Search results for "provocation"
showing 10 items of 67 documents
Urtica dioica pollen allergy
2016
Abstract Background The most emblematic members of Urticaceae at allergic risk level are wall pellitories ( Parietaria ), whereas nettle ( Urtica ) pollen is considered as poorly allergenic. No allergen from nettle pollen has yet been characterized, whereas 4 are listed for Parietaria pollen by the International Union of Immunological Societies. Clinical and biological profiles of 2 adult men who developed symptoms against nettle pollen and/or leaves were studied. Objective To characterize the allergic reaction and identify the potential nettle pollen sensitizing allergens. Methods IgE-mediated reaction to nettle pollen extract was evaluated by skin prick test, immunoassay, nasal provocatio…
Bronchial reactivity and intracellular magnesium: a possible mechanism for the bronchodilating effects of magnesium in asthma
1998
1.Increased bronchial smooth muscle contractility with consequent bronchial hyperreactivity are characteristic physiopathological events of asthma. Since magnesium intervenes in calcium transport mechanisms and intracellular phosphorylation reactions, it constitutes an important determinant of the contraction/relaxation state of bronchial smooth muscle. In the present study we investigated the relationship between bronchial reactivity, assessed by methacholine-provocation test, and magnesium concentrations both at extracellular and intracellular levels measured by spectrophotometry. Twenty-two patients with mild-to-moderate asthma and 38 non-asthmatic subjects with allergic rhinitis (24 all…
Effects of allergen exposure on methacholine and AMP-induced air trapping in pollen-sensitive subjects
2011
Summary Background The effect of pro-inflammatory stimuli on bronchoconstrictor-induced air trapping has not been studied. Objective To determine the effect of natural allergen exposure, a pro-inflammatory stimulus, on methacholine- and adenosine 5′-monophospate (AMP)-induced air trapping. Methods Airway responsiveness to methacholine and AMP before and during the pollen season was obtained in 25 subjects with pollen allergy and in 10 healthy controls. The response was expressed by the sensitivity (PC 20 value) and by the slope and intercept of the FVC values recorded at each step of the challenge against the corresponding FEV 1 values. Results The slope and intercept FVC versus FEV 1 value…
Correlation of Skin Test Results and Specific Immunoglobulin E Blood Levels with Nasal Provocation Testing for House-Dust Mite Allergies
2016
Background Allergen-specific immunotherapy for house-dust mite (HDM) allergies is associated with lower success rates when compared with similar treatments for other inhalant allergens, such as grass or birch. One reason might be the greater difficulty in diagnosing patients with assumed HDM allergies because symptoms occur perennially and may differ from those of a conventional allergic rhinitis. Objective The aim of the study was to compare the different methods of diagnosis in patients with assumed HDM allergy. Methods We performed a retrospective analysis of nasal provocation tests (NPT) from patients (n = 161) evaluated for Dermatophagoides pteronyssinus (n = 127) and Dermatophagoides …
Is Quantitative sIgE Serology Suitable for Distinguishing Between Silent Sensitization and Allergic Rhinitis to Dermatophagoides pteronyssinus?
2019
BACKGROUND AND OBJECTIVE An increasing number of studies have recently discussed whether provocation tests might be replaced by specific IgE serology in patients sensitized to airborne allergens. Objective: Our study aimed to analyze the concordance between a nasal provocation test with Dermatophagoides pteronyssinus and specific IgE measurements based on real-life data. METHODS We retrospectively analyzed concordance between the result of the provocation test and the IgE titer for house dust mite components and extracts in 223 patients with proven sensitization to D pteronyssinus. RESULTS In contrast to findings from other studies, the anti-Der p 1 level alone was not sufficient to disting…
The effect of short-term immunotherapy with molecular standardized grass and rye allergens on eosinophil cationic protein and tryptase in nasal secre…
1999
Activation of mast cells and eosinophils under pollen exposure can be inhibited by specific immunotherapy.The effect of short-term immunotherapy with 7 preseasonal injections of molecular standardized allergens from grass and rye pollen on eosinophil cationic protein (ECP) and tryptase levels in nasal secretions has been compared with symptomatic drug treatment in an open, randomized study with 48 patients.Nasal reactivity and mediator levels in nasal secretions were measured at baseline, before season, in season, and after season.Symptom scores in the immunotherapy group were 134.5 (95% CI, 65 to 336) versus 386. 0 (95% CI, 185 to 563), significantly lower as in the drug-treated group. ECP…
Agreement in Asthmatics' Perception of Dyspnea During Acute and Chronic Obstruction
2005
Objective Three types of asthmatic patients can be identified during periods of clinical stability: “poor perceivers,” “normal perceivers,” and “over perceivers.” When asthmatics undergo bronchial challenge in the laboratory, the same distinctions in type of perception can be observed. The aim of the present study was to determine the level of agreement between the 2 situations. Patients and methods A total of 93 patients with persistent moderate asthma (36 men and 57 women; mean age 40 years) were studied. We asked them to assess their dyspnea on a modified Borg scale when stable and after each histamine dose in a bronchial provocation test. When a patient's Borg scale assessment in stable…
Potent bronchoprotective effect of deep inspiration and its absence in asthma
2000
In the absence of deep inspirations, healthy individuals develop bronchoconstriction with methacholine inhalation. One hypothesis is that deep inspiration results in bronchodilation. In this study, we tested an alternative hypothesis, that deep inspiration acts as a bronchoprotector. Single-dose methacholine bronchoprovocations were performed after 20 min of deep breath inhibition, in nine healthy subjects and in eight asthmatics, to establish the dose that reduces forced expiratory volume in 1 s by >15%. The provocation was repeated with two and five deep inspirations preceding methacholine. Additional studies were carried out to assess optimization and reproducibility of the protocol …
Bronchoconstriction induced by inhaled adenosine 5′-monophosphate in subjects with allergic rhinitis
2001
Adenosine and its related nucleotide, adenosine 5′-monophosphate (AMP) induce bronchoconstriction in asthmatics, probably caused by histamine release from airway mast cells. The objective of this study was to determine the effect of inhaled AMP on lung function in subjects with allergic rhinitis.A total of 52 adults (28 subjects with allergic rhinitis, 14 asthmatics and 10 healthy subjects) were challenged with increasing concentrations of AMP and methacholine. Airflow was assessed after each concentration and the response to each bronchoconstrictor agent was measured by the provocative concentration required to produce a 20% fall (PC20) in forced expired volume in one second (FEV1).All 14 …
Airway Responsiveness to Inhaled Acetaldehyde in Subjects with Allergic Rhinitis: Relationship to Methacholine Responsiveness
2002
<i>Background:</i> Asthmatic subjects have an exaggerated airway response to inhaled acetaldehyde, but no information is available on airway responsiveness to this bronchoconstrictor agent in subjects with allergic rhinitis. <i>Objective:</i> The aim of this study was to determine the effect of inhaled acetaldehyde on lung function in nonasthmatic subjects with allergic rhinitis. <i>Methods:</i> A total of 78 adults (43 subjects with allergic rhinitis, 16 asthmatics and 19 healthy subjects) were challenged with increased concentrations of acetaldehyde and methacholine. The response to each bronchoconstrictor agent was measured by the provocative concentra…