Background: SelexOn (Infopia, Korea) is a novel immunoassay instrument that measures the concentration of α-fetoprotein (AFP), creatine kinase isoenzyme (CK-MB), D-dimer, high-sensitivity C-reactive protein (hs-CRP), myoglobin, prostate-specific antigen (PSA), and thyroid-stimulating hormone (TSH) in whole blood. We evaluated the analytical performance of SelexOn.
Methods: The analytical performance of SelexOn was evaluated for precision and linearity, and compared with the ADVIA Centaur XP Immunoassay System (Siemens, Germany) and the STA-R coagulation analyser (Diagnostica Stago, France).
Results: Within-run CV ranged from 2.9% to 8.9% for all biomarkers. Between-run precision ranged from 1.6% to 11.3% for all biomarkers, except at low levels of D-dimer (16.1%). Observed linearity ranges were AFP, 8.7 to 47.0 ng/mL; CK-MB, 4.7 to 38.7 ng/mL; D-dimer, 393.2 to 2,760.3 ng/mL; hs-CRP, 2.1 to 9.0 mg/L; myoglobin, 67.2 to 441.5 ng/mL; PSA, 2.6 to 23.7 ng/mL; and TSH, 3.3 to 38.9 mIU/L. Upon comparing SelexOn with the Centaur XP and STA-R systems, values of AFP, CK-MB, hs-CRP, and PSA showed good correlation, with correlation coefficients greater than 0.975. The correlation coefficients of TSH, myoglobin, and D-dimer were 0.9723, 0.9649, and 0.8379, respectively. The concordance was excellent for hs-CRP (kappa [κ]=0.958), PSA (κ=0.854), and TSH (κ=0.810); good for AFP (κ=0.655), CK-MB (κ=0.759), and myoglobin (κ=0.783); and moderate for D-dimer (κ=0.561).
Conclusions: SelexOn demonstrated acceptable precision, linearity, and correlation with the Centaur XP and the STA-R for seven biomarkers. Because of its speed and performance, SelexOn may facilitate the rapid screening of patients for cardiovascular disease, thyroid disease, prostate cancer, and hepatocellular carcinoma.
(J Lab Med Qual Assur 2014;36:30-38)

Keywords: Immunoassay, Cardiovascular diseases, Performance, Tumour markers

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