Chronic thromboembolic pulmonary hypertension associated with initial pulmonary involvement in Takayasu arteritis

A 37-year-old non-smoking woman was admitted to our hospital because of nocturnal coughing and exertional dyspnea after using an ultrasonic humidifier. Chest roentgenograms and computed tomography showed many ground-glass opacities in the right upper lobe and left upper lung field. Her symptoms were alleviated and erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels returned to normal following the administration of prednisolone (40 mg/day). The same symptoms subsequently recurred, and ESR and CRP levels increased proportionately to a decreased dosage of prednisolone. In addition, chest computed tomography showed new opacities in the left lower lobe. Transbronchial lung biopsy specimens revealed multiple stenotic or obstructive changes in the small pulmonary arteries by organizing thromboemboli, with no vasculitis. The diagnosis of chronic thromboembolic pulmonary hypertension was made on the basis of multiple defects from lung perfusion scintigraphy, irregular or tapering of the pulmonary arteries detected by pulmonary arteriograms, and increased pulmonary pressure measured by echocardiography. We propose that the pulmonary thromboembolism observed in this case was related to the initial pulmonary involvement of Takayasu arteritis, since the patient's symptoms, ESR and CRP levels all improved markedly following the administration of prednisolone.