of these infants will help determine if there are any significant effects on postnatal immune development and expression of allergic disease.

Elevated basal serum tryptase and hymenoptera venom allergy: relation to severity of sting reactions and to safety and efficacy of venom immunotherapy.

Abstract: Summary Background Mastocytosis and/or elevated basal serum tryptase may be associated with severe anaphylaxis. Objective To analyse Hymenoptera venom-allergic patients with regard to basal tryptase in relation to the severity of sting reactions and the safety and efficacy of venom immunotherapy. Methods Basal serum tryptase was measured in 259 Hymenoptera venom-allergic patients (158 honey bee, 101 Vespula). In 161 of these (104 honey bee, 57 Vespula), a sting challenge was performed during venom immunotherapy. Results Nineteen of the 259 patients had an elevated basal serum tryptase. Evidence of cutaneous mastocytosis as documented by skin biopsy was present in 3 of 16 patients (18.8%). There was a clear correlation of basal serum tryptase to the grade of the initial allergic reaction (P<0.0005). Forty-one of the 161 sting challenged patients reacted to the challenge, 34 to a bee sting and 7 to a Vespula sting. Thereof, 10 had an elevated basal serum tryptase, i.e. 1 (2.9%) of the reacting and 2 (2.9%) of the non-reacting bee venom (BV) allergic individuals, as compared to 3 (42.9%) of the reacting and 4 (8%) of the non-reacting Vespula venom-allergic patients. Thus, there was a significant association between a reaction to the sting challenge and an elevated basal serum tryptase in Vespula (χ2=6.926, P<0.01), but not in BV-allergic patients. Systemic allergic side-effects to venom immunotherapy were observed in 13.9% of patients with normal and in 10% of those with elevated basal serum tryptase. Conclusions An elevated basal serum tryptase as well as mastocytosis are risk factors for severe or even fatal shock reactions to Hymenoptera stings. Although the efficacy of venom immunotherapy in these patients is slightly reduced, most of them can be treated successfully. Based on currently available data, lifelong treatment has to be discussed in this situation.

Sensitization to fungi: epidemiology, comparative skin tests, and IgE reactivity of fungal extracts

Abstract: Summary Background Several fungal species are known to cause severe respiratory and cutaneous allergicdiseases. Extracts from several allergenic fungi are used for in vivo and in vitro tests, as standardpreparations are still not available.Objective The aims are to define the pattern of in vivo and in vitro IgE reactivity to fungal species inan allergic population with respiratory symptoms; to determine the influence of different extractpreparations on diagnostic results; and to evaluate whether there exists a relationship between thediagnostic pattern of reactivity and the pattern of specific IgE reactivity in immunoblots.Methods Skin prick tests were applied to a cohort of 4962 respiratory subjects, aged 3–80 years.Fungal extracts from Alternaria, Aspergillus, Candida, Cladosporium, Penicillium, Saccharomyces,and Trichophyton were used, along with extracts from pollens, mites, and animal dander.Demographical and diagnostic data were recorded. IgE detection was carried out with the sameallergenic extracts plus Malassezia. Comparative skin tests and IgE detection were carried out usingextracts from three commercial suppliers. IgE immunoblots were carried out with the same panel ofcommercial fungal extracts and were compared with in-house extracts. Data analysis was carried outby grouping the population on the basis of their reactivity to a single, to two or to more than two,mould species.Results Nineteen percent of the allergic population reacted to at least one fungal extract by meansof the skin test. Alternaria and Candida accounted for the largest number of positive tests, and alongwith Trichophyton they were the main sensitizers in the subset of patients with an isolatedsensitization. The prevalence of skin test reactivity increased for these three fungi in the subsets withtwo associated reactivities and, furthermore, in the subset showing reactivity to more than twomould species. In the latter group, a steady increase of the skin test reactivity was recorded for all theother fungal sources, suggesting a clustered reactivity. Comparative skin and IgE testing withdifferent groups of subjects with a simple pattern of skin reactivity resulted in sensitivity differencesbetween in vivo and in vitro tests, whereas discrepant results were recorded in the subsets of patientswith multiple fungi sensitization. Although hampered by the limited reliability of fungal extracts, IgEimmunoblots revealed differing patterns of reactivity when sera from the three subsets were used.This suggests a link between the diagnostic reactivity pattern and the IgE sensitization to extracts’components. Age and gender distribution differed among the Alternaria-, Candida-, andTrichophyton-sensitized subjects, but not in the subset with more than two fungi sensitizations.Conclusions The preliminary assessment of a new classification of the mould-sensitized populationhas been reached. The limiting quality of fungal extracts requires future studies using an allergenicmolecule-based approach. The diagnostic process and the definition of the reactivity pattern wouldthus be easy, and it could lead to a novel specific immunotherapy approach.Keywords allergens, comparative study, epidemiology, fungal allergy diagnosis, fungal extract, IgEdetection, immunoblotting, prevalence, skin tests.Submitted 18 November 2002; revised 4 June 2003; accepted 28 July 2003

Characterization of wheezing phenotypes in the first 10 years of life.

Abstract: Summary Background Childhood wheezing illnesses are characterized into different phenotypes. However, severity of the disease associated with these phenotypes has not been extensively studied. Objectives To determine characteristics of childhood wheezing phenotypes in the first decade of life using health outcomes plus measurements of atopy, lung function and bronchial hyper-responsiveness. Methods A whole population birth cohort (n = 1456) was prospectively studied to examine the natural history of childhood wheezing. Children were seen at 1, 2, 4 and 10 years for questionnaire completion and prospectively collected data used to define wheezing phenotypes. Assessment was made of adverse health outcomes plus spirometry, bronchial hyper-responsiveness, serum IgE measurement at 10 years and skin test sensitization at both 4 and 10 years for wheezing phenotypes. Results Phenotypic analysis identified that 37% early life wheezers (symptom onset by age 4 years) still wheezed at 10 years. These persistent wheezers showed significantly more physician-diagnosed asthma in early life (P < 0.005 at 2 years) than early transient wheezers (wheezing transiently with onset by age 4 years). Overall they experienced greater multiple hospital admissions (P = 0.024), specialist referral (P = 0.009) and use of inhaled (P < 0.001) and oral steroids (P < 0.001) than early transient wheezers. They also demonstrated enhanced bronchial hyper-responsiveness compared with early transient wheezers (P < 0.001). However, both groups of early life wheezers showed impairment of baseline lung function at 10 years in comparison with non-wheezers: FEV1 (P < 0.029) and FEV1/FVC ratio (P < 0.001) with persistent wheeze and PEF (P = 0.036) with early transient wheeze. Late-onset wheezers (onset from 5 years onwards) had similar BHR to persistent wheezers but maintained normal lung function at age 10 and had lower cumulative prevalence of adverse health outcomes than persistent wheezers. Conclusions Persistent wheezing with early childhood onset is associated with substantial morbidity in the first decade of life in association with high levels of atopy, bronchial hyper-responsiveness and impaired lung function at 10 years of age. Late-onset wheezing in the first decade of life could harbour potential for similarly significant disease subsequently.

'Entopy': localized mucosal allergic disease in the absence of systemic responses for atopy.

Abstract: _Background_ The Th2 immune response in the nasal mucosa of subjects with allergic rhinitis is mediated by allergen-specific IgE. Moreover, these subjects show positive responses for markers of systemic atopy, including allergen-specific skin sensitivity and raised serum IgE titres. In contrast, idiopathic rhinitis (IR) subjects with similar histological nasal mucosal features differ in being defined as non-allergic because they have negative atopic responses. _Objective_ We hypothesized that it is possible to have an allergic Th2 disease pathway localized in the nasal mucosa of ‘non-allergic’ rhinitis subjects despite an absence of atopic responses. _Methods_ The presence of house dust mite and grass pollen-specific IgE antibodies was investigated in non-atopic (n=10) and atopic (n=11) subjects with persistent rhinitis and compared to normal (n=12) control subjects. Biotin-labelled allergen was used to localize specific allergen-binding antibodies in situ in sections of nasal mucosa. _Results_ Grass pollen allergen binding was detected in the nasal mucosa of 3/10 non-atopic IR subjects but, in contrast, dust mite-specific antibodies were not detected. Specific antibodies were present in a total of 8/11 mucosal samples from the allergic group, but none was detected in normal control tissues. _Conclusion_ These findings support the concept of localized nasal allergy in ‘non-atopic’ rhinitis subjects. We propose the term ‘entopy’ to define this phenomenon and believe that this concept has a wider implication for localized allergic responses in other mucosal sites.

Thresholds of clinical reactivity to milk, egg, peanut and sesame in immunoglobulin E-dependent allergies: evaluation by double-blind or single-blind placebo-controlled oral challenges.

Abstract: Summary Background The prevalence of food anaphylaxis due to masked allergens has increased within the last 10 years. Contamination of manufactured products by food allergens is a key concern for food industries. Objective To determine quantities eliciting reactions in patients who have an IgE-dependent food allergy, thanks to standardized oral provocation tests. To evaluate the subsequent levels of sensitivity required for the detection tests of allergens for egg, peanut, milk and sesame. Methods Prick-in-prick tests, Cap system RAST, and single or double-blind placebo-controlled food challenges (SBPCFC or DBPCFC) were performed. The doses of natural food were gradually increased from 5 to 5000 mg for solid food and from 1 to 30 mL for peanut oil, sunflower oil, soy oil and sesame oil. Results Data from 125 positive oral challenges to egg, 103 to peanut, 59 to milk and 12 to sesame seeds were analysed. Haemodynamic modifications were observed in 2%, 3%, 1.7%, and 8% of the oral challenges (OCs) to egg, peanut, milk and sesame, respectively. Respiratory symptoms were observed in 12%, 20%, 10% and 42% of egg, peanut milk and sesame allergies, respectively. A cumulative reactive dose inferior or equal to 65 mg of solid food or 0.8 mL of milk characterized 16%, 18%, 5% and 8% of egg, peanut, milk and sesame allergies, respectively. 0.8% of egg allergies, 3.9% of peanut allergies, and 1.7% of milk allergies reacted to 10 mg or less of solid food or to 0.1 mL for milk. The lowest reactive threshold has been observed at less than 2 mg of egg; 5 mg of peanut, 0.1 mL of milk and 30 mg of sesame seed. Ten out of 29 OC with peanut oil, two out of two OC with soy oil and three out of six OC with sunflower oil were positive. Five out six OC with sesame oil were positive: 1 and 5 mL induced an anaphylactic shock. Conclusion The risk of asthma and anaphylactic shock to sesame and peanut is confirmed. Minimal reactive quantities show that, in order to guarantee a 95% safety for patients who are allergic to egg, peanut and milk, and on the basis of consumption of 100 g of food, the detection tests should ensure a sensitivity of 10 p.p.m. for egg, 24 p.p.m. for peanut and 30 p.p.m. for milk proteins. Oil allergies being considered, the limit of sensitivity should fall to 5 p.p.m.

Allergen microarray: comparison of microarray using recombinant allergens with conventional diagnostic methods to detect allergen-specific serum immunoglobulin E.

Abstract: Summary Background The availability of recombinant allergens and recent advances in biochip technology led to the development of a novel test system for the detection of allergen-specific IgE. Objective To test the performance of this allergen microarray in a serological analytical study. Methods Standard allergens contained in grass pollen (Phl p 1, Phl p 2, Phl p 5 and Phl p 6) and tree pollen (Bet v 1 and Bet v 2) were used as a model system. The detection of allergen-specific serum IgE using microarrays was compared with standard test systems: CAP/RAST and an in-house ELISA. In order to test the analytical sensitivity of the assays, geometric dilutions of a serum pool containing high levels of pollen-specific IgE from allergic individuals were tested in each system. To assess the analytical specificity, the sera of 51 patients with presumptive allergic symptoms were collected before diagnosis. Thereafter, the results for grass/tree-pollen-specific IgE were compared. Results The microarray has a good dynamic range similar to the CAP/RAST system. Microarray and ELISA showed comparable analytical sensitivity exceeding the CAP/RAST system. With respect to the analytical specificity, no significant cross-reactivity of the allergens was observed. For two of the allergens tested, weak positive signals were detected in the microarray test system, whereas they were not detectable by CAP/RAST. Conclusion A good correlation of presently used methods to detect serum IgE and the novel microarray test system was observed. As a next step, a careful validation of this method for a multitude of allergens and a thorough clinical evaluation has to be provided. Microarray testing of allergen-specific IgE can be presumed to be the method of choice for a prospective component-resolved diagnosis of Type I allergy, and the basis for the design and monitoring of a patient-tailored specific immunotherapy in the future.

Interpretation of tests for nut allergy in one thousand patients, in relation to allergy or tolerance

Abstract: Background Peanut and tree nut allergy are common, increasing in prevalence and the commonest food cause of anaphylaxis. In the USA, 7.8% are sensitized (have nut-specific IgE), but not all those sensitized are allergic. Lack of data makes interpretation of tests for nut-specific IgE difficult. Objectives This is the first study to investigate the clinical significance of test results for peanut and tree nut allergy in allergic or tolerant patients. Findings are related to the severity of the allergy. Method An observational study of 1000 children and adults allergic to at least one nut. History of reactions (severity graded) or tolerance to up to five nuts was obtained and skin prick test (SPT)/serum-specific IgE (CAP) performed. Results There was no correlation between SPT size and graded severity of worst reaction for all nuts combined or for peanut, hazelnut, almond and walnut. For CAP, there was no correlation for all nuts. Where patients tolerated a nut, 43% had positive SPT of 3-7 mm and 3% > or = 8 mm. For CAP, 35% were positive (0.35-14.99 kU/L) and 5% > or = 15 kU/L. In SPT range 3-7 mm, 54% were allergic and 46% were tolerant. There was poor concordance between SPT and CAP (66%). Of patients with a clear nut-allergic history, only 0.5% had negative SPT, but 22% negative CAP. Conclusions Magnitude of SPT or CAP does not predict clinical severity, with no difference between minor urticaria and anaphylaxis. SPT is more reliable than CAP in confirming allergy. Forty-six per cent of those tolerant to a nut have positive tests > or = 3 mm (sensitized but not allergic). One cannot predict clinical reactivity from results in a wide 'grey area' of SPT 3-7 mm; 22% of negative CAPs are falsely reassuring and 40% of positive CAPs are misleading. This emphasizes the importance of the history. Understanding this is essential for accurate diagnosis. Patients with SPT > or = 8 mm and CAP > or = 15 kU/L were rarely tolerant so these levels are almost always (in > or = 95%) diagnostic.

Mucosal and systemic inflammatory changes in allergic rhinitis and asthma: a comparison between upper and lower airways.

Abstract: Summary Background Local airway inflammation and airway remodelling are considered important in the clinical expression of allergic asthma. Objective The aim of this study was to compare airway inflammation and remodelling in nasal and bronchial mucosa of subjects with allergic rhinitis with or without asthma. Methods Four experimental groups were formed: allergic asthma and rhinitis (n = 19); allergic rhinitis, no asthma (n = 18); atopic subjects, no asthma, no rhinitis (n = 8) and non-allergic healthy control subjects (n = 16). Blood samples, nasal and bronchial biopsy specimens were collected during stable disease. Immunohistochemistry was performed for eosinophils (MBP), mast cells (CD117) and vascular endothelium (CD31). Epithelial loss, reticular basement membrane (RBM) thickness and subepithelial vascularity was assessed with a computer-assisted image analysis system. Results In nasal and bronchial mucosa, numbers of eosinophils were significantly higher in rhinitis patients with and without asthma than in asymptomatic atopics (P < 0.05) and controls (P ≤ 0.01). In bronchial mucosa, the RBM was significantly thickened in rhinitis patients with and without asthma compared to asymptomatic atopics (P < 0.05) and controls (P < 0.01), while in nasal mucosa no differences were seen. Patients with asthma and rhinitis had increased numbers of blood eosinophils (P = 0.05) and skin test reactivity (P = 0.01) compared to patients with rhinitis only. No significant differences could be found between the investigated groups with respect to serum IL-5 and eotaxin levels, the number of mucosal mast cells and the degree of epithelial loss and subepithelial vascularity. Epithelial desquamation was significantly increased in the bronchial mucosa compared to nasal mucosa, not only in asthmatics (P < 0.001), but also in atopics without asthma and rhinitis (P = 0.02). Conclusions This study shows that allergic inflammation, increased basement membrane thickness and epithelial desquamation are present in the lower airways of atopic subjects, even before the onset of clinical symptoms. Despite the presence of inflammatory cells, no structural changes could be assessed in nasal mucosa of allergic patients.

Consensus group on new‐generation antihistamines (CONGA): present status and recommendations

Abstract: CONTENTS Prefacey1305 Executive summary and recommendationsy1306

Increased levels of vascular endothelial growth factor in induced sputum in asthmatic patients.

Abstract: Summary Background Vascular endothelial growth factor (VEGF) is highly expressed in the airway of asthmatic patients. As VEGF increases airway vascular permeability, consequent thickening of the airway wall mucosa may lead to narrowing of the airway lumen. Objective We evaluated the relationship between VEGF levels in induced sputum and eosinophilic inflammatory profiles, and the degree of airway vascular permeability in asthmatic patients and we evaluated the effect of inhaled corticosteroids on VEGF levels in induced sputum. Methods Induced sputum specimens were obtained from 28 glucocorticosteroids free asthmatics and 11 healthy control subjects. We examined VEGF levels and airway vascular permeability index in induced sputum. After the initial sputum induction, 21 asthmatics received 8-week inhaled beclomethasone dipropionate (BDP, 800 µg/day) therapy, then sputum induction was repeated. Results The VEGF levels in asthmatics were significantly higher than in healthy control subjects (P < 0.0001). The VEGF levels were negatively correlated with forced expiratory volume of 1 s (FEV1, % predicted, r = − 0.68, P < 0.001), the percentage of eosinophils (r = 0.51, P < 0.01) and ECP levels (r = 0.39, P < 0.05). Moreover, the VEGF levels were significantly correlated with airway vascular permeability index (r = 0.61, P < 0.001). After 8-week inhaled BDP therapy, the VEGF levels were significantly decreased compared to pretreatment levels (P < 0.0001) and the VEGF levels were significantly correlated with airway vascular permeability index even in post-treatment asthmatics (r = 0.62, P < 0.01). Conclusion The VEGF levels in induced sputum were increased in asthmatics and its levels were associated with degree of airway narrowing and airway vascular permeability. These findings provide strong evidence that VEGF may play an important role in the pathogenesis of bronchial asthma.

Oral magnesium and vitamin C supplements in asthma: a parallel group randomized placebo-controlled trial

Abstract: Summary Background Epidemiological studies suggest that higher intakes of dietary vitamin C and magnesium may be associated with a reduced risk of asthma. Objective To determine whether vitamin C or magnesium supplements improve the clinical control of asthma in primary care patients. Methods A randomized, placebo-controlled, double-blind parallel group trial of 16 weeks supplementation with 1 g/day vitamin C, 450 mg/day magnesium chelate or matched placebo. Three hundred patients aged 18–60 years with physician-diagnosed asthma, controlled with at least one dose of an inhaled corticosteroid daily, were recruited from 24 primary care practices in Nottingham, UK. The main outcome measures were change in forced expiratory volume in 1 s, forced vital capacity, airway responsiveness to methacholine, mean morning and evening peak flow, symptom scores and bronchodilator use, both individually and as a combined summary statistic. Results There was no evidence of any beneficial effect of either supplement on any outcome measure of asthma control in the primary intention-to-treat analysis, or in an analysis restricted to participants who completed the study. Conclusions Regular dietary supplementation with vitamin C or magnesium adds no clinical benefit to current standard therapy of asthma in primary care patients.

Direct and indirect exposure to pets – risk of sensitization and asthma at 4 years in a birth cohort

Abstract: INTRODUCTION: There are conflicting data on the association between early exposure to pets and allergic diseases. Bias related to retrospective information on pet ownership has been addressed as a ...

The role of the epidermal growth factor receptor in sustaining neutrophil inflammation in severe asthma

Abstract: BACKGROUND: The extent of epithelial injury in asthma is reflected by expression of the epidermal growth factor receptor (EGFR), which is increased in proportion to disease severity and is corticosteroid refractory. Although the EGFR is involved in epithelial growth and differentiation, it is unknown whether it also contributes to the inflammatory response in asthma. OBJECTIVES: Because severe asthma is characterized by neutrophilic inflammation, we investigated the relationship between EGFR activation and production of IL-8 and macrophage inhibitory protein-1 alpha (MIP-1alpha) using in vitro culture models and examined the association between epithelial expression of IL-8 and EGFR in bronchial biopsies from asthmatic subjects. METHODS: H292 or primary bronchial epithelial cells were exposed to EGF or H2O2 to achieve ligand-dependent and ligand-independent EGFR activation; IL-8 mRNA was measured by real-time PCR and IL-8 and MIP-1alpha protein measured by enzyme-linked immunosorbent assay (ELISA). Epithelial IL-8 and EGFR expression in bronchial biopsies from asthmatic subjects was examined by immunohistochemistry and quantified by image analysis. RESULTS: Using H292 cells, EGF and H2O2 increased IL-8 gene expression and release and this was completely suppressed by the EGFR-selective tyrosine kinase inhibitor, AG1478, but only partially by dexamethasone. MIP-1alpha release was not stimulated by EGF, whereas H2O2 caused a 1.8-fold increase and this was insensitive to AG1478. EGF also significantly stimulated IL-8 release from asthmatic or normal primary epithelial cell cultures established from bronchial brushings. In bronchial biopsies, epithelial IL-8, MIP-1alpha, EGFR and submucosal neutrophils were all significantly increased in severe compared to mild disease and there was a strong correlation between EGFR and IL-8 expression (r = 0.70, P < 0.001). CONCLUSIONS: These results suggest that in severe asthma, epithelial damage has the potential to contribute to neutrophilic inflammation through enhanced production of IL-8 via EGFR- dependent mechanisms.

Immunoglobulin E antibody reactivity to the major shrimp allergen, tropomyosin, in unexposed Orthodox Jews.

Abstract: Summary Background Assessment of allergic (IgE antibody-mediated) reactions to foods may become complicated by cross-reactivity that can occur among certain food families and between foods and seemingly unrelated allergens. Objective The allergenic properties of tropomyosin (muscle-derived protein) have been recently demonstrated in invertebrates such as cockroaches, dust mites, and shrimp. In view of a possible cross-reactivity between food allergens and related allergens from animal sources, we designed a study to assess IgE antibody reactivity to the major shrimp allergen, Pen a 1, in an unexposed population of Orthodox Jews, who observe Kosher dietary laws that prohibit eating shellfish. Methods Nine subjects, who reacted positively by skin tests to shrimp (Penaeus setiferous), were selected for the study. Subjects (two females, seven males) ranged in age from 14 to 32 years (mean 20.4). All subjects were strictly observant of Jewish tradition and had no prior exposure to seafood (regarded as a non-Kosher food). Serum was obtained from all the subjects and tested for IgE antibody reactivity to shrimp and dust mite. Results All subjects reported symptoms of perennial allergic rhinitis, five had history of asthma, atopic dermatitis, and/or sinusitis. All had positive skin prick tests to shrimp and house dust mite (HDM) (Dermatophagoides farinae, D. pteronyssinus, or both); 2/7 subjects were positive to cockroach mix (Blattella germanica and Periplaneta americana). Sera of 4/9 subjects demonstrated specific IgE antibodies by RAST to shrimp (7.0–20.0%), 3/9 to Pen a 1 (6.3–24.1%), and 3/9 to shrimp or Pen a 1 by immunoblot. IgE binding to Pen a 1 was inhibited with either mite or cockroach extracts as demonstrated by RAST and/or immunoblot inhibition analysis. Conclusions These studies indicate that IgE antibody reactivity to a major food allergen, shrimp, can occur in an unexposed population of individuals; some subjects allergic to HDM and/or cockroach show substantial IgE antibody reactivity to the major shrimp allergen Pen a 1 (tropomyosin). Based on inhibition with cockroach and/or dust mite extracts, this reactivity appears to be due to cross-reacting tropomyosins.

The economic burden of antibiotic treatment of penicillin-allergic patients in internal medicine wards of a general tertiary care hospital.

Abstract: Summary Background Penicillin allergy poses a major problem in the management of infectious diseases. Objective We estimated the costs and usage of antibiotic treatment of ‘penicillin-allergic’ patients in comparison to non-allergic patients in a tertiary care hospital. Materials and methods The study was based on the records of 118 randomly chosen in-hospital patients labelled as being ‘allergic to penicillin’ and who were treated with antibiotics. The antibiotic selection and cost of the patients with alleged penicillin allergy were compared to 118 matched patients without an antibiotic allergy (controls). Results During in-hospital treatment, the mean antibiotic cost for penicillin-allergic patients was 63% higher than the cost for the controls. In addition, there was a 38% higher cost of the recommended anti-microbial treatment regimen to be followed upon discharge by the former compared to the latter. Conclusions Penicillin-allergic patients were more likely to receive broader spectrum antibiotics compared to the non-allergic ones. Since many of the patients who are labelled as being ‘allergic to penicillin’ are, in fact, not allergic to it, inaccurate reporting of penicillin allergies may have costly economic and epidemiologic repercussions in addition to more toxic effects which can occur when choosing alternative drugs in case of penicillin allergy.

Polymorphisms in the interleukin-4 and interleukin-4 receptor alpha chain genes confer susceptibility to asthma and atopy in a Caucasian population

Abstract: Summary Background IL-4 by binding to its receptor (IL-4R) is essential for the development of airway inflammation present in asthma, through the induction of IgE synthesis in B cells and differentiation of T cells to a Th2 phenotype. Objective To investigate the role of four common polymorphisms in the IL-4 (IL4-34CT and IL4-589CT) and IL-4Rα chain (IL4RAI50V and IL4RAQ576R) genes in conferring susceptibility to the development of atopy and/or asthma. Methods Two polymorphisms in the IL-4 gene promoter, IL4-34CT and IL4-589CT, and two polymorphisms in the IL-4Rα chain gene, IL4RAI50V and IL4RAQ576R, have been genotyped using PCR-based methods in 341 asthmatic families and in 184 non-asthmatic adults recruited from the south of England. Results Case–control analysis did not reveal differences in the distribution of the four polymorphisms between asthmatics and controls. However, the transmission disequilibrium test showed that the IL4-589 T allele was preferentially transmitted to asthmatic children (P=0.036) and that the IL4RAQ576 was preferentially transmitted to children with atopic asthma (P=0.018). Haplotype analysis showed a strong association between the IL4-34T/-589T haplotype and asthma per se (P=0.041), and a strong association between the IL4RA I50/Q576 haplotype and atopic asthma (P=0.006). Conclusion Our data suggest that polymorphisms in the IL-4 and IL-4Rα chain genes might play a role both conferring susceptibility to and modulating severity of atopy and asthma.

Blood Basophil Numbers in Chronic Ordinary Urticaria and Healthy Controls: Diurnal Variation, Influence of Loratadine and Prednisolone and Relationship to Disease Activity

Abstract: Summary Background The basopenia of chronic urticaria relates to histamine releasing autoantibodies in the serum of patients with autoimmune urticaria. This reduction in circulating basophils may be due to active recruitment into weals. If so, it might be expected that numbers in blood would be reduced when urticaria is active and increased after treatment. The primary aim of this study was to look at diurnal variation of basophil numbers in patients with chronic ordinary urticaria (not physical or vasculitic) in relation to disease activity and the effect of treatment with antihistamines and corticosteroids, and to compare the results with healthy controls. A secondary aim was to compare a standard manual counting method with automated basophil counts and to look at numbers of other circulating leucocytes that might be relevant to urticaria pathogenesis. Methods Manual basophil counts using a toluidine blue stain and automated 5-part differentials (Coulter® Gen. S™) were performed at 4-hourly intervals from 08.00 to 20.00 in 10 healthy controls (six women, age 24 to 63 years) and seven chronic urticaria patients (five women, 24 to 50 years). All chronic urticaria patients had severe daily or almost daily urticaria. Only one of six chronic urticaria sera showed in vitro basophil histamine releasing activity. Counts were performed without treatment, after a week of taking loratadine 10 mg daily and after 3 days of adding prednisolone at 0.6 mg/kg/day (maximum 40 mg). Daily urticarial activity scores (UAS) were derived from weal numbers and itch, maximum 7. Results There was no significant overall diurnal variation of basophil numbers in healthy controls or chronic urticaria patients. Mean (SE) manually counted basophil were higher in healthy controls than chronic urticaria (43.4/µL (2.1) vs. 4.4 (0.8), P < 0.001). Basophil counts were reduced in healthy controls on steroids (19.2 (1.9), P < 0.001) but increased in chronic urticaria (8.9 (1.9), P < 0.001). Loratadine did not influence them. UAS fell on treatment (3.3 (0.4) baseline, 1.4 (0.5) on loratadine and 0.5 (0.2) on prednisolone with loratadine, P < 0.001). There was a negative linear correlation between basophil numbers and UAS in untreated chronic urticaria patients (P = 0.001, Spearman rank correlation). Manual and automated basophil counts showed poor agreement. Lymphocyte numbers were lower in chronic urticaria than healthy controls. Neutrophils increased whereas lymphocytes and eosinophils decreased in all subjects on prednisolone. They were unaffected by loratadine. Conclusion The results are consistent with the hypothesis that circulating basophils may be recruited from blood into urticarial weals during disease activity. Automated counts are not suitable for assessing basophil numbers in chronic urticaria. The relevance of reduced lymphocyte numbers in chronic urticaria needs to be explored.

Immunological analysis of allergenic cross-reactivity between peanut and tree nuts.

Abstract: Summary Background Peanut and tree nut allergy is characterized by a high frequency of life-threatening anaphylactic reactions and typically lifelong persistence. Peanut allergy is more common than tree nut allergy, but many subjects develop hypersensitivity to both peanuts and tree nuts. Whether this is due to the presence of cross-reactive allergens remains unknown. Objective The aim of this study was to investigate the presence of allergenic cross-reactivity between peanut and tree nuts. Methods Western blotting and ELISA were performed using sera from subjects with or without peanut and tree nut allergy to assess immunoglobulin E (IgE) reactivity to peanut and tree nut extracts. Inhibition ELISA studies were conducted to assess the presence of allergenic cross-reactivity between peanut and tree nuts. Results Western blot and ELISA results showed IgE reactivity to peanut, almond, Brazil nut, hazelnut and cashew nut for peanut- and tree nut-allergic subject sera. Raw and roasted peanut and tree nut extracts showed similar IgE reactivities. Inhibition ELISA showed that pre-incubation of sera with almond, Brazil nut or hazelnut extracts resulted in a decrease in IgE binding to peanut extract, indicating allergenic cross-reactivity. Pre-incubation of sera with cashew nut extract did not cause any inhibition. Conclusion These results show that multiple peanut and tree nut sensitivities observed in allergic subjects may be due to cross-reactive B cell epitopes present in different peanut and tree nut allergens. The plant taxonomic classification of peanut and tree nuts does not appear to predict allergenic cross-reactivity.

Microarrayed recombinant allergens for diagnosis of allergy.

Abstract: We suggest that the coapplication of recombinant allergens and microarray technology can lead to the development of new forms of multi-allergen tests which allow the determining and monitoring of complex sensitization profiles of allergic patients in single assays. The allergen extracts which have so far been used for diagnosis only allowed the determining of whether an allergic patient is sensitized against a particular allergen source, but the disease-eliciting allergens could not be identified. Through the application of recombinant DNA technology a rapidly growing panel of recombinant allergen molecules has become available which meanwhile comprises the epitope spectrum of most of the important allergen sources. We demonstrate that microarray technology can be used to establish multi-allergen tests consisting of microarrayed recombinant allergen molecules. Microarrayed recombinant allergens can be used to determine and monitor the profile of disease-eliciting allergens using single tests that require minute amounts of serum from allergic patients. The wealth of diagnostic information gained through microarray-based allergy testing will likely improve diagnosis, prevention and treatment of allergy.

Marked improvement of the basophil activation test by detecting CD203c instead of CD63.

Abstract: Summary Background The flow cytometric basophil activation test by detection of CD63 expression has been developed as an alternative method for in vitro diagnosis of IgE-mediated reactions to various allergens. Despite promising initial studies, the test remains disappointing in terms of sensitivity. CD203c has recently been demonstrated as a specific activation marker of basophils that is rapidly up-regulated after allergen challenge in sensitized patients. Objective The goal of the present study was to compare basophil activation tests by using either CD203c or CD63 in the diagnosis of immediate-type allergy to latex. Methods Twenty-seven patients (health care workers of our institution) who developed clinical features evocative of allergy after contact with latex were included and classified into two groups. Group 1 (n = 16) comprised true allergic patients who presented with typical signs of immediate allergic reaction associated with a positive skin test (prick test). Group 2 (n = 11) consisted of patients whose clinical history was not typical and had negative skin test. Twelve healthy subjects were also studied as controls. We compared the sensitivity of two triple-staining flow cytometric protocols measuring basophil activation after latex stimulation: CD45-IgE-CD63 and CD45-IgE-CD203c. Results The CD203c protocol showed a higher sensitivity than the CD63 protocol (75% vs. 50%). In comparison, latex-specific IgE sensitivity was found to be 69%. Furthermore, the magnitude of the basophil response was significantly higher with CD203c in comparison with CD63. Specificity was 100% for both protocols. Conclusion Due to superior gating of basophils and a higher range of activation in response to allergen, the basophil activation test is markedly improved by use of CD203c instead of CD63.

Interleukin-4 and -13 expression is co-localized to mast cells within the airway smooth muscle in asthma.

Abstract: Background: Airway smooth muscle infiltration by mast cells is a feature of asthma and not eosinophilic bronchitis. In asthma, Th2 cytokines have been implicated as playing a critical role in the development of airway inflammation and hyper-responsiveness. Whether inflammatory cells within the airway smooth muscle release these cytokines is unknown. Methods: We have undertaken a comparative immunohistochemical study in bronchial biopsies from 14 subjects with asthma, 10 with eosinophilic bronchitis and eight normal controls recruited from two centres. Results: The median number of IL-4+ cells/mm2 smooth muscle was significantly higher in subjects with asthma than eosinophilic bronchitis and normal controls for both the anti-IL-4 mAb 3H4 (2.4, 0, 0, respectively; P=0.001) and anti-IL-4 mAb 4D9 (1.6, 0, 0, respectively; P=0.02). There were no group differences in the number of IL-5+ cells (P=0.31). In six subjects with asthma, IL-13 expression by cells within the airway smooth muscle was studied. The median (range) of IL-13+cells was 2 (0.9–2.7). Ninety-four percent of the cells expressing IL-4 (3H4), 92% of those expressing IL-4 (4D9) and 100% expressing IL-13 in the airway smooth muscle were mast cells. Fifty-five percent of the mast cells within the airway smooth muscle co-localized to IL-4 (3H4), 29% to IL-4 (4D9) and 17% to IL-13. Conclusions: In asthma, IL-4+ and IL-13+ cells were present within the airway smooth muscle and were expressed predominantly by mast cells, suggesting that IL-4 and IL-13 may play an important role in mast cell–airway smooth muscle interactions.

Caesarean section increases the risk of hospital care in childhood for asthma and gastroenteritis

Abstract: ObjectiveTo investigate if caesarean section (CS) increases the risk for childhood asthma and gastroenteritis with reference made to children born with vaginal delivery (VD). MethodsRetrospective study of data from linked Swedish medical service registers - Medical Birth Registry (MBR) and Hospital Discharge Registry (HDR). Data were obtained from women without any background/perinatal morbidity noted, and from children without any neonatal complications. Children that had reached at least 1 year of age and were found in the HDR were considered as cases, whereas children not found in the HDR or hospitalized for other causes than asthma or gastroenteritis were defined as controls. Odds ratios (OR) stratified for year of birth, maternal age, parity and smoking in early pregnancy were calculated. Investigations were made comparing the risk for in hospital treatment for asthma or gastroenteritis in CS children and in VD siblings of CS children. The overall inpatient morbidity in CS and VD children were also investigated. ResultsThe OR for asthma in CS children was 1.31 [95% confidence interval (CI) 1.23-1.40]. The same OR, 1.31, was found for gastroenteritis (95% CI 1.24-1.38). The OR for CS children having experienced both asthma and gastroenteritis was further increased (1.74, 95% CI 1.36-2.23). The risk for asthma in VD siblings of CS children was not significantly increased, whereas VD siblings experienced a slightly increased risk for gastroenteritis. CS children had an increased overall in hospital morbidity when compared to VD children. ConclusionThere is a significant increase of the risk for developing symptoms of asthma and/or gastroenteritis that motivates admission for hospital care in CS children older than 1 year. It is speculated that a disturbed intestinal colonization pattern in CS children may be a common pathogenic factor.

Immunological effects of probiotics with special reference to lactobacilli.

Abstract: The concept of lactic bacilli as health-promoting environmental factors was presented by Metchnikoff, who made ‘a recommendation to absorb large quantities of microbes amongst which lactic bacilli have an honourable place’. Lactobacilli have been a natural component of the diet when fermentation has been used for improving the storage of food. Together with the ‘hygiene hypothesis’ linking a decreased exposure to microbial load and increasing incidence of allergic and other immune-mediated diseases, a century later, Metchnikoff ’s idea of the health-promoting lactic bacilli has induced an enormous scientific and economical interest to clarify the relationship between intestinal microbes and different immunological diseases. The definition of probiotics (‘for life’) is as follows: microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well-being of the host. The purpose of this review is to evaluate the immunological effects of probiotics including both mechanistic and clinical aspects.

Interrelationships among asthma, atopy, rhinitis and exhaled nitric oxide in a population-based sample of children.

Abstract: Background Exhaled nitric oxide (eNO) has attracted increasing interest as a non-invasive marker of airway inflammation in asthma. However, little evidence exists on the influences exerted on eNO by the interrelations among atopic status, asthma and rhinitis. Methods Among the 1156 children who participated in a large-scale epidemiological survey on asthma and allergies (ISAAC II: International Study of Asthma and Allergies in Childhood Phase II) in the city of Clermont-Ferrand, 53 asthmatics without corticosteroid treatment and 96 non-asthmatics were invited to perform eNO and skin prick tests (SPTs) to 12 common allergens. Results Atopic asthmatic children had higher eNO than non-atopic asthmatic children (28.9+/-9.1 vs. 17.1+/-13.1 p.p.b.; P=0.0004) with a significant increase when one SPT or more are positive (26.5+/-7.8 vs. 17.1+/-13.1 p.p.b.; P=0.03). Similarly, non-asthmatic, atopic subjects had higher eNO than non-atopic subjects with a significant increase when two SPTs or more are positive (19.4+/-9.8 vs. 11.7 +/-6.7 p.p.b.; P=0.003). In the case of equal levels of positive SPTs (0, 1, >/=2), asthmatic children always had higher eNO than non-asthmatic ones. Furthermore, among non-asthmatic children, the eNO level increased only in atopics who had rhinitis (20.7+/-13 vs. 12.5+/-6.4 p.p.b. in atopic controls (subjects without rhinitis and asthma) and 12.3+/-6.6 p.p.b. in non-atopic controls; P=0.001), whereas among asthmatic children, eNO level increased in atopics independently of rhinitis (28.2+/-9.5 p.p.b. in those with rhinitis and 30.9+/-8.1 p.p.b. in those without) as well as in non-atopics with rhinitis (22.5+/-17.2 p.p.b.). Conclusions Our data suggest that besides atopy and asthma, allergic rhinitis should also be taken into account in the assessment of eNO.

Food allergy to wheat: identification of immunogloglin E and immunoglobulin G-binding proteins with sequential extracts and purified proteins from wheat flour.

Abstract: BACKGROUND: Cereal-associated allergy is particularly considered a serious problem, because cereals are essential in our daily diet. Wheat proteins are classified into albumins, globulins and prolamins (insoluble gliadins and glutenins). OBJECTIVES: Our objectives were to study the involvement in food allergy to wheat of these different protein types by using purified fractions and to identify those binding IgE and IgG antibodies. METHODS: Sera were obtained from 28 patients with food allergy to wheat. Albumins/globulins, gliadins and glutenins were obtained by sequential extraction based on differential solubility; alpha-, beta-, gamma- and omega-gliadins and low molecular weight (LMW) and high molecular weight (HMW) glutenin subunits were purified by chromatography. IgE binding to these extracts and fractions were analysed by radioallergosorbent test (RAST), and immunoblotting; IgG binding was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: In RAST, 60% of sera were shown to have specific IgE antibodies against alpha-, beta-gliadins and LMW glutenin subunits, 55% to gamma-gliadins, 48% to omega-gliadins and 26% to HMW glutenins. Immunoblotting analysis confirmed results obtained in RAST concerning LMW and HMW glutenin subunits and showed that 67% of patients have IgE antibodies to the albumin/globulin fraction. CONCLUSION: Results obtained in the different tests showed common features and in agreement with other studies indicated the presence of numerous allergens in food allergy to wheat; alpha-, beta-, gamma- and omega-gliadins, LMW glutenin subunits and some water/salt-soluble proteins appeared as major IgE binding allergens, whereas HMW glutenins were only minor allergens. The same type of antigenic profile against gliadins and glutenins was observed with IgG antibodies. Important sequence or structural homologies between the various gliadins and LMW glutenin subunits could certainly explain similarity of IgE binding to these proteins.

Presentation of allergen in different food preparations affects the nature of the allergic reaction – a case series

Abstract: Background Characterization of fatal and non-fatal reactions to food indicates that the majority of reactions are due to the ingestion of prepared foods rather than the non-processed allergen In an ongoing study that used a double-blind placebo-controlled food challenge to investigate peanut allergy and clinical symptoms, the observed reaction severity in four of the first six subjects was greater than anticipated We hypothesized that this was due to differences in the composition of the challenge vehicle Objective The aim was to investigate whether the severity of observed challenge reactions would be repeated on re-challenge with a lower fat challenge vehicle Methods Peanut-allergic subjects were re-challenged with a lower fat recipe after reacting more severely than was anticipated to an initial peanut challenge Similar challenge vehicle recipes were used, the only difference being the lower fat content (229% compared with 315%) The peanut content of the two recipes was analysed using RAST inhibition studies and ELISA tests Results Three of four subjects reacted to much smaller doses of peanut protein on re-challenge (mean dose equivalence – 23 times less peanut) with the lower fat recipe RAST inhibition showed that neither recipe altered epitope recognition The higher fat recipe required twice as much peanut to cause 50% inhibition ELISA detected far lower levels of peanut in the higher fat recipe (220 000 parts per million (ppm)) than in the lower fat recipe (990 000 ppm) Conclusion The fat content of a challenge vehicle has a profound effect on the reaction experienced after allergen ingestion This is another factor to be considered in assessing the risk of certain foods to food-allergic consumers and adds another dimension to clinical, research and regulatory practice