RESUMO
Indirect immunofluorescent detection of anti-nuclear antibodies was conducted on sections of rat liver and on smears of human Hep 2 tumour cells in the serum of 1017 patients. Overall, the Hep 2 cells gave titres superior by 1 or 2 dilutions. Taking into account this difference, a good agreement was observed between the 2 cellular reagents in 83 per cent of the sera tested. The divergences, which affect almost one half of the positive sera, are largely due to the presence of anti-centromere antibodies, anti-nuclear antibodies giving a patchy "M3" appearance to the Hep 2 cells and, most importantly, anti-nucleolar antibodies. Such differences demonstrate that there are major qualitative or quantitative antigenic differences between the nuclei of rat hepatocytes and those of Hep 2 cells. Although technically rat liver and Hep 2 cells were found to be fairly easy to use and interpret, only a large comparative study of human pathology will be able to determine which is the better reagent for the routine detection of anti-nuclear antibodies.