Evaluation of a newly developed quantitative determination kit for tumor marker CA15-3 with chemiluminescent assay

Tumor marker carbohydrate antigen 15-3 (CA15-3) is used as a biomarker to aid to diagnose and monitor the prognosis of breast cancer patients. A new quantitative determination kit for CA15-3 with chemiluminescent assay was developed by Xiamen InnoDx Biotech Co., Ltd, China. Therefore, we conducted the report to evaluate the performance of the kit.

According to the "Guiding principles on performance analysis of diagnostic reagents in vitro", the calibration curve, limit of detection, reportable range, accuracy, precision, anti-interference capability, cross-reaction and comparison by measuring EDTA plasma and serum were carried out. In addition, the kit was performed in parallel to electrochemiluminescence immunoassay kit (Roche) to analyze the correlation between the two kits.

Regression equation of calibration curve of the kit was Y=0.7914X+4.1032 (R² =.990). Limit of detection was 0.0347 U/mL. The reportable range was 0.5-2400 U/mL. Recovery ratio was 100.0%-104.8%. Coefficient of variations (CVs) of within-run and between-run were 4.8%-7.6% and 5.8%-7.4% respectively. No remarkable interferences (all Bias% were less than ±10%) were detected when samples contained hemoglobin ≤183.8 μmol/L, bilirubin ≤340 μmol/L, triglyceride ≤18.1 mmol/L, or rheumatoid factor ≤400 U/mL. No cross-reaction was present in the kit. Moreover, compared with the results from electrochemiluminescence immunoassay kit (Roche) in 345 serum samples, there was a satisfied correlation coefficient of 0.977 (P<.01), and the kit was simultaneously fit for the detection of EDTA plasma and serum samples.

The new kit validated satisfactorily, and it can be used for detecting CA15-3 in clinical practice.