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Asthmatic Reaction (asthmatic + reaction)

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Medical Sciences	100%

Selected Abstracts

The allergen specificity of the late asthmatic reaction

ALLERGY, Issue 3 2010
M. Hatzivlassiou
To cite this article: Hatzivlassiou M, Grainge C, Kehagia V, Lau L, Howarth PH. The allergen specificity of the late asthmatic reaction. Allergy 2010; 65: 355,358. Abstract Background:, Allergen inhalation challenge in asthma may induce both early (EAR) and late (LAR) asthmatic reactions. The EAR is IgE and mast cell dependent. The mechanism of the LAR is less well defined and we have hypothesized may be allergen dependent. The aim of this study was to investigate the allergen specificity of the LAR to allergen inhalation in asthma. Methods:, In a randomized, double-blind, crossover design six asthmatic volunteers with dual sensitization to house dust mite (HDM) allergen and grass pollen (GP) allergen underwent inhalation allergen challenge with these separate allergens on two occasions separated by 14 days. Lung function changes were followed for 8-h postchallenge. Bronchial reactivity (histamine PC20) and airway inflammation, assessed by induced sputum differential cell count, were measured 24-h pre and postallergen challenge. The allergen inhalation challenges were matched to achieve the same magnitude of EAR. Results:, Despite comparable group mean EAR percent falls in FEV1 (25.8% following GP and 28.0% following HDM (P = 0.917), the LAR was statistically greater on the HDM challenge day (13.0%vs 22.8% [P = 0.046]) and was associated with a significant airway eosinophil recruitment (mean (SD) of 5.4 (4.8)% to 22.1 (18.2)% (P = 0.028) that was not evident on the GP allergen challenge day. Conclusions:, These findings identify the allergen specificity of the LAR and indicate that factors independent of IgE contribute to the LAR. Such findings have relevance both to the understanding of the allergen-induced airway responses in asthma and the need for homogeneity in inhaled-allergen challenge studies in asthma. [source]

Sputum eosinophilia: an early marker of bronchial response to occupational agents

ALLERGY, Issue 5 2009
O. Vandenplas
Background:, False-negative responses to specific inhalation challenge (SIC) with occupational agents may occur. We explored whether assessing changes in sputum cell counts would help improve the identification of bronchial reactivity to occupational agents during SICs. Methods:, The predictive value of the changes in sputum cell counts after a negative FEV1 response to a first challenge exposure to an occupational agent was determined using the changes in airway calibre observed during repeated challenges as the ,gold standard'. The study included 68 subjects investigated for work-related asthma in a tertiary centre. After a control day, the subjects were challenged with the suspected occupational agent(s) for up to 2 h. All subjects who did not show an asthmatic reaction were re-challenged on the following day. Additional challenges were proposed to those who demonstrated a , 2% increase in sputum eosinophils or an increase in nonspecific bronchial hyperresponsiveness to histamine after the second challenge day. Results:, Six of the 35 subjects without changes in FEV1 on the first challenge developed an asthmatic reaction on subsequent challenges. ROC analysis revealed that a >3% increase in sputum eosinophils at the end of the first challenge day was the most accurate parameter for predicting the development of an asthmatic response on subsequent challenges with a sensitivity of 67% and a specificity of 97%. Conclusions:, An increase in sputum eosinophils is an early marker of specific bronchial reactivity to occupational agents, which may help to identify subjects who will develop an asthmatic reaction only after repeated exposure. [source]

Rye flour allergens: An emerging role in baker's asthma

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 5 2008
Antonio Letrán
Abstract Background Exposure to wheat flour is usually considered the most important cause of baker's asthma. However, other flours frequently used in bakeries may play an emerging role as relevant allergens causing occupational asthma. Aims of study We report on two cases of baker's asthma mainly caused by exposure to rye flour. The profile of allergen sensitization to cereal flour was investigated. Methods Two bakery workers suffering from rhinoconjunctivitis and asthma symptoms at work underwent an in vivo study (skin prick tests and bronchial allergen challenge) and in vitro study (total serum IgE, specific serum IgE and immunoblotting). Results Specific inhalation challenge with wheat flour did not elicit an asthmatic reaction, however both patients showed an early asthmatic reaction with the rye flour challenge. Rye flour-immunoblotting showed IgE-binding bands around 12,15 kDa, that correspond to rye flour enzymatic inhibitors which were not present in the wheat flour immunoblot. Conclusions Both bakers had developed occupational asthma to rye flour (confirmed by specific inhalation challenge test). Rye flour allergens (enzymatic inhibitors) are important allergens that should be considered in the diagnosis of baker's asthma. Am. J. Ind. Med. 51:324,328, 2008. © 2008 Wiley-Liss, Inc. [source]

The allergen specificity of the late asthmatic reaction

Respiratory diseases caused by occupational exposure to 1,5-naphthalene-diisocyanate (NDI): Results of workplace-related challenge tests and antibody analyses

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 4 2001
X. Baur
Abstract Background 1,5-naphthalene-diisocyanate (NDI) is an aromatic diisocyanate with a very low vapor pressure which is mainly used in the automotive industry. Methods In the present study we described five cases with workplace-related asthma and one case with extrinsic allergic alveolitis associated with pulmonary hemorrhage after NDI exposure. Results Corresponding to case histories, extrinsic alveolitis on asthmatic reactions in three subjects and a rhinitis reaction in one patient could be reproduced by inhalative challenge tests to NDI at a concentration of 10 ppb. Preliminary IgE and IgG antibody analyses in patients' sera did not produce significantly positive results. Conclusions According to the outcome of our tests and in comparison with several other studies, we conclude that NDI should be classified as potent airway-sensitizing substance. Improved workplace conditions and decrease in threshold limit values should therefore be recommended. Am. J. Ind. Med. 39:369,372, 2001. © 2001 Wiley-Liss, Inc. [source]

Allergic and asthmatic reactions to alcoholic drinks: a significant problem in the community

CLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2008
H. Vally
No abstract is available for this article. [source]

CD4+ T cells from mice with intestinal immediate-type hypersensitivity induce airway hyperreactivity

CLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2007
C. Ozdemir
Summary Background A subset of food-allergic patients does not only respond clinically with symptoms in the gastro-intestinal tract but also with asthmatic reactions. Objective The aim of this study was to analyse whether CD4+ T cells from mice with intestinal immediate-hypersensitivity reactions to food allergen are involved in the development of experimental asthma. Methods BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA), followed by repeated intra-gastric (i.g.) OVA challenges. Control animals were either sham-sensitized or sham-challenged with phosphate-buffered saline (PBS). Duodenum, jejunum, ileum and colon were histologically examined. CD4+ T cells from mesenteric lymph nodes were transferred from various donor groups into recipient mice that received either OVA or PBS aerosol challenges. Recipients were analysed by measurements of lung function using head-out body-plethysmography and examination of broncho-alveolar lavage and lung histology. Results The highest levels of OVA-specific IgE antibody levels were detected in OVA-sensitized and OVA-challenged mice. Throughout the lower intestinal tract, a marked infiltration with eosinophils was observed, and goblet cell numbers as well as goblet cell area were significantly increased. The villus/crypt ratio was decreased compared with controls. The transfer of CD4+ T cells from mesenteric lymph nodes of OVA-sensitized and OVA-challenged mice triggered airway hyperreactivity and eosinophilic airway inflammation in recipients aerosol challenged with OVA, but not with PBS. Conclusion We conclude that CD4+ T cells from mesenteric lymph nodes of mice with allergen-induced immediate-type hypersensitivity reactions in the gut are able to transfer the phenotype of experimental asthma. [source]

The effects of T cell peptides in patients sensitive to cats

CLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 2004
Mark Larché
Summary Synthetic peptides representing T cell epitopes of the major cat allergen Fel d 1 were administered by intradermal injection or inhalation to cat allergic asthmatic volunteers. Both routes of administration were associated with the induction of IgE-independent, MHC-restricted isolated late asthmatic reactions (LAR; prolonged bronchoconstriction initiating 2,4 hours after peptide challenge) in a proportion of individuals. Administration via the intradermal, but not the inhaled route, was associated with the induction of antigen-specific hyporesponsiveness or "tolerance", both in vivo and in vitro. Following intradermal peptide administration, the magnitude of both the early- and late-phase skin reaction to intradermal challenge with whole allergen extract were significantly reduced. In vitro, proliferative responses of peripheral blood mononuclear cells (PBMC) were reduced together with both Th1 and Th2 cytokines. Production of IL-10 was increased. LAR were not a pre-requisite for the induction of tolerance. Hyporesponsiveness was transient but several months were required to return to basal reactivity. [source]