Asthma Oct13 M3 Flashcards
asthma broad causes
genetic predisposition and environmental exposure
asthma 2 components and main one
main: airway inflammation, causes obstruction
some have bronchial hyperresponsiveness
affected of asthma worldwide
300M
3 consequences of the chronic inflammation in asthma
- obstruction
- leads to airways irritability (hyperresponsiveness)
- injures the airways
asthma: first step to triggering
inhale something from environment, goes to epithelial lining of airways
what happens to pollutant in epith lining of airways and after
picked up by dendritic cell + presented to other inflammatory cells
what inflammatory cells the dendritic cell presents antigen to
lymphocytes, T lymphocytes in particular
what T lymphocytes do after antigen is presented
differentiate in diff types and cells
what TH2 cells do
T helper cell, liberate IL4,5,13 which stimulte other cells like B cells
what is special about the TH2 pathway
characteristic of allergic reaction
what B cells do once activated by ILs
produce IgE which stimulates mast cells, eosinophils, basophils
what mast cells, eosinophils, basophils do once stimulated by IgE
produe other ILs to keep pathway going
other proteins the stimulant can stimulate
IL33, IL35, TSLP (thymic stromal lymphopoeitin) which also stimulate inflamm response
Other response (than TH2) in asthma and what it does
TH17, produces IL17 to stimulate neutrophils
characteristic of neutrophils in the TH17 response
Are not reponsive to steroids
what inflamm mediators of asthma are steroid sensitive
all except Th17 and neutrophils
other component of asthma, what happens to SM
hypetrophy and hyperplasia of SM: excess bronchoconstriction
when suspect asthma
cough, wheeze (+ after excersie, + prolonged after infection, +at night, + when exposed to pollutant)
number 1 trigger for asthma
human rhinovirus (and other resp tract infections)
how is asthma diagnosed (4)
clinical, lung function, airway responsiveness, sputum to check inflamm status
lung function test done at home to test for asthma
blow in machine to get peak flow and check how it varies with time. more than 20% variability = asthma
something necessary when diagnosing asthma and why
spirometry. without it, wrong 30% of the time
criteria for improvement of of FEV1 with bronchodilator to diagnose asthma
at least 12% increase and at least 200 ml increase in 30 minutes
criteria for FEV1 improvement if asthma when given antiinflamm therapy over multiple days
20% and 250 mL improve in FEV1
