Pre-analytical and biological variability of prostatic acid phosphatase and prostate-specific antigen in serum from patients with prostatic pathology.
We determined the pre-analytical and biological variation of prostatic acid phosphatase and prostate-specific antigen in the same patient samples. Prostatic acid phosphatase and prostate-specific antigen were both stable when stored for at least 3 weeks with acidification (acetate buffer) or without acidification, except for prostate-specific antigen in samples stored unacidified at 4 degrees C. A significant elevation of prostate-specific antigen was noted in four patients with benign prostatic hyperplasia between 1/2 and 6 hours after prostatic massage. No significant effect was shown of changes in the glomerular filtration rate on prostate-specific antigen concentration, in spite of its low molecular mass. The estimate of within-subject biological variation showed a coefficient of variation of 33.8% for prostatic acid phosphatase and 14% for prostate-specific antigen. Desirable analytical imprecisions based on these findings were about 17% for prostatic acid phosphatase and 7% for prostate-specific antigen, these goals being achieved in practice for marker values higher than or equal to the upper reference limit.
Panteghini
M
M
1 Laboratorio Analisi Chimico-Cliniche, Spedali Civili, Brescia, Italy.
Pagani
F
F
Bonora
R
R
D000135:Acid Phosphatase / Q000097:blood*; D000230:Adenocarcinoma / Q000201:enzymology / Q000276:immunology; D000951:Antigens, Neoplasm / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D010808:Physical Examination; D017430:Prostate-Specific Antigen; D011469:Prostatic Diseases / Q000175:diagnosis / Q000201:enzymology* / Q000276:immunology; D011470:Prostatic Hyperplasia / Q000201:enzymology / Q000276:immunology; D011471:Prostatic Neoplasms / Q000201:enzymology / Q000276:immunology
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen