Comparison of various assay systems for prostate-specific antigen standardization

Area of Science:

• Clinical Chemistry
• Biomedical Assays
• Prostate Cancer Diagnostics

Background:

• Discrepancies in serum prostate-specific antigen (PSA) values across different assay systems pose a challenge for clinical interpretation.
• Standardization of PSA measurements is crucial for accurate diagnosis and monitoring of prostate conditions.

Purpose of the Study:

• To investigate the feasibility of converting serum PSA values obtained from various commercial assay kits.
• To establish a reliable method for inter-assay PSA value comparison and harmonization.

Main Methods:

• Comparison of nine different serum PSA assay kits: MARKIT-F PA, MARKIT-M PA, EIKEN PA, PA test WAKO, Ball ELSA PSA, E-Test Tosoh II PA, PROS-CHECK PSA, DELFIA PSA, and TANDEM-R PSA.
• Assay of calibrators from each system and analysis of 142 serum samples from patients with benign prostatic hyperplasia or prostate cancer.
• Statistical analysis including determination of slopes, coefficients of correlation, and linear regression lines.

Main Results:

• Slopes obtained from detecting standards for each kit were nearly identical to those from the original assay systems.
• High coefficients of correlation were observed among the PSA detection systems when using patient sera.
• Linear regression lines confirmed a strong linear relationship between PSA values from different assay systems.

Conclusions:

• Serum PSA values from different assay systems can be harmonized using conversion formulas or coefficients.
• This standardization facilitates consistent interpretation of PSA levels across diverse clinical laboratories.
• The findings support the reliable use of comparative PSA data in clinical studies and patient management.