Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1B Cardiorespiratory > Asthma and Respiratory Immunology > Flashcards

Asthma and Respiratory Immunology Flashcards

1
Q

what are the cardinal features of asthma?

A
  • Wheeze +/- dry cough- on exertion, worse with colds, with allergen exposure- most important
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the tests for asthma?

A
  • Atopy/ allergen sensitisation
  • Reversible airway obstruction
  • Airway inflammation
    • Eosinophilia
    • Type 2- lymphocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the pathophysiology of asthma?

A
  • Reversible airway obstruction
    • Thickened airway due to increased smooth muscle and inflammation

Wheeze due to narrow airway causing turbulent airflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what can be used to determine airway flow?

A

spirometry

red- mornal, black= asthma

asthmatics can change from black to red with treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the pathogenesis of allergic asthma?

A

asthma requires genetic susceptibility to develop allergic disease rather than an allergy

If have the susceptibility when exposed to allergen/infection/pollution causes allergy, reversible airflow obstruction and inflammation

Genome studies have shown there are specific genes increased in the expression of asthma (GSDMB and IL33)

  • Polygenic disease so gene therapy not a solution for asthma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what immune respone is generated in allergic asthma?

A

Type 2 immunity in allergic asthma:

  1. Exposed to inhaled allergy (antigen)
  2. Presented to APC- dendritic cells in lungs
  3. Carry antigen via MCHII to mediastinal lymph nodes where naive Th0 cells differentiate into Th1 and Th2 cells
  4. Th2 cells secrete cytokines IL4,5 and 13
  5. IL-5 recruits eosinophils into airways and promotes eosinophil survival
  6. IL-4 helps conversion plasma cells or B-cells to secrete an IgE
  7. IL-3 is involved in mucus secretion
  8. When exposed to same allergen again will recognise and produce allergic response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how can you test for allergic sensitisation?

A
  • Intradermal injection of positive control (histamine) and saline (negative control) and compare to allergens
  • Will develop a wheal and flare reaction and measure size of wheal to determine whether sensitized
  • Can look in blood for specific IgE antibodies to allergens of interest
  • Total IgE alone not sufficient to define atopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how can you test for eosinophilia?

A
  • Blood eosinophilia count when stable
    • >300 cells/mcl is abnormal
  • Induced sputum eosinophilia count
    • >2.5% eosinophils is abnormal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the allergen pathway to allergic asthma?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what can be used as a biomarker for type 2 inflammation?

A

exhaled nitric oxide

diagnosis

  • fractional concentration of exhaled nitric oxide (FeNO) is a quantative, non-invasive and safe measure of airway inflammation
  • indirect marker of T2-high eosinophilic airway inflammation in asthma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what can be measures for adherence and steroid response?

A
  • FeNO has a role in aiding asthma diagnosis, predicting steroid responsiveness and assessing adherence to inhaled corticosteroids
  • Elevated if not taking medication (steroids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the order of tests in allergic asthma?

A
  1. Spirometry
  2. Repeat tests every 6 to 12 months and treat on observation if unable to perform spirometry
  3. Exhaled nitric oxide if diagnostic uncertainty remained after spirometry and BDR
  4. If diagnostic uncertainty after FeNO, monitor peak flow variability for 2-4 weeks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what results on objective tests indicate asthma?

A
  1. airway obstruction on spirometry
    1. FEV1/FVC ration <0.7
  2. reversible airway obstruction-bronchdilator reversibility >12%
  3. exhaled nitric oxide (FeNO)
    1. >35ppb (children)
    2. >40ppb (adults)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the management of asthma?

A
  1. Reduce airway eosinophilic inflammation
    1. Inhaled corticosteroids (ICS)- target eosinic inflammation
    2. Leukotriene receptor antagonists -reduce type 2 inflammation
  2. Acute symptomatic relief
    1. Beta-2-agnosts (smooth muscle relaxation)
    2. Anticholinergic therapies (smooth muscle relaxation)- ipratropium bromide
  3. Severe asthma- steroid sparing therapies
    1. Biologic targeted to IgE
      1. Anti-IgE antibody
    2. Biologics targeted to airway eosinophils
      1. Anti-interleukin-5 antibody
      2. Anti-interleukin-5 receptor antibody

Must give a preventative and then give an as needed bronchodilator- do not give bronchodilators only!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the mechanism of action of corticosteroids?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the pathogenesis of an acute lung attack?

A
17
Q

how does Anti-IgE antibody therapy work?

A
  • Humanised anti-IgE monoclonal antibody
  • Bind and captures circulating IgE – to prevent interaction with mast cells and basophils to stop allergic cascade
  • IgE production can decrease with time when patients given anti-IgE Ab
  • Reduction in serum IgE over time means the therapy may not need to be used indefinitely
  • No evidence yet that stopping anti-IgE Ab after some time is a long-term solution
  • Example= omalizumab
18
Q

what does a prescription of omalizumab require?

A
  • severe, persistent allergic asthma in patients >6 yrs who need continuous of frequent treatment with oral corticosteroids
  • total serum IgE between 30-1500
  • Dosing based on weight and serum IgE 2-4 weekly s/c injections
    • Min 75mg 4 weekly = £1,665 /patient/year
    • Max 600mg 2 weekly = £26,640 /patient/year
19
Q

how does an anti-IL5 antibody work?

A
  • IL-5 = eosinophil recruitment, growth, activation and prolonged survival
    • Steroid decrease eosinophil recruitment and promote apoptosis
20
Q

what anti-IL5 antibody is used during asthma?

A

mepolizumab

  • Anti- IL5 antibody for severe eosinophilic asthma
    • Blood eosinophils >300 cells/mcl in last 12 months
    • At least 4 exacerbations requiring oral steroids in last 12 months
    • Trial for 12 months- if 50% reduction in attacks then continue
      • Characteristics of responders:
        • Elevated blood eosinophils
        • Number of previous exacerbation
        • Dose of inhaled steroids
  • Licenced for adults and children >6 years

1B Cardiorespiratory (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions