Test Details
Methodology
Siemens Centaur immunochemiluminometric assay (ICMA)
Result Turnaround Time
2 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
PSA is a single-chain glycoprotein normally found in the cytoplasm of the epithelial cells lining the acini and ducts of the prostate gland.1,2 PSA is a neutral serine protease of 240 amino acids involved in the lysis of seminal coagulum.1,3,4 PSA is present in the serum of males with normal, benign hyperplastic and malignant prostate tissue. PSA exists predominantly in circulation in complexes with various protease inhibitors. The most prevalent form of complexed cPSA that can be detected is bound to α1-antichymotrypsin.1,5
cPSA can be useful for determining residual disease and early recurrence after therapy when used in conjunction with other diagnostic indices. cPSA levels increase in men with cancer of the prostate, and after prostatectomy, cPSA levels routinely fall to a very low level.
Limitations
Serum cPSA measurement is not an absolute test for malignancy. The cPSA value should be used in conjunction with information available from clinical evaluation and other diagnostic procedures. Some cases of benign prostatic hypertrophy and prostatitis show elevation of cPSA, but such increases are below those found with adenocarcinoma of prostate stages C and D. Elevations may also be associated with urethral instrumentation, TUR, prostatic needle biopsy, urinary retention, or prostatic infarct.
Results for this test should not be used as absolute evidence of presence or absence of malignant disease without confirmation of the diagnosis by another medically established diagnostic product or procedure. Values obtained with different assay methods or kits cannot be used interchangeably.
Specimen Requirements
Specimen
Serum
Volume
0.5 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
0.0−3.6 ng/mL
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Plasma or whole blood specimen; hemolysis
Footnotes
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 140674 | PSA, Complexed | 33667-7 | 140685 | PSA, Complexed | ng/mL | 33667-7 |
| Order Code | 140674 | |||||
| Order Code Name | PSA, Complexed | |||||
| Order Loinc | 33667-7 | |||||
| Result Code | 140685 | |||||
| Result Code Name | PSA, Complexed | |||||
| UofM | ng/mL | |||||
| Result LOINC | 33667-7 |