Evaluation of Samples with DFS Staining Pattern Detected by Indirect Immunofluorescence Assay.

Background: In this study, we aimed to determine the presence of anti DFS70 antibody by a specific IB method in samples showing the DFS pattern and to determine the distribution of DFS pattern in different patient groups. Methods: 2,401 serum samples, which were received for ANA screening, were tested by IIF method at Akdeniz University Hospital Diagnostic Laboratory. Out of 139 samples with DFS pattern, 75 samples were tested for the presence of anti DFS70 antibody by IB and were included in the study. Patients' clinical diagnoses were obtained retrospectively from medical records. Results: 63 (84%) of 75 samples, which showed DFS patern by IIF, were found to have anti DFS70 antibody by IB. Five of these patients were diagnosed with SARD while the rest (58) had diseases other than SARD. Conclusions: DFS pattern detected by IIF and isolated anti DFS70 antibody positivity detected by IB show high concordance. However IIF results should be confirmed because of the patterns that can be misidentified as DFS pattern. The presence of anti-DFS70 antibodies, which help to exclude SARD, prevent further unnecessary referral demands.