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HelpTest Code MCRPL Macroprolactin, Serum
Reporting Name
Macroprolactin, SUseful For
Determining biologically active levels of prolactin, in asymptomatic patients with elevated prolactin levels
Ruling out the presence of macroprolactin
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TOPRL | Prolactin,Total,S | Yes, (order PRL) | Yes |
| PEGPR | Prolactin,Unprecipitated,S | No | Yes |
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.
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.6 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 90 days | ||
| Ambient | 24 hours |
Reference Values
PROLACTIN, TOTAL
Males
<18 years: not established
≥18 years: 4.0-15.2 ng/mL
Females
<18 years: not established
≥18 years: 4.8-23.3 ng/mL
PROLACTIN, UNPRECIPITATED
Males
<18 years: not established
≥18 years: 2.7-13.1 ng/mL
Females
<18 years: not established
≥18 years: 3.4-18.5 ng/mL
When the percent of the precipitated (complexed) prolactin fraction of the total prolactin is 60% or less, the result is considered negative for macroprolactin.
Day(s) Performed
Monday through Sunday
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
84146 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MCRPL | Macroprolactin, S | 78993-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PROU | Prolactin,Unprecipitated,S | 38926-2 |
| T_PRL | Prolactin,Total,S | 20568-2 |
| RATIO | Prolactin, Percent PEG-precipitated | 51441-4 |
| CMT42 | Interpretive Comment | 48767-8 |
Interpretation
When the fraction (percentage) of polyethylene glycol (PEG)-precipitated (complexed) prolactin is 60% or less of total prolactin, the specimen is considered negative for macroprolactin. When total prolactin exceeds the upper reference limit and macroprolactin is negative, other causes for hyperprolactinemia should be explored.
When the fraction (percentage) of polyethylene glycol (PEG)-precipitated (complexed) prolactin is above 60%, the specimen is considered positive for the presence of macroprolactin.
Following polyethylene glycol (PEG)-precipitation, a patient whose unprecipitated prolactin concentration is greater than the upper limit of the unprecipitated prolactin reference interval may have hyperprolactinemia.
See PRL / Prolactin, Serum for interpretation of prolactin levels.
Clinical Reference
1. Fahie-Wilson M: In Hyperprolactinemia, Testing for Macroprolactin is Essential. Clin Chem 2003;49(9):1434-1436
2. Gibney J, Smith TP, McKenna TJ: Clinical relevance of macro-prolactin. Clin Endocrinol 2005 Jun;62:633-643
Report Available
Same day/1 to 3 daysMethod Name
TOPRL: Electrochemiluminescent Immunoassay
PEGPR: Polyethylene Glycol (PEG) Precipitation Followed by Electrochemiluminescent Immunoassay
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.