Abstract
Background: Prostate-specific antigen (PSA) exists in human serum in two principal forms, free PSA (fPSA) and protein-complexed PSA, predominantly PSA-ACT (α1-antichymotrypsin). Equimolar response (EMR) total PSA (tPSA) immunoassays measure each of these forms equally while skewed-response (SKR) assays overestimate or underestimate the tPSA concentration. The advantages of EMR over SKR tPSA assays are controversial. Methods: We used five nonhuman serum-based samples each containing a different proportion of fSPA:PSA-ACT (0:100 to 100:0, %:%) and patients' serum samples from men with histologically confirmed benign prostatic hyperplasia (BPH) (n=94) or PCA (n=30) and a wide range of fPSA concentrations to investigate the molar response status of six tPSA assays. Receiver-operator characteristic (ROC) curve analysis was used to compare the discriminatory power of these assays in distinguishing men with BPH from those with PCA. Results: The Bayer Immuno-1 tPSA (BtPSA) assay demonstrated EMR characteristics and diagnostic accuracy similar to the Hybritech Tandem-E and Tandem-R tPSA assays. At 90% sensitivity, EMR tPSA assays had higher specificity than SKR tPSA assays. Conclusions: The BtPSA assay is an EMR tPSA assay and EMR assays provide improved diagnostic specificity over SKR tPSA assays.
Original language | English (US) |
---|---|
Pages (from-to) | 81-95 |
Number of pages | 15 |
Journal | Clinica Chimica Acta |
Volume | 326 |
Issue number | 1-2 |
DOIs | |
State | Published - Dec 2002 |
Keywords
- Benign prostatic hyperplasia
- Equimolar-response assay
- Prostate cancer
- Prostate-specific antigen
- Receiver-operator characteristic curve
- Skewed-response assay
ASJC Scopus subject areas
- Biochemistry
- Clinical Biochemistry
- Biochemistry, medical