Alpha-1 antitrypsin deficiency Flashcards
what type of enzyme is neutrophil elastase?
chymotrypsin protease
effect of neutrophil elastase on lung tissue?
eats elastin
what triggers neutrophil elastase?
- 2 common things
infection & smoking
what is Alpha-1 antitrypsin?
an antiprotease
what does Alpha-1 antitrypsin stop and thus protect?
stops neutrophil elastase
protects lung tissue
A1AT deficiency causes what most commonly?
emphysema
A1AT is caused by mutation to what gene on what chromosome?
SERPINA 1 gene
Chromosome 14
A1AT deficiency is recessive or dominant?
recessive
how does smoking cause emphysema?
Smoke –> inflammatory cytokine –> neutrophils released into lung –> activates neutrophil elastase –> this eats up the lung tissue –> emphysema
which granulocyte activates neutrophil elastase?
neutrophils
how does smoking release neutrophil elastase?
Smoke –> inflammatory cytokine released –> trigger neutrophil release –> neutrophil elastase released
how does smoking increase activity of neutrophil elastase?
smoke –> ROS made –> deactivated alpha 1AT –> increases neutrophil elastase activity.
pt has A1AT deficiency.
main CXR finding?
big black chest
Ix?
- 3 main ones
- state the Ix and +ve finding
Plasma A1AT – low
Spirometry – obstructive low FEV1
CXR – big black lungs
pt has A1AT deficiency.
why might you do CT scan?
look for bronchiectasis.
