[Evaluation of a Fully Automated Analyzer for Antinuclear Antibody Test Using Indirect Immunofluorescence Assay].

The fully automated HELIOS® system for antinuclear antibody (ANA) test is capable of automatically per- forming all IFA procedures. We evaluated the analytical performance, characteristics and utility of HELIOS system as ANA screening test. We compared HELIOS system and the conventional methods in sera from 161 connective tissue disease (CTD) patients and 250 healthy individuals. The presence and titer of ANA were automatically determined by performing HELIOS system at 1:80 dilution and the ANA titers were com- pensated by several dilution and visual determination in sera with a high ANA titer and ANA-positive sera combined with anti-cytoplasmic antibody. The ANA staining patterns were assessed by visual determination of the digital image on HELIOS system. The total concordance rate between the conventional method and HELIOS system was 94.4%. The concordance of ANA titer (within ± 1 tube difference) between the con- ventional method and automated or compensated evaluation of HELIOS system was 85.7% or 98.8%, respec- tively. The concordance rate of six nuclear staining patterns was from 81.4% to 100% and the discrepancies of granular staining pattern might be caused by the fixation of HEp-2 cells. The positive rates of ANA in CTD patients and healthy individuals were comparable with the conventional methods. Taken together, HELIOS system can appropriately perform the automated determination of ANA except in some cases and is useful as ANA screening test. Furthermore, this system can contribute not only an efficient IFA procedure but also the ANA standardization by IFA. [Original].