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Comparability of the tandem-R andIMx assays for the measurement of serum prostate-specific antigen

Jacobsen, Steven J. ; Lilja, Hans LU orcid ; Klee, George G. ; Wright, George L. ; Pettersson, Kim and Oesterling, Joseph E. (1994) In Urology 44(4). p.512-518
Abstract

Objectives.: To assess the comparability of the Tandem-R and IMx serumprostate-specific antigen (PSA) assays across levels of the ratio of free-to-total serum PSA found in a community-based population of healthy men. Methods.: Banked serum samples from the baseline component of the Olmsted CountyStudy of Urinary Symptoms and Health Status Among Men were thawed and analyzed using the Tandem-R and IMx PSA assays. Serum levels also were determined for the free, noncomplexed form of PSA, PSA complexed to alpha-1 antichymotrypsin, and total PSA with a research-based immunofluorometric assay. Results.: The results of the Tandem-R and IMx assays were strongly correlated at alllevels of the ratio of free-to-total serum PSA. The Spearman... (More)

Objectives.: To assess the comparability of the Tandem-R and IMx serumprostate-specific antigen (PSA) assays across levels of the ratio of free-to-total serum PSA found in a community-based population of healthy men. Methods.: Banked serum samples from the baseline component of the Olmsted CountyStudy of Urinary Symptoms and Health Status Among Men were thawed and analyzed using the Tandem-R and IMx PSA assays. Serum levels also were determined for the free, noncomplexed form of PSA, PSA complexed to alpha-1 antichymotrypsin, and total PSA with a research-based immunofluorometric assay. Results.: The results of the Tandem-R and IMx assays were strongly correlated at alllevels of the ratio of free-to-total serum PSA. The Spearman correlation coefficients ranged from 0.87 to 0.98 (all p < 0.001). The relationship between the Tandem-R and IMx assays, however, differed at low levels of free-to-total serum PSA compared with high levels. In the lowest 10th percentile of the ratio of free-to-total serum PSA (0.04 to 0.18), the IMx assay read lower than the Tandem-R (slope ± standard error = 0.92±0.04, intercept ± standard error = 0.21 ± 0.14); whereas in the upper 10th percentile of free-to-total ratio (0.46 to 0.65) the IMx assay yielded values higher than the Tandem-R assay (slope = 1.21 ± 0.07, intercept = 0.14 ± 0.05). In the middle 90%, the slope did not statistically differ from 1.0. Conclusions.: For the majority of men, results of the Tandem-R and IMx PSA assays were virtually identical. The small differences found would not be of clinical significance for most men but should be considered when comparing results of different assays in sequential determinations for a specific man.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Urology
volume
44
issue
4
pages
512 - 518
publisher
Elsevier
external identifiers
  • scopus:0028575751
  • pmid:7524236
ISSN
0090-4295
DOI
10.1016/S0090-4295(94)80049-9
language
English
LU publication?
yes
id
9d560fe7-ae6c-43bd-a76d-932dee00d9e9
date added to LUP
2022-12-06 17:07:29
date last changed
2024-01-03 19:32:27
@article{9d560fe7-ae6c-43bd-a76d-932dee00d9e9,
  abstract     = {{<p>Objectives.: To assess the comparability of the Tandem-R and IMx serumprostate-specific antigen (PSA) assays across levels of the ratio of free-to-total serum PSA found in a community-based population of healthy men. Methods.: Banked serum samples from the baseline component of the Olmsted CountyStudy of Urinary Symptoms and Health Status Among Men were thawed and analyzed using the Tandem-R and IMx PSA assays. Serum levels also were determined for the free, noncomplexed form of PSA, PSA complexed to alpha-1 antichymotrypsin, and total PSA with a research-based immunofluorometric assay. Results.: The results of the Tandem-R and IMx assays were strongly correlated at alllevels of the ratio of free-to-total serum PSA. The Spearman correlation coefficients ranged from 0.87 to 0.98 (all p &lt; 0.001). The relationship between the Tandem-R and IMx assays, however, differed at low levels of free-to-total serum PSA compared with high levels. In the lowest 10th percentile of the ratio of free-to-total serum PSA (0.04 to 0.18), the IMx assay read lower than the Tandem-R (slope ± standard error = 0.92±0.04, intercept ± standard error = 0.21 ± 0.14); whereas in the upper 10th percentile of free-to-total ratio (0.46 to 0.65) the IMx assay yielded values higher than the Tandem-R assay (slope = 1.21 ± 0.07, intercept = 0.14 ± 0.05). In the middle 90%, the slope did not statistically differ from 1.0. Conclusions.: For the majority of men, results of the Tandem-R and IMx PSA assays were virtually identical. The small differences found would not be of clinical significance for most men but should be considered when comparing results of different assays in sequential determinations for a specific man.</p>}},
  author       = {{Jacobsen, Steven J. and Lilja, Hans and Klee, George G. and Wright, George L. and Pettersson, Kim and Oesterling, Joseph E.}},
  issn         = {{0090-4295}},
  language     = {{eng}},
  number       = {{4}},
  pages        = {{512--518}},
  publisher    = {{Elsevier}},
  series       = {{Urology}},
  title        = {{Comparability of the tandem-R andIMx assays for the measurement of serum prostate-specific antigen}},
  url          = {{http://dx.doi.org/10.1016/S0090-4295(94)80049-9}},
  doi          = {{10.1016/S0090-4295(94)80049-9}},
  volume       = {{44}},
  year         = {{1994}},
}