What is vasculitis
Inflammation of a blood vessel (arteries or veins), which is characterised by the presence of an inflammatory infiltrate and destruction of the vessel wall.
Heterogenous conditions
What does endothelial injury lead to
Results in thrombosis + ischaemia/infarction of dependent tissues
Types of Vasculitis Affecting The Large Vessels: arteries and major tributaries
- Giant cell arteritis
- Takayasu’s arteritis
Types of Vasculitis Affecting The Medium Sized Vessels: small arteries and arterioles
- Polyarteritis nodosa
- Kawasaki Disease
Types of Vasculitis Affecting The Small Vessels: small arteries, arterioles, venuoles and capillaries
ANCA +ve:
- Microscopic polyangiitis
- Granulomatosiswith polyangiitis (Wegener’s granulomatosis)
- Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss syndrome)
Types of Vasculitis Affecting The Small Vessels: small arteries, arterioles, venuoles and capillaries
ANCA -ve:
Henoch-Schonlein purpura
Cryoglobulinemic vasculitis
Anti-C1q vasculitis
Aetiology of vasculitis
May be primary (this may be due to direct or indirect damage of endothelial cells of the vessel) or secondary to other conditions such as RA, SLE, hepatitis B & C, HIV, polymyositis and some allergic drug reactions.
What is medium and large vessel vasculitis typically due to?
due to an autoimmune disease, where the immune system confuses a part of normal body as a foreign invader
body confuses the innermost layer of the blood vessel, which is the endothelial layer, with a foreign pathogen and directly attacks it
white blood cellsmix up the normal antigens on the endothelial cells with the antigens of foreign invaders like bacteria -
what are small vessel vasculitides due to?
immune system attacks healthy cells that are near the vascular endothelium, and the endothelial cells are only getting indirectly damaged.
situation in many small-vessel vasculitides, where theimmune system attacks white blood cell enzymes or other non-endothelial cell targets.
How do all vasculitis progress basically?
damaged endothelium exposes the underlying collagen and tissue factor, and these exposed materials increase the chance of blood coagulation
Blood vessels - weaker and become damaged - more likely aneurysms - as vessel wall heals becomes harder and stiffer as fibrin deposited in vessel wall as part of healing proces
What does presentation of vasculitis depend on?
vessel affected and the corresponding organ - could have ischaemia
- Blood cells clump onto the exposed tissue factor and collagen on the inside of blood vessels forming blood clots that can restrict blood flow.
- ## As fibrin is deposited in the vessel wall, the walls become thicker and bulge into the vessel, reducing the diameter of the vessel lumen, and restricting blood flow.
Typical general symptoms of vasculitis
- Fatigue
- Fever
- Weight loss
- Anorexia (loss of appetite)
- Anaemia
Typical specific presentations (depending on vessel and organ affected)
- Joint and muscle pain
- Peripheral neuropathy - vessels to the head are affected
- Anterior uveitis and scleritis - vessels to the head affected, causing ischaemia of the eye
- Gastrointestinal disturbance (diarrhoea, abdominal pain and bleeding)
- Renal impairment
- Hypertension
- Purpura. These are purple-coloured non-blanching spots caused by blood leaking from the vessels under the skin.
Markers for vasculitis
- Elevated ESR and CRP
- Anti neutrophil cytoplasmic antibodies (ANCA) - positive in most small vessel vasculitis
- 2 types: P-ANCA are also called anti-MPO antibodies. C-ANCA are also called anti-PR3 antibodies.
General management for vasculitis
Steroid:
Prednisolone - oral
Hydrocortisone - IV
Nasal sprays
Immunosuppressants:
- Cyclophosphamide
- Methotrexate
- Azathioprine
- Rituximab and other monoclonal antibodies
What is Giant cell arteritis (GCA)
Inflammation of the lining of your arteries
Sometimes called temporal arteritis as it commonly affects the temporal branch of the carotid artery.
What does giant cell arteritis co exist with normally?
Polymyalgia Rheumatica (PMR)
Epidemiology of GCA
- Common in elderly >55 years.
- F>M
- Associated with PMR in 50%
-0.4% of people - commonest vasculitis
- common in white people
Pathophysiology of GCA
- Arteries become inflamed, thickened and can obstruct blood flow
- Cerebral arteries affected in particular e.g. temporal artery
- Opthalmic artery can also be affected potentially resulting in permanent or
temporary vision loss - Blue dots around adventitia media and intima, cells blur margin between media and adventitia - intima proliferated into lumen causing it to narrow
S + S of GCA (non cranial)
- Malaise
- Dyspnoea
- Weight loss
- Morning stiffness
- Unequal or weak pulse
- anaemia
- limb claudication
Symptoms of GCA due to arteries in the head being affected (Cranial GCA)
- New Headache
- Scalp tenderness (pain when combing hair)
- Tongue/ jaw claudication - pain when chewing - lingual or facial artery involvement
- Amaurosis fugax - unable to see from one or both eyes
- Sudden unilateral blindness
Bloods in GCA
- Elevated ESR and CRP
- Elevated ALP
- Elevated platelets
- Reduced Hb
- ANCA -ve
Biopsy in GCA (temporal artery)
- Can see skip lesions - GCA is segmental so doesn’t affect the whole length of the artery
- Histology - giant cells (granulomas) seen in the internal elastic lamina
Specifity 100%, sensitivity 39%
Diagnostic criteria for GCA
- Age at disease onset ≥50 years
- New headache
- Temporal artery abnormality
- Elevated ESR(> 50 mm/hr)
- Abnormal temporal artery biopsy(typical vasculitis features)
3 of the following criteria have to be met
