Takayasu Arteritis

Takayasu arteritis (TAK) is a large vessel vasculitis characterized by chronic granulomatous inflammation of the aorta and major branches, particularly the renal and subclavian arteries; stenosis, occlusions, dilations, and aneurysms can form. Affected children range in age from young infants to late adolescents. Although it is widespread around the world, it is more prevalent among Asian ethnicities.

EULAR/PRINTO/PRES classification of childhood Takayasu arteritis*

*Ozen S, Pistorio A, Lusan SM, et al. EULAR/PRINTO/PRES criteria for Henoch–Schönlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part II: Final classification criteria. Annals of the Rheumatic Diseases 2010;69:798-806.

Clinical manifestations: The disease progresses via two stages: an acute inflammatory phase and a chronic phase (vascular sequelae). The acute inflammatory phase is characterized by nonspecific symptoms such as fever, night sweats, malaise, muscular pains, arthralgia, weight loss, and anorexia. Patients at this phase are frequently misdiagnosed as TAK owing to the lack of particular symptoms. The chronic phase is characterised by the development of arterial stenosis symptoms such as pulse deficit, claudication, hypertension, blood pressure (BP) discrepancy, and bruits. A patient with severe disease can present with stroke, congestive heart failure, and renal failure.

Investigation: There is no specific blood test for the diagnosis. Acute phase reactants can increase in the acute inflammatory phase and then return to normal levels in the chronic phase, even if the disease progresses. As a result, utilizing acute phase reactants alone to monitor disease activity should be done cautiously. Physicians should also assess patients with clinical signs, symptoms, and imaging.

Imaging: Imaging procedures such as angiography, CTA, or MRA are required in TAK since they aid with diagnosis and are included in the obligatory categorization criteria. Each imaging modality offers a unique set of benefits. Conventional angiography remains the gold standard for diagnosing TAK because to its capacity to visualize blood flow within blood arteries and their collateral branches. However, it is an intrusive treatment that does not reveal artery wall inflammation. Although MRA is non-invasive and has been used to detect aortic wall thickening/oedema/irregularity, it has the disadvantage of being unable to visualize tiny branch arteries and calcification. CTA can be used in place of MRA to diagnose and monitor Takayasu's arteritis. The downside of CTA, however, is radiation exposure.

Differential diagnosis: 

Infection: tuberculosis, syphilis, HIV

Inflammation: Kawasaki, polyarteritis nodosa, Cogan’s syndrome

Non-inflammatory conditions: Coarctation of the aorta, fibromuscular dysplasia, Marfan’s syndrome

Treatment:

• Early diagnosis and prompt therapy can prevent irreversible vessel and organ damage. Disease activity assessment by evaluating clinical manifestations along with acute phase reactants and imaging is recommended. 
• Immunosuppressive medications: high dose corticosteroids along with methotrexate, azathioprine, mycophenolate mofetil, or cyclophosphamide.  Biologic agents (tumor necrosis factor inhibitor, anti-IL6 receptor (tocilizumab)) are also used in refractory cases.
• Other treatments: control of blood pressure, surgical consultation for angioplasty or reconstruction.