Accessible Prostate-Specific Antigen Testing through Finger-Stick Dried Blood Spots and Routine Laboratory Analyzers

Area of Science:

• Clinical Chemistry
• Biomarker Analysis
• Point-of-Care Testing

Background:

• Prostate-specific antigen (PSA) is crucial for prostate cancer management.
• Traditional PSA testing via venipuncture presents logistical challenges.
• Dried blood spot (DBS) technology offers a less invasive alternative.

Purpose of the Study:

• To evaluate the analytical performance of PSA quantification using finger-stick DBS.
• To compare DBS PSA measurements with traditional venous serum assays.
• To assess the stability and potential influencing factors of PSA in DBS.

Main Methods:

• Paired finger-stick DBS and venous serum samples from 75 patients were analyzed.
• PSA was extracted from DBS using PBS before measurement on a Siemens analyzer.
• Validation included stability, hematocrit effects, precision, and limits of detection/quantitation.

Main Results:

• The DBS PSA assay showed good analytical performance (CVs 4.5-6.1%).
• Excellent agreement was observed between DBS and serum PSA (R² = 0.987).
• PSA remained stable in DBS for 31 days; hematocrit had minimal impact.

Conclusions:

• Accurate PSA measurement is feasible using finger-stick DBS on automated analyzers.
• This minimally invasive method facilitates at-home self-sampling.
• The DBS method supports remote diagnostics, screening, and monitoring of prostate cancer.