Takayasu Arteritis

Takayasu arteritis is a form of granulomatous arteritis that primarily affects the aorta and its major branches. It is most prevalent in adolescent girls and young women and is characterized by ocular disturbances and marked weakening of the pulses in the upper extremities. It is categorized as a large-vessel vasculitis (Jennette, 2013).

Quick Answers for Clinicians

Which testing algorithms are related to this topic?

Vasculitis in Adults Testing Algorithm

Vasculitis in Children Testing Algorithm

Diagnosis

Indications for Testing

Clinical symptoms suggestive of Takayasu arteritis
- Asymmetric blood pressure
- Decrease of brachial artery pulse
- Bruit over subclavian arteries or aorta
- Claudication of extremities
- Blood pressure difference between arms

Criteria for Diagnosis

American College of Rheumatology Criteria for the Classification of Takayasu Arteritis (1990)
Criteria	Definition
Age at disease onset	Symptoms or findings related to Takayasu arteritis before age 40 years
Claudication of extremities	Development/worsening of fatigue and discomfort in muscles of ≥1 extremity while in use, particularly upper extremities
Decreased brachial artery pulse	Decreased pulse in 1 or both brachial arteries
BP difference >10mmHg	Difference in systolic BP of >10 mmHg between arms
Bruit over subclavian arteries or aorta	Bruit over 1 or both subclavian arteries or abdominal aorta audible on auscultation
Arteriogram abnormality	Arteriographic narrowing or occlusion of entire aorta, its primary branches, or large arteries in proximal upper or lower extremities, not as a result of arteriosclerosis, fibromuscular dysplasia, or similar causes – changes typically focal or segmental
Note: For purposes of classification, a patient will be considered to have Takayasu's arteritis if ≥3 of these 6 criteria are present. The presence of ≥3 criteria yields a sensitivity of 90.5% and a specificity of 97.8%. BP, blood pressure Source: American College of Rheumatology

Ishikawa's criteria for Takayasu arteritis (modified according to Sharma, 1995)
- Proposed modifications to criteria include
  - Removal of age criterion of <40 years
  - Inclusion of characteristic signs and symptoms as a major criterion
  - Removal of age in defining abdominal aortic lesion
  - Addition of coronary artery lesion in absence of risk factors

Laboratory Testing

Nonspecific testing – helpful in excluding other diagnoses or identifying organ dysfunction
- Urinalysis – negative for hematuria
- CBC – may show elevated white blood cell (WBC) count
- C-reactive protein (CRP)
  - Preferred test to detect inflammatory processes (Choosing Wisely, American Society for Clinical Pathology, 2016)
  - Usually elevated
  - If CRP not available, order erythrocyte sedimentation rate (ESR)
- Antineutrophil cytoplasmic antibodies (ANCA) – rule out ANCA-associated vasculitis

Histology

Inflammation, granulomas, and giant cells in large artery walls
Often indistinguishable from giant cell arteritis

Imaging Studies

Magnetic resonance angiography (MRA)/computed tomography (CT) angiography – narrowings, occlusions, or aneurysms of the aorta and its branches
- Ultrasound (US) is not as well-established as a diagnostic tool

Differential Diagnosis

Mycotic aneurysm
Atherosclerosis
Congenital – aortic coarctation
Hereditary disorders
- Ehlers-Danlos syndrome
- Marfan syndrome
- Loeys-Dietz syndrome
Fibromuscular dysplasia
Postradiation syndrome
Chronic aortic aneurysm
Chronic infection
- Mycobacterium tuberculosis
- Treponema pallidum

Background

Epidemiology

Incidence – rare
Age – 20s (mean)
Sex – F>M, 29:1 in U.S.
Ethnicity – predominantly Asian

Pathophysiology

Large-vessel vasculitis characterized by adventitial thickening and cellular infiltration of tunica media with local destruction of vascular smooth muscle cells and elastin
- Strong predilection for aorta, its branches, and pulmonary arteries
Pathogenic T-lymphocyte response

Clinical Presentation

Constitutional – fever, fatigue, malaise, weight loss
Cardiovascular – hypertension, asymmetric blood pressure between limbs, diminished pulses, bruits (carotid most common)
Musculoskeletal – arthralgias, myalgias, limb claudication
Neurologic – syncope, lightheadedness, headache, visual disturbances