Asthma and Respiratory Immunology Flashcards
What are the main features of asthma?
Wheeze Bronchoconstriction Dry cough Sensitisation by allergens Reversible airflow obstruction Airway inflammation
What cells cause inflammation in asthma?
Eosinophils mainly
Type 2 lymphocytes
How do genes play a part in asthma?
There must be underlying genetic susceptibility- a lot of people are allergic but won’t develop asthma unless they have genetic susceptibility
Describe the basic pathophysiology of asthma
There is bronchoconstriction due to increased airway smooth muscle and allergen sensitisation, this causes a wheeze and narrowing of the lumen, which results in turbulent flow
How do we test for reversible flow obstruction?
Do spirometry
How will a flow volume loop of an asthmatic look different?
There right side of the peak in the positive axis will be more scooped
What is airway remodelling?
Change in the structural cells in the airway
What type of cells will the epithelium make more of in asthma?
Goblet cells
Smooth muscle cells
Matrix cells
What type of immunity is present in those with asthma?
Type 2
Describe an asthma flare up pathway starting at the asthmatic being exposed to an allergen
An antigen presenting cell takes up the antigen on the allergen
The APC displays the antigen on their MCH II
They carry this to the lymph nodes
Naive T0 cells in the nodes differentiate into Th2 cells
Th2 cells make IL 4, 13, 5
Interleukins recruit eosinophils to the airway and promote their survival
IL 13 is involved with causing IgE release from eosinophils
On second exposure to the allergen, IgE binds to mast cells
Mast cells release cytokines and chemokines
Eventually histamine is released and this is what causes an attack
What do APCs cause in lymph nodes in those with asthma?
The differentiation of naive t0 cells into th2 cells
In asthmatics what do th2 cells make?
IL 4, 13, 5
What recruits eosinophils to airways in asthma?
Interleukins produced by th2 cells
Which interleukin is involved in IgE release?
IL 13
What 2 tests can be done for asthma?
Skin prick
Blood tests