GCA Flashcards
What is the age range?
> 50
peak 80
Which sized arteries are effected?
Median and large
Which arteries are commonly affected?
External carotid Ophthalmic Vertebral Distal subclavian and axillary Thoracic aorta
What is the pathophysiology?
Antigenic stimulation in the vessel-specific toll-like receptors on vascular dendritic cells in the adventitia of arteries
> CCL19 and CCL21 draw in T cells
> Tissue macrophages become giant cells
Which cell signalling molecules are associated with ischaemic complications?
interferon gamma, CXCL9/10/11, platelet-derived growth factor, fibroblast growth factor, vascular endothelial growth factor
Which aspects of the arterial wall are narrowed?
intima and media
What are the four common patterns of disease
Isolated cranial GCA - 80% - headache, jaw claudication
Symptomatic Large vessel vasculitis (9%)
Isolated fever or inflammatory response (9%)
Isolated polymyalgia rheumatica w vasculitis on imaging (2%)
What are the eye symptoms and signs of GCA?
Vision loss - partial or complete Transient visual blurring Sudden loss of vision Eye pain Diplopia Ptosis, nystagmus, INO
What are the mechanism of vision loss?
Occlusion of posterior ciliary arteries most commonly
What are the Plt, ESR and CRP cut offs?
Plt >300
ESR >50
CRP >20
What is the gold standard for Dx?
Temp art bx
What is the sensitivity of TAB?
70-90% in cranial GCA
as low as 52% in large vessel GCA
Causes for negative TAB?
Skip lesions
Sampling errors
Extra-cranial GCA
When in relation to steroid is imagining helpful?
2-4 days
Which imaging modalities are useful?
High res MRI w GAD
US
CT-A
PET
