NZB/NZW mice as a model of systemic lupus erythematosus.

In 1961, Helyer and Howie1described a strain of hybrid New Zealand mice (NZB/BL-NZY/ BL) in which a positive response to lupus erythematosus (LE) cell test spontaneously developed. They subsequently reported that these animals also had acquired hemolytic anemia and renal disease which simulated human lupus nephropathy.2,3This was the first description of a disease resembling human systemic lupus erythematosus (SLE) in the animal. The purpose of this paper is to confirm their findings and to describe the results of immunohistochemical and electron microscopical analyses. In addition, two new lesions suggestive of human SLE were observed. The first was an acute hepatitis reminiscent of early human lupoid hepatitis, and the second was a peculiar splenic fibrosis without evidence of onionskin arrangement about the arterioles. These additional observations emphasize the close similarity between this model and the human illness. The disease occurred most frequently in the hybrid F-1 generation