[A case of Churg-Strauss syndrome in which MPO-ANCA (antibodies to myeloperoxidase) appeared to reflect the disease activity].

A 42-year-old housewife was admitted to our hospital because of an asthma attack, fever, severe eosinophilia, mononeuritis-multiplex, arthralgia, skin-eruptions, transient pulmonary infiltration, and other symptoms. Chung-Strauss syndrome was diagnosed. When there were signs and symptoms of vasculitis, chest radiography revealed that pulmonary infiltrates had decreased, but her chest CT showed ground glass opacities of both lung fields and fine granular shadows. Differential cell count of bronchoalveolar lavage fluid revealed a high level of eosinophils, and transbronchial lung biopsy specimens showed vasculitis and marked infiltration of eosinophils. When signs and symptoms of vasculitis were prominent, antineutrophil cytoplasmic antibodies (ANCA) in the serum were examined. PR3-ANCA (antibodies to serine-protease, nearly equal to c-ANCA), which is specific to Wegener's granulomatosis, was negative, but MPO-ANCA (antibodies to myeloperoxidase, nearly equal to p-ANCA) was positive and the level was very high (478 EU/ml). After corticosteroid therapy, her symptoms markedly improved, and MPO-ANCA became negative. MPO-ANCA appeared to reflect the disease activity in this case.