SearchPublisher and Institutes
You are here: Home :: Area NEM :: Medical science :: Human medicine
Bert G. Blijenberg, Bert N. Storm, Arto E. Boeken Kruger, Fritz H. Schröder
On the Standardization of Total Prostate-Specific Antigen: an Exercise with Two Reference Preparations
In this study, 112 serum samples were analyzed for total prostate-specific antigen with three well-established assays i.e. Tandem R and Tandem E (both from Hybritech Inc., San Diego, USA) and Prostatus Free/Total from Wallac Oy, Turku, Finland. Thirty-two samples were collected from prostate cancer patients, 32 from patients with benign prostate hyperplasia and 48 from men participating in a screening study for prostate cancer.
The aim of the study was to compare the results before and after recalculation with the data obtained with two reference preparations for total prostate-specific antigen: Stanford 90:10 PSA Calibrator and Certified Reference Material 613 Prostate-Specific Antigen.
Comparing the actual results revealed almost perfect correlations between Tandem R and Tandem E and between both Tandem assays and Prostatus. We observed statistically significant differences in accuracy between Tandem R and Tandem E:
y(Tandem E)= 1.05 × (Tandem R)+0.07,
and between Tandem E and Prostatus:
y(Prostatus)= 0.94 × (Tandem E)+0.02
In both comparisons prostate-specific antigen values ranged from 0–40 ?g/l.
Recalculation with both reference preparations did not solve these discrepancies. One exception was the combination Tandem R and Tandem E. The application of either reference preparation solved the differences in accuracy here.
In conclusion, even after recalibration, assays for total prostate-specific antigen are still not completely interchangeable.
Clinical Chemical Laboratory Medicine, Walter de Gruyter
Print ISSN: 1434-6621
Volume: 37, 05/1999
Pages: 545 - 552