[A case of HTLV-1 associated bronchiolo-alveolar disorder showing progressive air trapping]

A 65-year-old woman whose parents were from Okinawa Prefecture, had productive cough and bilateral diffuse nodular lesions on chest X-ray. She had been shown a human T-cell lymphotropic virus type-1 (HTLV-1) carrier. Video-assisted thoracoscopic lung biopsy showed marked peribronchiolar infiltration of lymphocytes and stenosis of bronchioles. HTLV-1 associated bronchiolo-alveolar disorder (HABA) was diagnosed. The symptoms, hypoxemia and chest X-ray findings improved with oral erythromycin. However, expiratory chest CT showing mosaic perfusion, pulmonary function test demonstrating increased thoracic gas volume, and ventilation scintigraphy resulting in decreased clearance during 8 years, all of those findings indicated progression of air trapping. Abnormalities on chest CT partially improved, but bronchiolar lesions have deteriorated. Expiratory chest CT, body phlethysmography and ventilation scintigraphy were recommended to clarify the course of HABA.