Asthma Flashcards
5 examples of relevance to asthma
- NHS spends £1 billion a year treating people with asthma
- Asthma is the most common chronic medical condition that complicates pregnancies
- 235 million people suffer with asthma
- Every ten mins someone is having a life threatening asthma attack
In 2016/17 there where 77124 hospital admissions caused by asthma in the uk
Asthma is a complex inherited disease what 5 chromosomes can be involved with this?
Chromosomes:
- 5
- 6
- 11
- 12
- 14
Why is Chromosome 5 the leading site for investigation in terms of asthma treatment?
Chromosome 5 has lots of Genesis that code for molecules in the inflammatory response seen in asthma, including:
- Cytokines
- Growth factors
- Receptors
However a gene for asthma has not been found here
The fundamental causes for asthma are not completely understood.
What is known to be cause of asthma ?
- Genetic pre- disposition
- environmental exposure to inhaled substances + particles that may provoke or irritate the airway such as:-
- Indoor allergens ( dust mites, stuffed furniture, pet hair)
- Outdoor allergens (pollen, mould)
- Smoke
7 factors that may be an irritant to the airways
- Chemical irritants
- Air pollution
- Cold air
- Extreme emotion ( anger or fear)
- Physical exercise
- Certain medication ie aspirin and beta blockers
Why may aspirin trigger asthma?
Can cause asthma attack because it acts as a deregulator of leukotrienes
What are leukotrienes?
Leukotrienes are substances in the body that cause inflammation
Why are beta blockers a trigger for asthma?
Beta blockers cause restrictions in the bronchial tree
- B2 receptors are located in the liver, LUNGS🫁 , muscles 💪, uterus, gastrointestinal tract and vascular smooth muscles 💪
What are cytokines, and Interleukins?
- Cytokines are proteins
- There are lots of different types
- Interleukins (IL)are a type of Cytokine
- Interleukins (IL) are any group of naturally occurring proteins that mediate (control) communication between cells
- Interleukins are important when stimulating an immune response such as inflammation
How do cells communicate?
- cells (in particular white blood cells) communicate via a group of ‘super family proteins’. AKA Cytokines
- Cytokines allow one cell to communicate with another to cause an action.
Major pathway in Asthma pathophysiology.
Pathway 1 - The TH2 (white blood cells) - The inflammatory response.
What happens
- Helper type 2 (TH2) cells are a specific type of white blood cell (AKA T cells)
- TH2 cells secrete interleukins (IL-4, IL-5, IL-9, IL-13, IL-17)
- These interleukins ( cytokines ) are inflammatory mediators
- In asthma the TH2 cell is inappropriately activated.
- Once activated TH2 cells release a variety of interleukins
- These interleukins cause eosinophils activation (IL-5) and promote mast cell activation (IL-9)
- Excessive TH2 type immune response causes alveoli inflammation and Asthma
Explain the inflammatory cascade… GO
- TH2 stimulation ( trigger is unknown)
- Cytokine/ Interleukin (IL-) released
- Causes white cell stimulation
- Causes more cytokines / interleukins to be released
- symptoms such as inflammation in the bronchial tree 🌳 become apparent
What do inflammatory mediators (interleukins) cause?
5 things
- Obstruction of the smooth bronchioles and terminal bronchioles
- Oedema (obstruction) of the airway
- Increased mucous secretion
- Cellular infiltration of the airway walls
- Injury + shedding of the airway epithelial cells
Sputum is characterised into two categories these are?
1) Charcot- Leyden Crystals - these consist of collections if bipyramidal crystalloid, and is made up of eosinophilic membrane proteins
2) Curschmann’s spirals - microscopic findings in the sputum of asthmatics. They are spiral shaped mucous plugs. They are formed in the sub- epithelial mucous gland ducts of the Bronchi
What is immunoglobulin E (IgE)
IgE is an antibody that destroys foreign objects (antigens) such as other antibodies
