The comparison study between UniCAP EliA and former kit for measuring the autoantibodies

Measurements of autoantibodies are served for diagnosis of autoimmune diseases in routine. Results of UniCAP EliA (Phadia), based on fluorescence-enzyme immunoassay, were compared to those of the current ELISA method, MESACUP DNA-II test [ds] and MESACUP-2 test (MBL) with total of 404 sera. The full automated instrument of UniCAP 250 was used for measurement of UniCAP EliA. The CVs of within day reproducibility (n=10) were 3.0-9.6% by UniCAP EliA, meanwhile 1.7-11.7% by MESACUP. The CVs of between day reproducibility(5 days) were 1.0-11.8% by UniCAP EliA, meanwhile 1.0-19.9% by MESACUP. The concordance of U1RNP, SS-A/Ro, SS-B/La, Scl-70 and Jo-1 between UniCAP EliA and MESACUP were 89.5-100%, but the positive concordance in dsDNA, Sm andJo-1 showed lower concordance percentage (40.0-62.9%). UniCAP EliA had better reproducibility than MESACUP. Some sera showed discrepant results between UniCAP EliA and MESACUP. These discrepancies might be occurred by the purification of antigens or different measurement principle of kits. The antigens' purification of UniCAP EliA seemed enough for the routine tests, and the results from UniCAP EliA would give high clinical importance.