494356.fig.004
Figure 4: Characteristic staining pattern and suggested test algorithm considering anti-DFS70 antibodies. The characteristic dense fine speckled (DFS) staining pattern of interphase cells is indicated by the red arrow and the strong chromosome staining of metaphase cells by the blue arrow. Samples with a DFS pattern should be tested for anti-DFS70 antibodies by a confirmatory test and by ANA Screen ELISA (QUANTA Lite ANA Screen ELISA) containing various autoantigens. Patients with negative ANA Screen ELISA and positive DFS70 result have a low likelihood for having SARD. Patients with a positive ANA Screen ELISA either in combination with a positive or a negative DFS70 test result have an increase likelihood of having SARD.