Vasculitis (systemic vasculitides) Flashcards
What are systemic vasculitides
Autoimmune mediated inflammation of blood vessels –> BV necrosis
There are pauci-immune variants
Pathognomonic features of systemic vasculitides
- Fibrinoid necrosis of BV wall
- Karyorrhexis of BV wall
- RBC extravasation
How are systemic vasculitides classified
Large, medium, small vessel vasculitides
- What are ANCAs?
- What are the 2 types of ANCAs?
- How do they relate to vasculitides?
- Anti-neutrophil cytoplasmic antibodies
- c-ANCA = cytoplasmic
p-ANCA = perinuclear - small vessel vasculitides are classified into ANCA + non-ANCA mediated
Give an important example of a large vessel vasculitis
Giant cell arteritis (GCA)
GCA pathophysiology
DCs attract CD4 cells to arteries via vasa vasorum where they become active + undergo clonal expansion. They activate tissue macrophages in the media which:
(1) release cytokines –> systemic inflammation
(2) MMP + ROS release –> oxidative stress –> destruction of internal elastic lamina –> media + intima separate
(3) form multinucleate giant cells (IFNg, IL1, IL6)
Damaged blood vessels respond by releasing VEGF/PDGF –> new blood vessel formation + intimal thickening –> luminal narrowing –> ischemia –> symptoms
GCA pathophysiology
DCs attract CD4 cells to arteries via vasa vasorum where they become active + undergo clonal expansion. They activate tissue macrophages in the media which:
(1) release cytokines –> systemic inflammation
(2) MMP + ROS release –> oxidative stress –> destruction of internal elastic lamina –> media + intima separate
(3) form multinucleate giant cells (IFNg, IL1, IL6)
Damaged blood vessels respond by releasing VEGF/PDGF –> new blood vessel formation + intimal thickening –> luminal narrowing –> ischemia –> symptoms
GCA clinical Px
F > M (2:1)
typically >50yo
(1) Headache (new onset + scalp tenderness)
(2) Sudden painless loss of vision/diplopia
(3) Jaw/tongue claudication
(4) temporal artery tenderness / reduced pulsations
(5) polymyalgia rheumatica (30%)
(6) aortic arch syndrome (involvement of subclavian + brachial arteries –> pulseless disease)
GCA Cx
(1) increased risk of thoracic aortic aneurism –> rupture
(2) permanent blindness
GCA Ix
ESR
temporal artery biopsy (+/- US)
GCA Dx criteria
3+ of the following:
(1) Age >50
(2) New headache
(3) temporal artery tenderness/reduced pulsations
(4) ESR high
(5) Arterial abnormality on biopsy
GCA Rx
(1) high-dose prednisolone (bisphosphonates, vit D, calcium, PPI)
(2) yearly CXR +/- abdominal US to screen for aortic aneurism
(3) consider aspirin
Why is GCA a medical emergency? Name another serious cx
Untreated –> permanent blindness in 20-25%
Thoracic aortic aneurism rupture
Why is GCA a medical emergency? Name another serious cx
Untreated –> permanent blindness in 20-25%
Thoracic aortic aneurism rupture
Important example of medium vessel vasculitis
Polyarteritis nodosa
