Determination of Non-α1-Antichymotrypsin-complexed Prostate-specific Antigen as an Indirect Measurement of Free Prostate-specific Antigen: Analytical Performance and Diagnostic Accuracy
| Autor: | Brigitte Brux, Axel Semjonow, Pranav Sinha, Stefan A. Loening, Michael Lein, Klaus Jung, Carsten Stephan, Sebastian Wesseling |
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| Rok vydání: | 2003 |
| Předmět: |
Male
medicine.medical_specialty alpha 1-Antichymotrypsin Clinical Biochemistry Prostatic Hyperplasia Urology Diagnostic accuracy urologic and male genital diseases Sensitivity and Specificity Prostate cancer Prostate Internal medicine medicine Humans In patient Aged Retrospective Studies Immunoassay Autoanalysis Receiver operating characteristic business.industry Biochemistry (medical) Prostatic Neoplasms Free prostate specific antigen Middle Aged Prostate-Specific Antigen medicine.disease Prostate-specific antigen medicine.anatomical_structure Endocrinology ROC Curve Luminescent Measurements α1 antichymotrypsin business Protein Binding |
| Zdroj: | Clinical Chemistry. 49:887-894 |
| ISSN: | 1530-8561 0009-9147 |
| DOI: | 10.1373/49.6.887 |
| Popis: | Background: A new assay measures prostate-specific antigen (PSA) not complexed to α1-antichymotrypsin (nACT-PSA) after removing PSA complexed to ACT by use of anti-ACT antibodies. We evaluated nACT-PSA and its ratio to total PSA (tPSA) as alternatives to free PSA (fPSA) and its ratio to tPSA in differentiating prostate cancer (PCa) and benign prostatic hyperplasia (BPH) in patients with tPSA of 2–20 μg/L. Methods: PSA in serum of 183 untreated patients with PCa and 132 patients with BPH was measured retrospectively on the chemiluminescence immunoassay analyzer LIAISON® (Byk-Sangtec Diagnostica) with the LIAISON tPSA and LIAISON fPSA assays. The nACT-PSA fraction was determined with a prototype assay measuring the residual PSA after precipitation of ACT-PSA with an ACT-precipitating reagent. Results:nACT-PSA was higher than fPSA in samples with fPSA concentrations 1 μg/L fPSA. The median ratios of fPSA/tPSA and of nACT-PSA/tPSA were significantly different between patients with BPH and PCa (19.4% vs 12.2% and 17.4% vs 13.0%, respectively). Within the tPSA ranges tested (2–20, 2–10, and 4–10 μg/L), areas under the ROC curves for the fPSA/tPSA ratios were significantly larger than those for nACT-PSA/tPSA. In the tPSA ranges Conclusions: nACT-PSA and its ratio to tPSA provide lower diagnostic sensitivity and specificity than fPSA/tPSA. The fPSA/tPSA ratio represents the state-of-the-art method for differentiating between PCa and BPH. |
| Databáze: | OpenAIRE |
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