bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced risk of hay fever and asthma among children of farmers
Authors: Von Ehrenstein  , Von Mutius  , Illi  , Baumann  , Böhm  , Von Kries
Published: March 2003

Background

The prevalence of atopic diseases is on the rise. Traditional lifestyles may be associated with a reduced risk of atopy.

Objectives

To test the hypothesis that children living on a farm have lower prevalences of atopic diseases. To identify differences in living conditions between farmers and other families which are associated with the development of atopic conditions.

Design

Cross‐sectional survey among children entering school (aged 5–7 years). A written questionnaire including the ISAAC core questions and asking for exposures on a farm and elsewhere was administered to the parents. Setting: School health entry examination in two Bavarian districts with extensive farming activity. Subjects: 10 163 children.

Main outcome measures

The prevalence of doctor's diagnoses and symptoms of hay fever, asthma and eczema as assessed by parental report.

Results

Farmers' children had lower prevalences of hay fever (adjusted odds ratio = 0.52, 95% CI 0.28–0.99), asthma (0.65, 0.39–1.09), and wheeze (0.55, 0.36–0.86) than their peers not living in an agricultural environment. The reduction in risk was stronger for children whose families were running the farm on a full‐time basis as compared with families with part‐time farming activity. Among farmers' children increasing exposure to livestock was related to a decreasing prevalence of atopic diseases (aOR = 0.41, 95% CI 0.23–0.74).

Conclusions

Factors related to environmental influences on a farm such as increased exposure to bacterial compounds in stables where livestock is kept prevent the development of allergic disorders in children.
Quantitative structural and biochemical analyses of tight junction dynamics following exposure of epithelial cells to house dust mite allergen Der p 1
Authors: Wan  , Winton  , Soeller  , Gruenert  , Thompson  , Cannell  , Stewart  , Garrod  , Robinson
Published: March 2003

Background

House dust mite allergen Der p 1 is a cysteine peptidase. Previously, we have suggested that the proteolytic activity of this allergen may contribute to asthma by damaging the barrier formed by the airways epithelium.

Objective

The present study applied novel techniques to compare changes in permeability with quantitative events in tight junctions (TJs) and desmosomes (DMs) of epithelial cells exposed to Der p 1.

Methods

Confluent monolayers of Madin‐Darby canine kidney (MDCK) and 16HBE14o‐human bronchial epithelial cells were used as experimental models. Permeability was estimated from mannitol clearance. Digital imaging with quantification of TJs and DMs was achieved by fluorescent antibody staining and 2‐photon molecular excitation microscopy (2PMEM). Biochemical changes in TJs were studied by immunoblotting, radiolabelling and immunoprecipitation.

Results

Der p 1 caused a time‐dependent breakage of TJs and reduction in their content of the protein ZO‐1. Reduction in ZO‐1 immunofluorescence at TJs occurred with a small increase in the amount of diffuse, cytoplasmic immunoreactive ZO‐1 staining. Morpho‐logical changes in TJs occurred in synchrony with increases in epithelial permeability. DM puncta increased both in size and intensity of staining. Immunoblotting demonstrated that the disruption of TJ morphology was associated with cleavage of ZO‐1 and occludin. Cells recovered from allergen exposure by de novo synthesis of occludin.

Conclusion

Der p 1 could contribute to sensitization and allergic responses by degrading the function of the airway epithelial barrier.
Warfarin treatment of chronic idiopathic urticaria and angio‐oedema
Authors: Parslew  , Pryce  , Ashworth  , Friedmann
Published: March 2003

Background

Chronic idiopathic urticaria is a disabling condition that does not always respond to antihistamine drugs and other agents are sometimes needed to control disease activity. Warfarin has demonstrated efficacy in single unblinded case studies [ 1] but has been dismissed by others [
2].

Objective

We investigated the effect of warfarin treatment in eight patients with chronic idiopathic urticaria unresponsive to antihistamines in an open study. Six of the eight patients responded to treatment and three had a dramatic response. These three were included in a double‐blind placebo‐controlled trial of warfarin therapy to confirm significant benefit from treatment.

Methods

The three warfarin responders had their stable warfarin dose encapsulated and placebo capsules were provided. A double‐blind placebo‐controlled crossover trial was performed on each patient. Visual analogue scores recorded disease activity.

Results

Comparison of visual analogue scores showed a significant benefit while on warfarin with a reduction in pruritus and angio‐oedema.

Conclusion

This is the first double‐blind placebo‐controlled study to show a response of chronic idiopathic urticaria to warfarin. The mechanisms of action are unclear and require further study.
Macrophage migration inhibitory factor (MIF) in bronchial asthma
Authors: Yamaguchi  , Nishihira  , Shimizu  , Takahashi  , Kitashiro  , Hizawa  , Kamishima  , Kawakami
Published: March 2003

Background

Macrophage migration inhibitory factor (MIF) is a pro‐inflammatory cytokine favouring the secretion of TNFα and IL‐8 and counteracts anti‐inflammatory effects of corticosteroids. Airways inflammation is a central feature of bronchial asthma and is characterized by the accumulation of eosinophils.

Objective

The aim of this study was to investigate whether MIF is related to asthma symptoms and eosinophil accumulation in the airways.

Methods

Serum MIF levels were measured by an enzyme‐linked immunosorbent assay in 44 healthy subjects and 44 asthmatics. Levels of MIF in induced sputum were measured in 10 healthy subjects and 15 asthmatics. Levels of eosinophil cationic protein (ECP) in induced sputum were measured by a radioimmunosorbent assay. Fluorescence double immunostaining was conducted to examine cellular source and localization of MIF.

Results

Serum MIF levels were significantly increased in asthmatic patients compared with age and sex‐matched control subjects. Symptomatic patients had a higher MIF level than asymptomatic patients. Induced sputum obtained from asthmatics contained higher levels of MIF than those from control subjects. MIF levels in induced sputum were correlated with ECP levels in induced sputum. MIF was colocalized with eosinophil peroxidase staining in the cytoplasm of sputum cells.

Conclusion

Increased MIF levels are associated with asthma symptoms and one of the cellular sources of MIF in the airways are eosinophils.
Comparative molecular modelling identifies a common putative IgE epitope on cysteine protease allergens of diverse sources
Authors: Furmonaviciene  , Sewell  , Shakib
Published: March 2003

Background

Previous approaches for studying common allergenic epitopes have mainly focused on sequence comparisons, which unfortunately yield little or no information on the shape of the epitope which is the most important determinant of cross‐reactivity.

Objectives

The aim of this study was to investigate the structural basis for cross‐reactivity between a previously identified immunodominant epitope of the house dust mite allergen Der p 1 (Leu147‐Gln160) and the corresponding epitopes on other allergens that are either taxonomically closely related (i.e. cysteine proteases of other mite species) or representing evolutionary conserved structures (i.e. plant, human and parasite cysteine proteases).

Methods

We carried out comparative molecular modelling on a range of cysteine proteases, including those of other mite species (Der f 1 and Eur m 1), human (cathepsins B, K, L, S and O), plants (papain, chymopapain and actinidin) and parasites (cruzain, cathepsin l‐like Leishmania protease, Entamoeba ACP1 protease and Schistosoma Q26534, Q11003 and cathepsin L proteases).

Results

Our study shows that all the cysteine proteases investigated here display an epitope corresponding to that previously identified on Der p 1, but with varying shapes and degree of accessibility. It appears that the core of the epitope on these homologous cysteine proteases consists of a centrally located conserved Tyr residue flanked on either sides by accessible amino acids.

Conclusion

Therefore, these cysteine proteases seem to use similar accessible structures, which may form the basis for the rational design of generic epitope‐directed treatment strategies for controlling allergic diseases.
IgE receptor‐mediated release of nerve growth factor by mast cells
Authors: Xiang Z. , Nilsson G.
Published: March 2003

Background

It has previously been demonstrated that the level of nerve growth factor (NGF) is increased in serum from humans with allergic diseases and asthma.

Aim

A question raised by these observations is whether NGF could be released from degranulating mast cells during an allergic reaction. The aim of this study was to investigate if NGF is released from mast cells after activation through cross‐linkage of the high‐affinity IgE receptor.

Methods

Mouse and human in vitro cultured mast cells were activated by IgE and specific antigen, stem cell factor or lipopolysaccharide. Release of NGF was measured by ELISA and mRNA expression was detected by RT PCR.

Results

We found that mast cells not only express NGF transcripts, but also release NGF polypeptide in response to IgE and specific antigen. Activation of mouse mast cells for 30 min induced significant release of NGF (32.9 ± 1.3 pg/2 × 106 cells) compared to spontaneous release (13.9 ± 2.7 pg/2 × 106 cells) (P < 0.01). Similarly, activation of human cultured mast cells also resulted in a significant increase of NGF release (733 ± 310 pg/3 × 105 cells) compared to spontaneous release (9.2 ± 4.0 pg/3 × 105 cells). Two other mast cell secretogogues studied, stem cell factor and lipopolysaccharide, were not able to induce release of NGF.

Conclusion

This study provides evidence that NGF could be specifically released by stimuli causing an allergic reaction, and mast cells can thereby be the source of NGF in IgE‐mediated allergic diseases. Our findings add further support for a close correlation between NGF and mast cells that could be of importance for the allergic inflammation.
Association of β2‐adrenergic receptor polymorphisms with severe asthma
Authors: Holloway  , Dunbar  , Riley  , Sawyer  , Fitzharris  , Pearce  , Le Gros  , Beasley
Published: March 2003

Background

There is considerable interest in the role of different candidate loci in the development of asthma. This study investigates the association between asthma severity and previously identified polymorphisms at two sites within the β2‐adrenergic receptor (β2AR) gene: the Arg16→Gly16 and Gln27→Glu27 alleles.

Methods

Restriction enzyme analysis of amplified β2AR gene products (PCR‐RFLP) was used to analyse the frequency of the Arg16→Gly16 and Gln27→Glu27 polymorphisms within the β2AR gene in 95 severe asthmatic patients (with a markedly increased risk of death from asthma), 59 mild asthmatic patients, and a control group of 92 nonasthmatic subjects.

Results

The Gly16 polymorphism was significantly associated with asthma severity with odds ratios (95% CI) for the Gly16 allele being 1.56 (1.02–2.40, P = 0.04) and 0.98 (0.61–1.57, P = 0.92) for the severe and mild asthma groups, respectively. The corresponding odds ratios (95% CI) for Gly16 homozygotes were 1.91 (0.82–4.41, P = 0.13) and 0.82 (0.35–1.92, P = 0.65) for the severe and mild asthma groups, respectively. There was no significant association between either polymorphism at amino acid 27 and asthma or asthma severity.

Conclusions

We conclude that the polymorphisms of amino acids 16 and 27 of the β2AR gene are not associated with the development of asthma per se, but that the Gly16 polymorphism may play a role in the pathogenesis of asthma severity.
Uptake of the yeast Malassezia furfur and its allergenic components by human immature CD1a+ dendritic cells
Authors: Buentke E. , Zargari A. , Heffler L. C. , Avila‐Cariño J. , Savolainen J. , Scheynius A.
Published: March 2003

Atopic dermatitis (AD) is a chronic inflammatory skin disease with increasing prevalence, though still little is known of the pathomechanisms and the causes of the disease. Patients with AD often have specific IgE reactivity to the yeast Malassezia furfur (M. furfur), present in the normal microflora on human skin.

To investigate the possible interaction of immature and mature antigen‐presenting dendritic cells with the yeast M. furfur and its allergenic components.

Monocyte‐derived dendritic cells (MDDCs) generated from human peripheral blood were allowed to interact with FITC‐labelled whole M. furfur yeast cells, M. furfur extract, a recombinant allergen from M. furfur designated rMal f 5 and M. furfur mannan, in the absence of IgE antibodies. Interaction and uptake were detected using flow cytometry and confocal laser scanning microscopy.

Internalization of M. furfur yeast cells and yeast components by immature MDDCs was found using confocal laser scanning microscopy. Results from flow cytometric studies showed that a median of 94% (range, 65–98%) of the immature CD1a+ MDDCs were M. furfur extract positive, 81% (75–97%) rMal f 5 positive and 93% (62–98%) mannan positive. Mature CD1a+ MDDCs were significantly less efficient in this respect, with the corresponding figures only 26% (6–37%, P < 0.01), 6% (2–15%, P < 0.05) and 32% (9–50%, P < 0.01), respectively. Uptake of the non‐glycosylated rMal f 5 by immature CD1a+ MDDCs was decreased to 27% (15–38%) by inhibition of pinocytosis. The binding of M. furfur extract and mannan was inhibited in a dose‐dependent manner by methyl‐α‐d‐mannopyranoside, suggesting uptake via the mannose receptor.

Human immature CD1a+ MDDCs can efficiently take up M. furfur and allergenic components from the yeast in the absence of IgE antibodies, implying that sensitization of AD patients to M. furfur can be mediated by immature dendritic cells in the skin.
Interleukin‐2 inhibits eosinophil migration but is counteracted by IL‐5 priming
Authors: Lampinen M. , Håkansson L. , Venge P.
Published: March 2003

Conflicting data on the role of interleukin‐2 in the recruitment of eosinophil granulocytes (EOS) to sites of inflammation have been presented. The objective of the present study was to investigate the effect of recombinant human IL‐2 and anti‐IL‐2 on the migration of purified blood EOS.

Neutralizing antibodies to IL‐2 were added to a cytokine mixture with significant eosinophil chemotactic activity (ECA), and afterwards the ECA was tested on EOS from both normal and allergic donors. EOS migration was measured by a modification of the Boyden technique, using a 48‐well microchemotaxis chamber. Recombinant human IL‐2 was either added to the lower compartment of the chemotaxis chamber, or to the EOS for a pre‐incubation period of 20 min, before migration assays towards the chemotaxins were performed.

Anti‐IL‐2 caused a significant increase of EOS migration towards the cytokine mixture. Pre‐incubation of the EOS with rhIL‐2 inhibited the chemotaxis towards RANTES, PAF, IL‐8 and eotaxin, and EOS migration towards IL‐2 was lower than that towards buffer. These effects were more pronounced on EOS from normal than from allergic donors. Priming of the EOS with IL‐5 prevented the inhibitory effect of IL‐2.

We hypothesize that IL‐2 acts as an autocrine regulator of EOS migration, and that this inhibitory effect may be downregulated in allergy, allowing an increased migration of EOS towards chemotactic factors.
Occupational asthma as identified by the Surveillance of Work‐related and Occupational Respiratory Diseases programme in South Africa
Authors: Hnizdo E. , Esterhuizen T. M. , Rees D. , Lalloo U. G.
Published: March 2003

Background The nationwide Surveillance of Work‐related and Occupational Respiratory Diseases in South Africa, SORDSA, was established in 1996 to provide systematic information on occupational respiratory diseases.

Objective SORDSA's objectives are to monitor the nature, extent and distribution of occupational respiratory diseases, and to increase awareness of their diagnosis and prevention. This paper describes the programme and results obtained for occupational asthma in the first 2 years, ending in October 1998.

Methods SORDSA identifies newly diagnosed cases of occupational respiratory disease through voluntary reporting by pulmonologists, occupational medicine doctors and occupational health nurses. Initially, recruitment of the above health care providers was done through the membership infrastructure of their respective professional societies. Booklets with prescribed monthly reporting forms were distributed annually to all reporting members and a core of reporting providers was established through a proactive method of data collection. Information dissemination and reporting feedback takes place through quarterly newsletters and issue‐specific brochures on certain hazardous agents.

Results Over the initial 2‐year period, 3285 cases of occupational respiratory disease were reported to SORDSA by 203 doctors and 97 occupational health nurses. After pneumoconiosis and associated respiratory conditions, occupational asthma was the second most commonly reported disease with 225 cases (6.9%). The average annual incidence for occupational asthma in South Africa was 13.1 per million employed people, with the highest incidence reported from the Western Cape province (37.6 per million). Latex was the most frequently reported agent for occupational asthma, followed by isocyanates and platinum salts. Low molecular weight agents accounted for 59.6% of the cases of occupational asthma.

Conclusion The results from this initial phase show that despite some limitations, SORDSA has the potential to obtain useful data on the industries, agents and occupations causing occupational asthma in South Africa.
Atopy, intestinal helminth infection and total serum IgE in rural and urban adult Gambian communities
Authors: Nyan O. A. , Walraven G. E. L. , Banya W. A. S. , Milligan P. , Van Der Sande M. , Ceesay S. M. , Del Prete G. , McAdam K. P. W. J.
Published: March 2003

Background The rarity of atopy in traditional societies has been attributed to high parasite‐driven blocking IgE concentrations. Information is lacking on the relationship between atopy, IgE and intestinal helminth infection in African populations.

Objective To determine the prevalence of atopy and intestinal helminth infection and to relate these to wheeze history and serum total IgE in a community sample of adults from an urban (Banjul) and a rural (Farafenni) area of the Gambia.

Methods Six hundred and ninety‐three adults were interviewed about respiratory symptoms using a modified version of the IUTLD questionnaire, and had skin prick testing using four allergens. Stools were examined after formol‐ether concentration. Total serum IgE concentration was measured in a subset of participants.

Results The prevalence of atopy (mean weal diameter > = 3 mm) in the urban and rural area was 35.3% and 22.5% (P = 0.05); D. pteronyssinus and Mold mix being the common sensitizing allergens. Prevalence of wheeze in the previous 12 months was 4.4% and 3.5% for the urban and rural areas, respectively. Wheezing was not significantly associated with atopy. Seventeen per cent of urban and 8.2% of rural subjects had helminths detected in stools. There was an inverse association between atopy and intestinal helminth infection; 7% of atopic subjects had helminths, compared to 13% of non‐atopic subjects (unadjusted odds ratio 0.51, 95%CI 0.24–1.1, P = 0.09; adjusted odds ratio 0.37, 95%CI 0.15–0.92, P = 0.03). Non‐atopics had total serum IgE concentrations about 2.5 times the upper limit of the reference range in non‐atopic Western populations. Geometric mean total serum IgE concentration was significantly higher among atopic subjects (570 IU/mL, IQR 91–833) than non‐atopic subjects (259 IU/mL, IQR 274–1303) (P < 0.001). IgE concentration was not associated with the presence of helminth infection.

Conclusion Further studies are needed to clarify why asthma is still relatively uncommon in spite of the prevalence of atopy in Gambian adults. Our data are also compatible with the idea that atopy might protect against helminth infection.
Interaction of cigarette smoke and house dust mite allergens on inflammatory mediator release from primary cultures of human bronchial epithelial cells
Authors: Rusznak C. , Sapsford R. J. , Devalia J. L. , Shah S. S. , Hewitt E. L. , Lamont A. G. , Davies R. J. , Lozewicz S.
Published: March 2003

Several studies have shown that exposure to cigarette smoke and/or house dust mite (HDM) can lead to increased airway inflammation in susceptible individuals. The underlying mechanisms, however, are not defined.

To investigate the interaction between cigarette smoke and HDM allergen on mediator release from primary cultures of human bronchial epithelial cells.

Confluent human bronchial epithelial cell cultures were exposed to cigarette smoke in the absence or presence of HDM allergen and investigated for the release of IL‐8, IL‐1β, and sICAM‐1. Damage to the epithelial cells themselves was assessed by release of 51Cr. On separate occasions, we investigated the effect of PTL11028, a highly potent and selective Der p1 inhibitor, on HDM allergen‐induced release of IL‐8, following activation of HDM allergen by incubation with cysteine. The effect of cigarette smoke exposure on the stability of these released mediators in prepared solutions in the absence/presence of reduced glutathione was also studied.

Both HDM allergens and short‐term (20 min) cigarette smoke exposure led to a significantly increased release of IL‐8, IL‐1β and sICAM‐1 from the epithelial cell cultures. Longer exposure (1–6 h) to cigarette smoke led to a dramatic decrease in the amount of these mediators detected in the culture medium. Whilst incubation of epithelial cultures with HDM allergen did not cause any significant change in the release of 51Cr from pre‐loaded cells, cigarette smoke on its own led to a marked, exposure and incubation‐time dependent increase in the release of 51Cr. Incubation with HDM allergen led to a significant, dose and time‐dependent increase in the release of IL‐8, which was further enhanced when the allergen extract was pre‐activated with cysteine. This effect was completely abrogated by PTL11028, a novel Der p1 inhibitor. Prepared solutions of various concentrations of IL‐8, IL‐1β and sICAM‐1 exposed to cigarette smoke demonstrated a dramatic exposure time‐dependent decrease in the detectable amount of these mediators, an effect which was abrogated by GSH.

HDM‐induced airway inflammation may include Der p‐mediated release of inflammatory mediators from epithelial cells. Additionally, short‐term cigarette smoke exposure may induce airway inflammation by release of inflammatory mediators from these cells, an effect which may be potentiated by Der p allergens. Longer term cigarette smoke exposure may cause damage to epithelial cells and changes in the structure of inflammatory mediators.
Exhaled nitric oxide in seasonal allergic rhinitis: influence of pollen season and therapy
Authors: Gratziou C. , Rovina N. , Lignos M. , Vogiatzis I. , Roussos CH.
Published: March 2003

Exhaled nitric oxide (eNO) has been proposed as a potential indirect marker of lower airway inflammation in asthma. To investigate the existence of lower airways inflammation in allergic rhinitis eNO measurements were performed in 32 patients with symptomatic and asymptomatic seasonal allergic rhinitis early in and out of pollen seasons and in 80 healthy volunteers. To further define how exhaled NO is modified by therapy, NO levels were detected following 1‐month treatment with either inhaled steroids or non‐steroids therapy with nedocromil. Exhaled NO (mean ± SE) was significantly elevated in patients with seasonal allergic rhinitis with and without symptoms (24.2 + 2.5 and 13.9 + 2.9 ppb, respectively) as compared to healthy volunteers (4.5 + 0.3 ppb) both in and out of pollen season (21.2 + 2.1 and 9.0 + 1.4 p.p.b., respectively) with a higher increase during the allergen exposure in season. Higher levels of exhaled NO were detected in patients with symptoms, either from the upper or lower airways, and with bronchial hyperreactivity. The increased exhaled NO in symptomatic patients was reduced only by inhaled steroids and not by nedocromil. These findings possibly suggest the existence of lower airway inflammation in both symptomatic and asymptomatic patients with seasonal allergic rhinitis in and out of pollen season. Thus, exhaled NO may be used as a non‐invasive index for early detection of lower airway inflammation and for monitoring the optional treatment in patients with seasonal allergic rhinitis.
A monoclonal antibody specific for a carbohydrate epitope recognizes an IgE‐binding determinant shared by taxonomically unrelated allergenic pollens
Authors: Iacovacci P. , Pini C. , Afferni C. , Barletta B. , Tinghino R. , Schininà E. , Federico R. , Mari A. , Di Felice G.
Published: March 2003

Carbohydrate epitopes are capable of binding human IgE from allergic subjects and these epitopes play a role in the cross‐reactivity between allergens from unrelated sources. A monoclonal antibody (5E6), specific for a carbohydrate epitope detectable on components of Cupressus arizonica pollen extract, has been produced and characterized.

To study the relationship between the epitopes recognized by the monoclonal antibody and by IgE from allergic subjects. To investigate the presence of such carbohydrate IgE determinant in extracts from 21 pollen species belonging to 16 taxonomically related and unrelated families, by means of the monoclonal antibody.

IgG‐depleted fraction from protein G‐purified human allergic serum was obtained. The monoclonal antibody and the IgE from the purified fraction were tested on two glycoproteins, polyamine oxidase and ascorbate oxidase, adsorbed on the ELISA plates. The relationship between the monoclonal‐ and the IgE‐recognized epitopes was investigated by ELISA‐competition experiments. Analysis of the distribution of this carbohydrate epitope was performed by direct binding of the monoclonal antibody onto the various extracts.

The monoclonal antibody and the IgE were able to bind carbohydrate epitopes on the two plant glycoproteins, ascorbate oxidase and polyamine oxidase. Polyamine oxidase shows only one N‐glycosilation site whose carbohydrate moiety seems to be composed of a branched chain of seven ordered sugars, i.e. two N‐acetyl‐d‐glucosamine‐, three mannose‐, one fucose‐ and one xylose‐residues. This structure bears the epitope recognized by mAb 5E6. Human IgE from the IgG‐depleted fraction were found capable of inhibiting the monoclonal antibody binding. The allergenic epitope identified was shared by a large number of extracts with different levels of reactivity (OD490 ranging from 0.110 to 2.060).

Our data support the finding that a monoclonal antibody specific for a carbohydrate epitope of Cupressus arizonica pollen extract detects an epitope which is also recognized by IgE from allergic subjects. This characterized reagent could be a useful tool for studying distribution of cross‐reactive carbohydrate determinants in allergenic pollen extracts and their components.
Having lived on a farm and protection against allergic diseases in Australia
Authors: Downs S. H. , Marks G. B. , Mitakakis T. Z. , Lëuppi J. D. , Car N. G. , Peat J. K.
Published: March 2003

Background Farmers' children in northern Europe have a lower prevalence of atopy, hay fever and asthma than other children. Farms in Australia differ in scale and operation from those in Europe and the prevalence of allergic diseases in children is higher.

Objective To investigate whether having lived on a farm as a child in Australia is associated with a lower risk of allergic diseases.

Methods Cross‐sectional study of children (n = 1500) aged 7–12 years from two rural towns: Wagga Wagga in a mixed farming region, and Moree in a crop farming region. Parents answered a questionnaire and children had a skin prick test for atopy.

Results Twenty percent of children had lived on a farm for at least 1 year. The effect of having lived on a farm differed between the towns (P < 0.001). It was associated with a lower risk of atopy in Wagga (adjusted odds ratio (aOR) 0.47, 95% confidence interval (CI) 0.32–0.72) but not in Moree (aOR 0.97, 95% CI 0.62–1.53). Children from Wagga were more likely to have lived on a livestock farm than children from Moree (26.1% vs. 9.1%, 95% CI for the difference 8.9–25.4).

Conclusion Having lived on a farm in Australia can confer protection against atopy in children. Further studies are needed to identify possible protective mechanisms associated with farm animals or to establish whether the protective effect is explained by other related exposures.
Release of cysteinyl leukotrienes with aspirin stimulation and the effect of prostaglandin E2 on this release from peripheral blood leucocytes in aspirin‐induced asthmatic patients
Authors: Çelik G. , Bavbek S. , Misirligil Z. , Melli M.
Published: March 2003

Background The decrease in prostaglandin E2 (PGE2) release due to aspirin (ASA)‐induced cyclooxygenase inhibition and the increment in cysteinyl leukotriene (Cys‐LT) release secondary to the removal of the inhibitory effect of PGE2 on Cys‐LT release have been suggested in the pathogenesis of aspirin‐induced asthma (AIA).

Objective In this study, we aimed to investigate the in vitro release of Cys‐LT and to determine the effect of PGE2 on Cys‐LT release from peripheral blood leucocytes of patients with AIA after stimulation by ASA.

Patients and methods Patients with AIA (n = 13), patients with ASA‐tolerant asthma (ATA) (n = 12) and healthy volunteers as controls (n = 13) were included to the study. ASA and PGE2 at three different concentrations were applied to the peripheral blood leucocytes of the study group, and Cys‐LT levels following stimulants were assessed by enzyme immunoassay method.

Results There was no difference in baseline Cys‐LT levels between groups (AIA 353.4 ± 55.5 pg/mL, ATA 354.7 ± 40.3 pg/mL, and control group 368.5 ± 30.2 pg/mL; P > 0.05). Though not present in other groups, the Cys‐LT level of 453.6 ± 70.0 pg/mL following ASA stimulation was higher than baseline in patients with AIA (P = 0.04). When PGE2 was added to the ASA‐stimulated samples of patients with AIA, Cys‐LT levels were measured as 298.7 ± 78.6 pg/mL, 279.8 ± 79.9 pg/mL, and 243.4 ± 51.3 pg/mL at PGE2 10−7 m, 10−6 m and 10−5 m concentrations, respectively. These levels were lower than the ASA‐stimulated Cys‐LT values (P = 0.03, P = 0.01 and P = 0.01, respectively). The inhibitory effect of different PGE2 concentrations on Cys‐LT release was also present in patients with ATA and in controls.

Conclusion The increase in Cys‐LT levels following ASA stimulation seems to be unique to AIA, which was not present in patients with ATA and in healthy controls. The inhibitory effect of PGE2 on stimulated Cys‐LT levels is another important finding to elucidate the role of PGE2 in the pathogenesis of AIA.
IL‐5 deficiency abolishes aspects of airway remodelling in a murine model of lung inflammation
Authors: Trifilieff A. , Fujitani Y. , Coyle A. J. , Kopf M. , Bertrand C.
Published: March 2003

Background and objectives Lung remodelling is a recognized feature of chronic asthma. In the present study, we have used IL‐5‐deficient mice to evaluate the role of this cytokine and eosinophilic inflammation in the initial stages of the structural changes occurring in the lung after antigen challenge.

Methods Ovalbumin‐sensitized wild type and IL‐5‐deficient mice were daily challenged for 5 consecutive days and killed 3 or 7 days after the last challenge to study the inflammatory and remodelling events, respectively.

Results Wild type mice challenged with ovalbumin exhibited an accumulation of eosinophils in the bronchoalveolar lavage (BAL) fluid, associated with a production of BAL cellular fibronectin. Histological analysis also revealed an antigen‐specific increase in epithelial and alveolar cell proliferation together with an increase in mucus producing epithelial cells. Eosinophilic infiltration and the associated lung remodelling were totally abrogated in IL‐5‐deficient mice. In wild type mice, treated intranasally with 1 µg of murine IL‐5 for 5 consecutive days, no BAL eosinophilia and structural changes of the lungs could be observed.

Conclusion Our results demonstrate that eosinophil accumulation, but not IL‐5 alone, plays a central role in the initial stages of the lung remodelling process and suggests that therapies directed at inhibiting eosinophilic inflammation may be beneficial in treating chronic asthma.
IFN‐γ but not IL‐4 T cells of the asthmatic bronchial wall show increased incidence of apoptosis
Authors: Cormican L. , O'Sullivan S. , Burke C. M. , Poulter L. W.
Published: March 2003

Background Previous observations have established that IFN‐γ production is depressed in CD4+ T cells from atopic asthmatics compared with non‐asthmatics.

Objective The aim of this study was to determine if decreased IFN‐γ production could be due to a dissociation between levels of apoptosis within the T cell subsets of the asthmatic bronchial wall.

Methods Twenty asthmatics (10 atopic and 10 non‐atopic) and eight non‐atopic non‐asthmatics underwent bronchoscopy. Cryostat sections of these biopsies were investigated using immunohistological techniques to determine the relative number of CD4/FAS+ and CD4/Bcl‐2+ cells. Detection of IFN‐γ+ and IL‐4+ was combined with TUNEL staining to determine the proportions of the Th1 and Th2 cells undergoing apoptosis.

Results Experiments revealed raised proportions of activated CD4+ T cells as assessed by expression of HLA‐DR and CD25+ expression in the asthmatic samples. Expression of Bcl‐2 by the CD4+ cell population was significantly reduced in the asthmatic compared with the control group (P = 0.002). There was no significant difference in the expression of CD4+ Fas‐ligand or the number of CD4+ undergoing apoptosis in the asthmatic and non‐asthmatic groups. However, the IFN‐γ+ (P = 0.04) but not IL‐4+ T cells in the asthmatic biopsies had significantly higher proportions of apoptotic cells compared with the control group.

Conclusion The evidence supports the hypothesis that Th1/Th2 imbalance in asthmatic inflammation may be a result of premature apoptosis within the Th1 subset.
Induction, distribution and modulation of upper airway allergic inflammation in mice
Authors: Hussain I. , Randolph D. , Brody S. L. , Song S.‐K. , Hsu A. , Kahn A. M. , Chaplin D. D. , Hamilos D. L.
Published: March 2003

Background To further elucidate mechanisms of human allergic rhinosinusitis, we studied the induction, distribution and modulation of allergen‐induced upper airway inflammation in a BALB/c mouse model.

Methods Allergic inflammation induced with ovalbumin (OVA) by intraperitoneal (IP) injection in alum was compared to repeated intranasal instillation. The type and distribution of inflammatory cells was compared in the respiratory and olfactory epithelial compartments. Eosinophil distribution was assessed using Scarlet Red stain and a polyclonal antibody recognizing eosinophil major basic protein (MBP). The role of interleukin (IL)‐5 in upper airway inflammation was tested by administration of polyclonal anti‐IL‐5 antibody during the sensitization protocol.

Results Unsensitized control mice receiving saline failed to develop upper airway eosinophil infiltration. IP OVA‐sensitized mice developed marked upper airway mucosal eosinophil infiltration after aerosol OVA challenge, whereas repeated intranasal instillation of OVA produced qualitatively similar, but less intense eosinophil infiltration. Using either sensitization protocol, eosinophil infiltration was seen in areas of the lower portion of the nasal septum, the floor and the lower lateral walls of the mid‐caudal region of the nasal cavity. Immunofluorescence staining for MBP confirmed this distribution of eosinophils but also demonstrated some eosinophils in the maxillary sinuses and in circumscribed regions of the ethmoturbinates. All areas of eosinophil infiltration were lined by respiratory epithelium. The selective infiltration of respiratory but not olfactory epithelium by eosinophils was unassociated with a measurable induction of epithelial ICAM‐1 or eotaxin expression. OVA‐induced upper airway eosinophil infiltration was found to be IL‐5 dependent, since administration of a polyclonal anti‐IL‐5 antibody (TRFK‐5) during OVA sensitization resulted in a marked modulation (80% decrease) in eosinophil infiltration in response to subsequent OVA challenge.

Conclusion The mouse upper airway, specifically in areas containing respiratory epithelium, is a target for OVA‐induced allergic inflammation. This selective infiltration of respiratory, but not olfactory, epithelium is, in part, dependent upon IL‐5. This model is useful for further dissection of the inflammatory response with genetic manipulations and targeted immunological approaches.
A prospective study of the association between home gas appliance use during infancy and subsequent dust mite sensitization and lung function in childhood
Authors: Ponsonby A.‐L. , Dwyer T. , Kemp A. , Couper D. , Cochrane J. , Carmichael A.
Published: March 2003

Background Home gas appliance use has been associated with child respiratory illness but prospective data on the relationship between infant exposure and the development of child allergic disease has not been readily available.

Objectives (a) To determine if home gas appliance use is associated with increased risk of house dust mite (HDM) sensitization. (b) To examine whether any association between current home gas use and airway obstruction is influenced by HDM sensitization.

Methods Design: an 8‐year follow‐up birth cohort study of children born during 1988 and 1989. Participants: a population‐based sample (n = 498) of children who participated in the Tasmanian Infant Health Survey (TIHS) and resided in Northern Tasmania in 1997 (84% of eligible children). Main outcome measures: (a) Skin prick test reaction to nine allergens, including Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1). (b) Spirometric lung function indices, including forced expiratory volume in one second (FEV1) and forced vital capacity (FVC).

Results The relative risk for home gas appliance use at 1 month of age and HDM sensitization was 1.98 (1.04, 3.79) in a cohort analysis with confounder matching. Current home gas use was also associated with HDM sensitization (ARR 1.73 (1.43, 2.76)). Current home gas use was related to a stronger (P = 0.006) reduction in the FEV1 : FVC ratio among HDM‐sensitive children (adjusted difference − 6.2% (− 10.0 to − 2.4)) than non‐HDM‐sensitive children (adjusted difference − 0.3% (− 2.5 to 1.8)).

Conclusion Indoor pollutants from gas combustion may increase the likelihood of initial sensitization to HDM and play a role in the development of atopic asthma. HDM‐sensitized children may be more vulnerable to indoor pollutant‐induced airway obstruction. The ability of this study to detect such effects may partly reflect unflued gas appliance use among this sample.
Quantification in mass units of group 1 grass allergens by a monoclonal antibody‐based sandwich ELISA
Authors: Arilla M. C. , Ibarrola I. , Eraso E. , Aguirre M. , Martínez A. , Asturias J. A.
Published: March 2003

Background Grass pollen extracts currently used for allergy diagnosis and immunotherapy are a complex mixture of proteins of which only a few have allergenic activity. Lol p 1 is one of the most important allergens in grass pollen extracts.

Objectives To develop a two‐site enzyme‐linked immunosorbent assay for the quantification of Lol p 1 and other group 1 allergens from grass species, and to assess its suitability for quantifying this group of allergens.

Methods Balb/c mice immunized with recombinant Lol p 1 were used for the production of monoclonal antibodies. Screening of hybridomas was performed by direct ELISA, and selected monoclonal antibodies were immobilized on ELISA plates and incubated with samples containing group 1 allergens. Bound allergens were detected by a combination of biotinylated Lol p 1‐specific monoclonal antibody and peroxidase‐streptavidin conjugate.

Results The assay is based on three Lol p 1‐specific monoclonal antibodies with different epitope specificities. The optimized ELISA measured Lol p 1 concentrations ranging from 125 to 1000 ng/mL and could quantify group 1 allergen from grass species belonging to the Pooidea subfamily. The assay does not depend on anti‐sera production or availability of human sera and thus reactives can be produced in unlimited amounts.

Conclusion This sensitive and specific Lol p 1 assay will be helpful both for quantifying the group 1 allergen content of Pooideae pollen extracts intended for clinical use and for studying cross‐reactivities among pollen extracts.
Venom immunotherapy induces monocyte activation
Authors: Magnan A. , Marin V. , Mély L. , Birnbaum J. , Romanet S. , Bongrand P. , Vervloet D.
Published: March 2003

Background Venom immunotherapy (VIT) is an efficient treatment of hymenoptera venom allergy. The mechanism of VIT is based on the induction of tolerance of allergen‐specific Th2 cells. The mechanisms of this T cell modulation are unknown, and could depend on cytokines produced by other cell types such as interleukin (IL)‐12, tumour necrosis factor (TNF)‐α and IL‐10 by monocytes.

Objective To assess if VIT modifies the monocyte production of IL‐12, TNF‐α and IL‐10 during the 45 first days of treatment.

Methods Fourteen patients and seven controls were included. Blood samples were taken once in controls and at day (D)1, D30 and D45 of VIT in patients. Monocytes were isolated, cultured with and without lipopolysaccharide (LPS), and the culture supernatant was harvested. IL‐10, IL‐12 and TNF‐α were assayed in supernatants by ELISA.

Results Baseline cytokine levels were not statistically different between patients and controls. During treatment, an increase of spontaneous monocyte production of IL‐12 and TNF‐α was observed at D15 and D45. The production of IL‐10 increased at D15 and D45 but not significantly. After LPS‐stimulation, IL‐12, TNF‐α and IL‐10 monocyte production was not modified by VIT.

Conclusion VIT induces a monocyte activation characterized by a delayed overproduction of IL‐12 and TNF‐α. These cytokines could be relevant to the inhibition of Th2 cells during VIT. Therefore, VIT‐induced tolerance could depend not only on the specific action of venom antigens on T cells, but also on a secondary non‐specific action of monocytes.
Lymphoproliferative responses in cord blood and at one year: no evidence for the effect of in utero exposure to dust mite allergens
Authors: Smillie F. I. , Elderfield A. J. , Patel F. , Cain G. , Tavenier G. , Brutsche M. , Craven M. , Custovic A. , Woodcock A.
Published: March 2003

Background Maternal allergen exposure beyond the 22nd week of pregnancy may be important in foetal T cell priming. Allergen‐specific cord blood mononuclear cell (CBMC) immunoproliferative responses without corresponding bacterial antigen responses (tetanus toxoid), have been suggested as evidence of in utero sensitization.

Objectives To investigate the relationship between lymphoproliferative responses at birth and at 1 year with maternal and 1‐year infants house dust mite allergen exposure.

Methods Home visits and dust sampling were performed by the 20th week of pregnancy, immediately after birth, and then at 1 years of age. Der p 1 was assayed using a two‐site immunometric ELISA. CBMC immunoproliferative responses (AIM V serum‐free medium; 1 × 105 cells/well) were measured for 225 neonates (171 had a high risk of atopy (HR) – both parents skin test positive; 59 had a low risk of atopy (LR) – both parents skin test negative, no history of atopy) by 3H‐Thymidine (1µCi/well) incorporation after stimulation in primary culture with phytohaemagglutinin (PHA) (1 µg/mL), house dust mite [HDM] extract (30 µg/mL), immunopurified Der p 1 (30 µg/mL), Tetanus toxoid (TT) (aluma free, 30 Lf/mL) or vehicle. Blood was collected from 144 infants at the age of 1 years and stimulated proliferative responses were assessed using the same procedure.

Results PHA‐stimulated lymphoproliferative response was significantly lower in HR compared to LR neonates (mean difference 38%, 95% CI 15%−54%; P = 0.003); significantly lower proportion of positive CBMC responses to HDM occurred in LR than in HR neonates (30.4% vs. 46.6%; P = 0.034). There was no relationship between Der p 1 levels in maternal bed and CBMC immunoproliferative responses, despite the 21 000‐fold range of maternal Der p 1 exposure. No significant differences in magnitude, or in proportion of positive responses to any stimulant were observed between the neonates at low, medium or high tertile of allergen exposure. Immunoproliferative responses at birth were not predictive of 1‐year PBMC responses. There was no relationship between maternal allergen exposure in pregnancy and 1‐year PBMC proliferative responses. However, the proportion of positive proliferative responses at 1 years significantly increased with increasing infant Der p 1 exposure at 1 years.

Conclusion These results indicate that the magnitude of immunoproliferative responses are unrelated to maternal mite allergen exposure and cannot be used as evidence for in utero sensitization to inhalant allergens. The immunoproliferative responses at 1 year seem to shift away from the genetically influenced responses at birth towards responses to specific stimulants which correlate with environmental exposure to those specific stimulants. These data support the concept of sensitization to inhalant allergens occurring in early life, but not in utero.
Local increase in the number of mast cells and expression of nerve growth factor in the bronchus of asthmatic patients after repeated inhalation of allergen at low‐dose
Authors: Kassel O. , De Blay F. , Duvernelle C. , Olgart C. , Israel‐Biet D. , Krieger P. , Moreau L. , Muller C. , Pauli G. , Frossard N.
Published: March 2003

Background Repeated inhalation of allergen at low‐dose induces an increase in bronchial hyper‐responsiveness, without any associated symptom. The concomitant events in the bronchus have not been described.

Objective We have studied the dynamic number of mast cells in the airways of patients with mild asthma before and after repeated inhalation of allergen at low‐dose and the expression of nerve growth factor (NGF), which is reported to promote growth and survival of mast cells.

Methods Twelve patients with mild asthma to cat allergen were enrolled at random in a blind placebo‐controlled study, and submitted to repeated low‐dose allergen exposure (1/5 of the provocative dose). Mast cells were immunolocalized using an antibody against mast cell tryptase. NGF and its high affinity receptor, TrkA, were immunolocalized using anti‐NGF and anti‐TrkA antibodies, respectively. NGF mRNA was quantified by competitive polymerase chain reaction (PCR) after reverse transcription of total RNA extracted from bronchial biopsy. NGF protein levels were measured by ELISA in bronchoalveolar lavage (BAL) fluid.

Results Bronchial mast cell number was increased significantly after allergen exposure as compared with before. NGF expression in the bronchus was immunolocalized mainly to epithelial cells, but also to fibroblasts, blood vessels, and a few infiltrated cells. NGF mRNA levels in bronchial biopsies were increased significantly after allergen exposure. The high affinity receptor for NGF, TrkA, was immunolocalized to the infiltrated mast cell membrane.

Conclusion Our study shows that the increase in the number of mast cells and in the expression of NGF induced by allergen exposure in the bronchus of asthmatic patients is occurring before the onset of symptoms. In addition, our finding of the presence of the TrkA receptor on the membrane of the infiltrated mast cell in situ brings evidence of the mast cell as a target cell for the growth factor activity of NGF in the airways in asthma.