Steroid Resistant Takayasu Arteritis

Takayasu’s arteritis (TA), is a large vessel vasculitis, more common in Orient, mainly Asia1. It has been reported in adults of every age specially in adolescent. More than half of patients(60%) with Takayasu arteritis achieve control on corticosteroids alone, some proportion of cases are Glucocorticoid resistant2. This disease is the commonest cause of renovascular hypertension in Asian children2,3. Here we report such a case requiring a steroid sparing immunosuppressive for disease control.


Introduction
T akayasu's arteritis (TA), is a large vessel vasculitis, more common in Orient, mainly Asia 1 .It has been reported in adults of every age specially in adolescent.More than half of patients(60%) with Takayasu arteritis achieve control on corticosteroids alone, some proportion of cases are Glucocorticoid resistant 2 .This disease is the commonest cause of renovascular hypertension in Asian children 2, 3 .Here we report such a case requiring a steroid sparing immunosuppressive for disease control.

The Case
Our case is a 12 year old girl admitted with a history of sudden onset weakness of left side of the body for 2 days with inability to sit, associated with headache and vomiting.On asking there was also a history of pain in different joints and irregular fever for 8-10 months.Other history was uneventful.
General examination revealed wasting and stunting ( Wt-19 kg, Height -128 cm, BMI-12kg/m 2 -all are < 5 th percentile for age) , pallor and absence of all pulses of upper limb (Radial, Brachial), bilaterally weak femoral pulses, pulsation of right carotid artery is totally absent, in left side it is palpable with a thrill and a bruit on auscultation.Blood pressure could not be measured clinically.On neurological examination positive fi ndings were left sided UMN type of facial nerve palsy, UMN type of weakness of left upper and lower limb (Power 3/5), without any sensory loss.Weakness was improved over few days and she was able to walk within a week.Based on these clinical features we diagnosed the case as Vasculitc Syndrome (Primary/Secondary) with CNS vascular insuffi ciency.
Investigation showed-Hb%-9.65gm%, normal WBC & platelet count, high ESR-102/hr, positive CRP (> 52.4mg/dl), negative ASO, RA factor, anti-phospholipid antibody, ANCA (p & c).Serum biochemistry including sugar, urea, creatinine, LFT, RFT was normal so as chest X-ray, ECG, echocardiography.CT scan revealed ischemic changes in right basal ganglion region.Angiography was done to delineate the vessel involvement.It showed narrowing of subclavian arteries bilaterally with extensive collateral formation, right carotid artery was totally non-visualised and in left side it was severely narrowed.Tracing below abdominal aorta showed normal diameter of vessels blood pressure measured during this procedure was high 140/90 mm of Hg.
As soon as diagnosis was confi rmed, treatment was started with oral prednisolone 2 mg/kg and angiographic stenting of left carotid artery was contemplated but due to high risk for procedure consent was not given by parents, so only steroid was continued and after one month dose was gradually tapered but clinical response was poor.Review after 3 months of tapering dose, pulses were still not palpable, there were frequent history of headache, acute phase reactant was still high, and signs of steroid toxicity (Cushinoid facies, excessive weight gain) also was obvious.Pulse course of cyclophosphamide was started as steroid sparing agent, patient became symptom free within three months, acute phase reactant became negative but peripheral pulses didn't return till date (around a year).

Discussion
Takayasu arteritis affects the aorta and its major branches.The clinical presentation of TA includes three following phases-Pre-pulseless phase, pulseless phase and occlusive phase 1 .Exact etiopathogenesis of the disease is unknown 2 .Despite the term pulseless disease, which is a synonym for Takayasu arteritis, the predominant fi nding in individuals with Takayasu arteritis is asymmetrical pulse.Absent peripheral pulses occur late in the course of the disease.
Based on angiographic fi ndings Takayasu's arteritis is divided into type I (involving aortic arch and its branches), type II (thoracoabdominal aorta and its branches) and type III (involving lesions of both type I & II).Involvement of pulmonary arteries in addition to any of the above types is grouped as type IV.Thoracoabdominal aortic involvement is commoner (type II/III) in children 2 .The unique character of our case is pure involvement of Aortic arch which is uncommon in the paediatric age group.
Takayasu's arteritis is the commonest cause of renovascular hypertension in Asian children 2, 3 .Though in our case there was no renal artery involvement, this probably resulted from less renal blood fl ow due to narrowing at arch of aorta.
Angiogram is the gold standard for assistance in the diagnosis of Takayasu arteritis.It is performed either with conventional invasive angiography or CT angiography.Although the luminal changes of Takayasu arteritis are well depicted with conventional angiography, its mural changes can be best evaluated with spiral computed tomography (CT) angiography 4 .More recently MRI has been used to establish the diagnosis of TA in children, to monitor disease activity and to guide treatment 5 .

Fig 4 :
Fig 4: Extensive collateral circulations around the right and left Subclavian and Common Carotid Arteries.

Fig 1 :
Fig 1: Branches of Arch of Aorta.Markedly narrowed Brachiocephalic artery and left Subclavian artery