Objective. To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality.Methods. We retrospectively identified 167 consecutive hospital-based patients with MPA in 3 hospitals in Japan. We longitudinally collected clinical information for 150 of these patients, for whom CT images obtained before treatment were available. We then determined the presence of 22 imaging components of lung abnormalities in these patients.Results. The vast majority of patients (97%) had at least 1 lung abnormality on chest CT images, including interstitial lung lesions (66%), airway lesions (66%), pleural lesions (53%), and emphysematous lesions (37%). In multivariate analyses, ground-glass opacity was associated with the Birmingham Vasculitis Activity Score, whereas 3 of 4 airway lesions were associated with myeloperoxidase-antineutrophil cytoplasmic antibodies. Latent class analysis identified a distinct group of patients with airwaypredominant lung lesions. Airway lesions such as bronchiolitis and bronchovascular bundle thickening were among the components that showed improvement within 3 months of the initial treatment. An idiopathic pulmonary fibrosis pattern was the only chest CT variable that was independently associated with shorter survival.Conclusion. Abnormalities in a wide range of anatomic areas, including the whole airway, can be identified in the lungs of patients with MPA before treatment. The prevalence, clustering patterns, and responsiveness to treatment of individual lung abnormalities provide groundwork for informing future studies to understand the pathophysiology of MPA.Microscopic polyangiitis (MPA) is a necrotizing systemic vasculitis that affects small to medium-sized vessels. In MPA, immune deposits on the vessel wall are usually absent, and serum antineutrophil cytoplasmic antibodies (ANCAs) are frequently present. MPA shares these

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Carbon tetrachloride (CC1₄) was intraperitoneally injected into Balb/c mice 4 times at biweekly intervals, and the morphological changes of the liver and kidney were examined during 12 weeks after the last injection. The renal injuries progressed in spite of cessation of CC1₄ treatment; microcysts with tubular-cell degeneration were manifest on day 42 after the last injection of CC1₄. At the end of the experiment, however, interstitial fíbrosis with inflammatory cell infiltration was much more prominent. Glomerular changes with IgG deposits also developed following the tubulointerstitial changes. The CC1₄ treatment induced liver damage as well, but it promptly subsided without formation of cirrhosis. The CC1₄ nephrotoxicity was completely inhibited by whole body irradiation (200 rad) exposed at each injection of CC1₄. In contrast, the hepatic damage was not changed by irradiation. These results seem to indicate etiologic independence of renal and hepatic events induced by CC1₄ treatment. It is also suggested that chronic CC1₄ nephrotoxicity is mediated, at least in part, by radiosensitive responses of the mice themselves.

A case of a 36-year-old woman with progressive systemic sclerosis (PSS) was reported. The patient had two additional immune-mediated diseases: Hashimoto's thyroiditis and membranous nephropathy. It was implicated that overlapping of systemic lupus erythematosus (SLE) occurred in the course of PSS. Notably, immune complex deposition along the follicular basement lamina of the thyroid was suggested by immunofluorescence and electron microscopy. Although the glomerular lesion was in general accord with membranous nephropathy, it was complicated by occasional crescent formations and necrotic arterial changes, probably resulting from malignant hypertension that appeared during the terminal stage. It was implied that the same circulating antigen-antibody complexes might have been involved in the pathogenesis of Hashimoto's thyroiditis and membranous nephropathy in this case.