Introduction

Named after the ophthalmologist, Takayasu.

Begins in the second decade.

Delay from onset to diagnosis is 15 months.

Aetiopathogenesis

The hypothesized mechanisms are TB, viral infections, autoimmunity and genetic factors.

Histology

Panarteritis in acute phase.

Fibrosis of all layers in chronic phase leads to stenosis. Lack of fibrosis leads to aneurysms.

Patchy affection with skipped areas.

Clinical phases

Early phase- inflammation

Vascular phase- stenosis (93%) or aneurysm (7%)

Burnt out phase- remission

Classification

Ishikawa classification- into groups. I – uncomplicated. II- single complication (A- mild/moderate, B- severe). III- two or more complications. Complications included are AR, aneurysm, retinopathy and hypertension.

American College of Rheumatology criteria- 3 out of 6 of the following needed to diagnose TA. Age < 40 yrs, claudication, decreased brachial pulse, arm BP difference > 10 mmHg, aortic or subclavian bruit and arteriogram showing aortic or branch stenosis not typical for atherosclerosis or fibromuscular dysplasia.

Sharma modified criteria for diagnosis of TA- two major, one major and two minor or four minor needed. Major criteria are left mid subclavian A lesion, right midsubclavian A lesion and characteristic signs and symptoms of > 1 months duration. Minor criteria are carotodynia, hypertension, AR, ESR > 20, pulmonary A lesion, coronary A lesion, distal innominate A lesion, left middle common carotid A lesion, descending thoracic aorta lesion and abdominal aortic lesion.

Serological markers

ESR has low sensitivity and specificity as a marker of disease severity. IL-6, RANTES, MMP-3 and MMP-6 may be useful.

Radiologic findings

ACR classification is as in the figure below. Add C+ or P+ for coronary or pulmonary artery involvement respectively.

 

PET and Doppler are useful for follow-up. Chest X-ray may show linear calcification of aortic arch and descending thoracic aorta.

Treatment

Medical management is with corticosteroids first followed by other immunosuppressive drugs if there is no response [prednisone at 0.7-1 mg/kg/day for 1-3 months, cyclophosphamide (1-2 mg/kg/day), azathioprine (1-2mg/kg/day), or methotrexate (0.3 mg/kg/week)].

Surgical or endovascular treatment for vascular complications.

Follow-up

Active disease is present if at least two of the following four criteria are present (Sabbadini et al, 2001)- systemic features, elevated ESR, signs and symptoms of vascular ischaemia or inflammation and typical angiographic features.