Pollen Exposure (pollen + exposure)

Distribution by Scientific Domains


Selected Abstracts


Sustained effect of SQ-standardized grass allergy immunotherapy tablet on rhinoconjunctivitis quality of life

ALLERGY, Issue 6 2010
L. Frølund
To cite this article: Frølund L, Durham SR, Calderon M, Emminger W, Andersen JS, Rask P, Dahl R. Sustained effect of SQ-standardized grass allergy immunotherapy tablet on rhinoconjunctivitis quality of life. Allergy 2010; 65: 753,757. Abstract Background:, The prevalence of allergic rhinoconjunctivitis has increased significantly over the past decades with grass pollen being a common trigger. The impact of allergy on patient's quality of life is substantial. Aim:, To investigate the sustained effect on quality of life during the grass pollen season 1 year after 3 years of treatment with the SQ-standardized grass allergy immunotherapy tablet (AIT), Grazax® (Phleum pratense 75,000 SQ-T/2800 BAU; ALK, Denmark). Methods:, The trial was a randomized, parallel-group, double-blind, placebo-controlled trial in adult subjects with a history of moderate-severe grass pollen induced rhinoconjunctivitis inadequately controlled by symptomatic medications. Subjects received 3 years of grass AIT (n = 157) or placebo (n = 126), followed by 1 year of follow-up. Quality of life assessments were based on the standardized rhinoconjunctivitis quality of life questionnaire (RQLQ(S)); completed weekly during the entire grass pollen season. Results:, During follow-up, the overall RQLQ(S) score for the entire grass pollen season was significantly improved in the active group (relative difference to placebo: 23%, P = 0.004). The improvement was higher during the peak pollen season (28%, P = 0.001). The treatment effect of grass AIT during the follow-up year and the previous three treatment years was similar. Improvements were found in all seven RQLQ(S) domains. The RQLQ(S) as a function of the weekly average pollen counts showed a clear separation between the treatment groups (P < 0.001). Conclusion:, In subjects inadequately controlled by symptomatic medications, grass AIT provided sustained and clinically relevant improvements in rhinoconjunctivitis quality of life compared to placebo. The effect increased with increasing grass pollen exposure. [source]


Time-series nasal epithelial transcriptomics during natural pollen exposure in healthy subjects and allergic patients

ALLERGY, Issue 2 2010
P. Mattila
To cite this article: Mattila P, Renkonen J, Toppila-Salmi S, Parviainen V, Joenväärä S, Alff-Tuomala S, Nicorici D, Renkonen R. Time-series nasal epithelial transcriptomics during natural pollen exposure in healthy subjects and allergic patients. Allergy 2010; 65: 175,183. Abstract Background:, The role of epithelium has recently awakened interest in the studies of type I hypersensitivity. Objective:, We analysed the nasal transcriptomics epithelial response to natural birch pollen exposure in a time series manner. Methods:, Human nasal epithelial cell swabs were collected from birch pollen allergic patients and healthy controls in winter season. In addition, four specimens at weekly intervals were collected from the same subjects during natural birch pollen exposure in spring and transcriptomic analyses were performed. Results:, The nasal epithelium of healthy subjects responded vigorously to allergen exposure. The immune response was a dominating category of this response. Notably, the healthy subjects did not display any clinical symptoms regardless of this response detected by transcriptomic analysis. Concomitantly, the epithelium of allergic subjects responded also, but with a different set of responders. In allergic patients the regulation of dyneins, the molecular motors of intracellular transport dominated. This further supports our previous hypothesis that the birch pollen exposure results in an active uptake of allergen into the epithelium only in allergic subjects but not in healthy controls. Conclusion:, We showed that birch pollen allergen causes a defence response in healthy subjects, but not in allergic subjects. Instead, allergic patients actively transport pollen allergen through the epithelium to tissue mast cells. Our study showed that new hypotheses can arise from the application of discovery driven methodologies. To understand complex multifactorial diseases, such as type I hypersensitivity, this kind of hypotheses might be worth further analyses. [source]


Risk factors for allergic rhinitis in Costa Rican children with asthma

ALLERGY, Issue 2 2010
S. Bunyavanich
To cite this article: Bunyavanich S, Soto-Quiros ME, Avila L, Laskey D, Senter JM, Celedón JC. Risk factors for allergic rhinitis in Costa Rican children with asthma. Allergy 2010; 65; 256,263 DOI: 10.1111/j.1398-9995.2009.02159.x. Abstract Background:, Risk factors for allergic rhinitis (AR) in asthmatics are likely distinct from those for AR or asthma alone. We sought to identify clinical and environmental risk factors for AR in children with asthma. Methods:, We performed a cross-sectional study of 616 Costa Rican children aged 6,14 years with asthma. Candidate risk factors were drawn from questionnaire data, spirometry, methacholine challenge testing, skin testing, and serology. Two outcome measures, skin test reaction (STR)-positive AR and physician-diagnosed AR, were examined by logistic regression. Results:, STR-positive AR had high prevalence (80%) in Costa Rican children with asthma, and its independent risk factors were nasal symptoms after exposure to dust or mold, parental history of AR, older age at asthma onset, oral steroid use in the past year, eosinophilia, and positive IgEs to dust mite and cockroach. Physician-diagnosed AR had lower prevalence (27%), and its independent risk factors were nasal symptoms after pollen exposure, STR to tree pollens, a parental history of AR, inhaled steroid and short-acting ,2 agonist use in the past year, household mold/mildew, and fewer older siblings. A physician's diagnosis was only 29.5% sensitive for STR-positive AR. Conclusions:, Risk factors for AR in children with asthma depend on the definition of AR. Indoor allergens drive risk for STR-positive AR. Outdoor allergens and home environmental conditions are risk factors for physician-diagnosed AR. We propose that children with asthma in Costa Rica and other Latin American nations undergo limited skin testing or specific IgE measurements to reduce the current under-diagnosis of AR. [source]


Effect of natural seasonal pollen exposure and repeated nasal allergen provocations on elevation of exhaled nitric oxide

ALLERGY, Issue 11 2009
K. Bergmann-Hug
Background:, Exhaled nitric oxide (FENO) is a marker for allergic airway inflammation. We wondered whether in patients with intermittent allergic rhinitis only (i) natural pollen exposure and (ii) artificial pollen exposure by repeated nasal allergen provocations may lead to an elevation of FENO. Methods:, In two prospective studies, we compared the FENO of nonatopic controls with the FENO of nonasthmatic individuals with mild intermittent rhinitis to tree and/or grass pollen. Study I: 13 atopic individuals and seven controls had measurements of FENO, blood eosinophils and eosinophilic cationic protein (ECP) before, during and after pollen season. Study II: 16 atopic individuals and 12 controls had nasal allergen provocations on four following days out of pollen season, with daily measurements of FENO before, 2 and 6 h after provocation, and determination of blood eosinophils, ECP and FEV1 at baseline, on days 5 and 10,12. Results:, Natural pollen exposure (study I) caused a significant elevation of FENO in allergic individuals. Nasal allergen provocations (study II) did not elicit a statistically significant rise neither of FENO nor of blood eosinophils between baseline and day 5. However, a subgroup of four individuals with a rise of blood eosinophils during nasal allergen provocations showed also a rise of FENO. Conclusions:, We suppose that in allergic rhinitis a concomitant reaction of the bronchial system is dependent on a strong local inflammation leading to a generalized immune stimulation. [source]


Allergic rhinitis in the child and associated comorbidities

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 1-Part-II 2010
Tania Sih
Sih T, Mion O. Allergic rhinitis in the child and associated comorbidities. Pediatr Allergy Immunol 2010: 21: e107,e113. © 2009 John Wiley & Sons A/S Allergic rhinitis (AR) typically presents after the second year of life, but the exact prevalence in early life is unknown. AR affects 10,30% of the population, with the greatest frequency found in children and adolescents. It appears that the prevalence has increased in the pediatric population. As the childs' immune system develops between the 1st and 4th yr of life, those with an atopic predisposition begin to express allergic disease with a clear Th2 response to allergen exposure, resulting in symptoms. In pediatric AR, two or more seasons of pollen exposure are generally needed for sensitization, so allergy testing to seasonal allergens (trees, grasses, and weeds) should be conducted after the age of 2 or 3 years. Sensitization to perennial allergens (animals, dust mites, and cockroaches) may manifest several months after exposure. Classification of AR includes measurement of frequency and duration of symptoms. Intermittent AR is defined as symptoms for <4 days/wk or <4 consecutive weeks. Persistent AR is defined as occurring for more than 4 days/wk and more than 4 consecutive weeks. AR is associated with impairments in quality of life, sleep disorders, emotional problems, and impairment in activities such as work and school productivity and social functioning. AR can also be graded in severity , either mild or moderate/severe. There are comorbidities associated with AR. The chronic effects of the inflammatory process affect lungs, ears, growth, and others. AR can induce medical complications, learning problems and sleep-related complaints, such as obstructive sleep apnea syndrome and chronic and acute sinusitis, acute otitis media, serous otitis media, and aggravation of adenoidal hypertrophy and asthma. [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+ population

CLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2009
A. 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]


Pollen counts in relation to the prevalence of allergic rhinoconjunctivitis, asthma and atopic eczema in the International Study of Asthma and Allergies in Childhood (ISAAC)

CLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2003
M. L. Burr
Summary Background Although pollens are major allergens associated with allergic rhinoconjunctivitis and asthma, there is little information about the relative prevalence of these conditions in populations with different pollen exposures. Objective The purpose of this study was to investigate the relationship between pollen exposure and allergic symptoms among children in different countries. Methods An ecological analysis was conducted to see whether pollen exposure (pollen counts, and duration and severity of pollen seasons) is associated with symptoms of allergic rhinoconjunctivitis, asthma and atopic eczema in 28 centres within 11 countries (nine being in Europe). Data on the prevalence of symptoms in 13,14-year olds were based on the responses to the written questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC). The analysis was adjusted for gross national product and mean annual relative humidity. Results There was little relationship between pollen exposure and symptom prevalence, except for a significant inverse association between grass pollen counts and lifetime prevalence of the symptoms of allergic rhinitis (P=0.03). Almost all the regression coefficients were negative. The associations were even weaker and all non-significant when the analyses were conducted within countries, using a random intercept fixed slope model, but there was still no evidence of a positive association between pollen exposure and symptoms. Conclusion There is a weak but consistent tendency for the prevalence of allergic symptoms to be inversely associated with pollen exposure. This finding accords with evidence from several countries, suggesting that the prevalence of hayfever and asthma tends to be lower in rural than in urban areas, and lowest among people living on farms. Exposure to allergenic pollen in early life does not appear to increase the risk of acquiring symptoms of respiratory allergy, and may even give some protection against them. [source]


Exposure to grass pollen in Europe

CLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2008
S. JaegerArticle first published online: 7 APR 200
Summary Pooideae encompass both common wild and cultivated grasses, which are responsible for grass pollen exposure and sensitization in Europe. Across Europe, the pollination period of different members of this subfamily overlap and hayfever sufferers are therefore naturally exposed to a mixture of pollens from different grass species. Because of their morphological homology, Pooideae pollens are evaluated together in pollen counts and cannot be distinguished. Neither patients themselves, nor physicians can link the onset of hayfever symptoms to a specific grass species. [source]


Pollen counts in relation to the prevalence of allergic rhinoconjunctivitis, asthma and atopic eczema in the International Study of Asthma and Allergies in Childhood (ISAAC)

CLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2003
M. L. Burr
Summary Background Although pollens are major allergens associated with allergic rhinoconjunctivitis and asthma, there is little information about the relative prevalence of these conditions in populations with different pollen exposures. Objective The purpose of this study was to investigate the relationship between pollen exposure and allergic symptoms among children in different countries. Methods An ecological analysis was conducted to see whether pollen exposure (pollen counts, and duration and severity of pollen seasons) is associated with symptoms of allergic rhinoconjunctivitis, asthma and atopic eczema in 28 centres within 11 countries (nine being in Europe). Data on the prevalence of symptoms in 13,14-year olds were based on the responses to the written questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC). The analysis was adjusted for gross national product and mean annual relative humidity. Results There was little relationship between pollen exposure and symptom prevalence, except for a significant inverse association between grass pollen counts and lifetime prevalence of the symptoms of allergic rhinitis (P=0.03). Almost all the regression coefficients were negative. The associations were even weaker and all non-significant when the analyses were conducted within countries, using a random intercept fixed slope model, but there was still no evidence of a positive association between pollen exposure and symptoms. Conclusion There is a weak but consistent tendency for the prevalence of allergic symptoms to be inversely associated with pollen exposure. This finding accords with evidence from several countries, suggesting that the prevalence of hayfever and asthma tends to be lower in rural than in urban areas, and lowest among people living on farms. Exposure to allergenic pollen in early life does not appear to increase the risk of acquiring symptoms of respiratory allergy, and may even give some protection against them. [source]