FIDIS (BMD, France) is a multiplex analytical flow cytometry system for the detection of antibodies. The aim of this study was to evaluate the FIDIS connective assay system for the detection of antinuclear antibodies (ANA), and to assess the clinical utility of these parameters in the diagnosis of connective tissue diseases. The FIDIS system simultaneously measures IgG antibodies directed at dsDNA, Ro, La, RNP, Sm, Jo-1, Scl-70, rRNP, and CENP-B.

Sera were obtained from 100 patients with SLE and 100 patients with Sjögren's syndrome. A total of 78 sera from patients with rheumatoid arthritis (RA) and 100 from normal healthy blood donors were also tested.

Antibodies to Scl-70, Jo-1, and rRNP were not detected in any of the sera from the disease groups. In the normal control group, the only positive result obtained was in one sera that gave a weak positive result for anti-CENP-B.