PROGRESSIVE OBSTRUCTIVE LUNG-DISEASE ASSOCIATED WITH MICROSCOPIC POLYANGIITIS

Small airway involvement and progressive severe airflow obstruction ar e unexpected features in patients with microscopic polyangiitis. We re port the case of a patient with microscopic polyangiitis and circulati ng anti-neutrophil cytoplasmic antibodies (ANCA), who developed pulmon ary hyperinflation and airflow obstruction over a 7-yr period. Systemi c manifestations of this vasculitis improved under corticosteriods and cyclophosphamid therapy, a treatment that did not influence either th e very high level of anti-myeloperoxidase antibodies or the ventilator y impairment. Small airway involvement was suspected on the basis of p athologic small airway lesions and a mild emphysematous pattern on com puted tomography (CT) scan, which was out of proportion with the sever ity of the obstructive lung disease.