- IL-12, IL-6 and IL-2.
- HLA-Bw5 and HLA-B39.2.
The condition is most likely to affect young women.
The incidence is higher in Asian countries including Japan, Korea, China, India, Thailand, and Singapore. It is also more likely in patients of Asian descent.
- Inflammatory markers:
- Both ESR and CRP are likely to be raised.
- The sensitivity of CRP is better than ESR but both tests have poor specificity.
- Computerised tomography angiography (CTA):
- The investigation of choice, with high sensitivity and specificity. Magnetic resonance angiography (MRA) may also be used, depending on availability and local guidelines.
- Catheter angiogram:
- The traditional method of angiography which has been largely superseded by CT and MR angiography in most centres.
- Ultrasound (+/- doppler enhancement):
- This is more readily available than other imaging methods and is preferred in early or mild disease and children.
- Giant cell arteritis:
- More likely to affect older patients and have temporal artery involvement. CT/MRI imaging will differentiate the diagnoses.
- Behcet's disease:
- More likely to present with arthritis, ulcers and uveitis. Angiography and lumbar puncture (raised protein) will differentiate the diagnoses.
- Kawasaki disease:
- More likely to affect young children. Presents with strawberry-tongue, lymphadenopathy and high grade fever. Echocardiogram is the investigation of choice.
- IgG4-related disease:
- A rare chronic inflammatory disease which can affect almost any organ including the heart and aorta. It is most common in middle-aged and older men.
- May present with vasculitis of ascending aorta in tertiary disease. Firm painless chancre should be present and serology positive.
- Tuberculosis (TB):
- Both can present with haemoptysis and pleuritis. Chest X-ray and QuantiFERON® gold test are diagnostic.
- Oral prednisolone (1mg/kg/day) is usually first line.
- Length of treatment is dependent on factors including severity of disease and comorbidities.
- Glucocorticoids must be tapered to reduce the risk withdrawal effects.
- Steroids should be given alongside low dose aspirin (75mg daily).
- Considered 2nd line and are utilised when patients relapse during steroid tapering.
- Options include:
- Methotrexate (given with folic acid).
- Mycophenolate mofetil.
- Bone protection is required due to the long-term use of steroids.
- Alendronic acid with calcitriol and calcium carbonate should be used.
- Patients on high dose prednisolone may require pneumocystis pneumonia prophylaxis with trimethoprim.
- If both steroids and immunosuppressive treatments are ineffective, a tumour necrosis factor (TNF)-alpha inhibitor (such as infliximab) may be started.
- Surgical intervention is indicated in patients with severe limb claudication or organ dysfunction.
- Options include percutaneous angioplasty and vascular bypass surgery.
- Hypertension: a long term complication which may result either from renal artery stenosis (causing activation of the renin-angiotensin-aldosterone system), or aortic stenosis (increasing systemic vascular resistance), or both.
- Hypertension should be aggressively treated with antihypertensive medications.
- Peripheral vascular ischaemia: stenosis and occlusions of arteries are common. These should be investigated regularly with vascular imaging studies.
- Aortic aneurysm or regurgitation: structural abnormality to the aortic root and thoracic aorta may occur.
- Angina and congestive heart failure: occurring in about 25% of patients
- Cerebrovascular disease: there is a low risk of both stroke and transient ischaemic attack.