Pathophysiology of asthma Flashcards
What type of disease is asthma?
Asthma is a chronic, inflammatory and obstructive disease of the airways
Steps involved from inflammation to airways dysfunction in asthma
- Allergen inhalation, exercise
- Immune system response
- Airway inflammation
- Impaired airway function
- Symptoms:
- Wheeze
- Cough
- Dyspnoea
Who are more likely to develop asthma?(Genetics)
Parental asthma Susceptibility genes(ADAM33)
Who are less likely to develop asthma?(Genetics)
No parental asthma Protective genes(GSPT1+)
Who are more likely to develop asthma?(Immunological development)
Infant respiratory virus infection
Modern hygiene
Caesarean delivery
Who are less likely to develop asthma?(Immunological development)
Helminth exposure
Healthy microbiota
Vaginal delivery
Older siblings
Who are more likely to develop asthma?(Lifestyle)
- Urban dwelling
- Pollution
- Poor diet
- Obesity
Who are less likely to develop asthma?(Lifestyle)
- Rural dwelling
- Lower pollution environment
- Healthy diet
What do allergic responses require?
Allergic responses require prior exposure and sensitization
Steps involves in allergen sensitization
- Allergen exposure
- Allergen encountered and processed by adaptive immune system
- Antibodies generated, immune system primed
What does allergen sensitization lead to and what are the steps involved in that?
- Leads to an allergic response
- Steps involved:
- Subsequent allergen response
- Allergen binds antibodies(Immune cell activation and inflammatory response)
- Leads to symptoms
What does sensitization involve?
Sensitization involves presentation of antigen to T cells and B cell-Ab production
What is the asthmatic immune response triggered by?
-Triggered by allergen-induced degranulation and airway inflammation
What are the steps involved in an asthmatic response?
- Allergen inhaled, enters airway tissue
- Allergen binds and cross-links IgE Abs on mast cells, inducing degranulation
- Eosinophils and Th2 cells are both recruited
- Recruitment of eosinophil to airways release further mediators and ROS
- Degranulation and recruitment of eosinophils lead to the contraction of smooth muscles, excess muscle secretion and oedema
What can an asthmatic response to an allergen have?
Can have early and late phases
