A microfluidic immunoassay platform for the detection of free prostate specific antigen: a systematic and quantitative approach

The Analyst ◽  
2015 ◽  
Vol 140 (13) ◽  
pp. 4423-4433 ◽  
Author(s):  
Narayanan Madaboosi ◽  
Ruben R. G. Soares ◽  
Virginia Chu ◽  
João Pedro Conde
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Quantitative Approach ◽  
Free Psa ◽  
Microfluidic Immunoassay ◽  
Antigen A ◽  
Relevant Range

A novel physisorption- and bio-affinity amplification-based microfluidic immunoassay platform for free PSA detection within a clinically relevant range is reported.

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.

Purification and characterization of prostate-specific antigen (PSA) complexed to alpha 1-antichymotrypsin: potential reference material for international standardization of PSA immunoassays

1995 ◽  
Vol 41 (9) ◽  
pp. 1273-1282 ◽  
Author(s):  
Z Chen ◽  
A Prestigiacomo ◽  
T A Stamey
Keyword(s):  
Molecular Mass ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
Free Psa ◽  
Apparent Homogeneity ◽  
International Standardization

Abstract We describe for the first time a protocol to purify to apparent homogeneity an in vitro-prepared complex of prostate-specific antigen (PSA) and alpha 1-antichymotrypsin (ACT) by using a combination of gel filtration and ion-exchange chromatography. The purity of the PSA-ACT complex was confirmed by gel electrophoresis and Western blot. The PSA-ACT complex was stable in the pH range 6.0 to 7.8; it was also stable in various matrices, temperatures, and high concentrations of salt. Purification of the PSA-ACT complex was highly reproducible. An absorptivity of 0.99 L x g-1 x cm-1 at 280 nm was assigned to the PSA-ACT complex, based on amino acid analysis. Because PSA and ACT bind in a 1:1 molar ratio, we determined the molecular mass of the PSA-ACT complex as the mass encoded by the cDNA of ACT (plus 26% carbohydrate) plus the molecular mass of PSA (28,430 Da), which totals 89,280 Da. Using this material, we made two common calibrators, one of 100% PSA-ACT complex and one of 90% PSA-ACT complex plus 10% free PSA by volume (90:10 calibrator). Substitution of these calibrators for the manufacturers' calibrators in nine commercial immunoassays substantially reduced differences between immunoassays, especially for serum PSA values between 4 and 10 micrograms/L. The 90:10 calibrator is recommended as a universal calibrator for international standardization of PSA immunoassays.

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.

scholarly journals The proportion of free to total prostate specific antigen: A method of detecting prostate carcinoma

Cancer ◽  
1996 ◽  
Vol 77 (6) ◽  
pp. 1137-1143 ◽  
Author(s):  
Takayoshi Demura ◽  
Nobuo Shinohara ◽  
Motoyoshi Tanaka ◽  
Nobuyasu Enami ◽  
Hitoshi Chiba ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Prostate Carcinoma ◽  
Specific Antigen ◽  
Total Prostate Specific Antigen ◽  
Antigen A

Application of various optical and electrochemical aptasensors for detection of human prostate specific antigen: A review

2019 ◽  
Vol 142 ◽  
pp. 111484 ◽  
Author(s):  
Farzaneh Ghorbani ◽  
Hossein Abbaszadeh ◽  
Jafar Ezzati Nazhad Dolatabadi ◽  
Leili Aghebati-Maleki ◽  
Mehdi Yousefi
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Human Prostate ◽  
Antigen A

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 Quantitative immunoassay for complexes of prostate-specific antigen with alpha2-macroglobulin

1996 ◽  
Vol 42 (4) ◽  
pp. 545-550 ◽  
Author(s):  
F España ◽  
J Sánchez-Cuenca ◽  
A Estellés ◽  
J Gilabert ◽  
J H Griffin ◽  
...  
Keyword(s):  
Detection Limit ◽  
Prostate Specific Antigen ◽  
Protein C ◽  
Seminal Fluid ◽  
Specific Antigen ◽  
The Other ◽  
Diagnostic Significance ◽  
Healthy Men ◽  
Free Psa ◽  
Quantitative Immunoassay

Abstract We have developed two ELISAs for quantifying complexes of prostate-specific antigen (PSA) with alpha2-macroglobulin (alpha2M), using partially purified PSA:alpha2M complex as the calibrator. One ELISA was designed to evaluate )SA:alpha2M complex in fluids containing a huge excess of PSA over the amount of complex (semen-derived fluids), the other for use in fluids containing an excess of alpha2M over PSA (blood plasma). The range of the assays was 2-1000 micrograms/L for PSA complexed to alpha2M; the detection limit was 3 micrograms/: Intra- and interassay CVs were 7-13% and 11-17%, respectively, at complexed PSA concentrations of 6-500 micrograms/L. Seminal fluid from healthy men (n = 60) contained 5.2 +/- 2.6 micrograms/L PSA complexed with alpha2M. Prostatic and seminal vesicle fluids contained 6.5 +/- 2.9 ad 0.3 +/- 0.2 mg/L PSA complexed to alpha2M, respectively. When purified PSA was incubated with citrated plasma, between 45% and 65% of the added PSA was recovered as free PSA, whereas approximately 25% formed complexes with alpha2M, 10% complexed with alpha1-antichymotrypsin, and only 0.1-6% was complexed with protein C inhibitor. Of 30 patients with prostate disease, 20 showed detectable plasma PSA:alpha2M complexes; however, the potential diagnostic significance of this complex requires further investigation.

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.

Sign in / Sign up

Export Citation Format

Share Document