[Automation of the Examination for Autoantibodies]

Antinuclear antibody (ANA) testing is indispensable for diagnosing and estimating clinical conditions of autoimmune diseases. This literature explains the usability and problem points regarding routine laboratory tests with examples of our own experiments regarding ANA diagnostics with some new technologies. The indirect immunofluorescence assay (IFA) is the gold standard for ANA screening, and it can detect more than 100 different antibodies, including the anti-proliferating cell nuclear antigen as well as anti- cytoplasmic antibodies. However, complicated procedures of conventional IFA and visual interpretation require highly skilled laboratory staff. The EUROPattern Cosmic IFA System (EUROIMMUN, Cosmic Corporation) and HELIOS* (Aesku Diag- nostics, MBL), which are computer-aided microscope systems for ANA testing, showed concordance of the positivity rate as high as 93.3 and 91.9%, respectively, and concordance of the antibody titer as high as 94.0 and 98.8%, respectively (within +/-1 titer) compared with the conventional method, on the measurement of different populations for each system. Although the computer-aided microscope system is not considered a complete system and laboratory staff should verify each result, it is a useful system for routine ANA analysis because it contributes to ANA stand- ardization and an efficient workflow. In our previous study, we demonstrated that BioPlex2200 (Bio-Rad), a fully automated immunoassay ana- lyzer using suspension bead array technology, was useful for the clinical diagnosis of autoimmune diseases. As an ANA screening test, the positive rate was low (7.2%) in healthy subjects, and comparable with that of IFA ( X160). The prevalence of disease-specific ANA in connective tissue disease patients was comparable with the general occurrence rate except for anti-dsDNA antibody in SLE. In accordance with the results of double immunodiffusion and Western blotting with the conventional method, the concordance rate between BioPlex2200 and conventional methods was high (95.0-100%) except for anti-dsDNA antibody. To provide high-quality and prompt clinical tests while considering the efficiency of working and cost reduc- tion, each laboratory should actively innovate and operate these advanced inspection technologies. [Review].