Vasculitis

Question 1

what is the classical distribution of Immunoglobulin A vasculitis?

is there usually a prodrome? it is always necessary?

Answer 1

This was previously known as HSP.

The rash is typically in dependant locations (lower limbs, buttocks)

yes, the prodrome is usually an URTI, but this is not always necessary

Question 2

what is anti-C1q vasculitis?

Answer 2

this used to be known as “Hypocomplementemic urticarial vasculitis”

it is a deficiency in C1q

presents with low C3, C3

usually urticarial skin rash, but also systemic disease like GIT, skin, renal, lung

RARE AS RARE CAN BE

Question 3

what are the diagnostics used in giant cell arteritis?

Answer 3

CRP is now considered more useful than ESR

ESR, in fact, is no longer in the European diagnostic work up

MTX and cyclophosphamide are new supplementary treatments

MTX particularly has evolving evidence

Tocilizumab (IL6-R blocker) is likely to be beneficial

Question 4

in Takayasu’s arteritis, what are the most commonly involved vessels?

Answer 4

it is the ARTERIES, and most commonly, it is those come off the arch of the aorta

Question 5

Presentation of Takayasu’s vasculitis:

Answer 5

Takayasu’s Vasculitis = Large vessel vasculitis.

Chronic inflammatory granulomatous aortitis.
Stenotic disease.
Cause unclear

Usually M

Particularly affects vessels to head and neck.
Can involve any artery - incl. coronary arteries.

“Pulseless” disease.
Decreased brachial artery pulse, limb claudication, differential limb SBP >10mmHg, subclavian artery or aortic bruit, abnormal angiogram.

Question 6

Investigations for Takayasu Vasculitis:

Answer 6

Investigations for Takayasu Vasculitis:
Angiogram is gold standard.
- beading
- stenosis
- aneurysms

CT angiogram

MR angiogram

• no radiation
• helpful early in disease with just wall thickening and oedema
• poor resolution of distal arteries
• expensive

Ultrasound

• helpful for arteritis vs. atherosclerosis
• operator-dependent
• difficult to assess some arteries

FDG-PET

• useful for regular monitoring
• more sensitive in early disease than MRA
• poor specificity

Question 7

Treatment of Takayasu Vasculitis:

Answer 7

Treatment of Takayasu Vasculitis:
Mainstay is steroids

+/- steroid-sparing immunosuppresant:

• anti-IL-6Rc antagonist (tocilizumab)
• anti-CD20 (rituximab)
• TNF antagonists

Question 8

Giant cell arteritis - presentation:

Answer 8

Giant cell arteritis: a large vessel vasculitis.

Most common adult-onset vasculitis
>50yo (often >70yo)
F>M (3:1)

Stenosis, aneurysm, rupture, ischaemia downstream.

Insidious onset
Constitutional symptoms
Jaw claudication
Headache (2/3 pts; temporal or occipital)
Scalp tenderness
PMR
Aortic arch symptoms
Visual disturbances 25-50% (AION)
Can involve any elastic artery.
Extracranial large vessels, up to 30-80%
Rarely involves skin, lungs, kidneys.

Question 9

Giant cell arteritis - Investigations:

Answer 9

GCA Ix:

ESR: raised
CRP: raised
Acute phase reactants: raised
Anaemia of chronic disease.
Can have abnormal TFTs and LFTs.

Temporal artery biopsy = gold standard.

• panarteritis, granulomatous inflammatoy infiltrate
• disruption of internal elastic lamina
• can be delayed up to 2/52 after commencement of Tx without affecting Sn significantly
• be aware of skip lesions (repeat Bx if negative and strong suspicion).

USS temporal arteries: Sn 88%, Sp 97%.

Question 10

Giant cell arteritis - Treatment:

Answer 10

Giant cell arteritis - Treatment:

Steroids are mainstay.
MTX as steroid sparing agent.
May need to treat for up to 2 years before weaning.

Question 11

What is leukoclastic vasculitis?
What are the histological features?
What is the DDx?

Answer 11

Leukocytoclastic vasculitis is a vasculitis of the small vessels and is also described as a hypersensitivity vasculitis.

Need biopsy to confirm, and may help with DDx.

Histological hallmarks:
● Perivascular infiltrate composed mostly of neutrophils
● LEUKOCLASIS: Fragmentation of leukocytes with nuclear debris
● Extravasation of RBCs
● Fibrin deposition in and around the vessels
● Endothelial oedema

Immunofluorescence: to look for fibrinogen, C3, IgG, IgM.
Positive IgA = clue to Henoch Schonlein Purpura (IgA vasculitis), though not definitive.

DDx:
- HSP (look for IgA deposition)
- Urticarial vasculitis: may or may not be hypocomplementaemic – ie. decreased C1, C1q, C2, C3,and/or C4 levels, as well as a reduction in the CH50/100. May be associated with CTD.
- Septic vasculitis: vascular occlusion by thrombus; little / no leukocytoclasis
- Sweet syndrome: diffuse neutrophilic infiltrate.
May have fever, mucocutaneous involvement, other organ involvement. Association with malignancy and IBD.

Note: Leukocytoclasis is NOT present in Chronic Urticaria.