Eosinophil infiltration of the mucosa is a feature of asthmatic airways. Their adhesion to bronchial epithelial cells has been proposed to lead to the generation of inflammation mediators which may contribute to asthma pathology. Bronchial epithelial cells (BEAS-2B cell line) and peripheral blood eosinophils were cultured alone or in combination and the production of an inflammatory cytokine, IL-6, was measured. IL-6 was produced principally by epithelial cells and the production was enhanced more than 10-fold in the presence of eosinophils. Significant augmentation of epithelial IL-6 production persisted even when eosinophils were fixed with paraformaldehyde. The eosinophil-induced IL-6 production was extensively inhibited by inhibitors of p38 mitogen-activated protein (MAP) kinase or nuclear factor ??B (NF??B). (more…)
Exacerbations of asthma are frequently associated with rhinoviral infection. Rhinoviruses infect respiratory epithelial cells, ...
Toll-like receptors (TLRs) act as receptors for numerous stimuli of immune cells, including bacterial cell wall constituents (l ...
Airway hyper-responsiveness in asthma may involve smooth muscle growth, a manifestation of airway remodelling. The involvement ...
Contact of pathogens with the innate immune system will most frequently occur at epithelia, and the biology of the airway epitheliu ...
Vascular Endothelial Growth Factor (VEGF), originally described as a vascular permeability factor generating tissue oedema, has be ...
Two long-acting ß 2 -adrenergic agonists (LABAs), salmeterol and formoterol, have been demonstrated to be safe and effective agents in children, both in terms of bronchodilation and prevention of exercise-induced bronchospasm. Their onsets of action differ, with formoterol having an onset similar to albuterol (3 minutes), while salmeterol has a slower onset of action (10–20 minutes). Following a single-dose administration, both agents demonstrate durations of action up to 12 hours. Following regular twice-daily administration, bronchodilation remains effective; however, a level of tolerance (or tachyphylaxis) (more…)
For most patients, asthma is not controlled as defined by guidelines; whether this is achievable has not been prospectively stu ...
This study evaluated budesonide formoterol efficacy and safety of a novel asthma management strategy for both maintenance and s ...
Asthma control is improved by combining inhaled corticosteroids with long acting beta-agonists but patients still require relie ...
Regular use of ß-agonists has been known to lead to tolerance to their bronchodilator effects. It is not known how quickly toleranc ...
Current internationally recognized guidelines indicate that symptomatic asthmatics using a low to medium inhaled corticosteroid ...
More severe asthma can persist from childhood into adulthood without remission. Another important tendency in the natural history is for symptoms to remit in adolescence only to return again in adulthood. In general, the amount of wheezing in early adolescence seems to be a guide for severity in early adult years, with 73% of those with few symptoms at age 14 years continuing to have little or no asthma progression at age 28 years. Similarly 68% of those with frequent wheezing at 14 years still suffered from recurrent asthma at age 28 years. Most subjects with frequent wheezing at 21 years continued to have comparable asthma at 28 years. In addition to the importance of symptoms in childhood, childhood degree of bronchial responsiveness in combination with a low FEV-1 were also related to the outcome of asthma in adulthood. (more…)
In the Tucson CRS study, about 50% of young children experienced a period of recurrent wheezing and/or coughing in the first 6 ...
Exposure and allergic sensitization to cockroach was associated with a significantly greater risk of asthma hospitalization and ...
With the help of well-trained and experienced pulmonary function technicians, children as young as 4 to 5 years of age should b ...
Asthma is a complex syndrome rather than a single disease entity. Different phenotypes with varying prognosis and determinants have ...
It is clear from the results of large epidemiologic studies that while atopy is a major risk factor for asthma, it is usually n ...
A role for Leukotriene B4 in the induction of airway hyper-responsiveness was explored through the use of transgenic mice deficient in the BLT1 receptor for LTB4 . Ovalbumin challenge of sensitized wild-type mice resulted in the usual features of experimental asthma, including goblet cell hyperplasia, hyper-responsiveness to inhaled methacholine and elevated BAL fluid concentrations of the Th2 cytokine IL-13. In contrast, BLT1 –/– mice (i.e. genetically modified mice lacking the gene coding for the BLT1 receptor) exhibited significantly lower responses. BLT1 –/– mice also exhibited lower numbers of IL-13-positive T lymphocytes of both the helper (CD4 T Cells) and cytotoxic/suppressor (CD8 + ) types. (more…)
Vascular Endothelial Growth Factor (VEGF), originally described as a vascular permeability factor generating tissue oedema, has be ...
Airway hyper-responsiveness in asthma may involve smooth muscle growth, a manifestation of airway remodelling. The involvement ...
IgE plays an important role in allergic asthma. Reducing IgE in the airway mucosa should reduce airway inflammation. Omalizumab has ...
Some features seem to be common to severe asthma and Chronic Obstructive Pulmonary Disease with reversibility of airflow limita ...
Antihistamines have been shown to be effective in seasonal allergic rhinitis and chronic idiopathic urticaria. They improve qua ...
Leukotrienes can be found in the airway and urine following both spontaneous exacerbations of asthma and acute exposure to bronchoconstrictor stimuli in the laboratory. This in turn indicates that they may have a role in the pathogenesis of acute episodes of bronchoconstriction. Although antileukotrienes are not currently advocated in the management of acute asthma, there are data to suggest that they might be of some potential benefit. Prior treatment with montelukast asthma has been shown in several studies to significantly shorten the time taken to recover (in terms of FEV 1 ) following exposure to a bronchoconstrictor stimulus. (more…)
Despite optimum drug delivery and good compliance with inhaled corticosteroids, many patients experience symptoms and exacerbat ...
Current internationally recognized guidelines indicate that symptomatic asthmatics using a low to medium inhaled corticosteroid ...
The prevalence of aspirin-sensitive asthma is uncertain although it may exist in up to 20% of all asthmatics patients. The char ...
Montelukast has proven efficacy in the treatment of chronic asthma and seasonal allergic rhinitis, but it has not been evaluate ...
The guidelines for asthma management recommend the use of regular inhaled corticosteroid in patients with mild persistent asthma, b ...
Current internationally recognized guidelines indicate that symptomatic asthmatics using a low to medium inhaled corticosteroid dose (400–800 µg/day of beclomethasone or equivalent) alone should preferentially be commenced on a long-acting agonist ß2 prior to an leukotriene receptor antagonists LTRA (British guideline on the management of asthma 2003; GINA Workshop Report 2004). However, two recent large trials have performed head to-head comparisons of add-on long-acting ß2 agonist versus LTRA as therapeutic adjuncts to inhaled corticosteroids, using exacerbation frequency (rather than lung function and symptoms) as the primary end point. (more…)
Leukotrienes can be found in the airway and urine following both spontaneous exacerbations of asthma and acute exposure to bron ...
Despite optimum drug delivery and good compliance with inhaled corticosteroids, many patients experience symptoms and exacerbat ...
Two long-acting ß 2 -adrenergic agonists (LABAs), salmeterol and formoterol, have been demonstrated to be safe and effective ag ...
Treating allergic rhinitis may have a downstream effect on concomitant asthma and this may be due to attenuation of the underlying ...
Regular use of ß-agonists has been known to lead to tolerance to their bronchodilator effects. It is not known how quickly toleranc ...
Two main strategies have been developed to block the effects of cysteinyl leukotrienes in the airway. One method is to use drugs that prevent their synthesis (using a 5-lipoxygenase inhibitor) and the other involves interfering with the binding of cysteinyl leukotrienes to their cellular receptor using a leukotriene receptor antagonist (LTRA). (more…)
Leukotrienes can be found in the airway and urine following both spontaneous exacerbations of asthma and acute exposure to bron ...
Antihistamines have been shown to be effective in seasonal allergic rhinitis and chronic idiopathic urticaria. They improve qua ...
The cysteinyl leukotrienes (LTC 4 , LTD 4 and LTE 4 ) are lipid mediators produced from an arachidonic acid precursor following ...
A variety of proinflammatory cells, mediators, and cytokines orchestrate the development of airway hyperresponsiveness, which r ...
The prevalence of aspirin-sensitive asthma is uncertain although it may exist in up to 20% of all asthmatics patients. The char ...
The immunologic mechanisms of sublingual immunotherapy are less established. In Cochrane analysis, the authors concluded that there was an increase in IgG4 but no stable effect on IgE levels in adults. In addition, the induction of allergen-specific IgA has been reported. There are conflicting data concerning lympho-proliferative responses. So far the evidence on changes in Th1/Th2/Treg activity induced by sublingual immunotherapy need to be confirmed. The effects on T-cell reactivity and cytokine secretion show strong variation in a number of studies. (more…)
Allergen-specific immunotherapy aims to correct the underlying immune imbalance associated with specific immunotherapy allergic rhi ...
The precise mechanisms underlying the effects of Specific Immunotherapy are not well understood but several studies have shown ...
The increasing prevalence of allergic disease in the Western world has led to the concept of the ‘allergic march’ to describe t ...
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunc ...
Histamine is a low-molecular-weight monoamine that binds to four different G-protein-coupled receptors, and has recently been d ...
Treg cells or regulatory T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated immune response appears to be an important pathogenetic factor. Cardinal events during allergic inflammation can be classified as activation, organ-selective homing, survival and reactivation, and effector functions of immune system cells. T cells are activated by aeroallergens, food antigens, autoantigens, and bacterial exotoxins superantigens in allergic inflammation. They are under the influence of the skin, lung, or nose-related chemokine network and show organ-selective homing. (more…)
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunc ...
The induction of immune tolerance and specific immune suppression are essential processes in the control of immune responses. R ...
The intracellular forkhead winged transcription factor Foxp3 (forkhead box P3) appears to be specifically expressed by naturall ...
An emerging concept is that pro-inflammatory signals lead to loss of Regulatory T Cells (Treg) function. Pasare and Medzhitov ( ...
Regulatory T cells Treg (picture above) is the existence of suppressor cells, which limit ongoing immune responses and prevent ...
The cysteinyl leukotrienes (LTC 4 , LTD 4 and LTE 4 ) are lipid mediators produced from an arachidonic acid precursor following a series of enzymatic steps. Arachidonic acid is firstly released from the phospholipid bilayer by phospholipase A 2 and may be metabolized by either the cyclooxygenase (COX) or 5-lipoxygenase pathway. Once the unstable precursor LTA 4 has been produced, it may be converted in neutrophils or monocytes to the noncysteinyl LTB 4 by LTA 4 hydrolase. In mast cells, eosinophils, macrophages, and basophils, LTA 4 may alternatively be converted into LTC 4 by LTC 4 synthase and subsequently into LTD 4 and LTE 4. (more…)
The prevalence of aspirin-sensitive asthma is uncertain although it may exist in up to 20% of all asthmatics patients. The char ...
Some features seem to be common to severe asthma and Chronic Obstructive Pulmonary Disease with reversibility of airflow limita ...
A variety of proinflammatory cells, mediators, and cytokines orchestrate the development of airway hyperresponsiveness, which r ...
Leukotrienes are present in increased amounts in exhaled breath condensate (EBC) in patients with asthma. So far, no data have ...
Two main strategies have been developed to block the effects of cysteinyl leukotrienes in the airway. One method is to use drug ...