scholarly journals Benign Prostate-specific Antigen (BPSA) in Serum Is Increased in Benign Prostate Disease

2003 ◽  
Vol 49 (2) ◽  
pp. 253-259 ◽  
Author(s):  
Harry J Linton ◽  
Leonard S Marks ◽  
Lisa S Millar ◽  
Christine L Knott ◽  
Harry G Rittenhouse ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
Clinical Information ◽  
High Specificity ◽  
Wide Distribution ◽  
Cross Reactivity ◽  
Free Psa ◽  
Control Serum ◽  
Benign Prostate

Abstract Background: BPSA is a “benign” form of free prostate-specific antigen (PSA) that is increased in prostate transition zone tissues of men with pathologic benign prostatic hyperplasia (BPH). We developed an immunoassay to determine the concentration of BPSA in the serum of men with BPH. Methods: The BPSA antigen was purified by HPLC, and murine monoclonal antibodies were prepared by standard methods. A fluorogenic ELISA was developed with high specificity for BPSA and no cross-reactivity with other forms of PSA. Results: The BPSA immunoassay had a lower limit of detection of 6 ng/L and a cross-reactivity of <1% with all other clipped and nonclipped forms of PSA. The BPSA antibody was specific for the internal Lys182 cleavage site that characterizes BPSA. Biopsy-negative men with a median total PSA of 4.8 μg/L had a median of 0.22 μg/L BPSA, representing 25% of the free PSA in serum. BPSA ranged from 0% to 60% of the free PSA in serum. BPSA in a cohort of cancer serum also comprised 25% of the free PSA. Control serum from women or men without increased PSA had nondetectable BPSA. Conclusions: BPSA is a significant percentage of the free PSA in BPH serum but not in control serum. The presence of prostate cancer does not alter the relative proportions of BPSA in sera with <10 μg/L PSA. BPSA has a wide distribution of concentrations in the serum and may provide clinical information for the study of men with BPH.

scholarly journals Proenzyme Forms of Prostate-Specific Antigen in Serum Improve the Detection of Prostate Cancer

2004 ◽  
Vol 50 (6) ◽  
pp. 1017-1025 ◽  
Author(s):  
Stephen D Mikolajczyk ◽  
William J Catalona ◽  
Cindy L Evans ◽  
Harry J Linton ◽  
Lisa S Millar ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Cancer Detection ◽  
Specific Antigen ◽  
Serum Markers ◽  
Prostate Cancer Detection ◽  
Good Marker ◽  
Free Psa ◽  
Specificity And Sensitivity ◽  
Benign Prostate

Abstract Introduction: Pro or precursor forms of prostate-specific antigen (PSA) have emerged as potentially important diagnostic serum markers for prostate cancer detection. Immunoassays were developed to measure specific proPSA forms containing propeptides of 2, 4, and 7 amino acids [(-2)proPSA, (-4)proPSA, and (-7)proPSA, respectively]. Methods: Research-use dual monoclonal antibody immunoassays using europium-labeled detection monoclonal antibodies were developed for each form of proPSA. Sera from patients with prostate cancer or benign prostate disease containing 4–10 μg/L PSA were assayed and analyzed by area under the ROC curve (AUC) for specificity and sensitivity. Results: The proPSA forms had quantification limits of 0.015–0.025 μg/L in serum, with cross-reactivities <1% with PSA. The sum of the proPSA forms divided by free PSA (percentage proPSA) had a higher AUC than did percentage of (-2)proPSA, free PSA, and complexed PSA with AUC (95% confidence intervals) of 0.69 (0.64–0.74), 0.64 (0.58–0.68), 0.63 (0.58–0.68), and 0.57 (0.51–0.62), respectively. The proPSA comprised a median of 33% of the free PSA in cancer and 25% in noncancer sera (P <0.0001). One-third (33%) of cancer samples had >40% proPSA, whereas only 8% of noncancer samples did (P <0.0001). In men with cancer and >25% free PSA, the (-2)proPSA had an AUC of 0.77 (0.66–0.86), with 90% sensitivity and 36% specificity at 0.04 μg/L. Conclusions: The percentage of proPSA gave better cancer detection in the 4–10 μg/L range than did percentage of free PSA and complexed PSA. (-2)proPSA significantly discriminated cancer in men whose serum had >25% free PSA, for whom there is currently no good marker for cancer detection.

scholarly journals PREPARASI PEREAKSI KIT IMMUNORADIOMETRlCASSAY FREE PROSTATE SPECIFIC ANTIGEN UNTUK DETEKSI KANKER PROSTAT

2013 ◽  
Vol 15 (2) ◽  
pp. 14-24
Author(s):  
Puji Widayati ◽  
Gina Mondrida ◽  
Sri Setiyowati ◽  
Agus Ariyanto ◽  
V. Yulianti Susilo ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Prostate Gland ◽  
Specific Antigen ◽  
Prostatic Hyperplasia ◽  
Free Condition ◽  
Free Psa ◽  
Prostate Enlargement ◽  
Assay Design ◽  
Benign Prostate

Prostate Specific Antigen (PSA) is a glycoprotein with a molecular weight of approximately 34,000 daltons serine protease secreted exclusively by prostatic epithelial cells that lining acini and prostate gland. Increased of PSA levels can be caused by prostate cancer or benign prostate enlargement (benign prostatic hyperplasia, BPH). PSA in the blood was found in the free condition (free PSA) and most of the bound protein (complexed-PSA, c-PSA). Measuring levels of PSA was found in the blood can be done by several methods such as by immunoradiometricassay (IRMA) methods or ELISA methods. IRMA method is one of immunoassay techniques using radionuclides ,/' 125 oJ I as a tracer, so the sample in small 13 quantity can be detected The purpose of this study was obtained PSA reagent kit that includes 1251labeled PSA as a tracer, PSA coated tube and PSA standard that requirements of the kit, then it can be optimized assay design, that eventually PSA reagent kit can be used for early detection of prostate cancer. It has been done labeling of Mab PSA using 125 1with reaction time was 90 seconds, amount of PSA MAb was 75 ugram and the activity of Na_ 125I was 1000 flCi. Preaparation of PSA coated tube using 0.05 M Na2C03 solution, at pH: 9.6 with volume was 250 ml., standard PSA with 0.025 Mphosphate buffer at pH 7.4 containing 5% BSA and 0.1% NaN3, and resulting at 1,25% and 14,12% respectively of NSB and BIT that requirement of the kit.Keywords: Prostate cancer, PSA, IRMA,NSB, Maximum Binding

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 Analytical performance of the Tandem®-R free PSA immunoassay measuring free prostate-specific antigen

1997 ◽  
Vol 43 (7) ◽  
pp. 1203-1208 ◽  
Author(s):  
David L Woodrum ◽  
Chester M French ◽  
Timothy M Hill ◽  
Steven J Roman ◽  
Harold L Slatore ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Accurate Determination ◽  
Specific Antigen ◽  
Cross Reactivity ◽  
Analytical Performance ◽  
Minimum Detectable Concentration ◽  
Free Psa ◽  
Detectable Concentration ◽  
Total Psa

Abstract The analytical performance of the Tandem®-R free PSA assay available from Hybritech Inc. was evaluated. Comparison of recoveries of purified free (unbound) prostate-specific antigen (PSA) diluted in female serum in the Tandem-R free PSA assay and the Tandem-R (total) PSA assay demonstrated a link in calibration between the assays and an accurate determination of percent free PSA. The cross-reactivity of the assay to purified PSA–α1-antichymotrypsin was determined to be <1%. The minimum-detectable concentration was <0.05 μg/L. The within-run and between-day CVs were ≤5% for samples with >0.3 μg/L free PSA. Dilution and recovery showed no significant deviations from linearity across the assay range. The assay was insensitive to interference from blood components. The Tandem-R free PSA kit was shown to be an accurate, precise, and reliable assay for the measurement of free PSA.

scholarly journals Development of an Ultrasensitive Immunoassay for Human Glandular Kallikrein with No Cross-Reactivity from Prostate-specific Antigen

1999 ◽  
Vol 45 (6) ◽  
pp. 790-799 ◽  
Author(s):  
Margot H Black ◽  
Angeliki Magklara ◽  
Christina V Obiezu ◽  
Dimitrios N Melegos ◽  
Eleftherios P Diamandis
Keyword(s):  
Detection Limit ◽  
Prostate Specific Antigen ◽  
Seminal Plasma ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Specific Antigen ◽  
Cross Reactivity ◽  
Free Form ◽  
Glandular Kallikrein ◽  
Healthy Males

Abstract Background: Studies demonstrating that human glandular kallikrein (hK2) is increased in prostate cancer patients have prompted speculation that this marker may of use in addition to prostate-specific antigen (PSA). Methods: An ultrasensitive hK2 sandwich immunoassay was developed, and its detection limit, cross-reactivity, analytical recovery, precision, and linearity of dilution were evaluated. hK2 was measured in seminal plasma and sera from healthy males, females, and prostatectomized patients. Results: Our assay has an excellent detection limit (6 ng/L) and precision (>90%). Recovery studies indicated that hK2 binds to serum protease inhibitors. All sera from healthy males had measurable hK2 concentrations (median, 402 ng/L). Almost all female sera had undetectable hK2. Serum hK2 and PSA in males correlated positively (r = 0.44), but hK2 was present at concentrations ∼2.5-fold lower than PSA. The PSA/hK2 ratio in male sera was 0.1–34, with a median of 2.6. In seminal plasma, this ratio was 100–500. More than 94% of immunoreactive hK2 in serum was in the free form (∼30 kDa); traces of hK2 complexed to α1-antichymotrypsin were present. Conclusions: The limit of detection of the method for hK2 measurement described here (∼20-fold lower than any other reported assay for hK2) allows the generation of new clinical information. When combined with a previously described method for PSA measurement that has no cross-reactivity from hK2, this methods allows the relative proportions of hK2 and PSA in biological fluids to be measured.

scholarly journals Improved reverse transcriptase–polymerase chain reaction protocol with exogenous internal competitive control for prostate-specific antigen mRNA in blood and bone marrow

1997 ◽  
Vol 43 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Eva Corey ◽  
Edward W Arfman ◽  
Alvin Y Liu ◽  
Robert L Vessella
Keyword(s):  
Prostate Cancer ◽  
Bone Marrow ◽  
Reverse Transcriptase ◽  
Prostate Specific Antigen ◽  
Mononuclear Cells ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
High Specificity ◽  
Significant Advance ◽  
Peripheral Blood Mononuclear

Abstract The possibility of improving diagnosis of micrometastases from prostate cancer by further enhancing the detection of prostate-specific antigen-producing cells in circulation is being evaluated. We have developed a reverse transcriptase-PCR protocol with the desirable characteristics of low limit of detection, high specificity, reproducibility of response, and ease of performance. Among the procedural alterations that have contributed to these improvements are longer PCR primers, a two-step amplification cycle, and hot-start PCR. We have lowered the limit of detection to one LNCaP prostate-cancer cell in 108 peripheral blood mononuclear cells, and samples of blood and bone marrow from healthy donors have yielded no false positives. Because PCR procedures frequently exhibit tube-to-tube variability, we have incorporated a set of internal and external controls into the protocol—a significant advance in assuring assay reliability.

scholarly journals A fluorescence immunoassay for a rapid detection of Listeria monocytogenes on working surfaces

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alessandro Capo ◽  
Sabato D’Auria ◽  
Monique Lacroix
Keyword(s):  
Listeria Monocytogenes ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
Foodborne Pathogen ◽  
High Specificity ◽  
Cross Reactivity ◽  
Food Industries ◽  
Manufacturing Enterprises ◽  
Combined Use ◽  
Specialized Equipment

AbstractListeria monocytogenes is a foodborne pathogen responsible for human listeriosis. The increasing incidence of listeriosis induced governments and food manufacturing enterprises to act to diminish the problem. Several methods for the detection of Listeria monocytogenes in food industries were developed. However, they are time-consuming and require the use of specialized equipment. To reduce the detection time of Listeria monocytogenes in food, in this work we developed a fluorescence sandwich immunoassay based on the use of an innovative chitosan-cellulose nanocrystal (CNC) membrane that improves the antigen capture during bacterial growth. The combined use of CNC film for the capture of p60 protein-specific antigen together with the use of fluorescence detection reduced the time of analysis from 24 to 12 h with a limit of detection (LOD) of the assay of 102 CFU/mL (2 Log). In addition, the use of monoclonal anti-PepD covalently immobilized to a CNC membrane assured a high specificity of the assay. Interestingly, the obtained results show no cross-reactivity with the five most diffused pathogen bacteria strains tested.

scholarly journals Characterization of Monoclonal Antibodies for Prostate-specific Antigen and Development of Highly Sensitive Free Prostate-specific Antigen Assays

1999 ◽  
Vol 45 (3) ◽  
pp. 347-354 ◽  
Author(s):  
Margot H Black ◽  
C Linda Grass ◽  
Jari Leinonen ◽  
Ulf-Håkan Stenman ◽  
Eleftherios P Diamandis
Keyword(s):  
Monoclonal Antibodies ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Cross Reactivity ◽  
Free Form ◽  
Time Resolved ◽  
Free Psa ◽  
Glandular Kallikrein ◽  
Highly Sensitive

Abstract Background: The recent elucidation of the importance of serological free prostate-specific antigen (PSA) in the diagnosis of prostate cancer has created a demand for immunoassays specific for free PSA. Methods: We developed and characterized 11 monoclonal antibodies with high affinities for PSA (Kavalues from 1.1 × 108 to 1.8 × 1010L/mol), only 3 of which cross-react with human glandular kallikrein (hK2). Using these antibodies and PSA antibodies developed by others, in conjunction with time-resolved fluorometry, we developed ultrasensitive sandwich immunoassays specific for the free form of PSA. Results: The analytical detection limit of these immunoassays is 0.001 μg/L. To our knowledge, this is the most sensitive free PSA assay reported to date. The free PSA immunoassays exhibit <1% cross-reactivity with PSA-α1-antichymotrypsin, show no cross-reactivity with hK2, and correlate well with established free PSA kits. The 11 antibodies developed by our group, in conjunction with 4 commercially available antibodies, were used to generate a putative epitope map of the PSA molecule. Conclusion: The highly sensitive free PSA immunoassays may be used for measuring PSA subfractions in female serum, an application currently impossible with other reported free PSA immunoassays.

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.

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