Clinical Chemistry Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 43: 843-845, 1997;
This Article
Right arrow Full Text
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (17)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Blase, A. B.
Right arrow Articles by Smith, K. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Blase, A. B.
Right arrow Articles by Smith, K. M.
Related Collections
Right arrow Proteomics and Protein Markers
(Clinical Chemistry. 1997;43:843-845.)
© 1997 American Association for Clinical Chemistry, Inc.

Technical Briefs

Five PSA Methods Compared by Assaying Samples with Defined PSA Ratios,

Amy B. Blasea, Roger L. Sokoloff and Katie M. Smith

a author for correspondence: fax 619-536-8058, e-mail abblase@beckman.com

Prostate-specific antigen (PSA) has been established as a marker to aid in detection and monitoring of prostate cancer (1)(2). PSA in serum exists predominantly in three forms: free, uncomplexed PSA; PSA covalently complexed to {alpha}1-antichymotrypsin (PSA-ACT); and PSA covalently complexed to {alpha}2-macroglobulin (PSA-MG) (3). Immunoassays available today recognize free PSA and PSA-ACT but not PSA-MG, and their result for "total PSA" refers to the sum of the free and ACT-bound forms of PSA as measured by the immunoassay.

In general, the proportion of free PSA relative to PSA-ACT is lower in prostate cancer patients than in normal subjects or in patients with noncancerous prostatic disease (4). The percentage of free PSA ranges from 5% to 50% when total serum PSA is 4–10 µg/L (5)(6). However, increased serum concentrations of PSA do not necessarily indicate prostate cancer because such values can also occur in cases of benign prostate hyperplasia or prostatitis (7)(8)(9).

Assays of total serum PSA differ from one another in an important respect: They do not recognize the free and ACT-bound species of PSA equivalently (10)(11). "Equimolar-response assays" measure equal molar concentrations of free PSA and PSA-ACT equivalently; "skewed-response assays" measure these PSA forms differently (12)(13)(14).

The total PSA concentration measured by an equimolar assay depends on only the total concentration of free PSA plus PSA-ACT and is independent of their relative proportions. The interpretation of results reported by skewed-response assays, however, may be misleading because (a) the proportion of free PSA is generally higher in noncancer patients, and . . . [Full Text of this Article]


Acknowledgments


Footnotes


References




The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
S. A.R. Kort, F. Martens, H. Vanpoucke, H. L. van Duijnhoven, and M. A. Blankenstein
Comparison of 6 Automated Assays for Total and Free Prostate-Specific Antigen with Special Reference to Their Reactivity toward the WHO 96/670 Reference Preparation
Clin. Chem., August 1, 2006; 52(8): 1568 - 1574.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Chem.Home page
A. Semjonow, F. Oberpenning, C. Weining, M. Schon, B. Brandt, G. De Angelis, A. Heinecke, M. Hamm, P. Stieber, L. Hertle, et al.
Do Modifications of Nonequimolar Assays for Total Prostate-specific Antigen Improve Detection of Prostate Cancer?
Clin. Chem., August 1, 2001; 47(8): 1472 - 1475.
[Full Text] [PDF]

Home page
 Clin. Chem.Home page
R. J. Laffin, D. W. Chan, M. J. Tanasijevic, G. A. Fischer, W. Markus, J. Miller, P. Matarrese, L. J. Sokoll, D. J. Bruzek, J. Eneman, et al.
Hybritech Total and Free Prostate-specific Antigen Assays Developed for the Beckman Coulter Access Automated Chemiluminescent Immunoassay System: A Multicenter Evaluation of Analytical Performance
Clin. Chem., January 1, 2001; 47(1): 129 - 132.
[Full Text] [PDF]

Home page
 Clin. Chem.Home page
M. P. Fox, A. A. Reilly, and E. Schneider
Effect of the Ratio of Free to Total Prostate-specific Antigen on Interassay Variability in Proficiency Test Samples
Clin. Chem., August 1, 1999; 45(8): 1181 - 1189.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Chem.Home page
H. Nagasaki, M. Watanabe, N. Komatsu, T. Kaneko, J. Y. Dube, T. Kajita, Y. Saitoh, and Y. Ohta
Epitope Analysis of a Prostate-specific Antigen (PSA) C-Terminal-specific Monoclonal Antibody and New Aspects for the Discrepancy between Equimolar and Skewed PSA Assays
Clin. Chem., April 1, 1999; 45(4): 486 - 496.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Chem.Home page
C. D. Cheli, M. Marcus, J. Levine, Z. Zhou, P. H. Anderson, D. D. Bankson, J. Bock, S. Bodin, C. Eisen, M. Senior, et al.
Variation in the Quantitation of Prostate-specific Antigen in Reference Material: Differences in Commercial Immunoassays,
Clin. Chem., July 1, 1998; 44(7): 1551 - 1553.
[Full Text] [PDF]

Home page
 Clin. Chem.Home page
P. C. Tewari, J. S. Williams, A. B. Blase, and R. L. Sokoloff
Analytical Characteristics of Seminal Fluid PSA Differ from Those of Serum PSA
Clin. Chem., January 1, 1998; 44(1): 191 - 193.
[Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1997 by the American Association for Clinical Chemistry.