Takayasu arteritis is rare, with an estimated incidence of 1 to 3 cases per million people per year. It is more commonly observed in young people born biologically female of East and South Asian, South American, and African descent, typically between the ages of 20 and 40, though it can occur in all ethnicities and sexes.

The exact cause of Takayasu arteritis is unknown, but it is believed to be an autoimmune disorder. Genetic predisposition and environmental factors, such as viruses and other infections, may play a role in triggering the immune system to attack the body’s own blood vessels. The result is granulomatous inflammation (clusters of immune cells causing restricted blood flow) of the arterial wall, particularly in the aorta and its branches. 

Recent studies have shown a few genetic predispositions which may increase the risk of developing Takayasu arteritis. The human leukocyte antigen (HLA) region of chromosome 6, responsible for creating cell-surface proteins that regulate the immune system, has been associated with vasculitis diseases such as Takayasu arteritis. Specifically, the HLA-B*52 gene has been linked to cases of Takayasu arteritis in a number of individuals with this disease. Mutations in this specific gene are more common in individuals of Eastern Asian descent, but no link associated with gender assigned at birth has been determined. More research is needed to determine if these are the primary cause or merely fail to protect against autoimmune responses that weaken the arteries. 

Symptoms often develop gradually and can be divided into early (systemic) and late (vascular) phases:

• Early (pre-pulseless) symptoms: Fatigue, weight loss, low-grade fever, night sweats, and arthralgia (joint pain), weak pulse (often these symptoms occur before discrepancies in pulse can be identified, i.e. pre-pulseless symptoms)

• Vascular (occlusive - starts when arteries are blocked) symptoms:

  • Diminished or absent pulses in limbs (especially the upper extremities)

  • Blood pressure discrepancies between arms

  • Claudication (pain with exertion) in arms or legs

  • Dizziness, headaches, or visual disturbances due to reduced blood flow to the brain

  • Chest pain or shortness of breath if the heart or lungs are involved

  • Hypertension, often due to renal artery stenosis

  • High blood pressure from decreased blood flow to kidneys

  • Low red blood cell count (anemia)

Takayasu arteritis is diagnosed based on clinical features, imaging of large arteries, and exclusion of other causes of vasculitis or vessel damage. Because symptoms can be nonspecific in the early stages, diagnosis is often delayed.

• Imaging studies:

  • Magnetic Resonance Angiography (MRA) or Computed Tomography Angiography (CTA): Imaging to reveal arterial narrowing, occlusion, or aneurysms

  • Conventional angiography: Former gold standard, still used in complex cases

  • Ultrasound (especially Doppler): May show wall thickening or reduced flow in large vessels

• Blood tests for:

  • Elevated inflammatory markers:

    • Erythrocyte sedimentation rate (ESR) - how quickly red blood cells settle, clumping and inflammation will lead to faster rate

    • C-Reactive Protein (CRP) - produced in the liver in response to inflammation

  • Anemia - low red blood cell count

  • Autoimmune panel may be done to exclude other vasculitides

• Biopsy: Rarely done but would show granulomatous inflammation (clusters of immune cells causing restricted blood flow) if performed
   

Treatment aims to suppress inflammation and manage vascular complications:

• Glucocorticoids (e.g., prednisone): First-line therapy to reduce inflammation

• Steroid-sparing immunosuppressants: Such as methotrexate, azathioprine, or mycophenolate mofetil, used in refractory or relapsing cases

• Biologic agents: Including anti-TNF drugs (infliximab) or IL-6 inhibitors (tocilizumab) for treatment-resistant disease

• Antiplatelet or anticoagulant therapy: May be considered to reduce thrombotic risk

• Surgical or endovascular interventions: Angioplasty or bypass surgery may be necessary for critical arterial stenosis or aneurysms

The prognosis for Takayasu arteritis varies depending on the extent of vascular involvement and the response to treatment. With early diagnosis and effective immunosuppressive therapy, many patients achieve remission and maintain a good quality of life. However, relapses are common, and some individuals may develop permanent vascular damage, organ dysfunction, or require surgical interventions. Close monitoring with periodic imaging and inflammatory markers is essential to guide ongoing management.

1. Medline Plus - Takayasu arteritis

2. Mayo Clinic - Takayasu arteritis

3. Cleveland Clinic - Takayasu arteritis

4. Medscape - Takayasu arteritis

5. The Rheumatologist

6. MedCentral: ESR vs. CRP