Comparison of automated multiplexed bead-based ANA screening assay with ELISA for detecting five common anti-extractable nuclear antigens and anti-dsDNA in systemic rheumatic diseases.
BACKGROUND
A newly developed and totally automated Luminex-based assay, the BioPlex™ 2200 system, is able to detect various autoantibodies simultaneously from a single sample. We compared the BioPlex™ 2200 system with ELISA for the detection of six autoantibodies.


METHODS
A total of 127 serum samples from the patients with systemic rheumatic diseases were collected and assayed with the BioPlex™ 2200 system (Bio-Rad, USA) and conventional ELISA (INOVA Diagnostics, USA) for 5 anti-extractable nuclear antigens. Additionally, relative sensitivity of the BioPlex™ 2200 system for detecting anti-dsDNA was evaluated with 79 specimens from SLE patients, which were positive for anti-dsDNA by ELISA.


RESULTS
The concordance rates between ELISA and the BioPlex ranged from 88.1% for anti-RNP to 95.2% for anti-Scl-70, and the kappa coefficients between the results by the two assays were from 0.48 to 0.67. Among the 79 anti-dsDNA positive specimens by ELISA, seventy-eight (98.7%) showed positive results for anti-dsDNA by the BioPlex.


CONCLUSIONS
The BioPlex™ 2200 system showed comparable results with those by conventional ELISA for detecting autoantibodies, and this automated assay could measure multifarious autoantibodies concurrently in a single sample. It could be effectively used in clinical laboratories for screening autoimmune diseases.
Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
Yoonjung
Y
Kim
Yongjung
Y
Park
Eun Young
EY
Lee
Hyon-Suk
HS
Kim
D034961:Antigens, Nuclear / Q000032:analysis*; D001331:Automation; D004247:DNA / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D008856:Microscopy, Fluorescence; D012216:Rheumatic Diseases / Q000276:immunology*
D034961:Antigens, Nuclear; D004247:DNA