What is the diagnostic approach and treatment for Takayasu arteritis?

Diagnostic Approach and Treatment for Takayasu Arteritis

For patients with suspected Takayasu arteritis (TA), the diagnostic approach should include thoracic aorta and branch vessel imaging with CT or MRI, followed by treatment with glucocorticoids plus a non-glucocorticoid immunosuppressive agent such as methotrexate for active disease. 1, 2

Diagnostic Approach

Clinical Presentation

• Constitutional symptoms (acute phase):
  • Fatigue, weight loss, night sweats, anorexia, general malaise 1
• Vascular symptoms:
  • Upper extremity claudication
  • Carotid artery pain
  • Diminished or absent peripheral pulses
  • Vascular bruits over subclavian arteries and aorta 1
• Neurological symptoms:
  • Vision loss, lightheadedness, stroke 1
• Hypertension (especially in Indian-type distribution) 1

Diagnostic Criteria

According to the American College of Rheumatology (1990), diagnosis requires at least 3 of the following 6 criteria 1:

1. Age of onset less than 40 years
2. Intermittent claudication of extremities
3. Decreased pulse of the brachial artery
4. Systolic blood pressure difference >10 mmHg between arms
5. Murmur over subclavian arteries or aorta
6. Angiographic evidence of stenosis or occlusion of the aorta or its major branches

Laboratory Testing

• Inflammatory markers:
  • Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are elevated in approximately 70% of patients in acute phase and 50% in chronic phase 1
  • Important caveat: ESR is not a consistently reliable marker of disease activity 3

Imaging Studies

• First-line imaging: MRI/MRA or CT/CTA of thoracic aorta and branch vessels 1
  • MRI is particularly valuable as it:
    • Shows mural thickening with luminal stenosis 4
    • Can detect early wall changes before luminal narrowing occurs 5
    • Avoids ionizing radiation (important for young patients and follow-up) 4
  • For disease monitoring: Noninvasive imaging is conditionally recommended over catheter-based dye angiography 2
  • Follow-up: Regularly scheduled noninvasive imaging in addition to routine clinical assessment 2

Treatment Approach

Initial Therapy

• For active TA: Glucocorticoids plus a non-glucocorticoid immunosuppressive agent is conditionally recommended over glucocorticoids alone 2
  • Initial glucocorticoid dose: 40-60 mg/day (0.7-1 mg/kg/day) of prednisone 1
  • First-line non-glucocorticoid agent options:
    • Methotrexate (often preferred, especially in children)
    • Azathioprine
    • TNF inhibitors 2, 1
  • Note: Tocilizumab is not recommended as initial therapy as its efficacy in TA is not established 2
  • Abatacept is not recommended as it has been shown to be inefficacious in TA 2

Treatment Based on Disease Status

1. Active TA not on immunosuppressive therapy:

   • High-dose daily oral glucocorticoids + non-glucocorticoid immunosuppressive agent 2

2. Clinical remission with new vascular territory inflammation:

   • Escalate immunosuppression 2

3. Clinical remission with increased inflammation markers only:

   • Clinical observation without escalation of therapy 2

4. Progressive ischemia:

   • Consider surgical intervention 2
   • Important: Revascularization should be delayed until acute inflammation is controlled 1

Monitoring and Follow-up

• Disease activity monitoring:

  • Repeated physical examinations
  • Inflammatory markers (ESR or CRP)
  • Regularly scheduled noninvasive imaging 2, 1

• Important caveat: Histologically active disease may be present in 44% of patients despite clinical inactivity 3

Treatment Challenges

• About 80% of patients require ongoing medical therapy, while only 20% have self-limiting disease 3
• Approximately 25% of patients fail to achieve remission with immunosuppressive treatment, and about half of those who achieve remission later relapse 3
• Patient-specific factors that may influence immunosuppressant choice:
  • Alcohol use
  • Plans for childbearing
  • Medication compliance
  • Medical comorbidities 2

Management of Complications

• Control cardiovascular risk factors (hypertension, dyslipidemia, smoking) 1
• Common complications requiring monitoring:
  • Pulmonary thrombosis
  • Aortic regurgitation
  • Congestive heart failure
  • Cerebrovascular events
  • Vision problems
  • Hearing problems 6

By following this structured approach to diagnosis and management, clinicians can improve outcomes for patients with this rare but serious vasculitis that predominantly affects young women.