Reproducibility and Accuracy of Measurements of Free and Total Prostate-Specific Antigen in Serum vs Plasma after Long-Term Storage at -20 {degrees}C.
Ulmert, David LU ; Becker, Charlotte LU ; Nilsson, Jan-Ake ; Piironen, Timo ; Björk, Thomas LU ; Hugosson, Jonas ; Berglund, Göran LU and Lilja, Hans LU
(2006)
In Clinical Chemistry
52(2).
p.235-239
- Abstract
- Background: Long-term frozen storage may alter the results of prostate-specific antigen (PSA) measurements, mainly because of degradation of free PSA (fPSA) in vitro. We compared the effects of long-term storage on fPSA, total PSA (tPSA), and complexed PSA (cPSA) in serum vs EDTA-plasma samples. Methods: We measured fPSA and tPSA concentrations in matched pairs of archival serum and EDTA-plasma samples (stored frozen at -20 degrees C for 20 years) from a large population-based cohort in Malmo, Sweden. We also compared concentrations in age-matched men with those in samples not subjected to long-term storage, obtained from participants in a population-based study of prostate cancer screening in Goteborg, Sweden. These contemporary samples... (More)
- Background: Long-term frozen storage may alter the results of prostate-specific antigen (PSA) measurements, mainly because of degradation of free PSA (fPSA) in vitro. We compared the effects of long-term storage on fPSA, total PSA (tPSA), and complexed PSA (cPSA) in serum vs EDTA-plasma samples. Methods: We measured fPSA and tPSA concentrations in matched pairs of archival serum and EDTA-plasma samples (stored frozen at -20 degrees C for 20 years) from a large population-based cohort in Malmo, Sweden. We also compared concentrations in age-matched men with those in samples not subjected to long-term storage, obtained from participants in a population-based study of prostate cancer screening in Goteborg, Sweden. These contemporary samples were handled according to standardized preanalytical. and analytical protocols aimed at minimizing in vitro degradation. tPSA and fPSA measurements were performed with a commercial assay (Prostatus Dual Assay; Perkin-Elmer Life Sciences). Results: Concentrations of tPSA and fPSA and calculated cPSA (tPSA-fPSA) in archival plasma were not significantly different from those in contemporary serum from age-matched men. In archival serum, however, random variability of fPSA was higher vs plasma than in contemporary samples, whereas systematic error of fPSA analyses was similarly small in archival and contemporary serum and plasma. Conclusions: Concentrations of tPSA and calculated cPSA were highly stable in plasma and serum samples subjected to long-term storage at -20 degrees C. Greater random variability, rather than a systematic decrease, may explain differences in fPSA analyses observed in archival serum. (c) 2006 American Association for Clinical Chemistry. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/148425
- author
- Ulmert, David
LU
; Becker, Charlotte
LU
; Nilsson, Jan-Ake
; Piironen, Timo
; Björk, Thomas
LU
; Hugosson, Jonas
; Berglund, Göran
LU
and Lilja, Hans
LU
- organization
- publishing date
- 2006
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Clinical Chemistry
- volume
- 52
- issue
- 2
- pages
- 235 - 239
- publisher
- American Association for Clinical Chemistry
- external identifiers
-
- pmid:16384894
- wos:000235069600009
- scopus:31844447749
- ISSN
- 0009-9147
- DOI
- 10.1373/clinchem.2005.050641
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Division of Urological Cancers (013243420), Internal Medicine (013242500), Urology (013243400), Clinical Chemistry, Malmö (013016000), Internal Medicine Research Unit (013242520)
- id
- 3e140d26-569f-46d8-aef5-c6d371d87410 (old id 148425)
- alternative location
- http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16384894&dopt=Abstract
- date added to LUP
- 2016-04-01 12:03:27
- date last changed
- 2022-01-26 22:12:52
@article{3e140d26-569f-46d8-aef5-c6d371d87410,
abstract = {{Background: Long-term frozen storage may alter the results of prostate-specific antigen (PSA) measurements, mainly because of degradation of free PSA (fPSA) in vitro. We compared the effects of long-term storage on fPSA, total PSA (tPSA), and complexed PSA (cPSA) in serum vs EDTA-plasma samples. Methods: We measured fPSA and tPSA concentrations in matched pairs of archival serum and EDTA-plasma samples (stored frozen at -20 degrees C for 20 years) from a large population-based cohort in Malmo, Sweden. We also compared concentrations in age-matched men with those in samples not subjected to long-term storage, obtained from participants in a population-based study of prostate cancer screening in Goteborg, Sweden. These contemporary samples were handled according to standardized preanalytical. and analytical protocols aimed at minimizing in vitro degradation. tPSA and fPSA measurements were performed with a commercial assay (Prostatus Dual Assay; Perkin-Elmer Life Sciences). Results: Concentrations of tPSA and fPSA and calculated cPSA (tPSA-fPSA) in archival plasma were not significantly different from those in contemporary serum from age-matched men. In archival serum, however, random variability of fPSA was higher vs plasma than in contemporary samples, whereas systematic error of fPSA analyses was similarly small in archival and contemporary serum and plasma. Conclusions: Concentrations of tPSA and calculated cPSA were highly stable in plasma and serum samples subjected to long-term storage at -20 degrees C. Greater random variability, rather than a systematic decrease, may explain differences in fPSA analyses observed in archival serum. (c) 2006 American Association for Clinical Chemistry.}},
author = {{Ulmert, David and Becker, Charlotte and Nilsson, Jan-Ake and Piironen, Timo and Björk, Thomas and Hugosson, Jonas and Berglund, Göran and Lilja, Hans}},
issn = {{0009-9147}},
language = {{eng}},
number = {{2}},
pages = {{235--239}},
publisher = {{American Association for Clinical Chemistry}},
series = {{Clinical Chemistry}},
title = {{Reproducibility and Accuracy of Measurements of Free and Total Prostate-Specific Antigen in Serum vs Plasma after Long-Term Storage at -20 {degrees}C.}},
url = {{http://dx.doi.org/10.1373/clinchem.2005.050641}},
doi = {{10.1373/clinchem.2005.050641}},
volume = {{52}},
year = {{2006}},
}