bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison between the in vitro cytokine production of mononuclear cells of young asthmatics with and without immunotherapy (IT)
Authors: Van Bever  , Vereecke  , Bridts  , De Clerck  , Stevens
Published: March 2003

Background

The underlying mechanisms of immunotherapy (IT) are still unknown but may be related to modifications of cytokine production of T lymphocytes.

Objective

In this study we determined the in vitro allergen‐induced production of IL‐2, IL‐4, IL‐5, IL‐12 and IFNγ of peripheral blood mononuclear cells (PBMC) of eight young asthmatics, aged 15 ± 2 years, receiving IT (IT group) and of eight comparable asthmatics, aged 13 ± 3.5 years, who never received IT (non‐IT group).

Methods

All patients suffered from perennial asthma and were allergic to house dust mite (HDM). They were selected if they showed a positive stimulation index (SI) of PBMC after in vitro incubation with HDM (i.e. SI > 2). Cells were incubated with and without HDM (10 μg/mL) during 24 h, 48 h and 7 days. Cytokines were determined in the supernatant at the three time points and are expressed as median values in pg/mL.

Results

In the IT group the secretion of IL‐2 was lower compared with the non‐IT group after 7 days incubation of PBMC with HDM (0 vs 33.2, P = 0.008). In both groups maximal secretion of IL‐2 was observed after 48 h. In the non‐IT group a high value of IL‐2 persisted after 7 days, whereas in the IT group a significant decline of IL‐2 occurred after 7 days. Although IL‐4 secretion was low in all subjects, more patients of the non‐IT group showed detectable IL‐4 in the HDM cultures after 24 h and 48 h, although the difference was not statistically significant (P = 0.08 and P = 0.28, respectively). Furthermore, IL‐4 secretion was lower in the HDM cultures after 24 h in the IT group (1.75 vs 4.1, P = 0.011) and 48 h (2.2 vs 4.1, P = 0.035). IL‐5 secretion was lower in the HDM cultures after 24 h (12.4 vs 47.6, P = 0.035) and 48 h (26.8 vs 135, P = 0.046) in the IT group than in the non‐IT group. After 7 days of incubation with HDM there was no difference between the groups. There was no difference between both groups in secretion of IFNγ and IL‐12.

Conclusions

These results show a difference in vitro cytokine secretion of PBMC of asthmatics receiving IT compared with asthmatics who never received IT. PBMC of patients receiving IT secrete less IL‐2 and IL‐5 after in vitro incubation with HDM and show a tendency to secrete less IL‐4. The efficacy of IT may be attributed to a modified cytokine secretion of PBMC.
Dysregulation of monocyte differentiation in asthmatic subjects is reversed by IL‐10
Authors: Tormey  , Leonard  , Faul  , Bernard  , Burke  , Poulter
Published: March 2003

Background

IL‐10 can modulate the differentiation of normal monocytes to macrophages, increasing the proportion of maturing cells with a phenotype consistent with T cell suppressive activity. Analysis of the immunopathology in endobronchial biopsies from asthmatic subjects has revealed significantly reduced proportions of suppressive macrophage populations associated with chronic T‐cell mediated inflammation.

Objective

This study investigates whether the altered homeostasis within the lung macrophage populations in asthma is reflected in aberrant differentiation of peripheral blood monocytes and whether this differentiation may be influenced by IL‐10.

Methods

Monocytes from 14 normal individuals and 14 atopic asthmatics were grown in culture for 7 days in the presence or absence of IL‐10, added on day 5. Double immunofluoresence studies were performed on cytospins of the differentiated macrophages using the monoclonal antibodies RFD1 and RFD7 to distinguish inductive and suppressive macrophages by their respective phenotypes. HLADR expression was quantified using the monoclonal antibody RFDR1. Macrophage function was determined by quantifying allostimulation in a mixed leucocyte reaction and by measuring TNFα and TGFβ production.

Results

With no cytokine addition the proportion of maturing macrophages with a suppressive phenotype (D1+ D7+) at day 7 was lower in the asthmatic samples (18%) compared with normals (25%). IL‐10 increased the proportion of suppressive cells in cultures of both asthmatic and normal monocytes with the increase in the asthmatic subjects (94% increase) being significantly greater than that in normal subjects (32% increase) (P < 0.01). Asthmatic monocytes had a greater effect in stimulating MLR than normals (P < 0.05) but the addition of IL‐10 reduced T cell proliferation in an MLR to a equivalent level in both groups.

Conclusions

These results suggest that a fundamental problem may exist in the differentiation of monocytes in asthma which may be reversed by IL‐10.
Mast cell tryptase stimulates both human dermal fibroblast proliferation and type I collagen production
Authors: Abe  , Kurosawa  , Ishikawa  , Miyachi  , Kido
Published: March 2003

Background

Mast cell tryptase has been shown to be mitogenic for fibroblasts, however, it still remains unknown whether mast cell tryptase stimulates collagen production by human dermal fibroblasts.

Objective

We have investigated the effect of mast cell tryptase on type I collagen production by human dermal fibroblasts as well as the proliferation of the fibroblasts.

Methods

Tryptase isolated from human lung tissue was added to the culture of fibroblasts from normal dermis, and the fibroblast proliferation and the activity of type I collagen synthesis in the supernatants were assayed, respectively.

Results

Fibroblast proliferation was increased with tryptase in a concentration‐dependent manner, and a significant increase was observed in the presence of tryptase at concentrations from 0.01 to 10 μg/mL. The increase of fibroblast proliferation with 3 μg/mL tryptase was significantly reduced by 15 μg/mL antitryptase IgG antibody, which was demonstrated to inhibit fibrinogenolysis of tryptase. On the other hand, the production of type I collagen by the fibroblasts was significantly increased with tryptase at a concentration of 10 μg/mL. The collagen production in the presence of 10 μg/mL tryptase was significantly inhibited by 50 μg/mL antitryptase IgG antibody.

Conclusion

Tryptase increases not only the proliferation of human dermal fibroblasts but also type I collagen production.
Kinetics of apoptosis in the lung of mice with allergic airway inflammation
Authors: Kodama  , Matsuyama  , Miyata  , Nishimura  , Nishioka  , Kitada  , Sugita
Published: March 2003

Background

Apoptosis has been suggested as a means to facilitate the resolution of eosinophilic inflammation in bronchial asthma. However, the natural course of apoptosis has not been elucidated in vivo, and there is no direct evidence for eosinophilic apoptosis within lung tissue.

Objective

The purpose of this study is to clarify whether the apoptosis occurs within the lung tissue, and to define the time‐course of change in apoptosis ratio during the resolution of pulmonary eosinophilic inflammation.

Methods

Ovalbumin (OVA)‐sensitized Balb/c mice were challenged with aerosolized OVA. We studied apoptotic cells in the lung of OVA‐sensitized mice at 1, 3, 7 and 14 days after OVA challenge by in situ detection of DNA fragmentation with deoxynucleotidyl transferase deoxyuridyl triphosphatase nick endlabelling (TUNEL) technique. Apoptotic cells also were identified by electron microscopic analysis in the lung 7 days after OVA challenge.

Results

The TUNEL‐method revealed that eosinophils localized in the subepithelium of bronchi undergo apoptosis following OVA challenge. Electron microscopy confirmed the presence of apoptotic cells, apoptotic bodies, and macrophages ingesting apoptotic bodies within the lung tissue. The number of apoptotic cells increased concomitantly with the increase in eosinophilic infiltration for 3 days post‐challenge. However, both the apoptotic cell counts and the apoptotic ratio continued to increase even after the eosinophil count peaked, indicating rather late induction of apoptosis in the lung. In addition, TUNEL‐positive cells were localized in the lung for 14 days post‐challenge, indicating prolonged induction of apoptosis after the OVA challenge.

Conclusion

Our findings constitute direct evidence of eosinophilic apoptosis in situ, and display the kinetics of apoptosis in the lung of the allergic inflammation.
Expression of two isoforms of Lep d 2, the major allergen of Lepidoglyphus destructor, in both prokaryotic and eukaryotic systems
Authors: Olsson  , Van Hage‐Hamsten  , Whitley  , Johansson  , Hoffman  , Gafvelin  , Schmidt
Published: March 2003

Background

The dust mite Lepidoglyphus destructor is a major cause of allergic diseases among farmers. We have previously cloned and sequenced two isoforms of the major allergen Lep d 2 (formerly designated Lep d 1) and found significant homology to group 2 allergens of the house dust mite species Dermatophagoides. We now report on the production and characterization of recombinant Lep d 2.

Objective

We have expressed both isoforms in two different expression systems; a eukaryotic system, baculovirus in insect cells and a prokaryotic system, E. coli. We have compared the two systems in regard to production yields and immunoreactivity of the recombinant allergens.

Methods

The complete cDNA including the natural leader sequence was cloned into the pBlueBacIII transfer vector, and the rLep d 2 was produced as a secreted protein in baculovirus. For the expression in E. coli, the cDNA was cloned into the pET vector, and the rLep d 2 was produced with six C‐terminal histidine residues.

The purified recombinant allergens were tested for immunoreactivity with 10 sera from subjects allergic to Lepidoglyphus destructor and were compared with native Lep d 2 using inhibition immunoblotting. The ability of the recombinant allergens to release histamine from basophils was evaluated using a histamine release assay.

Results

Both expression systems produced immunoreactive recombinant allergens. They inhibited the binding of human sera to native Lep d 2 confirming their retained IgE binding properties. The yield of pure recombinant protein from the prokaryotic system was ≈ 1 mg/L compared to the eukaryotic system which produced up to 4 mg/L in an adherent cell culture system.

Conclusions

We have produced recombinant Lep d 2 in prokaryotic and eukaryotic expression systems which are comparable to the native allergen. Recombinant Lep d 2 might now be included in more extensive clinical studies to confirm its usefulness in the in vitro and the in vivo diagnosis of Lepidoglyphus destructor.
Indoor factors associated with concentrations of house dust mite allergen, Der p 1, in a random sample of houses in Norwich, UK
Authors: Luczynska  , Sterne  , Bond  , Azima  , Burney
Published: March 2003

Background

Studies of house dust mite allergen concentrations suggest large variations both within and between homes. It is likely that different household characteristics influence allergen levels in different locations within the house.

Objectives

To investigate household characteristics associated with higher concentrations of house dust mite allergen in a random sample of houses.

Methods

Information on indoor environment was obtained from 158 adults aged 20–44. Dust samples were collected from their living room floor, bedroom floor and mattress. Concentrations of Der p 1, the major allergen from the house dust mite Dermatophagoides pteronyssinus, were measured by monoclonal antibody immunoassay. Associations between mite allergen concentrations and household characteristics were examined using censored‐normal regression models. Factors that were related to Der p 1 (P ≤ 0.2) in univariate analyses were included in multivariable regression models.

Results

Der p 1 was not detected in any location in 10 (6.3%) houses. Geometric mean concentrations of Der p 1 were 1.9 μg/g in living room floor dust, 1.7 μg/g in bedroom floor dust and 2.0 μg/g in mattress dust. Approximately 25% of living room floor and mattress, and over 30% of bedroom floor samples had Der p 1 concentrations greater than 10 μg/g. Household characteristics associated with Der p 1 concentrations in both living room and bedroom were floor level, extractor fan in the kitchen, and age of carpet. Living room Der p 1 concentrations were also associated with gas oven/hob, window condensation, open fires, vacuum cleaner type, smokers in the house and age of house. Bedroom Der p 1 concentrations were also associated with use of blankets and wash temperature of bedding. Mattress Der p 1 concentrations were associated with window condensation, concrete bedroom floor and age of mattress.

Conclusion

Different household characteristics were associated with high Der p 1 concentrations in different parts of the house. These findings are relevant to design of allergen avoidance regimes or formulation of policy recommendations for reduction of disease associated with allergen exposure.
Adenoviral infection inhibits allergic airways inflammation in mice
Authors: STÄmpfli  , Ritz  , Neigh  , Sime  , Lei  , Xing  , Croitoru  , Jordana
Published: March 2003

Background

Recent epidemiological studies have suggested that exposure to certain viruses and bacteria influences the development of allergy and allergic diseases, such as asthma. However, there is a paucity of experimental evidence examining the consequences of concurrent exposure to allergen and infectious agents, and the potential mechanisms by which allergic disease might be averted as a result.

Objective

To model this situation experimentally, we investigated whether a virally induced immune response, elicited by a replication‐deficient human type 5 adenovirus (RDA) administered at a site distant from the airways, could inhibit ovalbumin (OVA)‐induced airways eosinophilic inflammation.

Methods

C57BL/6 mice were infected intramuscularly with RDA 16 h prior to intraperitoneal OVA sensitization. Cellular and cytokine responses in the lung/airways were examined after an OVA aerosol challenge.

Results

RDA infection significantly inhibited the inflammatory response in the lung tissue after antigen challenge. In the bronchoalveolar lavage (BAL), total cell number, eosinophils and lymphocytes were decreased by 70, 85 and 65%, respectively, after antigen challenge in RDA‐treated, compared with untreated, mice. RDA infection had no effect on IgE synthesis. The levels of IL‐5, IL‐4 and IFNγ in the BAL after antigen challenge were significantly lower in RDA‐treated mice. In vitro production of cytokines by splenocytes in response to OVA restimulation revealed a shift from IL‐4 in sensitized, PBS‐treated mice, to IFNγ in sensitized mice treated with RDA. Flow cytometric analysis revealed that RDA infection increased the proportion of CD8 T cells in the BAL; this change in T‐cell subsets was accompanied by an increase in both CD4 and CD8 T cells positive for intracellular IFNγ. Inhibition of antigen‐induced airways inflammation was IFNγ‐dependent but did not require IL‐12, as RDA‐treatment inhibited airways inflammation in IL‐12 but not IFNγ knock‐out mice.

Conclusion

This study demonstrates that an immune response against a replication‐deficient adenovirus during the initial exposure to OVA inhibits the development of airways inflammation after antigen aerosol challenge.
Phenotype stability in asthma and atopy in childhood
Authors: Clough
Published: March 2003

The asthma phenotype can be described using a combination of the following: symptom type, pattern and severity; markers of atopy; and measurement of bronchial responsiveness. Because of the very nature of the disease, symptoms of asthma are variable in both the short‐ and the long‐term, and the natural history of the disease is such that symptoms in an individual may evolve over time through different patterns. Although atopy appears to be a life‐long attribute resulting from an early life switching to a TH2 immune response, the surrogate markers of atopy each are subject to their own time‐related determinants and patterns of change with age. Bronchial responsiveness in childhood is neither specific nor sensitive for asthma, and although showing good short‐term repeatability, can vary widely when measured over a period of months or years. Stimuli for responsiveness testing should be chosen which can be inhaled safely in high doses so as to allow an end point to be reached by as many subjects within a population as possible, and individuals may have to be tested repeatedly over time so as to avoid misclassification.
Analytic options for asthma genetics
Authors: Rich
Published: March 2003

The analytic methods currently being used for the study of the genetics of asthma have primarily focused on the evaluation of linkage by non‐parametric methods as applied to genome screen data in affected sibling pairs. Complexity in the analysis of asthma genetics has been shown to occur at several levels, including phenotypic definition (wide vs narrow criteria for asthma, including restriction based upon multiple phenotypes) and joint analysis of asthma with associated phenotypes. Alternative approaches that purport to treat asthma as a quantitative trait (a ‘score’ or ‘index’) rather than as a qualitative (asthma, yes or no) trait were presented, including the development of a ‘Framingham Risk Score’ for asthma, a selection index, or a propensity score. While each of these alternatives have interesting features, issues relating to estimation and incorporation in a family structure have yet to be resolved. Nonetheless, collection of a standard set of clinical data from multiple studies could be used in a score to increase the power of genetic mapping studies for asthma.
Treating severe eye allergy
Authors: Verin
Published: March 2003

Allergic eye conditions, particularly seasonal allergic conjunctivitis (SAC), are common. Itching, oedema and hyperaemia are relieved with topical H1‐antagonists or sodium cromoglycate. The newer mast‐cell stabilizing agent nedocromil sodium has a similar safety profile to sodium cromoglycate, but is more potent and has a more convenient twice‐daily dosing regimen. When several placebo‐controlled studies of its use in the treatment of SAC were analysed, it was found that 80% of patients reported symptom relief. In a further study, nedocromil sodium eyedrops (twice‐daily dosing) had similar overall efficacy to sodium cromoglycate eyedrops (four‐times‐daily dosing) in subjects with SAC during the birch season, but during the period of highest pollen challenge, only the former agent was significantly more effective than placebo. Another study found that nedocromil sodium had efficacy equivalent to levocabastine over 7 days, but tended to have a more rapid onset of action. In patients with perennial allergic conjunctivitis (PAC) unresponsive to sodium cromoglycate, both clinicians and patients reported significantly better control of symptoms with nedocromil sodium eyedrops than with placebo. Recently, in a long‐term study of treatment for vernal keratoconjunctivitis (VKC), it was found that nedocromil sodium 2% eyedrops produced a more rapid and marked improvement in symptoms than sodium cromoglycate 2% eyedrops and enabled lower use of steroid rescue medication. Both drugs were well tolerated and without serious side‐effects.
Antihistamines in severe/chronic rhinitis
Authors: Bousquet
Published: March 2003

Oral antihistamines generally represent the first line of treatment (after allergen avoidance) in mild seasonal allergic rhinitis (SAR), and in perennial allergic rhinitis (PAR) where symptoms are intermittent. They are safe, effective and easily administered. First‐generation antihistamines experienced problems mainly with sedation and anticholinergic activity. Second‐generation antihistamines are safer and have largely eliminated these effects, although a very small number of patients taking terfenadine or astemizole have developed a characteristic ventricular dysrhythmia, ‘torsade de pointes’.

 Ebastine is a potent second‐generation H1‐blocker that compares well with others in the class. It demonstrates no interaction with alcohol, does not induce sedation and has no clinically relevant effect on QTc interval at up to five times the maximum recommended dose. Ebastine acts rapidly to relieve symptoms of allergic rhinitis (including stuffiness) and has a long duration of action, allowing once‐daily dosing. Whilst comparable in efficacy to other second‐generation antihistamines at 10 mg, ebastine also has the advantage of flexible dosing. Thus, the lower dose of 10 mg is effective for treatment of mild SAR or PAR, and the dose can be increased to 20 mg once daily for control of patients with severe or chronic symptoms.
Genetic factors in asthma severity
Authors: Hall
Published: March 2003

The development of asthma in an individual depends upon the interaction of genetic factors with the environment. Asthma is a polygenic disease and both genome screening and candidate gene strategies have identified a number of putative genes that may predispose to the development of asthma. However, there are few data regarding genes that may either dictate disease severity or chronicity and genes that dictate response to treatment. Analysing asthma as a categorical variable will fail to identify genes solely involved in determining disease severity, whereas studies designed to analyse asthma as a semiquantitative trait may identify these genes in addition to disease‐initiating genes. However, identifying genes specifically involved in the determination of disease severity (e.g. in airway remodelling) will be ideally performed in cohorts of asthmatics specifically recruited and using appropriate end points. This review discusses methodological issues concerned with identifying disease‐modifying genes in individuals with asthma, and summarizes the potential contribution of known candidate genes to the determination of disease severity.
Maternal programming in asthma and allergy
Authors: Warner  , Jones  , Williams  , Warner
Published: March 2003

There has been increasing interest in the possibility that the mother has an important role to play in influencing the development of fetal and infant immune responses to allergens during gestation. This finding, by several groups, of specific immune responses of infants at birth to individual trigger factors associated with an underlying immaturity of cytokine production, is intriguing in the light of the development of subsequent allergic disease. The interactions between mother, placenta and fetus are now forming a focus for ongoing research and may be a potential target for intervention aimed at preventing allergic asthma.
The rising trends in asthma and allergic disease
Authors: Von Mutius
Published: March 2003

Considerable variation in the prevalence of childhood asthma and allergic conditions has been shown in previous studies. These differences may in part be attributable to methodological problems in defining childhood asthma and wheezing illnesses. However, the results of recent surveys using identical study instruments suggest that the variation in the distribution of the disease is real. In western societies serial prevalence studies have furthermore shown an increasing trend in the prevalence of childhood asthma and airway hyperresponsiveness. A concomitant increase in the prevalence of hay fever and atopic eczema has been reported by others. Moreover, hospitalization rates for childhood wheezing illnesses have increased in affluent countries suggesting that indeed the morbidity from these causes has increased in the last decades. Interestingly, areas of low prevalence of asthma and atopic conditions have recently been identified in developing countries and in Eastern Europe. In Eastern Germany where drastic changes towards westernization of living conditions have occurred after reunification an increase in the prevalence of hay fever and atopic sensitization has been documented over the last 4–5 years in children aged between 9 and 10 years of age. The prevalence of asthma and airway hyperresponsiveness, however, remained virtually unchanged in this age group. These children spent their first 3 years of life under socialist living conditions and were exposed to a western lifestyle only after their third birthday. Therefore, environmental factors may affect an individual’s inherited susceptibility for the development of asthma and hay fever at different ages inducing changes in the prevalence of atopic diseases in populations in a time‐ and age‐dependent way.
The prospects for long‐term intervention in asthma with antileukotrienes
Authors: Smith
Published: March 2003

The antileukotriene drugs are the first new therapeutic agents approved for the treatment of asthma in more than 20 years. The currently available compounds are orally active and either prevent the cysteinyl leukotrienes from binding to and activating the cysLT‐1 receptor in the lung (leukotriene receptor antagonists, LTRAs) or inhibit leukotriene synthesis (leukotriene synthesis inhibitors, LTSIs). The antileukotrienes acutely bronchodilate the airways of patients with baseline broncho‐constriction, although usually not as well as beta‐agonists. When used regularly they produce rapid improvements of pulmonary function and symptoms in patients with mild‐to‐moderate asthma, and probably of those with more severe asthma as well, which persists for the duration of treatment. Yet, individual responses to the antileukotrienes are variable and not predictable based on clinical criteria. Recent studies suggest they reduce asthmatic airway inflammation. The few comparator studies with other asthma medications indicate they are equal or more effective than cromolyn but equal or less effective than low‐to‐moderate doses of inhaled corticosteroids. Initial experience with the antileukotrienes reveals limited toxicity and a favourable therapeutic‐to‐toxic ratio. The exact role of the antileukotrienes in the treatment of asthma remains to be determined, as does the relative potency of the various agents.
Pharmacogenetics of the 5‐lipoxygenase pathway in asthma
Authors: Silverman  , In  , Yandava  , Drazen
Published: March 2003

It is now well appreciated that asthma is a chronic inflammatory disease of the airways; among the inflammatory cells that have been implicated in the asthmatic lesion are eosinophils and mast cells. Although these cells have the capacity to produce a number of distinct chemical mediators, the cysteinyl leukotrienes have recently been identified as important mediators of the asthmatic response. The leukotrienes are derived from arachidonic acid released from membrane phospholipids by the action of phospholipases. The archidonic acid so released in the presence of the 5‐lipoxygenase (5‐LO) activating protein becomes a substrate for the enzyme 5‐LO. This enzyme catalyses the stereo‐specific addition of molecular oxygen to arachidonic acid to form the product known as leukotriene A4. Leukotriene A4 subsequently becomes a substrate for one of two enzymes, leukotriene A4 epoxide hydrolase or LTC4 synthase. The former catalyses the formation of LTB4 while the later catalyses the formation of the cysteinyl leukotrienes. Thus the enzyme 5‐LO is critically posed to serve as a regulator of leukotriene synthesis. 5‐LO action is known to be regulated at a number of levels; the mechanisms include regulation of action of the mature protein and regulation of 5‐LO gene transcription and translation; there is good reason to believe that all forms of 5‐LO regulation are highly interdependent. In this regard we describe the presence and functional consequences of a series of naturally occuring mutations in 5‐LO core promoter. These mutations modify gene transcription in vitro, and may have functional consequences in vivo.
Rhinovirus infections: induction and modulation of airways inflammation in asthma
Authors: GRÜnberg K. , Sterk P. J.
Published: March 2003

There is renewed interest in the role of respiratory virus infections in the pathogenesis of asthma and in the development of exacerbations in pre‐existing disease. This is due to the availability of new molecular and experimental tools. Circumstantial evidence points towards a potentially causative role as well as to possibly protective effects of certain respiratory viruses in the cause of allergic asthma during early childhood. In addition, it now has become clear that exacerbations of asthma, in children as well as adults, are mostly associated with respiratory virus infections, with a predominant role of the common cold virus: rhinovirus. Careful human in vitro and in vivo experiments have shown that rhinovirus can potentially stimulate bronchial epithelial cells to produce pro‐inflammatory chemokines and cytokines, may activate cholinergic‐ or noncholinergic nerves, increase epithelial‐derived nitric oxide synthesis, upregulate local ICAM‐1 expression, and can lead to nonspecific T‐cell responses and/or virus‐specific T‐cell proliferation. Experimental rhinovirus infections in patients with asthma demonstrate features of exacerbation, such as lower airway symptoms, variable airways obstruction, and bronchial hyperresponsiveness, the latter being associated with eosinophil counts and eosinophilic cationic protein levels in induced sputum. This suggests that multiple cellular pathways can be involved in rhinovirus‐induced asthma exacerbations. It is still unknown whether these mechanisms are a distinguishing characteristic of asthma. Because of the limited effects of inhaled steroids during asthma exacerbations, new therapeutic interventions need to be developed based on the increasing pathophysiological knowledge about the role of viruses in asthma.
STAT6 deficiency in a mouse model of allergen‐induced airways inflammation abolishes eosinophilia but induces infiltration of CD8+ T cells
Authors: MIYATA  , MATSUYAMA  , KODAMA  , NISHIOKA  , KURIBAYASHI  , TAKEDA  , AKIRA  , SUGITA
Published: March 2003

Background

The TH2‐type cytokines have been reported to contribute to the asthmatic response. STAT6 has an essential role in IL‐4 signalling and in production of TH2 cytokines from T cells and is involved in IgE and IgG1 responses after nematode infections, indicating that STAT6 has an important role in allergic diseases.

Objective

In this study we investigated the effects of STAT6 deficiency on allergen‐induced airways inflammation in mice.

Methods

Both ovalbumin (OVA)‐sensitized STAT6 deficient (STAT6−/−) mice and wild‐type C57BL/6 mice were challenged with aerosolized OVA. Changes in inflammatory cell infiltration and cytokine levels in lung tissue as well as serum immunoglobulin levels were analysed in OVA‐challenged STAT6−/− and wild‐type mice.

Results

The eosinophilia and lung damage normally resulting from aeroallergen challenge were not seen in STAT6−/− mice. Expression of TH2 cytokines (IL‐4 and IL‐5) in the lung tissue as well as IgE and IgG1 responses after OVA challenge were profoundly reduced in STAT6−/− mice, whereas expression of IFNγ was the same in STAT6−/− mice and wild‐type mice after OVA challenge. Immunocytochemical analysis of T cells showed the infiltration of CD4+ T cells but not CD8+ T cells increased into the lung of wild‐type mice after OVA challenge. However, the OVA‐exposed STAT6−/− mice demonstrated the infiltration of both CD4+ T cells and CD8+ T cells with a significant increase in percentage and total number of CD8+ T cells compared with OVA‐exposed wild‐type mice.

Conclusion

These results indicate that factors which signal through STAT6 are important regulators of eosinophilia of allergic airway inflammation, regulating TH2‐type cytokine production both in CD4+ T cells and CD8+ T cells.
Nedocromil sodium eye drops are more effective than sodium cromoglycate eye drops for the long‐term management of vernal keratoconjunctivitis
Authors: VERIN  , DICKER  , MORTEMOUSQUE
Published: March 2003

Background

Vernal keratoconjunctivitis (VKC) is a severe though transient form of ocular allergy, predominant in young males, which requires careful management. Corticosteroids are effective but also cause serious topical side‐effects in the eye, such as glaucoma and cataracts. The safer, mast cell stabilizing anti‐inflammatories (commonly sodium cromoglycate) therefore have an important role. This parallel group study compared efficacy, tolerability and safety of sodium cromoglycate 2% with nedocromil sodium 2%, administered as one drop per eye four times daily for a period of 5 months.

Methods

Children aged 4–17 years, with a diagnosis of mostly limbal VKC in the last 12 months, entered a 2‐week baseline during which they used only artificial tears, and were then randomized to treatment, in groups of 18, on an investigator single‐masked basis. Daily symptom diary cards were kept by patients/guardians, and VKC was assessed by the clinician at approximately monthly intervals. Dexamethasone was provided for rescue control of severe symptoms, if needed.

Results

A total of 34 patients completed the study.Both trial treatments produced rapid improvements and many ocular signs and symptoms, including Trantas' dots, chemosis, itching, soreness and sticky discharge, were fully controlled by the end of the study. However, nedocromil sodium took effect more quickly, with a significant reduction compared to sodium cromoglycate for itching, grittiness, hyperaemia and keratitis within 6 weeks. In addition, nedocromil sodium was the more efficacious overall (significant vs sodium cromoglycate for hyperaemia, keratitis, papillae and pannus at 22 weeks). Both treatments were well tolerated and without serious adverse effects. Final opinions favoured nedocromil sodium, with full control of VKC recorded for 94% (patient opinion) and 100% (clinician opinion) of this treatment group, compared with 29% and 0%, respectively, in the sodium cromoglycate group.

Conclusions

Nedocromil sodium 2% eye drops is significantly more effective than sodium cromoglycate for treatment of VKC.
Salbutamol pretreatment does not change eosinophil percentage and eosinophilic cationic protein concentration in hypertonic saline‐induced sputum in asthmatic subjects
Authors: CIANCHETTI  , BACCI  , RUOCCO  , BARTOLI  , CARNEVALI  , DENTE  , DI FRANCO  , GIANNINI  , SCUOTRI  , VAGAGGINI  , PAGGIARO
Published: March 2003

Background    Sputum induction by inhalation of hypertonic saline (HS) is usually preceded by β2‐agonist pretreatment, to prevent severe bronchoconstriction. Objective    To evaluate whether salbutamol pretreatment may influence cell counts and concentrations of soluble mediators in induced sputum. Methods    We studied 22 patients who randomly underwent HS sputum induction after pretreatment with either 200 μg salbutamol or placebo. Sputum was induced by means of HS inhalation (3, 4, 5% NaCl, 10 min each), measuring FEV1 every 5 min until it fell ≥ 20% from baseline. Collected sputum was diluted 1 : 1 with 0.1% DTT, incubated at 37 °C for 20 min, and total and differential cell counts were measured. ECP and histamine levels were measured in the supernatant. Results    Sputum volume, percentages of inflammatory cells, squamous cell counts and quality of the slides were not different after the two pretreatments, while sputum total inflammatory cells after salbutamol tended to be higher than after placebo (8.3 [1–41] ×106 vs 6.3[0.2–40] ×106; P = 0.09). Eosinophilic cationic protein (ECP) did not significantly change (260 [8–900] μg/L after salbutamol vs 200 [8–800] μg/L, n = 19), while histamine levels tended to be lower after salbutamol (140.9 [39.9–236.5] n
m) than after placebo (190.4 [72.2–322.6] n
m, P = 0.09, n = 17). The airway response to HS inhalation was significantly greater after placebo and the duration of the test was significantly different (median: 15 min after placebo and 30 min after salbutamol). Similar results were obtained when patients who differed for more than 15 min in the duration of HS‐inhalation in the two tests were selected (n = 11). Conclusion    Salbutamol pretreatment reduces the severity of bronchoconstriction induced by HS inhalation without significantly affecting the percentages of inflammatory cells and the levels of soluble mediators in induced sputum.
Allergen challenge primes for IL‐5 mRNA production and abrogates β‐adrenergic function in peripheral blood T lymphocytes from asthmatics
Authors: BORGER  , JONKER  , VELLENGA  , POSTMA  , DE MONCHY  , KAUFFMAN
Published: March 2003

Background

In previous studies, we have found a dysfunctional adenylyl cyclase (AC) system in patients with asthma after allergen provocation, which resulted in a 40–50% decreased generation of intracellular cAMP. In addition, in activated T helper lymphocyte clones, it has been demonstrated that IFN‐γ (TH1‐like cytokine) and IL‐5 (TH2‐like cytokine) are differentially regulated by the AC system. Therefore, we postulate that an increased IL‐5/IFN‐γ ratio as observed in asthmatics might be due to a dysfunctional AC system.

Objective

To assess whether a dysfunctional AC system as observed in asthmatics after allergen provocation, is responsible for an increased IL‐5/IFN‐γ cytokine ratio.

Methods

Peripheral blood T lymphocytes of seven asthma patients were stimulated with anti‐CD3 plus anti‐CD28 MoAbs in the absence and presence of isoproterenol (ISO) and prostaglandin E2 (PGE2) to activate the AC system. Before, 3 h and 24 h after allergen provocation, IFN‐γ and IL‐5 mRNAs were detected by semiquantitative RT‐PCR.

Results

Before allergen provocation, ISO (10−5 mol/L) significantly downregulated IFN‐γ mRNA (P < 0.03, n = 6), and showed a trend to upregulate IL‐5 mRNA (P = 0.138, n = 5). Three and 24 h after allergen provocation, ISO was not longer able to modulate IFN‐γ and IL‐5. In contrast with the observations with ISO, PGE2 still dose‐dependently inhibited IFN‐γ mRNA, both before, 3 h and 24 h after allergen provocation (n = 7). IL‐5 mRNA, but not IFN‐γ mRNA, was significantly upregulated in anti‐CD3 plus anti‐CD28‐activated T cells (P < 0.05, n = 5) 24 h after allergen provocation, compared with before allergen provocation.

Conclusion

Twenty‐four hours after allergen provocation, a significant reduction of β‐adrenergic control on IFN‐γ and IL‐5 mRNA expression was observed in peripheral blood T lymphocytes, which coincides with a selective priming of IL‐5 mRNA production.
Effects of exposure to gas cooking in childhood and adulthood on respiratory symptoms, allergic sensitization and lung function in young British adults
Authors: Moran  , Strachan  , Johnston  , Anderson
Published: March 2003

Background

There is evidence that people who use gas for cooking have reduced lung function and experience more respiratory symptoms than those who use other fuels for cooking.

Objectives

To study the effect of the presence of a gas cooker in the home, during both childhood and adulthood, on respiratory symptoms, allergic sensitization and ventilatory function among young adults.

Methods

A sample of 1449 young adults born in Britain 3–9 March 1958, who have been followed from birth to ages 7, 11, 16, 23 and 33 years, were examined at home at age 34–35 years. FEV1 and FVC were measured before and 20 min after inhalation of 400 μg salbutamol, and skin prick tests performed with three allergen extracts (grass, Der p 1 and cat). An interview on respiratory symptoms and indoor environmental exposures was included.

Results

No association was found between gas cooking in childhood or adulthood and incidence or prognosis of asthma/wheeze, allergic sensitization or current severity of respiratory symptoms. Subjects who currently used gas for cooking had a significantly reduced FEV1 (– 70 mL, 95% CI ± 56) but not FVC (– 35 mL, 95% CI ± 61) compared with those who used electricity for cooking. This reduction in FEV1 was concentrated among men and current asthmatics.

Conclusion

The use of gas for cooking is unlikely to be a major influence on respiratory morbidity in young adults.
Modified T‐cell activation pattern during specific immunotherapy (SIT) in cat‐allergic patients
Authors: MEISSNER  , KOCHS  , COUTELLE  , KUSSEBI  , BAUMGARTEN  , LØWENSTEIN  , KUNKEL  , RENZ
Published: March 2003

Objective

The aim of the study was to analyse early effects of specific immunotherapy (SIT) on immune functions in cat‐allergic patients.

Methods

Immunological responses of peripheral blood mononuclear cells from eight cat‐allergic patients were analysed before and after SIT in comparison with 11 nonallergic controls. Cells were stimulated in vitro with either bacterial superantigen, mitogen, or cat allergen. Production of IL‐12 and TH1/TH2 cytokines was analysed by ELISA and lymphocyte subset distribution was assessed by flow‐cytometry.

Results

We found a significantly reduced secretion of IL‐12 (P < 0.05) from cells of allergic individuals compared with the controls. This finding was associated with significantly lower IFN‐γ production after stimulation with allergen (P < 0.05) that did not increase during SIT. However, no significant differences were seen after stimulation with mitogen indicating an allergen specific IFN‐γ secretion response in allergic individuals. Prior to SIT IL‐5 production was significantly higher in cells of allergic donors stimulated with allergen < 0.005 or mitogen (< 0.05). After reaching the maintenance dose for SIT, allergen‐induced IL‐5 production returned to normal levels, whereas it remained elevated after stimulation with mitogen. These changes were associated with a reduced frequency of CD45 RO T cells following SIT.

Conclusion

These results suggest that SIT exerts early effects on allergen‐specific T‐cell responses with selective inhibition of the up‐regulated TH2 immune response.
Characterization of eosinophils and detection of eotaxin in skin chamber fluid after challenge with relevant allergen in patients with mild asthma
Authors: Fernvik  , Grönneberg  , Lundahl  , Raud  , Zetterström  , Van Hage‐Hamsten  , Halldén
Published: March 2003

Background

A selective recruitment of eosinophils to sites of allergic inflammation is suggested to be controlled by regulation of cytokines, chemokines and adhesion molecules.

Objective

The aim of this study was to examine whether allergen challenge in skin chambers, applied on patients with allergic rhinitis and mild asthma, results in a selective influx of activated eosinophils and detectable levels of cytokines/chemokines related to eosinophil recruitment, such as interleukin (IL)‐5 and eotaxin.

Methods

A skin blister was induced on the volar aspect of each forearm; one contained PBS‐heparin buffer (control) and the other was challenged with relevant allergen. Peripheral blood was drawn before the allergen was applied to the skin chamber, and the expression of CD9, CD11b and EG2‐epitope on intracellular eosinophil cationic protein (ECP) was analysed in eosinophils. Chamber fluid was collected 8 h after allergen application and analysed for differential cell counts, expression of eosinophil activity markers, the presence of ECP, eotaxin, and IL‐5.

Results

The number of recruited leucocytes was equal in the allergen‐challenged chambers and in controls. However, the number of eosinophils was significantly increased in the allergen‐challenged chambers, and elevated levels of released ECP were measured. Moreover, the eosinophils recruited were activated, as shown by increased expression of EG2 and CD11b, and decreased expression of CD9, in comparison with blood eosinophils. In the skin chamber fluids, higher levels of eotaxin were detected in the allergen‐challenged chambers than in controls, but there were no detectable levels of IL‐5.

Conclusion

We have demonstrated a selective recruitment of eosinophils, and higher levels of released ECP and eotaxin, in skin chambers stimulated with allergen, as compared with control chambers. Allergen challenge in skin chambers is a useful tool for studies of eosinophil recruitment, their state of activation, and their involvement in the allergic inflammatory response.
Nasal response to a single antigen challenge in patients with allergic rhinitis — inflammatory cell recruitment persists up to 48 hours
Authors: MIADONNA  , MILAZZO  , GIBELLI  , SALMASO  , LORINI  , TEDESCHI
Published: March 2003

Background

Allergen challenge in some patients with respiratory allergy is followed by an early and a late reaction.

Objective

To evaluate the duration of mediator release and inflammatory cell recruitment during the late antigen‐induced nasal response.

Methods

Eight patients with seasonal allergic rhinitis due to grass pollen underwent local challenge with the relevant allergen, a non‐relevant allergen (Parietaria judaica), and nebulized saline solution. Nasal lavages were performed at baseline and 6, 24, 48, 72 h after challenge. Eosinophil cationic protein (ECP), leukotriene C4 (LTC4), leukotriene B4 (LTB4) myeloperoxidase (MPO) and prostaglandin D2 (PGD2) levels were radioimmunoassayed and histamine concentration was measured by an automated fluorometric method.

Results

Nasal challenge with the relevant antigen induced a response 6 h after stimulation, which subsided within 24 h. Eosinophilia, observed in the nasal lavages collected from 6 to 24 h after this challenge, was accompanied by ECP release. Neutrophilia were found in the nasal lavages collected from 6 to 24 h after challenge. The increase in neutrophil number correlated with MPO levels and LTB4 concentrations, but not with the intensity of nasal obstruction. Antigen challenge also induced significant recruitment of mononuclear cells 48 h after provocation. The challenge significantly raised histamine, but not PGD2, levels in the nasal lavages collected 6 h after provocation. A trend towards an increase in LTC4 levels in the nasal lavages collected 6 h after specific antigen challenge was also found. Nasal challenge with a non‐relevant allergen or with saline solution did not cause either inflammatory cell recruitment or mediator release.

Conclusion

Nasal challenge with the relevant antigen can induce a late response characterized by local accumulation of eosinophils, neutrophils and mononuclear cells persisting for 48 h and accompanied by release of ECP, MPO, LTB4 and histamine. These results indicate that a single antigen challenge in patients with allergic rhinitis causes prolonged inflammatory alterations which may contribute to the development of airway hyperreactivity.
Identification and characterization of the major allergen of the Humulus japonicus pollen
Authors: Park  , Ko  , Kim  , Jeoung  , Hong
Published: March 2003

Background

Pollen of Humulus japonicus has been known as one of the important causes of pollinosis in Korea and China. To date, the major allergen of H. japonicus has not been determined.

Objective

To identify the major allergen of H. japonicus pollen and characterize its biochemical properties.

Methods

With the sera of 29 patients reactive to H. japonicus, the major allergen of H. japonicus was determined from the results of IgE immunoblotting and ELISA inhibition. The biochemical properties of the major allergen of H. japonicus were evaluated by lectin blotting assay and 2‐dimensional PAGE blot. N‐terminal amino acid sequences were determined by the Edman degradation method. The suggested major allergen was purified by DEAE anion exchange and gel filtration chromatography.

Results

Twenty‐nine sera contained IgE bound to the 10, 16, 20, 29 and 42 kDa proteins of H. japonicus in immunoblot analysis. A protein of 10 kDa was the most prevalent allergen in the sera of H. japonicus‐reactive patients (72%). The ELISA optical density of H. japonicus‐specific IgE was not inhibited by pollen extracts of birch, oak, rye grass and mugwort. The 10‐kDa allergen was neither stained with PAS nor bound with ConA and five other lectins. The isoelectric point of the 10‐kDa allergen was approximately pH 5.1. We sequenced the N‐terminal amino acids of the 10‐kDa allergen, which was not homologous with any previously characterized allergen. The 10‐kDa allergen could be purified with DEAE anion exchange and gel filtration chromatography. Maximum inhibitions of H. japonicus‐specific IgE ELISA by whole extract of H. japonicus and purified 10‐kDa allergen were more than 97 and 88%, respectively, while the 50% inhibitory concentration of the whole extract of H. japonicus and purified 10 kDa were 38 and 20 ng/mL, respectively.

Conclusion

The 10‐kDa peptide could be a major allergen of H. japonicus. Its isoelectric point was 5.1 and it did not bind with lectins. The N‐terminal amino acid sequence of the 10‐kDa major allergen was also determined.