Asthma Flashcards
Most common allergen to trigger asthma
Dermatophagoides species
Most common triggers of acute severe exacerbations
RSV,Rhinovirus, Coronavirus
Trigger of asthma that is linked to hyperventilation which results in increased osmolality in airway lining fluid and triggers mast cell mediator release resulting in bronchoconstriction..
Exercise
Asthma trigger that is used as a food preservative which may trigger asthma through the release of sulfur dioxide gas in the stomach
Metabisulfite
Dendritic cells
Specialized macrophage-like cells in the airway epithelium, which are the major antigen-presenting cells.
Which phenotype predominates in asthma? TH2 or TH1?
TH2 phenotype
TH2 cytokines that mediate allergic inflammation
IL-4, IL-5, IL-9, IL-13
Risk Factors and Triggers Associated with Asthma
Inflammation in the airways of asthmatic patients leads to airway hyperresponsiveness and symptoms
Which interleukin induces airway hypersecretion in experimental models of asthma?
IL-13
Limitation of airflow is mainly due to? What is the effect in FEV1/FVC ratio and PEF (peak expiratory flow)?
Bronchoconstriction( from mast cell mediators)
What are the characteristic symptoms of asthma?
Wheezing, dyspnea, and coughing, which are variable, both spontaneously and with therapy
Lung function tests (spirometry) in asthma
reduced FEV1, FEV1/FVC ratio, and PEF
Reversibility is demonstrated by a >12% and 200-mL increase in FEV1 15 min after an inhaled short-acting β2-agonist (SABA; such as inhaled albuterol 400 μg) or in some patients by a 2–4 week trial of oral corticosteroids (OCS) (prednisone or prednisolone 30–40 mg daily
Skin prick tests to common inhalant allergens (house dust mite, cat fur, grass, pollen) are _________in allergic asthma and _________ in intrisic asthma
Positive, Negative
*NOT helpful in diagnosis
What is now used as a noninvasive test to measure eosinophilic airway inflammation?
Fractional exhaled Nitric oxide (FeNO)
These act primarily on airway smooth muscle to reverse the bronchoconstriction of asthma.
Bronchodilators
What are the three classes of bronchodilators?
B2 adrenergic agonists, anticholinergics, theophylline.
What are the aims of asthma therapy?
Mechanism of B2 agonist
B2 Agonists activate B2 adrenergic receptors, which are widely expressed in the airways. B2 receptors are coupled through a stimulatory G Protein to adenylyl cyclase, resulting in AMP, which relaxes smooth muscle cells and inhibit cerain inflammatory cells, particularly mast cells.
What are the other additional non-bronchodilator effects that may be clinicaly useful in B2 agonists?
- Inhibition of mast cell mediator release
- Reduction in plasma exudation
- Inhibition of sensory nerve activation