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HelpTest Code LAB8914 Prostate Health Index Reflex, Serum
Additional Codes
PHI11
Specimen Required
Patient Preparation:
1. Specimens for testing should be collected prior to prostate manipulations such as digital rectal examination, prostatic massage, transrectal ultrasound, and prostatic biopsy.
2. A 6-week waiting period between needle biopsy and specimen collection is recommended.
3. Specimens should not be collected from patients receiving therapy with high biotin (vitamin B7) doses (ie, >5 mg/day) until at least 8 hours following the last biotin administration.
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Within 3 hours of collection, centrifuge, aliquot serum into a plastic vial, and refrigerate. Freeze sample within 24 hours of collection and send frozen.
Secondary ID
113000Useful For
As an aid in distinguishing prostate cancer from benign prostatic conditions in men aged 50 years and older with total PSA between 4.0 and 10.0 ng/mL and digital rectal examination findings that are not suspicious for cancer
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PHI13 | Prostate Health Index (phi) Reflex | No | No |
Testing Algorithm
This test begins with the analysis of prostate-specific antigen (PSA). If the PSA concentration is between 2.0 and 10.0 ng/mL, then the reflex test will be performed at an additional charge.
If the initial PSA concentration is between 2.0 and 10.0 ng/mL, then free PSA and [-2]pro-PSA isoform results will be reported.
If the initial PSA concentration is between 4.0 and 10.0 ng/mL, then the percent free PSA result and prostate health index (phi) will be calculated and reported.
If the initial PSA concentration is between 2.0 and 4.0 ng/mL, then the percent free PSA result and prostate health index (phi) will not be calculated or reported.
Method Name
Immunoenzymatic Assay
Specimen Type
Serum RedSpecimen Minimum Volume
0.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Frozen (preferred) | 150 days | |
| Ambient | 24 hours | ||
| Refrigerated | 24 hours |
On-campus collections: Tube to 99 or deliver to University Extension Hospital Room EH318
Submission Container/Tube: Plastic vial, Frozen
Off-campus collections: Centrifuge and aliquot within 2 hours. Specimen to be stored/transported Frozen.
Reject Due To
| Gross hemolysis | Reject |
| Gross icterus | Reject |
Reference Values
Females: Not applicable
PROSTATE-SPECIFIC ANTIGEN (PSA) MALES:
|
Age |
Reference range |
|
<40 years |
≤2.0 ng/mL |
|
40-49 years |
≤2.5 ng/mL |
|
50-59 years |
≤3.5 ng/mL |
|
60-69 years |
≤4.5 ng/mL |
|
70-79 years |
≤6.5 ng/mL |
|
≥80 years |
≤7.2 ng/mL |
PERCENT FREE PSA MALES:
When PSA is in the range of 4.0-10.0 ng/mL
|
% Free PSA |
Probability of cancer |
|
≤10% |
56% |
|
11-15% |
28% |
|
16-20% |
20% |
|
21-25% |
16% |
|
>25% |
8% |
PROSTATE HEALTH INDEX (phi) MALES:
When PSA is in the range of 4.0-10.0 ng/mL
|
phi range |
Probability of cancer |
95% Confidence interval |
|
0-26.9 |
9.8% |
5.2-15.4% |
|
27.0-35.9 |
16.8% |
11.3-22.2% |
|
36.0-54.9 |
33.3% |
26.8-39.9% |
|
≥55.0 |
50.1% |
39.8-61.0% |
Interpretation
The prostate health index (phi) may be used to determine the probability of prostate cancer on biopsy in men aged 50 years and older with total prostate-specific antigen (PSA) in the 4.0 to 10.0 ng/mL range. Low phi scores are associated with a lower probability of finding prostate cancer on biopsy, and higher phi scores are associated with an increased probability of finding prostate cancer on biopsy. The choice of an appropriate phi score to be used in guiding clinical decision-making may vary for each patient and may depend on other clinical factors or family history. The table below indicates the probability of finding prostate cancer on biopsy when total PSA is in the range of 4.0 to 10.0 ng/mL and may be used as guidance for interpreting the phi score.
|
phi range |
Probability of cancer |
95% Confidence interval |
|
0-26.9 |
9.8% |
5.2%-15.4% |
|
27.0-35.9 |
16.8% |
11.3%-22.2% |
|
36.0-54.9 |
33.3% |
26.8%-39.9% |
|
55.0+ |
50.1% |
39.8%-61.0% |
Method Description
Prostate Specific Antigen:
The Access Hybritech PSA (prostate-specific antigen) assay is a 2-site immunoenzymatic ("sandwich") assay. A sample is added to mouse monoclonal anti-PSA alkaline phosphatase conjugate and paramagnetic particles coated with a second mouse monoclonal anti-PSA antibody. The PSA in the sample binds to the immobilized monoclonal anti-PSA on the solid phase while the monoclonal anti-PSA alkaline phosphatase conjugate reacts with a different antigenic site on the sample PSA. After incubation, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. The chemiluminescent substrate Lumi-Phos* 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of PSA in the sample and is determined from a stored, multipoint calibration curve.(Package insert: Access Hybritech PSA/Prostate-Specific Antigen Instructions for Use. Beckman Coulter Inc; 08/2023)
Free Prostate Specific Antigen:
The Access Hybritech free PSA assay is a 2-site immunoenzymatic ("sandwich") assay. A sample is added to mouse monoclonal anti-free PSA-alkaline phosphatase conjugate and paramagnetic particles coated with a second mouse monoclonal anti-PSA antibody. The free PSA in the sample binds to the immobilized monoclonal anti-PSA on the solid phase while the monoclonal anti-free PSA-alkaline phosphatase conjugate reacts with different antigenic sites on the free PSA molecule. After incubation, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. The chemiluminescent substrate Lumi-Phos 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of free PSA in the sample and is determined from a stored, multipoint calibration curve.(Package insert: Access Hybritech free PSA/Free Prostate-Specific Antigen Instructions for Use. Beckman Coulter Inc; 06/2020)
[-2]ProPSA:
The Access Hybritech p2PSA ([-2]proPSA) is a 2-site immunoenzymatic ("sandwich") assay. A sample is added to mouse monoclonal anti-PSA-alkaline phosphatase conjugate, paramagnetic particles coated with a mouse monoclonal anti-[-2]proPSA antibody, and a blocking reagent. The [-2]proPSA in the sample binds to the immobilized monoclonal anti-[-2]proPSA on the solid phase while the monoclonal anti-PSA-alkaline phosphatase conjugate reacts with different antigenic sites on the [-2]proPSA molecule. After incubation, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. The chemiluminescent substrate Lumi-Phos*530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of [-2]proPSA in the sample and is determined from a stored, multipoint calibration curve.(Package insert: Access Hybritech p2PSA/[-2]proPSA Instructions for Use. Beckman Coulter Inc; 10/2023)
Percent free PSA:
The free PSA concentration is divided by the total PSA to derive the percent free PSA. The percentage is provided only when the total PSA is in the range of 4.0 to 10.0 ng/mL.
Prostate health index:
Prostate health index (phi) is calculated in the laboratory information system and provided only when the total PSA is in the range of 4.0 to 10.0 ng/mL.
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysSpecimen Retention Time
2 weeksPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84153 - Total PSA
84154 - Free PSA (if appropriate)
86316 - [-2]ProPSA (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PHI11 | Prostate Health Index Reflex, S | 53764-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PHI12 | Prostate Specific Antigen, S | 83112-3 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.