Test: Prostate Specific Antigen

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Background/Purpose

Prostate-specific antigen is a glycoprotein and occurs in three forms in the blood: 1) PSA complexed with the serine protease inhibitor or alpha-1-antichymotrypsin, 2) free or uncomplexed PSA, and 3) PSA complexed with alpha-2 macroglobulin. The first two are detectable and the third is undectectable in conventional immunoassay. Elevated levels of PSA in serum or plasma indicate a pathological condition of the prostate (e.g. carcinoma, benign prostatic hyperplasia (BPH), or prostatitis). Inflammation or trauma to the prostate, such as following a biopsy or colonoscopy, can result in PSA elevations. PSA levels are also checked to monitor therapy in patients with prostate cancer.

Procedure

Specimen Requirements
Specimen
Serum (preferred) or plasma

Volume
1 mL

Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)

Container
Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.

Collection
If a red-top tube or plasma is used, transfer separated serum or plasma to a plastic transport tube.

Storage Instructions
Maintain specimen at room temperature.
Performed: Bilaterally

Dialog

Prostate-specific Antigen (PSA)

Criteria

• Within normal range

Measurement

0-4.0 ng/mL

LOINC Code

2857-1

Scale/Grading

selection range; grade - LOINC ID
Option - Value option selection range; grade - LOINC IDPass ng/mL ; Pass - Fail ng/mL ; Fail -