2017 Volume 66 Issue 3 Pages 234-241
The antinuclear antibody (ANA) test is clinically important for the diagnosis of connective tissue diseases (CTDs). A screening test for 8 disease-specific ANAs by chemiluminescence enzyme immunoassay (CLEIA) has recently been developed. However, the commercial reagents had been improved after a previous study because of a prozone-like phenomenon observed in DNA-sensitized particles. In this study, we evaluated the correlation and concordance between the improved reagents (CLEIA-ANA) and the conventional method (ELISA-ANA) and the utility of CLEIA-ANA as the screening test for the 8 disease-specific ANAs by comparing with indirect immunofluorescence assay (IF-ANA). There was a statistically significant correlation between CLEIA-ANA and ELISA-ANA (p < 0.0001). The concordance rate between CLEIA-ANA and ELISA-ANA was 88.2% and the discrepancies might be caused by the differences in solid-phase antigens, measurement environments, and detection sensitivity. The positivity rate of CLEIA-ANA was low in healthy individuals and comparable to that of IF-ANA (1:160) in CTD patients and healthy individuals. The concordance rate between CLEIA-ANA and IF-ANA (1:160) was relatively low (86.3%) in 161 CTD patients. However, in the 19 sera with CLEIA-ANA+/IF-ANA (1:160)−, 14 samples were positive for anti-SS-A antibodies or anti-Jo-1 antibodies, which are frequently overlooked in IF-ANA. Furthermore, CLEIA-ANA was capable of efficiently capturing the 8 disease-specific ANAs in 99 CTD patients who had at least one or more disease-specific ANAs as compared with IF-ANA. In summary, a fully automated CLEIA-ANA is clinically useful as a rapid screening test for 8 disease-specific ANAs, although some ANAs are undetectable by CLEIA-ANA owing to solid-phase antigens or measurement environments.
