Isoniazid-induced Takayasu arteritis remission

A 75-year-old man was admitted because of fever, unproductive cough, neck pain and upper limb claudication. The patient was febrile and hypotensive, and a cardiac systolic ejection murmur was heard. Blood tests showed normochromic anemia, elevated erythrocyte sedimentation rate, C-reactive protein, fibrinogen, and alpha-2 and beta-2 globulins. In order to investigate neck pain, an ultrasound examination of the carotid arteries was performed which showed a carotid intima-media thickness reaching the maximum value of 2.3 mm in both carotid arteries. Ultrasound examination of the temporal artery and its rami demonstrated wall thickening, both in the common superficial temporal artery and its frontal and parietal rami. A temporal artery biopsy was performed and was consistent with Takayasu arteritis. A positive interferon-γ release assay revealed latent tuberculosis infection and isoniazid 300 mg every 24 hours was commenced. Neither corticosteroids nor other drugs were prescribed at that time. Two weeks later, ultrasound examination showed a significant reduction in the thickening of all investigated arteries. To our knowledge, this is the first case of isoniazid-induced Takayasu arteritis remission. We believe that isoniazid deserves further investigation regarding its potential immunomodulatory properties.