Multicenter evaluation of the Abbott IMx CA 15-3 assay

Area of Science:

• Clinical Chemistry
• Immunodiagnostics
• Cancer Biomarkers

Background:

• CA 15-3 is a tumor-associated antigen commonly used in monitoring breast cancer.
• Accurate and efficient quantification of CA 15-3 is crucial for patient management.
• Existing methods may have limitations in automation and throughput.

Purpose of the Study:

• To introduce and evaluate a novel, fully automated microparticle enzyme immunoassay (MEIA) for quantitative CA 15-3 measurement.
• To assess the performance characteristics of the new assay on the Abbott IMx automated immunoassay analyzer.

Main Methods:

• Utilized microparticle enzyme immunoassay (MEIA) technology on the Abbott IMx analyzer.
• Employed two specific mouse monoclonal antibodies (115D8 and DF3) for CA 15-3 detection.
• Conducted multi-site studies to evaluate assay performance, including linearity, precision, and correlation.

Main Results:

• The assay demonstrated excellent linearity (94-101% recovery) and a wide dynamic range (up to 250 kilounits/L).
• Intra- and inter-assay coefficients of variation (CVs) were low (< 4.7% and < 5.6%, respectively), with between-laboratory CV < 5.9%.
• Strong correlation (r = 0.9899) was observed when comparing results with a reference CA 15-3 radioimmunoassay (RIA).

Conclusions:

• The Abbott IMx CA 15-3 MEIA is a reliable and automated method for quantitative CA 15-3 determination.
• The assay exhibits robust performance characteristics suitable for clinical laboratory use.
• This automated assay offers an efficient alternative for monitoring cancer biomarkers.