%0 Journal Article %A MANUEL M. GARRIDO %A JOSÉ C. MARTA %A RUY M. RIBEIRO %A LUÍS C. PINHEIRO %A STEFAN HOLDENRIEDER %A JOÃO T. GUIMARÃES %T Comparison of Three Assays for Total and Free PSA Using Hybritech and WHO Calibrations %D 2021 %R 10.21873/invivo.12643 %J In Vivo %P 3431-3439 %V 35 %N 6 %X Background/Aim: Lack of interchangeability between prostate-specific antigen (PSA) assays could have a clinical impact. We compared PSA assays from different manufacturers and calibrations. Patients and Methods: A total of 233 men who underwent prostate biopsy (PSA: 2-10 ng/ml; Beckman Coulter Access® Hybritech® as reference) were enrolled. Total (tPSA) and free PSA (fPSA) were also measured using the Roche cobas® and the Abbott Architect® methods. Results: Roche tPSA values were ≈1% higher than Beckman, while Abbott values were ≈5% lower. Roche had the highest diagnostic sensitivity (92%) compared to Beckman Coulter (87%) and Abbott (85%). Roche fPSA was ≈3% lower and Abbott ≈17% higher than that of Beckman. For the percentage of fPSA, Roche had the highest sensitivity (98%). Conclusion: Roche cobas® and Beckman Coulter Access® Hybritech® tPSA were almost interchangeable. While the agreement was acceptable for tPSA, this did not happen with fPSA and greater efforts for harmonization are required. %U https://iv.iiarjournals.org/content/invivo/35/6/3431.full.pdf