Pathology: Obstructive Lung Disease 2

Question 1

Define asthma

Answer 1

Recurrent attacks of wheezing, coughing and dyspnea

(atopic & non-atopic; obstructive & inflammatory disease)

Question 2

Describe the path of physiology of asthma

Answer 2

Increased Airway responsiveness to a variety of stimuli → episodes of inflammation, bronchospasm and increased mucus secretion

Question 3

Atopic Asthma is _______ mediated

Answer 3

IgE (TYPE I HYPERSENSITIVITY)

Question 4

How is a topic asthma diagnosed?

Answer 4

1. Skin test: wheal & flare reaction
2. Immunoassay: IgE Ab specific

Question 5

Non-atopic asthma is triggered by ______

Answer 5

viral infection

(inhaled irritants, cold or exercise may exacerbate sx)

Question 6

Allergens are presented to CD4 T cells, which then differentiates into ______ or ______.

Answer 6

• T_H1
• T_H2 (typically hypersensitivity)

Question 7

Differentiation of a CD4 T-cell into a T_H2 cell can secrete IL-4 causing an induction of ______.

Answer 7

Antibody production by B cells (type 1 hypersensitivity)

(atopic asthma patients have a genetic propensity to respond to Ag this way)

Question 8

If a T_H2 cell secretes IL-4, IgE will be produced from B cells. IL-5 will trigger _____.

Answer 8

Eosinophil recruitment → activation of degranulation → inflammation

(sensitization phase of asthma)

Question 9

In immediate phase atopic asthma, the mast cell degranulation mediators open tight junctions between epithelial cells → antigen enters mucosa → activates mucosal mast cells and eosinophils, releasing more mediators. Collectively, either directly or via neuronal reflexes, the mediators induce _______ (3) and recruit additional mediator-releasing cells from the blood.

Answer 9

1. bronchospasm
2. increased vascular permeability
3. mucus production

Question 10

Some of the most important mediators involved in eliciting these inflammatory responses (seen in atopic asthma) are ______ (2)

Answer 10

1. Leukotrienes C4, D4, E4
2. acetylcholine released from vagal efferent nerve fibers

Question 11

How is the epithelium damaged from atopic asthma?

Answer 11

recruitment of leukocytes → release major basic protein & eosinophil cationic protein

Question 12

Polymorphisms associated with which genes increase risk of asthma?

Answer 12

1. IL-4
2. IL-13
3. ADAM₃₃
4. B₂-adrenergic receptor

Question 13

IL-13 polymorphisms stimulate ________ (2)

Answer 13

1. Mucus secretion
2. IgE production

Question 14

ADAM₃₃ polymorphisms stimulate ______ (2).

Answer 14

1. proliferation of bronchial smooth muscle cells
2. fibroblasts

Question 15

B₂-adrenergic receptor polymorphisms decrease _______ and increase _______.

Answer 15

• response to B2 agonists
• tendency for bronchospasm

Question 16

What are the physiologic changes associated w/asthma (3)?

Answer 16

1. hypertrophied/hyperplasia of mucous glands
2. inflammation: lymphocytes, MF and mast cells
3. smooth muscle hypertrophy

(chronic bronchitis same, but has squamous metaplasia instead of smooth muscle)

Question 17

How is asthma diagnosed (3)?

Answer 17

1. Prolonged expiration, decreased FEV₁
2. Increased eosinophil count & IgE levels
3. Sputum: eosinophils/Charcot-Leyden crystals & Curschmann spirals

Question 18

Asthma used to be called _______

Answer 18

status asthmaticus