To evaluate the clinical performance of chemiluminescent immunoassay (CLIA) on anti-nuclear antibody(ANA) specific autoantibodies testing.

A multi-center clinical study A total of 811 Sera samples were collected from 6 collaborating hospitals during the period of April to July 2016, and tested with CLIA and line immunoassay (LIA) in parallel for autoantibodies to ribonucleoprotein(RNP), smith antigen(Sm), SSA/Ro60, SSB/La, centromere protein B(CENPB), double-stranded DNA(dsDNA), nucleosome(Nuc), and ribosome P protein(Rib-P). The positive rate, specificity and qualitative coincidence rate for each antibody between CLIA and LIA methods were analyzed. All discrepant samples for systemic lupus erythematosus (SLE) highly specific autoantibodies (including anti-Sm, dsDNA, Nuc and Rib-P) were retested by enzyme linked immunosorbent assay (ELISA) and further analyzed with SLE disease cohort using McNemar test.

The positive rate and specificity of CLIA and LIA for antibodies to ANA specific antigens were comparable. Excellent qualitative coincidence were found between CLIA and LIA for the detection of anti-RNP, SSA/Ro60, SSB/La and CENPB (Kappa>0.75), while the coincidence rate foranti-Sm, dsDNA, Nuc and Rib-P detection were moderate (0.4<Kappa<0.75). The data from discrepant samples retested with ELISA showed there was no significant difference between CLIA and ELISA for the detection of anti-Sm (χ²=3.333, P=0.067) and Rib-P (χ²=0.888, P=0.345), but a significant difference were observed between LIA and ELISA test results for anti-Sm (χ²=5.444, P=0.019), anti-dsDNA (χ²=5.812, P=0.015), anti-Nuc (χ²=12.071, P<0.001) and anti-Rib-P (χ²=25.861, P<0.001). When analyzing discrepant sample with SLE diagnosis, data from CLIA for anti-dsDNA (χ²=1.132, P=0.249) and anti-Nuc (χ²=0.571, P=0.449) showed no differencewith SLE diagnosis, while data from LIA for anti-Sm(χ²=21.125, P<0.001), anti-dsDNA(χ²=59.507, P<0.001), anti-Nuc(χ²=38.4, P<0.001) and anti-Rib-P (χ²=6.259, P=0.012)showed significant difference with SLE diagnosis.

CLIA and LIA showed similar positive rate and specificity when testing antibody to ANA specific antigens. The coincidence rate between CLIA and LIA for the detection of anti-RNP, SSA/Ro60, SSB/La and CENPB wereexcellent and moderate for anti-Sm, dsDNA, Nuc and Rib-P. CLIA test results were more comparable with ELISA and had a better correlation with SLE disease diagnosis among all discrepant samples. With the additional benefits of full automation, quantitative output, random-access and high flexibility, CLIA is a preferable test platform for the detection of ANA specific autoantibodies. (Chin J Lab Med, 2017, 40: 602-608)

Multi center study; Antibody, anti-nuclear; Lupus erythematosus, systemic; Sjögren′s syndrome; Enzyme-linked immunosorbent assay