scholarly journals Comparison of prostate-specific antigen (PSA) measured by four combinations of free PSA and total PSA assays

1997 ◽  
Vol 43 (9) ◽  
pp. 1588-1594 ◽  
Author(s):  
Ralf Junker ◽  
Burkhard Brandt ◽  
Christian Zechel ◽  
Gerd Assmann
Keyword(s):  
Prostate Specific Antigen ◽  
Patient Population ◽  
Specific Antigen ◽  
Prostate Hyperplasia ◽  
Predictive Values ◽  
Negative Results ◽  
Free Psa ◽  
Gray Area ◽  
Total Psa ◽  
Benign Prostate

Abstract We compared prostate-specific antigen (PSA) assay systems [i.e., free PSA (f-PSA) and the corresponding total PSA (t-PSA) assay] from four different manufacturers as well as the f-PSA/t-PSA ratios with regard to their ability to discriminate between benign prostate hyperplasia (BPH) and prostate cancer (PCA). ROC analysis showed similar areas under the curves (AUCs) with different assay systems. For the entire patient population the AUCs of the f-PSA/t-PSA ratio were not or slightly increased compared with the sole measurement of t-PSA (t-PSA, 0.792–0.820; f-PSA/t-PSA ratio, 0.685–0.859). In contrast, for only those patients who showed t-PSA concentrations within the diagnostic gray area of 4–25 μg/L t-PSA, the AUCs were greater for the f-PSA/t-PSA ratio than for measurement of t-PSA alone (t-PSA, 0.608–0.647; f-PSA/t-PSA ratio, 0.690–0.806). These results were confirmed by the predictive values of the negative results (NPVs) of the t-PSA assays and the f-PSA/t-PSA ratios (assay thresholds corresponding to a 95% detection limit). Compared with the sole t-PSA measurement there was no mentionable increase in the NPVs due to the f-PSA/t-PSA ratio for the entire patient population, but an increase up to 49% when limited to t-PSA concentrations within 4–25 μg/L. We therefore conclude that the f-PSA/t-PSA ratio may be helpful for differential diagnosis of BPH and PCA within the diagnostic gray area of 4–25 μg/L t-PSA.

scholarly journals Novel immunoassay for the measurement of complexed prostate-specific antigen in serum

1998 ◽  
Vol 44 (6) ◽  
pp. 1216-1223 ◽  
Author(s):  
W Jeffrey Allard ◽  
Zeqi Zhou ◽  
Kwok K Yeung
Keyword(s):  
Prostate Cancer ◽  
Monoclonal Antibody ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Binding Properties ◽  
Prostate Disease ◽  
Free Psa ◽  
Total Psa ◽  
Benign Prostate ◽  
Artificial Mixtures

Abstract Serum prostate-specific antigen (PSA) is an effective diagnostic tool for detection of prostate cancer (CaP) at an early and potentially curable stage, but specificity is low. Studies have shown that the proportion of serum PSA complexed with α-1-antichymotrypsin (ACT) is higher in men with CaP than in men with benign prostate disease. We developed a novel immunoassay for complexed PSA based on the unique binding properties of a monoclonal antibody that fails to bind free PSA in the presence of antibodies specific for free PSA. The assay measured mixtures of free and complexed PSA accurately, and the measured values of free + complexed PSA in artificial mixtures and in patient sera were equivalent to the measured value of total PSA. Both the serum concentration and the proportion of complexed PSA was substantially higher in patients with CaP compared with patients with benign prostate disease. The cPSA assay may have utility in improving specificity in screening for prostate cancer.

scholarly journals Comparison between Equimolar- and Skewed-Response Assays of Prostate Specific Antigen: Is There an Influence on the Clinical Significance When Measuring Total Serum Prostate Specific Antigen?

1996 ◽  
Vol 33 (3) ◽  
pp. 209-214 ◽  
Author(s):  
Klaus Jung ◽  
Michael Lein ◽  
Dietmar Schnorr ◽  
Brigitte Brux ◽  
Wolfgang Henke ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Benign Prostate Hyperplasia ◽  
Specific Antigen ◽  
Total Serum ◽  
Clinical Validity ◽  
Characteristic Analysis ◽  
Prostate Hyperplasia ◽  
Free Psa ◽  
Receiver Operation Characteristic ◽  
Benign Prostate

Using the Tandem®-E, Axsym® and LIA-mat® assays, prostate specific antigen (PSA) was measured in pure PSA solutions of known concentrations of free and complexed PSA and in serum of patients with prostate cancer ( n = 31), benign prostate hyperplasia ( n = 32) and in healthy controls ( n = 27). Measurements of pure PSA solutions showed that the AxSym® assay exemplified typical properties of the skewed-response assay reacting more to free PSA than to the complexed PSA forms whereas the other two assays showed an equimolar-response. When PSA was measured in the serum of the three groups, the AxSym® test and Tandem®-E gave similar PSA values whereas the LIA-mat test yielded significantly lower values. These results were not related to the amount of free PSA in the samples and proved that discordant PSA values between PSA assays were not mainly caused by the use of skewed- or equimolar assays. Despite these differences, receiver-operation characteristic analysis confirmed that the clinical validity of all three PSA tests did not differ.

Effect of Marathon Running on Total and Free Serum Prostate-Specific Antigen Concentrations

2003 ◽  
Vol 127 (3) ◽  
pp. 345-348 ◽  
Author(s):  
Alexander Kratz ◽  
Kent B. Lewandrowski ◽  
Arthur J. Siegel ◽  
Patrick M. Sluss ◽  
Kelly Y. Chun ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Physical Exertion ◽  
The United States ◽  
Marathon Running ◽  
Reliable Determination ◽  
Free Psa ◽  
Sporting Event ◽  
Exercise Induced ◽  
Total Psa

Abstract Context.—Prostate-specific antigen (PSA) is an important tumor marker for the most frequently diagnosed cancer in the United States. A major limitation of this marker is falsely elevated results in patients who are found not to have prostate cancer. The effects of vigorous physical exertion on PSA concentrations are controversial. Objective.—To determine the effects of marathon running on PSA levels. Design.—Measurement of total and free PSA levels in the sera of participants in a marathon before and within 4 and 24 hours after the race. Results.—None of the participants had elevated total PSA levels before the race. Although we found no statistically significant changes in average total or free PSA concentrations at either time point, after the marathon, 2 (11%) of 18 runners had total PSA concentrations outside the standard reference range. Changes in total PSA levels did not correlate with age or prerace PSA concentrations. Free PSA levels were not statistically significantly changed after the race and did not allow a reliable determination of exercise-induced PSA elevations. Conclusions.—Although it may not be necessary for men to abstain from exercise involving running before blood draws for PSA analysis, elevated PSA concentrations may be observed in some individuals after participation in a major sporting event. In these cases, repeat measurements should be considered at a time significantly removed from such exercise.

scholarly journals Analysis of Urinary Prostate-Specific Antigen Glycoforms in Samples of Prostate Cancer and Benign Prostate Hyperplasia

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Chun-Jen Hsiao ◽  
Tzong-Shin Tzai ◽  
Chein-Hung Chen ◽  
Wen-Horng Yang ◽  
Chung-Hsuan Chen
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Benign Prostate Hyperplasia ◽  
Clinical Sample ◽  
Specific Antigen ◽  
Ion Accumulation ◽  
Detection Sensitivity ◽  
Prostate Hyperplasia ◽  
Liquid Chromatography Tandem Mass ◽  
Benign Prostate

Glycans of prostate-specific antigen (PSA) in prostate cancer were found to be different from that in benign disease. It is difficult to analyze heterogeneous PSA glycoforms in each individual specimen because of low protein abundance and the limitation of detection sensitivity. We developed a method for prostate cancer diagnosis based on PSA glycoforms. Specific glycoforms were screened in each clinical sample based on liquid chromatography-tandem mass spectrometry with ion accumulation. To look for potential biomarkers, normalized abundance of each glycoform in benign prostate hyperplasia (BPH) and in prostate cancer was evaluated. The PSA glycoform, Hex5HexNAc4NeuAc1dHex1, and monosialylated, sialylated, and unfucosylated glycoforms differed significantly between the prostate cancer and BPH samples. The detection sensitivity (87.5%) and specificity (60%) for prostate cancer identification are higher than those of the serum PSA marker. As low as 100 amol PSA could be detected with the ion accumulation method which has not been reported before. The improved detection specificity can help reduce unnecessary examinations.

scholarly journals The Combination of Human Glandular Kallikrein and Free Prostate-specific Antigen (PSA) Enhances Discrimination Between Prostate Cancer and Benign Prostatic Hyperplasia in Patients with Moderately Increased Total PSA

1999 ◽  
Vol 45 (11) ◽  
pp. 1960-1966 ◽  
Author(s):  
Angeliki Magklara ◽  
Andreas Scorilas ◽  
William J Catalona ◽  
Eleftherios P Diamandis
Keyword(s):  
Prostate Cancer ◽  
Benign Prostatic Hyperplasia ◽  
Prostate Specific Antigen ◽  
Prostatic Carcinoma ◽  
Specific Antigen ◽  
Area Under The Curve ◽  
Prostatic Hyperplasia ◽  
Free Psa ◽  
Glandular Kallikrein ◽  
Total Psa

Abstract Background: Prostate-specific antigen (PSA) is the most reliable tumor marker available and is widely used for the diagnosis and management of prostate cancer. Unfortunately, PSA cannot distinguish efficiently between benign and malignant disease of the prostate, especially within the range of 4–10 μg/L. Among the refinements developed to enhance PSA specificity is the free/total PSA ratio, which is useful in discriminating between the two diseases within the diagnostic “gray zone”. Recent data indicate that human glandular kallikrein (hK2), a protein with high homology to PSA, may be an additional serum marker for the diagnosis and monitoring of prostate cancer. Methods: We analyzed 206 serum samples (all before treatment was initiated) from men with histologically confirmed benign prostatic hyperplasia (n = 100) or prostatic carcinoma (n = 106) with total PSA in the range of 2.5–10 μg/L. Total and free PSA and hK2 were measured with noncompetitive immunological procedures. Statistical analysis was performed to investigate the potential utility of the various markers or their combinations in discriminating between benign prostatic hyperplasia and prostatic carcinoma. Results: hK2 concentrations were not statistically different between the two groups of patients. There was a strong positive correlation between hK2 and free PSA in the whole patient population. hK2/free PSA ratio (area under the curve = 0.69) was stronger predictor of prostate cancer than the free/total PSA ratio (area under the curve = 0.64). At 95% specificity, the hK2/free PSA ratio identified 30% of patients with total PSA between 2.5–10 μg/L who had cancer. At 95% specificity, the hK2/free PSA ratio identified 25% of patients with total PSA between 2.5 and 4.5 μg/L who had cancer. Conclusions: Our data suggest that hK2 in combination with free and total PSA can enhance the biochemical detection of prostate cancer in patients with moderately increased total PSA concentrations. More specifically, the hK2/free PSA ratio appears to be valuable in identifying a subset of patients with total PSA between 2.5 and 4.5 μg/L who have high probability of cancer and who should be considered for biopsy.

Dual-label one-step immunoassay for simultaneous measurement of free and total prostate-specific antigen concentrations and ratios in serum

1995 ◽  
Vol 41 (8) ◽  
pp. 1115-1120 ◽  
Author(s):  
K Mitrunen ◽  
K Pettersson ◽  
T Piironen ◽  
T Björk ◽  
H Lilja ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Simultaneous Measurement ◽  
Solid Phase ◽  
Characteristic Curve ◽  
Specific Antigen ◽  
Sample Volume ◽  
Free Psa ◽  
One Step ◽  
Total Psa ◽  
Dual Label

Abstract We developed a simple one-step dual-label immunoassay for simultaneous measurement of the free, noncomplexed form of prostate-specific antigen (PSA) and total PSA. The assay is based on time-resolved fluorescence and includes a stable fluorescent chelate of Eu to label a monoclonal antibody (mAb) that detects only free PSA, whereas a second mAb labeled with a fluorescent chelate of Tb provides equimolar detection of both free PSA and PSA complexed to alpha 1-antichymotrypsin. A third mAb on a solid phase captures the free and complexed forms of PSA in an equimolar fashion. The simultaneous measurement of the free-to-total PSA ratio (F/T) with the one-step dual assay is not sensitive to variations in the sample volume. The discrimination between benign prostatic hyperplasia and prostate cancer patients, i.e., the area under the receiver-operating characteristic curve, increased from 0.64 (total PSA assay) to 0.78 and 0.81 when the F/T ratio was measured with single and dual assays, respectively.

scholarly journals Reference Reagents for Prostate-specific Antigen (PSA): Establishment of the First International Standards for Free PSA and PSA (90:10)

2000 ◽  
Vol 46 (9) ◽  
pp. 1310-1317 ◽  
Author(s):  
Brian Rafferty ◽  
Peter Rigsby ◽  
Matthew Rose ◽  
Thomas Stamey ◽  
Rose Gaines Das
Keyword(s):  
Confidence Interval ◽  
Prostate Specific Antigen ◽  
Recombinant Dna ◽  
Collaborative Study ◽  
Specific Antigen ◽  
International Standards ◽  
Serum Samples ◽  
International Standard ◽  
Free Psa ◽  
Total Psa

Abstract Background: Prostate-specific antigen (PSA) measurements in serum by immunoassay are widely used in the screening, diagnosis, and monitoring of patients with prostate cancer although the lack of common reference reagents has led in the past to wide differences in estimates. We report here the results of a WHO international collaborative study in which two preparations of PSA representative of the main immunoreactive components in serum, free PSA and PSA 90:10, and a preparation of recombinant DNA-derived PSA were assessed as potential standards for the calibration of diagnostic immunoassays for PSA. Methods: Coded vials of the candidate materials and serum preparations containing PSA in the clinically important range were provided to the 10 laboratories in the study, and participants were asked to perform PSA assays currently in use in their laboratories. Data from 89 immunoassays by 26 different method-laboratory combinations were contributed to the study and analyzed centrally at the National Institute for Biological Standards and Control. Results: Potency estimates of the preparations relative to the in-house calibrators were in good agreement with the target value of 1 μg of total PSA/vial, the preparation of free PSA giving 1.10 μg/vial (95% confidence interval, 0.99–1.21 μg/vial) and PSA 90:10, 1.11 μg/vial (95% confidence interval, 1.04–1.18 μg/vial). No immunoreactivity was detected in ampoules containing the recombinant material. Use of a common standard of PSA 90:10 significantly reduced the between-laboratory geometric coefficients of variation for serum samples included in the study and gave a much narrower range of potency estimates. Conclusions: The preparation of free PSA was established by WHO as the First International Standard for PSA (free) with an assigned content of 1 μg of total PSA per vial. In addition, the preparation of bound PSA was established as the First International Standard for PSA (90:10) with an assigned content of 1 μg of total PSA per vial.

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