A case of pulmonary arteritis with stenosis of the main pulmonary arteries with positive myeloperoxidase-antineutrophil cytoplasmic autoantibodies.

A 53-year-old woman was referred to our hospital with the main symptoms of productive cough, fever and exertional dyspnoea. Chest X-ray revealed enlargement of the left hilar shadow and cavitary infiltration in the right upper lobe. 99mTechnetium-macroaggregated albumin (99mTc-MAA) perfusion scintigram showed complete hypoperfusion through the entire right lung. A pulmonary angiogram revealed stenotic lesions in the right and left main pulmonary arteries. Right cardiac catheterization showed an elevated right ventricular systolic pressure. There was no evidence of systemic arterial lesions nor vasculitis. The patient was positive for myeloperoxidase (MPO)-antineutrophil cytoplasmic autoantibodies (ANCA) (168 EU). The Mycobacterium avium complex sputum culture was positive. The pulmonary stenotic lesions were surgically resected. The resected pulmonary arterial lesions were pathologically diagnosed as non-specific vasculitis. The cavitary lesion disappeared 6 months after the surgery. Two years after the surgery, although the MPO-ANCA level had decreased to 12 EU, stenosis of the pulmonary arteries reappeared. It is suggested that the patient became positive for MPO-ANCA in association with the Mycobacterium avium complex infection, and that the presence of MPO-ANCA may not be related to the development of pulmonary stenosis of the main pulmonary arteries.