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HelpTest Code PACP Prostatic Acid Phosphatase, Serum
Reporting Name
Prostatic Acid Phosphatase, SUseful For
Aiding in predicting recurrence after radical prostatectomy for clinically localized prostate cancer
Following response to androgen ablation therapy, when used in conjunction with prostate-specific antigen
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
Patient Preparation: For 12 hours before specimen collection, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 180 days |
Reference Values
≤2.1 ng/mL
Day(s) Performed
Monday, Wednesday, Friday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
84066
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PACP | Prostatic Acid Phosphatase, S | 20420-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PACP | Prostatic Acid Phosphatase, S | 20420-6 |
Clinical Information
Prostatic acid phosphatase (PAP), a glycoprotein synthesized by the prostate gland, is a member of a diverse group of isoenzymes that are capable of hydrolyzing phosphate esters in acidic medium. They are classified based on their electrophoretic mobilities.
PAP was a major tumor marker for prostate cancer for more than 50 years.(1) However, PAP is no longer used to screen for or stage prostate cancer. In most instances, serum prostate specific antigen (PSA) is used instead. PAP usefulness is now limited to niche applications. Pre-treatment PAP measurement may add unique, clinically useful prognostic information for predicting recurrence in men who are undergoing radical prostatectomy for clinically localized prostate cancer. PAP also may be useful for following the progression of disease response to therapy in men treated by androgen ablation. However, for both applications, PSA provides more information and also should be utilized.
Interpretation
Prostatic acid phosphatase (PAP) levels above the reference range may indicate prostate cancer but can be due to many other factors, see Cautions.
A rise in PAP levels in patients with known prostate cancer can indicate tumor progression or recurrence. However, there is considerable intra-subject biological variability, limiting the usefulness of this test.
Cautions
Prostatic acid phosphatase (PAP) measurement must not be regarded as an absolute test for malignancy since other factors, including benign prostatic hyperplasia, prostatic infarction, and manipulation of the prostate gland may result in elevated serum PAP concentrations.
PAP measurements provide little additional information beyond that provided by prostate-specific antigen measurements.
Human anti-mouse antibodies (HAMA) may be present in specimens from patients who have received immunotherapy utilizing monoclonal antibodies. Other heterophile antibodies also may be present in patient specimens. This assay has been specifically formulated to minimize the effects of these antibodies on the assay. However, carefully evaluate results from patients known to have such antibodies.
Clinical Reference
1. Moul JW, Connelly RR, Perahia B, McLeod DG. The contemporary value of pretreatment prostatic acid phosphatase to predict pathological stage and recurrence in radical prostatectomy cases. J Urol. 1998;159:935-940
2. Beaver TR, Schultz AL, Fink LM, et al. Discordance between concentration of prostate-specific antigen and acid phosphatase in serum of patients with adenocarcinoma of the prostate. Clin Chem. 1988;34:1524
3. Velonas VM, Woo HH, dos Remedios CG, Assinder SJ. Current status of biomarkers for prostate cancer. Int J Mol Sci. 2013;14(6):11034-60. doi:10.3390/ijms140611034
4. Kong HY, Byun J. Emerging roles of human prostatic acid phosphatase. Biomol Ther (Seoul). 2013;21(1):10-20. doi: 10.4062/biomolther.2012.095
Method Description
The patient sample is added to a solid phase that is coated with a mouse monoclonal antibody specific for prostatic acid phosphatase (PAP). A goat-anti-PAP-alkaline phosphatase conjugate is added to form an antibody sandwich complex. Excess conjugate is removed by washing, and an adamantyl dioxetane phosphate substrate is added to produce chemiluminescence. Light emission is proportional to PAP concentration in the specimen.(Package insert: IMMULITE 2000 PAP. PIL2KPA-17. Siemens Healthcare; 03/15/2018)
Report Available
1 to 3 daysSpecimen Retention Time
2 weeksReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
Method Name
Automated Chemiluminescent Immunometric Assay