allergy and asthma Flashcards
extreme form of asthma
anaphylaxis
what is atopy
genetic tendency to develop allergic diseases
type types of asthma
1) immediate hypersensitivity
2) delayed type hypersesitivity
(how fast does it occur, what molecule is it mediated by, example of what casues reaction)
1) minutes to hours
-mediated by IgE
e.g. hay fever and food allergies
2) 2-3 days
-mediated by T cells
e.g. poison ivy
function of T helper 2 cells
-main cytokine in positive feedback loop which activates TH2
-what cytokines drive TgE class swithcing
-what cytokine increases eosinophil production in bone marrow
-what cytokine increases mucous production
-mediates allergy by IL-4 positive feedback loop
-IL-4 and il-13 drives IgE
-IL-13 increases mucous production
-IL-5 increases eosinophil production in bone marrow
B cells can switch their constant domains
-antibodies of naive cells
-antibodies of activated/ memory B cells after class swithcing
naive= igM and IgD
activated/ memory = IgG, IgA, IgE
what cytokine help B cells turn into plasma cells
Il-4 and IL-13
what drives allergy symptoms?
what does histamine do?
mast cell degranulation which releases of granules that contain histamine
-histamine increases vascular permeability leading to swelling. smooth muscle contraction which increases heart rate and gastric secretion
prevention of anaphlyaxis
-how this device works
epi pen: epinephrine (adrenaline) device enables rapid delivery and prevents histamine release reducing vasoconstriction
the difference between allergic rhinitis and asthma
-what does it effect
-the response to antihistamine
rhinitis=affects upper respiritory tract.
- responds to anti histamine treatment e.g. pollen/dust
can be seasonal or present all year round
asthma= effects lower airways
-no benefit with anti histamine
-allergic trigger known as cat danger
-mild to severe symptoms
different types of asthma:
type 1 high asthma and
type 2 low asthma
-trigger
-causation
-late or early onset
-treatment
type 2 high asthma:
trigger= allergens and cytokine IL-33
causation= immune dominated with Th2 cells, eosinophils and igE bound mast cells
-allergic responses, early age onset
-treated with steroids
type 1 low asthma
trigger= viruses and pollution. epithelial cells damaged produe chemokine that attracts neutrophil and IL-1b and IL-6
causation= immune domination by neutrophils
-late onset and linked to obesity
-does not respond to steroids
function of eosinophils and other type 2 cells
release type 2 cytokine that drives smooth muscle contraction and mucous production
function of neutrophils
produce reactive ocygen species and elastase that casue epithelila cell damage and mucous release
treatment for type 2 asthma
-inhaled corticosteroids
-effective anti-inflammatory agent
-steroids induce eosinophil apoptosis
