Performance evaluation of CA242 by flow fluorescence assay

Carbohydrate antigen 24–2 (CA24–2) is usually used as a biomarker for the diagnosis of pancreatic cancer and colorectal cancer. Currentlly, a new quantitative assay kit for CA242 by flow fluorometry assay (FFA) was developed by Shanghai Tellgen Cooperation Co. Ltd. China. Therefore, we conducted the performance evaluation for it. According to the “Guiding principles on performance analysis of diagnostic reagents in vitro” and “American association of clinical laboratory standardization guidelines EP15-A2”, the accuracy, precision, linear range, reportable range, biological reference interval verification, carry-over contamination rate, anti-interference capability and cross reaction of the assay kit used in TESMI F3999-Luminex200 automatic immunoassay system were evaluated. In addition, the assay kit was performed in parallel to CanAg kit (CanAg Diagnostics Products Beijing Co., Ltd.) to analyze the correlation between the 2 kits. The bias of accuracy of the new assay kit was less than 12.5% and the coefficient of variations (CVs) of precision were all less than 10.0%. The linear range of CA242 concentration of the testing kit was between 3.46 U/ml and 434.76 U/ml and the reportable range was 6.00 to 535.13 U/ml. The CA242 reference interval 0.00 to 20.00 U/ml was suitable for use in laboratory. The carry-over contamination rate was −0.14%. Correlation analysis showed a satisfactory relevance and consistency (r = 0.982, P < .001) between the new assay kit and CanAg kit, with a regression equation Y = 1.0012X to 0.878 (R(2) = 0.9647, P < .001). No statistically significant difference between serum samples without interferences and samples containing lipemia, bilirubin and hemoglobin. And no cross reaction existed between the assay kit and the other tumor markers, such as carbohydrate antigen 125 (CA125), alpha-fetoprotein (AFP), and cytokeratin-19 soluble fragment (CYFRA21-1). The new CA242 quantitative assay kit possesses good detection performance when it is used in TESMI F3999-Luminex200 automatic immunoassay system, which can be used for the examination of CA242 in clinical practice.