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House Dust Mite (house + dust_mite)
Terms modified by House Dust Mite Selected AbstractsHLA DPB1*0201 allele is negatively associated with immunoglobulin E responsiveness specific for house dust mite allergens in TaiwanCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2000Background House dust mite (HDM) Dermatophagoides pteronyssinus is the most important source of indoor allergens that cause allergic diseases in Taiwan. We prepared purified HDM allergens (Der p 1, Der p 2 and Der p 5) to detect allergen-specific immunoglobulin (Ig) E responsiveness among a large number of test subjects. The robust genetic typing system for HLA class II genes also facilitated the study on association of HLA and allergic response toward HDM. Objective This study intended to investigate the association between HLA class II alleles and the IgE responsiveness to the major allergens from HDM, D. pteronyssinus. Methods Two hundred and forty-eight subjects were selected for HLA association study. Plasma HDM allergen (Der p 1, Der p 2, Der p 5) -specific IgE and Der p 2-specific IgG antibodies were detected by ELISA, while HLA class II -DRB1, -DQA1, -DQB1, -DPB1 genetic polymorphism was determined by polymerase chain reaction/sequence-specific oligonucleotide probe hybridization (PCR/SSOPH). Statistical comparison of the allelic distribution of each HLA class II genes among the individuals with/without HDM allergen-specific IgE and IgG antibodies were performed. Results There was no significant association between HLA DRB1, DQB1, DQA1 alleles and HDM-specific IgE responsiveness noted. Only DRB1*0803 and the linked DQA1*0103 alleles showed positive association with Der p 5-specific IgE responsiveness. However, we found that HLA-DPB1*1301 predisposed subjects to IgE responsiveness to HDM Der p 5. HLA DPB1*0501 was weakly associated with the IgE responsiveness to HDM Der p 1 and Der p 5. There was a strong negative association between the HLA-DPB1*0201 allele with IgE responsiveness to Der p 1 (OR: 0.30, P , 0.0001, P , 0.0007, Pc , 0.010). Conclusion We clearly observed the association between HLA DPB1 alleles and specific IgE responsiveness to HDM major allergens. The molecular mechanism of HLA-DPB1*0201 involvement in protecting subjects from HDM-specific IgE responsiveness awaits further investigation. [source] Which aeroallergens are associated with eczema severity?CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 4 2007K. L. E. Hon Summary We investigated if a correlation exists between aeroallergen sensitization and the severity of eczema. Data on aeroallergen response to skin-prick testing (SPT) and disease severity of children with eczema (n = 119) were evaluated. Atopy, as defined by at least one positive response to aeroallergen skin prick testing, was found in >,90% of eczema patients. House dust mite was the most commonly sensitized aeroallergen, followed by cat fur. Dermatophagoides pteronyssinus and Dermatophagoides farinae sensitization were associated with eczema severity (present in 67% of the mild and 97% of the severe group; P = 0.001). However, there was no association between eczema severity and higher strengths of SPT response (defined as SPT > 1+ to dust mites or dust). Atopy to moulds, Bermuda grass, cockroach, cat and dog was less prevalent and was not associated with eczema severity. It is sensible to advise parents on specific avoidance strategies only in severely affected children who have a definitive history of eczema exacerbation by specific aeroallergens and who are not responsive to conventional treatment. [source] Variability of IgE reactivity profiles among European mite allergic patientsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2008M. Weghofer Abstract Background, House dust mites (HDM) Dermatophagoides pteronyssinus are a frequent indoor allergen source. Our aim was to determine the frequencies of IgE reactivity to purified HDM allergen molecules in mite allergic patients from different parts of Europe in order to establish an allergen panel for diagnosis of HDM allergy. Materials and methods, Populations of D. pteronyssinus -allergic patients from Austria (n = 56), France (n = 55), Italy (n = 67) and Sweden (n = 65) and storage mite allergic patients from Sweden (n = 31) were analysed for IgE reactivity to eight purified natural (n) and recombinant (r) D. pteronyssinus allergens (nDer p 1, rDer p 2, nDer p 4, rDer p 5, rDer p 7, rDer p 8, rDer p 10 and rDer p 14) in RAST-based dot blot assays. Results, Using a combination of Der p 1 and Der p 2, at least 97% of the D. pteronyssinus -allergic patients could be diagnosed in each of the HDM allergic populations. However, more than 50% of the patients also reacted with other allergens and significant variabilities regarding the frequencies of IgE reactivity to individual allergen molecules were found. Patients with a predominant storage mite allergy showed none or only very weak IgE reactivity to purified D. pteronyssinus allergens. Conclusions, Purified Der p 1 and Der p 2 are sufficient for the diagnosis of , 97% of D. pteronyssinus allergic patients in Europe, but other allergens may also play an important role for the diagnosis and treatment of HDM allergy. [source] Crystallization and preliminary X-ray analysis of Der f 2, a potent allergen derived from the house dust mite (Dermatophagoides farinae)ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003Dana Roeber Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophagoides sp.) are ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis and asthma associated with allergic reactions to these arthropods are frequently caused by relatively small (125,129 amino acids) mite proteins of unknown biological function. Der,f,2, a major allergen from the mite D.,farinae, has been recombinantly expressed, characterized and crystallized. The crystals belong to the tetragonal space group I4122, with unit-cell parameters a = b = 95.2, c = 103.3,Å. An essentially complete (97.2%) data set has been collected to 2.4,Å at a synchrotron source. Attempts to solve the crystal structure of Der,f,2 by molecular replacement using the NMR coordinates for either Der,f,2 or Der,p,2 (the homologous protein from D.,pteronyssinus) failed, but preliminary searches using the crystalline Der p 2 atomic coordinates appear to be promising. [source] Airway eosinophilia is not a requirement for allergen-induced airway hyperresponsivenessCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2000Tournoy Background House dust mites (HDMs) are the major source of perennial allergens causing human allergic asthma. Animal models mimicking as closely as possible the allergic features observed in human asthma are therefore interesting tools for studying the immunological and pathophysiological mechanisms involved. Especially the role of eosinophils and allergen-specific immunoglobulin (Ig) E in the pathophysiology of airway hyperresponsiveness (AHR) remains a subject of intense debate. Objective To develop a mouse model of allergic airway inflammation and hyperresponsiveness based on the use of purified house dust mite allergen (Der p 1) as clinical relevant allergen. Furthermore, we studied the effects of low dose allergen exposure on the airway eosinophilia and AHR. Methods On day 0, C57Bl/6 mice were immunized with purified Der p 1 intraperitoneally. From day 14,20, the mice were exposed daily to a 30-min aerosol of different concentrations of house dust mite extract. Results Mice, actively immunized with Der p 1 and subsequently exposed to HDM aerosols, developed AHR, eosinophil infiltration of the airways and allergen-specific IgE. Moreover, lowering the concentration of the HDM aerosol also induced AHR and IgE without apparent eosinophil influx into the airways. Der p 1-sensitized mice exposed to PBS produced IgE, but did not show AHR or eosinophil influx. Conclusion This in vivo model of HDM-induced allergic airway changes suggests that AHR is not related to either eosinophil influx or allergen-specific serum IgE, thereby reducing the importance of these factors as essential elements for allergic AHR. [source] Epicutaneous aeroallergen sensitization in atopic dermatitis infants , determining the role of epidermal barrier impairmentALLERGY, Issue 2 2008F. Boralevi Background:, Sensitization to atopens is an early phenomenon that overlaps with the onset of atopic dermatitis (AD) in infancy. Early epidermal barrier impairment may facilitate the epicutaneous penetration of atopens. Objective:, To correlate transepidermal water loss (TEWL) and aeroallergen sensitization in infants with AD. Methods:, In this cross-sectional study we enrolled 59 AD children and 30 controls aged 3,12 months. Transepidermal water loss in uninvolved skin, specific immunoglobulin E, atopy patch test (APT) and skin prick tests were performed with respect to seven aeroallergens, i.e., Dermatophagoides pteronyssinus, D. farinae, cat, dog, birch pollen, ambrosia, and cockroach. Environmental conditions were assessed by a questionnaire, and the house dust mite (HDM) concentration was determined in dust samples. Results:, Eighty-nine percent of AD infants had a positive APT vs one out of eleven controls. AD infants had a significantly higher mean TEWL than controls (27.4 vs 11.1 g/m2/h, P < 0001). Children with two or more positive APT had higher TEWL than the others (31.1 vs 19.0 g/m2/h, P < 0.025). No correlation was found between indoor APT results and exposure to HDM, cats, and dogs at home. Conclusions:, This study confirms the high prevalence of delayed sensitization to indoor and outdoor aeroallergens in AD infants, and shows that the higher the TEWL, the higher the prevalence of sensitization to aeroallergens. These data are in favor of a major role of a constitutive epidermal barrier impairment in determining early atopen sensitization in infants with AD. [source] Allergic sensitization to cat in childhood as major predictor of incident respiratory allergy in young adultsALLERGY, Issue 11 2007T. Schäfer Background:, Little is known on the predictive value of sensitization to specific aeroallergens in children with respect to asthma and hay fever incidence in young adulthood. We followed the incidence of asthma and hay fever in children (mean age 11 years) over 9 years, and analyzed the predictive value of sensitization to five common aeroallergens. Methods:, Three consecutive surveys were conducted in East German school children. Specific IgE antibodies to birch and timothy grass pollen, house dust mite, cat, and cladosporium were measured. In 1207 out of the 2453 children, the 9-year incidence of asthma and hay fever was assessed by reported doctors' diagnoses. For sensitization, diagnostic parameters were determined and logistic regression analyses controlled for relevant confounders. Results:, A total of 176/78 incident hay fever/asthma cases occurred equaling a cumulative incidence of 1.93/0.86% per year. Incident asthma was associated with previous sensitization to cat [risk ratio (RR) 3.49, 1.57,7.74] and grass pollen (RR 1.79, 1.01,3.19), whereas incident hay fever was associated with each allergen, with grass pollen (RR 6.00, 4.04,8.90) and cat (RR 5.36, 2.87,9.99) exhibiting the strongest associations. When mutually adjusting for all allergens, sensitization to cat remained significantly associated with asthma and hay fever. The latter was also associated with sensitization to grass pollen. The highest positive predictive values for asthma and hay fever were obtained for cat sensitization (10/49 = 20.4% and 23/49 = 46.9%). Conclusions:, Childhood sensitization to cat and grass pollen predicts the incidence of asthma and hay fever in young adulthood. The predictive capacity differs by allergen and manifestation of atopy. [source] Original article: Predictors of response to bronchial allergen challenge in 5- to 6-year-old atopic childrenALLERGY, Issue 4 2007T. A. Douglas Background:, The relationship between atopy and bronchial allergy in young children is not completely understood. Objective:, To examine the association between response to bronchial allergen challenge, immune markers of atopy and other clinical characteristics in 5- to 6-year-old children. Methods:, Children with positive skin test (SPT) to aeroallergen, together with a proportion of SPT negative children (as controls), were recruited from a birth cohort of 198 children at high risk of developing atopic disease and underwent allergen challenge. Results:, Thirty-seven children (26 atopic and 11 SPT negative), median age 74.5 months, were challenged: 31 with house dust mite and six with grass allergen. Only atopic children responded to challenge: n = 12/26 (46%). Wheal size [odds ratio (OR) 2.5 (1.2,5.3), P = 0.01], allergen-specific immunoglobulin E (IgE) [OR 3.4 (1.23,9.61), P = 0.02], total IgE [OR 8.6 (1.1,68.7), P = 0.04], current wheeze [OR 12 (1.7,81.7), P = 0.006] and persistent eczema [OR 11.0 (1.7,68.3), P = 0.006] emerged as the strongest independent predictors of response to allergen challenge. Prediction of response to allergen challenge was significantly improved when immune markers of atopy, and in particular wheal size, were combined with clinical characteristics. Conclusion:, The relationship between atopy and bronchial allergy is quantitative at this age. There may be potential to create more powerful indicators of the presence of respiratory allergy in young children when immunological markers of atopy are considered quantitatively and when combined with clinical history of coexistent allergic disease. [source] Variance components analyses of multiple asthma traits in a large sample of Australian families ascertained through a twin probandALLERGY, Issue 2 2006M. A. R. Ferreira Background:, Intermediate phenotypes are often measured as a proxy for asthma. It is largely unclear to what extent the same set of environmental or genetic factors regulate these traits. Objective:, Estimate the environmental and genetic correlations between self-reported and clinical asthma traits. Methods:, A total of 3073 subjects from 802 families were ascertained through a twin proband. Traits measured included self-reported asthma, airway histamine responsiveness (AHR), skin prick response to common allergens including house dust mite (Dermatophagoides pteronyssinus [D. pter]), baseline lung function, total serum immunoglobulin E (IgE) and eosinophilia. Bivariate and multivariate analyses of eight traits were performed with adjustment for ascertainment and significant covariates. Results:, Overall 2716 participants completed an asthma questionnaire and 2087 were clinically tested, including 1289 self-reported asthmatics (92% previously diagnosed by a doctor). Asthma, AHR, markers of allergic sensitization and eosinophilia had significant environmental correlations with each other (range: 0.23,0.89). Baseline forced expiratory volume in 1 s (FEV1) showed low environmental correlations with most traits. Fewer genetic correlations were significantly different from zero. Phenotypes with greatest genetic similarity were asthma and atopy (0.46), IgE and eosinophilia (0.44), AHR and D. pter (0.43) and AHR and airway obstruction (,0.43). Traits with greatest genetic dissimilarity were FEV1 and atopy (0.05), airway obstruction and IgE (0.07) and FEV1 and D. pter (0.11). Conclusion:, These results suggest that the same set of environmental factors regulates the variation of many asthma traits. In addition, although most traits are regulated to great extent by specific genetic factors, there is still some degree of genetic overlap that could be exploited by multivariate linkage approaches. [source] Concentrations of domestic mite and pet allergens and endotoxin in PalestineALLERGY, Issue 6 2004N. El Sharif Background:, A few studies have compared indoor allergens and endotoxin levels between urban and rural settings as important determinants for asthma and atopy in children. However, no study was done in the Middle East or investigated refugee camps. Methods:, As part of a nested case,control study in Ramallah in 2001, we measured house dust mite and pet allergens, as well as endotoxin in dust collected from 110 children's mattresses and living room floors. Results:, Geometric mean (GM) concentrations of Dermatophagoides pteronyssinus (Der p1) antigen were 4.48 ,g/g in mattress dust and 1.23 ,g/g floor dust. The highest Der p1 levels were seen in refugee camps. Concentrations of Dermatophagoides farinae antigen (Der f1) were much lower (<0.08 ,g/g dust). Concentrations of cat allergen (Fel d1) were highest in villages, and those of dog allergen (Can f1) were highest in mattresses from cities and in floor dust from refugee camps. GM of endotoxin levels were 25.7 EU/mg in mattress dust and 49 EU/mg dust in floor dust. Conclusions:, Concentrations of Der p1 were high compared to Western European countries, but were lower compared to UK and Australia. Levels of pet allergens were lower than in Western Europe. Endotoxin levels were higher compared to developed countries. Indoor environmental factors such as dampness seemed to be important determinants for allergen and endotoxin, but living habits such as lack of mattress cover appeared unimportant. [source] Effect of montelukast on exhaled NO in asthmatic children exposed to relevant allergensPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2 2002Giorgio L. Piacentini The level of exhaled nitric oxide (FENO) is increased in house dust mite (HDM)-sensitized asthmatic children after exposure to HDM antigen, and inhaled steroids can prevent this increase. The aim of this study was to evaluate whether montelukast could prevent an increase in FENO levels in allergic asthmatic children after a brief period of exposure to relevant allergens. Sixteen children were evaluated at the residential house ,Istituto Pio XII' (Misurina, Bellunio, Italy) in the Italian Alps, a dust mite-free environment. FENO levels were evaluated before (t0) and immediately after (t1) the children were exposed to HDM allergens for 2 weeks in their homes at sea level. No significant difference in FENO was observed in the fluticasone-treated group of children after 2 weeks at sea level. In the group treated with montelukast, an increase in FENO was observed between t0 and t1, which failed to reach statistical significance. These preliminary data suggest that oral montelukast could be effective in preventing the relapse in airway inflammation in allergic asthmatic children who are occasionally exposed to relevant allergens for a short period of time. [source] Snail anaphylaxis during house dust mite immunotherapyPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2000Diego G. Peroni This study reports a 12-year-old girl who developed an anaphylactic reaction following snail ingestion during house dust mite (HDM) immunotherapy treatment. Radioallergosorbent (RAST) inhibition showed cross-reactivity between the two allergens, leading to consideration of HDM as the sensitizing agent. Children undergoing HDM immunotherapy treatment should be aware of the potential risks of hypersensitivity reactions to invertebrate foods. [source] Maternal history, sensitization to allergens, and current wheezing, rhinitis, and eczema among children in Costa RicaPEDIATRIC PULMONOLOGY, Issue 4 2002Manuel E. Soto-Quiros MD Abstract Little is known about the factors associated with asthma, allergic rhinitis, and eczema in Latin American countries. We investigated the relation between potential risk factors and current wheezing, allergic rhinitis, and eczema among 208 Costa Rican children aged 10,13 years participating in phase II of the International Study of Asthma and Allergies in Childhood (ISAAC). The geometric mean (,±,SD) serum total IgE level of children with current wheezing was significantly higher than that of children without current wheezing (533.8,±,5.2 vs. 144.7,± 6.0 IU/mL, P,<,0.01). In a multivariate analysis, a maternal history of asthma, skin test reactivity (STR) to house dust mites, and STR to Alternaria were significantly associated with current wheezing. Children who had a maternal history of asthma had 2.4 times higher odds of current wheezing than those without maternal history of asthma (95% CI for OR,=,1.1,5.3). Sensitization to either house dust mite or Alternaria was associated with 3.3 times increased odds of current wheezing (95% CI for OR for STR to dust mite,=,1.6,6.7; 95% CI for OR for STR to Alternaria,=,1.1,11.0). In a multivariate analysis, STR to house dust mite and STR to cat dander were significantly associated with allergic rhinitis, and a maternal history of eczema and STR to dog dander were associated with eczema in the child. The interaction between familial factors and lifestyle changes resulting from social reforms implemented 60 years ago may explain the high prevalence of atopic diseases in Costa Rica. Pediatr Pulmonol. 2002; 33:237,243. © 2002 Wiley-Liss, Inc. [source] Suspension-cultured BY-2 tobacco cells produce and mature immunologically active house dust mite allergensPLANT BIOTECHNOLOGY JOURNAL, Issue 1 2007David Lienard Summary The replacement of crude allergen extracts by selected allergens currently represents a major goal for the improvement of allergy diagnosis and immunotherapy. Indeed, the development of molecularly defined vaccines would facilitate both standardization and enhance batch-to-batch reproducibility as well as treatment specificity. In this study, we have investigated the potential of tobacco plant cells to produce biologically active forms of the two major allergens from the house dust mite. A detailed characterization of these plant-made allergens has shown similar proteolytic maturation and folding as well as comparable immunoreactivity to their natural counterparts. Altogether, our results exemplify that suspension-cultured BY-2 tobacco cells represent a low cost and environmentally safe expression system suitable to produce recombinant allergens from Dermatophagoides pteronyssinus under a form appropriate for diagnostic and therapeutic purposes. [source] ORIGINAL ARTICLE: Chronic urticaria is associated with a differential helminth,arthropod-related atopy phenotypeTHE JOURNAL OF DERMATOLOGY, Issue 9 2010Alvaro DASCHNER Abstract The relationship between atopic sensitization and chronic urticaria is still controversial. In this study, we aimed to compare the prevalence of aeroallergen sensitization in chronic urticaria patients with (CU/As+) and without (CU/As,) sensitization against Anisakis simplex. Forty-nine CU/As+ and 80 CU/As, patients were studied and skin prick tests (SPT) were performed against aeroallergens. We assessed sensitization in a subgroup of patients with allergic rhinoconjunctivitis and/or bronchial asthma (RCBA) and compared the prevalence with a control group of 522 non-urticaria patients with RCBA. Forty-five percent of CU/As, and 60.4% of CU/As+ patients displayed positive SPT to at least one aeroallergen. CU/As+ patients had a higher prevalence of sensitization against pollen, mould or dander (PMD) (52.2% vs 29.1%, P < 0.01), whereas the prevalence of house dust mite (HDM) sensitization was not statistically different (26.3% in CU/As, and 36.7% in CU/As+). However, in chronic urticaria patients with RCBA, 53.8% of CU/As, and 57.9% of CU/As+ patients differed in the prevalence of HDM sensitization compared to the control group (33.5%, P = 0.03), whereas no difference could be stated for PMD sensitization. Compared to RCBA patients, both CU/As+ and CU/As, patients have a higher clinically relevant sensitization rate against HDM, thus displaying a differential atopy phenotype. [source] Crystallization and preliminary X-ray analysis of Der f 2, a potent allergen derived from the house dust mite (Dermatophagoides farinae)ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003Dana Roeber Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophagoides sp.) are ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis and asthma associated with allergic reactions to these arthropods are frequently caused by relatively small (125,129 amino acids) mite proteins of unknown biological function. Der,f,2, a major allergen from the mite D.,farinae, has been recombinantly expressed, characterized and crystallized. The crystals belong to the tetragonal space group I4122, with unit-cell parameters a = b = 95.2, c = 103.3,Å. An essentially complete (97.2%) data set has been collected to 2.4,Å at a synchrotron source. Attempts to solve the crystal structure of Der,f,2 by molecular replacement using the NMR coordinates for either Der,f,2 or Der,p,2 (the homologous protein from D.,pteronyssinus) failed, but preliminary searches using the crystalline Der p 2 atomic coordinates appear to be promising. [source] Can sensitization to aeroallergens disappear over time in children with allergic disease?ACTA PAEDIATRICA, Issue 9 2010KD Jacobs Abstract Background:, Remittance of aeroallergen sensitization has been shown in population-based studies, but there is a common perception that sensitization to aeroallergens rarely if ever disappears in children with allergic disease. Methods:, We retrospectively reviewed all specific IgE tests carried out in children aged 0,18 years at our hospital laboratory over a 14-year period. Of 3115 children sensitized to one or more aeroallergens, 244 (7.8%) were retested after a mean (SD) period of 45 (28) months at their physician's discretion. Results:, Disappearance of sensitization to individual aeroallergens did occur, with remittance rates ranging from 3.1% for house dust mite to 17.5% for cat. However, complete remittance of aeroallergen sensitization was found in only one subject. In up to 35% of cases, remittance of sensitization was offset by the appearance of one or more new aeroallergen sensitizations. Remittance was only observed in children sensitized to multiple allergens (with a median of 3 aeroallergen sensitizations), and their median degree of sensitization was low (median 2.1 kU/L). Conclusion: Aeroallergen sensitization can disappear in children with allergic disease, but only in polysensitized individuals. Complete remittance of sensitization to aeroallergens is rare in symptomatic children. [source] Seasonal changes in suppressive capacity of CD4+ CD25+ T cells from patients with hayfever are allergen-specific and may result in part from expansion of effector T cells among the CD25+ populationCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2009A. E. Anderson Summary Background Suppression of allergen-stimulated peripheral blood CD4+ CD25, effector T cells by CD4+ CD25+ regulatory T cells obtained from subjects with allergic rhinoconjunctivitis is reduced during the pollen season when compared with out of season. Objective We examined possible explanations for this effect of seasonal pollen exposure on suppression of allergen responses. Methods CD4+ CD25, and CD4+ CD25+ T cells were isolated from blood obtained from 44 volunteers with allergic rhinoconjunctivitis during and out of the UK grass pollen season. Co-cultures were performed with grass pollen extract and house dust mite (HDM) to examine allergen specificity. The frequency of IL-5 and IL-10 producing cells was determined by ELISPOT and the expression of T cell activation markers and the CD25+ regulatory T cell-associated transcription factor Foxp3 were examined. Lactic acid stripping of IgE was used to determine IgE dependence of T cell responses. Results The seasonal reduction in suppression by CD4+ CD25+ T cells was confirmed and was shown to be allergen specific because suppression of HDM-stimulated cultures was not affected significantly. The CD4+ CD25+ population contained IL-5 and IL-10 producing cells but increases in their frequencies with seasonal pollen exposure were not significant. Both activation marker and Foxp3 expression increased during the pollen season. IgE stripping reduced CD4+ and CD4+ CD25, T cell responses to allergen, but had no effect on suppression by CD4+ CD25+ T cells. Conclusion The seasonal reduction in suppression of grass pollen-stimulated effector T cells by CD4+ CD25+ T cells is allergen specific and cannot be explained by increased IgE-facilitated allergen presentation. We suggest that changes in the proportion of effector to regulatory T cells among the CD25+ population isolated may partially explain these findings, and that trafficking to the site of allergic disease may reduce allergen-specific regulatory T cell numbers in peripheral blood. [source] Anti-bacterial IgE in the antibody responses of house dust mite allergic children convalescent from asthma exacerbationCLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2009B. J. Hales Summary Background Atopic sensitization to the house dust mite (HDM) is associated with altered antibody responses to the nasopharyngeal colonizing bacterium Haemophilus influenzae and children admitted to the emergency department for asthma exacerbation have reduced IgG responses to HDM allergens. Objective To investigate anti-bacterial and anti-allergen antibody responses during convalescence from asthma exacerbation and differences found in exacerbations associated with and without viral infection. Results IgE antibodies to the P6 bacterial antigen increased in 60% of sera during convalescence and for many children achieved titres as high as IgE titres to allergens. In contrast IgE anti-HDM titres declined during convalescence. The anti-bacterial IgE titres were the same in subjects with and without virus infection while the anti-HDM IgE declined more rapidly in virus-infected subjects. IgG titres to the major HDM allergens showed no consistent increase and the overall IgG anti-HDM titres even declined in subjects without a virus infection. Anti-bacterial IgG antibodies in contrast to IgE did not change. Patients with frequent episodic or persistent asthma had similar IgE anti-bacterial titres to patients with infrequent asthma during the acute phase, although they had reduced IgG titres to both the bacteria and the HDM. Conclusions During the period following an acute exacerbation of asthma there was a marked and specific increase in anti-bacterial IgE compared with a reduced IgE response to HDM. This provides further support for the concept of T-helper type 2 responses to bacterial antigens playing a role in asthma pathogenesis. [source] Production of native and modified recombinant Der p 1 molecules in tobacco plantsCLINICAL & EXPERIMENTAL ALLERGY, Issue 5 2009D. Burtin Summary Background As a complex molecule requiring post-translational processing, it has been difficult to produce the Der p 1 major allergen from the Dermatophagoides pteronyssinus house dust mite in a recombinant form. Objective Here, we tested whether transgenic tobacco plants are suitable to express Der p 1, either as a wild-type molecule or as variants lacking N -glycosylation sites (Gly,) and/or cysteine protease activity (Enz,). Methods Using Agrobacterium tumefaciens -based transformation, pro Der p 1 molecules bearing mutations within either the N -glycosylation sites (N34Q, N150Q) and/or the cysteine protease-active site (C132V) were expressed in tobacco plants. After purification by ion exchange chromatography, allergens were characterized using immunoblotting, circular dichroism (CD), as well as basophil and T lymphocyte stimulation assays. Results Four forms of recombinant Der p 1 (i.e. wild-type Gly+/Enz+, as well as Gly,/Enz+, Gly+/Enz, or Gly,/Enz, variants) were successfully expressed in tobacco leaves as pro Der p 1 molecules. Spontaneous cleavage of the pro-peptide was observed in tobacco leaf extracts for all forms of recombinant Der p 1 (r Der p 1). CD confirmed that all r Der p 1 molecules, with the exception of the Gly,/Enz, variant, exhibited secondary structures comparable to the natural protein. A cysteine protease activity was associated only with the Gly+/Enz+ form. All these molecules exhibit a profile similar to natural Der p 1 with respect to IgE immunoreactivity, basophil activation and T cell recognition. Conclusion A tobacco plant expression system allows the production of various forms of mature Der p 1, which could be used for diagnostic or immunotherapeutic purposes. [source] Use of A-type CpG oligodeoxynucleotides as an adjuvant in allergen-specific immunotherapy in humans: a phase I/IIa clinical trialCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2009G. Senti Summary Background B-type CpG oligodeoxynucleotides (ODN) is currently used in clinical trials because of its prolonged half,life, which is due to its phosphorothioate backbone. A-type CpG ODN is a stronger inducer of IFN but has an unstable phosphodiester backbone that has so far prohibited its clinical use. However, upon association with virus-like particles (VLP) consisting of the bacteriophage Q, coat protein, A-type CpG ODN can be stabilized and can become an efficient adjuvant in mice. Therefore, the phase I/IIa study presented represents the first test of A-type CpGs in humans. Objective To test the safety, tolerability and clinical efficacy of QbG10 as an adjuvant for subcutaneous immunotherapy with a house dust mite (HDM) allergen extract in allergic patients. Methods A single centre, open-label phase I/IIa study evaluated the safety, tolerability and clinical efficacy of QbG10 as an adjuvant to immunotherapy with a subcutaneous HMD allergen extract in 20 patients suffering from HDM allergy. Twenty-one patients were enrolled between March and July 2005. Individual immunotherapy lasted 10 weeks. Clinical end-points included questionnaires, conjunctival provocation, skin prick tests and the measurement of allergen-specific IgG and IgE. Results QbG10 was well tolerated. Almost complete tolerance to the allergen was observed in conjunctival provocation testing after treatment with QbG10, and symptoms of rhinitis and allergic asthma were significantly reduced. Within 10 weeks of therapy, patients were nearly symptom-free and this amelioration lasted for at least 38 weeks post-treatment. Following injections of QbG10 and HDM allergen extract, allergen-specific IgG increased, while there was a transient increase in allergen-specific IgE titres. Skin reactivity to HDM was reduced. Conclusion The subcutaneous application of HDM allergen, together with A-type CpG ODN packaged into VLP, was safe. All patients achieved practically complete alleviation of allergy symptoms after 10 weeks of immunotherapy. This promising clinical outcome calls for larger placebo-controlled phase II studies. [source] The temporal sequence of allergic sensitization and onset of infantile eczemaCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2007A. J. Lowe Summary Background Eczema is commonly associated with sensitization in infants, but the causative role of sensitization in the development of eczema has been questioned. Objective To determine if allergic sensitization increases the risk of developing eczema, or alternatively, if eczema increases the risk of developing allergic sensitization. Methods We used data from the Melbourne Atopy Cohort Study, a prospective birth cohort of 552 infants with a family history of atopic disease. The main outcomes were risk of developing eczema from 6 months to 7 years of age in asymptomatic infants; and risk of developing sensitization, as measured by skin prick tests to milk, egg white, peanut, house dust mite, rye grass pollen and cat extracts, in previously unsensitized infants. Results Sensitization to food extracts at 6 months was associated with an increased risk of developing eczema [hazard ratio (HR) 1.63, 95% confidence interval 1.13,2.35] up to 7 years of age, after excluding infants with eczema in the first 6 months. However, eczema in the first 6 months was also associated with increased risk of new sensitization at both 1 year (HR 2.34, 1.38,3.98) and 2 years (HR 3.47, 1.65,7.32). Conclusion In some infants, sensitization precedes and predicts the development of eczema, while in others eczema precedes and predicts the development of sensitization. This indicates that there are multiple pathways to atopic eczema. [source] Side-effects of allergen-specific immunotherapy.CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2006A prospective multi-centre study Summary Background and objective The safety of allergen-specific immunotherapy (SIT) is a parameter of great interest in the overall assessment of the treatment. A clinical database was developed in order to obtain early warnings of changes in the frequency and severity of side-effects and sufficient data for the evaluation of possible risk factors. Methods During a 3-year period, four allergy centres in Copenhagen, Denmark, included data from all patients initiating SIT to a common database. Information on initial allergic symptoms, allergens used for treatment, treatment regimens and systemic side-effects (SSEs) during the build-up phase was collected. Results A total of 1038 patients received treatment with 1709 allergens (timothy, birch, mugwort, house dust mite (HDM), cat, and wasp and bee venom), 23 047 injections in total. Most SIT patients completed the updosing phase without side-effects, but there was a significant difference between allergens: wasp (89%), birch (82%), HDM (81%), cat (74%) and grass (70%) (P=0.004). A total of 582 SSEs were registered in 341 patients. Most side-effects were mild grade 2 reactions (78%). A difference in severity between allergens was observed (P=0.02), with grass giving most problems. The type of allergen but not patient- or centre-related parameters seemed predictive of side-effects. Conclusions Allergen extracts differ in their tendency to produce side-effects. Multi-centre studies like the present one allow more patients to be evaluated, and thereby provide a more efficient surveillance of side-effects. Online Internet-based registration to a central national database of every allergen injection would be an even more powerful tool for evaluation of risk factors and surveillance of side-effects. [source] Transgenic mice expressing the T cell antigen receptor specific for an immunodominant epitope of a major allergen of house dust mite develop an asthmatic phenotype on exposure of the airways to allergenCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2005E. R. Jarman Summary Background Current studies on mechanisms underlying allergen-induced pulmonary inflammation and asthma are hampered by the lack of appropriate physiological in vivo models that reflect the natural route of allergen exposure and sensitization. Objective To generate and phenotype a transgenic mouse strain expressing the T cell receptor (TCR) specific for an immunodominant domain of the major inhalant allergen Dermatophagoides pteronyssinus species of house dust mite (Der p 1), for the development of an in vivo model of allergic asthma. Methods Der p 1 transgenic mice were generated using TCR-,, derived from a CD4+ T cell hybridoma reactive with Der p 1 residues p 110,131. The frequency and functional activity of peripheral T cells were determined and parameters of airway inflammation assessed following allergen challenge of the airways with Der p 1. Results CD4+ T cells are functionally active, exhibiting dose-dependent proliferation and IL-4 production on primary stimulation with Der p 1 or Der p 1, p 110,131 in vitro, independent of in vivo antigen priming. On sensitization of the airways with allergen, in the absence of systemic priming or the application of adjuvants, the TCR transgenic mice develop airway inflammation characterized by a marked lymphocytic and eosinophilic infiltrate with goblet cell hyperplasia and enhanced mucin production. Conclusion The Der p 1 TCR transgenic mice provide a model for investigating the pathophysiological mechanisms of pulmonary inflammation following sensitization by exposure of the airways to allergen and for investigating the mode of action and efficacy of novel immunotherapeutics. [source] The novel use of the human nasal epithelial cell line RPMI 2650 as an in vitro model to study the influence of allergens and cytokines on transforming growth factor-, gene expression and protein releaseCLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2005R. J. Salib Summary Background The epithelial accumulation of mast cells is a feature of allergic rhinitis and this has been linked to the expression of the known mast cell chemoattractant transforming growth factor-, (TGF-,) at this site. Little is known concerning the regulation of TGF-, gene expression or protein release by nasal epithelial cells. To address this we have utilized the RPMI 2650 human nasal epithelial cell line, which has some features that closely resemble normal nasal epithelium and has been reported to secrete a TGF-,-like molecule. Objectives To investigate the regulation of TGF-, gene expression and protein secretion in RPMI 2650 nasal epithelial cells following exposure to allergens (house dust mite (HDM) and grass pollen) and mast cell associated T-helper type 2 (Th2) cytokines (IL-4, IL-13, and TNF-,). Methods Light and scanning electron microscopy was used to evaluate the morphology of RPMI 2650 cells in culture, enzyme-linked immunosorbent assay was used to investigate their TGF-, secretory capacity and the identification of the TGF-, isotype(s) involved, flow cytometry was used to demonstrate the presence of TGF-, receptors on the RPMI 2650 cells, and the quantitative real-time TaqMan PCR was used to measure TGF-, gene expression. Results TGF-,2 was identified as the main isotype secreted by the RPMI 2650 cells. HDM allergens and TNF-, increased both TGF-, gene expression and protein release from these cells, whereas grass pollen, IL-4, and IL-13 were without effect. Conclusions The RPMI 2650 nasal epithelial cell line represents a valid in vitro model to evaluate the regulation of TGF-, biology. In this system HDM allergens have stimulatory activity that is fundamentally different from that of grass pollen allergens, and the Th2 cytokines IL-4 and IL-13 are without effect. The ability of TNF-, to up-regulate both TGF-, gene expression and protein release indicates that mast cell,epithelial interactions concerning TGF-, are bi-directional and this may be fundamental to epithelial immunoregulation. The availability of a model system, such as the RPMI 2650 cells, will enable the early evaluation of future novel and targeted interventions directed toward the aberrant responses of upper airway structural cells. [source] Exhaled nitric oxide: relation to sensitization and respiratory symptomsCLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2004A.-C. Olin Summary Background Conflicting data have been presented as to whether nitric oxide (NO) in exhaled air is merely reflecting atopy rather than airway inflammation. Objective To investigate the relationship between exhaled NO (eNO) and nasal NO (nNO), respiratory symptoms, and atopy, in the context of a cross-sectional study of the respiratory health of bleachery workers. Methods Two hundred and forty-six non-smoking bleachery and paper-mill workers answered a questionnaire and were examined by measurements of eNO and nNO and spirometry, outside the pollen season. Blood samples were collected and analysed for specific IgE against common aeroallergens (birch, timothy, cat and house dust mite). Atopy was defined as a positive PhadiatopÔ test. Results The atopic and the non-atopic subjects without asthma or rhinitis had similar levels of eNO. Subjects reporting asthma or rhinitis who were also sensitized to perennial allergens had higher levels of eNO, whereas those sensitized to only seasonal allergens had similar eNO levels as non-atopic subjects with asthma or rhinitis. In multiple linear regression models adjusted for nNO, eNO was associated with asthma and sensitization to perennial allergens. Conclusion The results indicate that only atopic subjects who have recently been exposed to the relevant allergen have elevated levels of eNO. Atopic subjects who are not being exposed to a relevant allergen or have never experienced symptoms of asthma or rhinitis show normal eNO. These data indicate that eNO relates to airway inflammation in atopic subjects. [source] Sensitization to cross-reactive carbohydrate determinants and the ubiquitous protein profilin: mimickers of allergyCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2004D. G. Ebo Summary Background During the last decade, evidence has been provided for profilins and cross-reactive carbohydrate determinants (CCDs) to be capable of inducing cross-reactive IgE antibodies with little clinical relevance. Objective To investigate the prevalence of sensitization to CCD and profilin in isolated allergies (birch, timothy grass, house dust mite, pets (cat and/or dog), natural rubber latex (NRL) and hymenoptera venom). To study the contribution of anti-CCD and anti-profilin IgE antibodies as a cause of clinically irrelevant IgE for NRL and apple. Methods For the first part of the study, 100 patients with inhalant allergy, 17 patients with NRL allergy and 40 patients with venom anaphylaxis were enrolled. Diagnosis was based on a questionnaire and a positive IgE determination and skin test for relevant allergen. Patients were identified as sensitized to CCD if they had a negative prick test and positive IgE for the glycoprotein bromelain. Sensitization to profilin was assessed by IgE for rBet v 2 (recombinant birch profilin). For the second part of the study, sera containing IgE against apple (n=82) or NRL (n=38) were classified as true-negative or false-positive according to the presence or absence of an oral allergy syndrome (OAS) or NRL-induced anaphylaxis. In these patients, sensitization to CCD and profilin was evaluated as described above. Results No sensitization to bromelain-type CCD and profilin was found in isolated birch pollen or NRL allergy. In contrast, sensitization to bromelain-type CCD was found in 4/17 patients with isolated grass pollinosis, 5/24 patients with combined pollinosis (birch, timothy, mugwort) and 7/33 patients with venom anaphylaxis. Sensitization to profilin was almost restricted to patients with combined pollen allergy (5/24). In pollen-allergic individuals with a false-positive IgE against NRL the prevalence of sensitization to bromelain-type CCD and profilin IgE was higher than in NRL-allergic patients (P<0.00001 and P=0.0006, respectively). In pollen-allergic individuals with a false-positive IgE to apple, the frequency of sensitization to bromelain-type CCD was higher than in OAS patients (P=0.004). Clinically irrelevant NRL and apple were also found in four and five out of the seven patients sensitized to venom CCD, respectively. In pollinosis, clinically irrelevant NRL and apple IgE antibodies were inhibited by bromelain and recombinant birch profilin, whereas in isolated venom anaphylaxis these antibodies were inhibited by bromelain. Conclusions Patients monoallergic to NRL or birch pollen showed no sensitization to bromelain-type CCD or profilin. Sensitization to profilin and/or bromelain-type CCD, caused by pollen (timothy grass, mugwort) or hymenoptera venom allergens, can elicit false-positive IgE antibodies against NRL and apple. [source] Long-lasting effect of sublingual immunotherapy in children with asthma due to house dust mite: a 10-year prospective studyCLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2003V. Di Rienzo Summary Background Subcutaneous immunotherapy for respiratory allergy has shown a long-lasting efficacy after its discontinuation, whereas this evidence is still lacking for sublingual immunotherapy, despite the fact that it is widely used. Objective We aimed to evaluate whether a long-lasting effect of SLIT occurs, in a prospective parallel group controlled study. Methods Sixty children (mean age 8.5 years) suffering from allergic asthma/rhinitis due to mites were subdivided into two matched groups: 35 underwent a 4- to 5-year course of SLIT with standardized extract and 25 received only drug therapy. The patients were evaluated at three time points (baseline, end of SLIT and 4 to 5 years after SLIT discontinuation) regarding presence of asthma, use of anti-asthma drugs, skin prick tests and specific IgE. Results We found that in the SLIT group there was a significant difference vs. baseline for the presence of asthma (P , 0.001) and the use of asthma medications (P , 0.01), whereas no difference was observed in the control group. The mean peak expiratory flow result was significantly higher in the active group than in the control group after 10 years. No change was seen as far as new sensitizations were concerned. Specific IgE showed a near-significant increase (baseline vs. 10 years, P = 0.06) only in the control group. Conclusion Our study demonstrates that sublingual immunotherapy is effective in children and that it maintains the clinical efficacy for 4 to 5 years after discontinuation. [source] Prevalence of immunoglobulin E for fungi in atopic childrenCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2001G. Nolles Background The prevalence of sensitization to fungi in young atopic patients in relation to age and clinical importance is largely unknown. Objective The aim of this study was to investigate the prevalence of sensitization to different fungi in atopic children in relation to age and other aeroallergens. Methods A total of 137 atopic children (male 62%, female 38%; mean age 5 years and 9 months, range 5 months,14 years) were studied. Sera of all patients were routinely tested for total IgE and specific IgE against aeroallergens and milk. Positive sera were also tested for IgE against Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum and Penicillium chrysogenum, using the Pharmacia Enzyme CAP procedure. Results In this study in atopic children total IgE showed a significant linear relation with age, whereas specific IgE against outdoor fungi, indoor fungi and house dust mite showed significant non-linearity with age. Prevalence of specific IgE for Cladosporium ranked first, followed closely by Aspergillus and Alternaria. Calculation of the sensitization of indoor and outdoor fungi showed maximum prevalence at 7.8 years, followed by lower values at higher ages. A similar significant relation was also found for Alternaria, while this relation was not significant for the other individual fungi. Specific IgE for indoor and outdoor fungi was associated with the presence of specific IgE for aeroallergen and milk. We found that all children aged 4 years and older showed IgE for house dust mite that did not decline with increasing age. Conclusions Sensitization to fungi is prevalent in childhood, with an age-dependent distribution reaching maximum values at 7.7,7.8 years, followed by a decline for all fungal sensitization with increasing age. The importance and relative contribution of fungal sensitization to airway disease, compared with the other allergens, remains to be established. [source] Total and specific IgE (house dust mite and intestinal helminths) in asthmatics and controls from Gondar, EthiopiaCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2000Selassie Background The role, if any, of parasitosis in the development of asthma remains incompletely understood; both ,protective' and ,predictive' associations have been reported. We report a study which examined immunoglobulin (Ig) E responses to two common helminths in asthmatics living in Ethiopia. Objective To compare the frequencies of specific IgE antibodies to Ascaris and Necator species and to Der p 1 among 84 adult asthmatics and a referent group of nonasthmatics. Methods A case-control analysis. Results Total IgE levels were not different between the two groups. The presence of specific IgE to Der p 1 was strongly associated with asthma (P = 0.001). Raised levels of Ascaris-(P = 0.010) and Necator- (P = 0.001) specific IgE antibodies were more common among referents; there were no associations between specific IgE production to Der p 1 and either of the two parasites. Conclusion These findings confirm the association between Der p 1 sensitization and asthma among urban, adult Ethiopians. While they also indicate a negative relationship with two indicators of helminth infestation it appears that this is not mediated through the immunological response to common aeroallergens. [source] | |||||||||||||||||||||||||||||||