INTRODUCTION:Takayasu’s arteritis (TA) is a chronic inflammatory disease that primarily affects the walls of large vessels. The presence of Langhan’s giant cells and granulomas similar to those in tuberculous lesions in biopsy specimen described 60 years ago has implicated Mycobacterium tuberculosis in the pathogenesis of TA.It is reported that patients with TA have substantially higher tuberculin sensitivity or active tuberculosis (TB) than the general population. We present two cases that support this postulate.
CASE PRESENTATION:Case 1 is of a 16 year old female who 5 years earlier presented with hypertension. She was found to have right renal artery stenosis and underwent right nephrectomy. Coincidentally, she was found to be tuberculin positive at that time and received Isoniazid for 6 months. After two years of normalization, she presented with recurrence of hypertension. An angiogram documented left renal artery stenosis which this time required splenorenal bypass. Her chest X-ray and CT-Scan showed hilar and mediastinal lymphadenopathy. Culture of the hilar nodes isolated M. tuberculosis. Angiography revealed marked thickening of the renal arteries resulting in stenosis and thickening of the infrarenal abdominal aorta with aortic luminal reduction. These findings were highly suggestive of TA. Electrocardiogram, Echocardiogram and CT-Scan of brain and neck vessels were normal. Serum complement and ANCA were normal, the ANA was weakly positive and ESR was mildly elevated. HLA-27 was positive with associated iritis. Prednisolone, immunosuppressive therapy, antihypertensive and antituberculosis regimens were given with noted clinical improvement. Case 2 is of a 17 year old female who presented with syncope. On examination, pulses and blood pressure were not appreciated in upper extremities and left leg. The only measurable blood pressure was in right leg. There was a palpable bruit over the suprasternal notch with bilateral carotid bruits. An echocardiogram confirmed normal cardiac structure and function but showed severe stenosis of both carotid and subclavian arteries due to severe intimae hyperplasia. She had history of latent TB infection treated with Isoniazid 4 years earlier. Chest X-ray revealed spinal mass (T10-12) and right hilar and paratracheal lymphadenopathy. MRI of the thoracic spine showed narrowing and loss of normal disc intensity with lytic lesions (T10-11). Angiography showed severe stenosis of the innominate artery extending into the right common carotid artery while the left common carotid artery was occluded with collaterals extending across and filling the left internal and external carotid arteries. The left subclavian artery was also occluded. Her infrarenal abdominal aorta was of small caliber and the left external iliac artery was occluded. CT-Scan showed thoracic and portahepatic lymphadenopathy and destruction of the lower thoracic spine with bilateral paraspinal fluid collection. Multiple bilateral scattered pulmonary nodules were described. Acid fast bacilli were isolated from her gastric aspirates and the aspirate from the spinal mass. DNA probe identified M. tuberculosis complex. She responded well similarly to prednisolone and antituberculosis therapy with clinical and radiological improvement.
DISCUSSIONS:Two adolescent girls developed TA within years of the appearance of TB. This unusual form of arteritis is common in Asia but has rarely been reported in individuals born in Canada. Sensitization to tuberculin has been suggested as its pathogenesis. We present two cases wherein a tuberculous process is documented prior to / concomitant with TA. The adolescents described in this paper have demonstrated complete symptomatic remission as well as return of pulses simultaneous with antituberculosis therapy.
CONCLUSION:The etiology of TA has an autoimmune basis and the exact role Mycobacterium tuberculosis plays in its pathogenesis remains unknown. The known tuberculin positivity, the progression of vascular involvement and improvement seen in both cases with antituberculosis treatment suggests an association between TB and TA.
DISCLOSURE:Abdulrahman Almohammadi, None.