SM 176a - Asthma Flashcards
Which of the following statements best describes the pathologic findings of asthma?
- granulomatous airway inflammation
- eosinophilic inflammation with epithelial cell disruption
- perivascular mononuclear cell inflammation
- smooth muscle hypertrophy without inflammation
b. eosinophilic inflammation with epithelial cell disruption
How does diffucing capacity (DCLO test) change in a patient with asthma?
DLCO will be normal or slightly elevated
Elevation would be due to increased blood within the thoracic cage due to new vessel growth within airway walls
____% of the United States population has asthma
5** **% of the United States population has asthma
How is asthma diagnosed?
Rely on clinical features + physical exam findings
- Cough (may be the only symptom)
- Wheeze
- Breathlessness
- Chest tightness
- Colds that “go to the chest” and take >10 days to clear
- Worse at night or early in the morning
- Variable intenstity over time
Pulmonary function tests in asthma classically do NOT demonstrate:
- A concave or scooped expiratory flow volume loop
- Increased residual volume
- A normal or slightly elevated diffusing capacity for carbon monoxide
- A flattened inspiratory loop
d. A flattened inspiratory loop
Describe the basic steps in IgE synthesis, relevant to asthma
-
Eosinophils, Th2 lymphocytes, mast cells, and other inflammatory cells release inflammatory factors in response to an antigen
- Cytokines (IL-4, IL-5, IL-13), arachidonic acid metabolites, bradkykinins
- Transcription factors responsible for cytokine signaling are activated
- This promotes IgE production by plasma cells against the specific antigen
- The antigen binds to the IgE attached to a mast cell
- Degranulation and histamine release
- Production of IL-4, IL-5
- Promotes differentiation of mast cells and Th2 lymphocytes
- Perpetuates inflammation
What are the key effector cells in asthma?
Eosinophils
Eosinophils are recruited to the lungs by Th2 lymphocytes and mast cells
Which Th2 cytokines drive IgE production?
IL-4
IL-5
IL-13
All are released by Th2 Lymphocytes
What are the pathologic hallmarks of asthmatic airway remodeling?
- Thickened basement membrane
- Due to deposition of type III and IV collagen
- Smooth muscle hypertrophy and hyperplasia
- Goblet cel hyperplasia
Th1 and Th2 lymphocytes are in balance in normal, healthy people.
How does this balance change in people with atopic asthma?
Increase in Th2 lymphocytes
These cells, along with mast cells, recruit eosinophils to the bronchial mucosa
Eosinophils release histamine, leukotriene, and IL-5, and are the major effector effector cells in asthma
A 4-year-old presents with sudden onset respiratory distress. She is found to have unilateral wheeze with volume loss on the same side on chest X-ray.
The leading diagnosis in this case is:
a) asthma
b) vocal cord paralysis
c) tumor
d) foreign body aspiration
d) foreign body aspiration
Which cells release histamine in asthma inflammation?
Mast cells, eosinophils
What PFT findings are characteristic of asthma?
Decreased FEV1
Decreased FVC
Decreased FEV1/FVC
Why is bronchoprovocation testing performed on people with suspected asthma?
Lung function tests may be normal between asthma exacerbations
It is important to diagnose asthma if it is present, even in people who do not present with symptoms during their office visit
What chemical is used for bronchoprovocation testing?
Methacholine
