Total PSA Test Performance Evaluation on Cobas Pure and Measurement System Comparison with Different Calibrators

Area of Science:

• Clinical Chemistry
• Immunoassays
• Prostate Cancer Biomarkers

Background:

• Total prostate specific antigen (tPSA) is a key biomarker for prostate cancer management.
• Standardization of tPSA testing is crucial for accurate clinical interpretation.
• Evaluating new diagnostic systems against established methods is essential.

Purpose of the Study:

• To assess the performance of the Cobas Pure integrated solutions system for tPSA testing.
• To compare tPSA results from Cobas Pure with established systems (Alinity i, Unicel DxI 800).
• To investigate the impact of different calibration traceability on tPSA measurements.

Main Methods:

• Performance evaluation included imprecision, linearity, and detection limit assessment.
• Correlation studies were conducted between Cobas Pure, Alinity i, and Unicel DxI 800.
• Systems were calibrated against WHO IS 96/670 or manufacturer-specific calibrators.

Main Results:

• Within-laboratory reproducibility and repeatability were below 1.2%.
• Linearity was confirmed within the claimed analytical measurement range.
• Good correlation was observed, but significant mean bias emerged with Unicel DxI 800 due to different calibrator traceability.

Conclusions:

• The Cobas Pure system demonstrates robust analytical performance for tPSA.
• Differences in calibrator traceability significantly impact tPSA results.
• This study underscores the importance of calibration in tPSA assay comparison and clinical decision-making.