Prolactin
Use
First test for work-up of galactorrhea (inappropriate lactation). Pituitary function test useful in the detection of prolactin-secreting pituitary tumors (microadenomas, macroadenomas) with or without galactorrhea, with or without structural evidence of sellar enlargement. An adult female premenopausal patient having amenorrhea and galactorrhea is highly suspect of pituitary prolactinoma and is a candidate for radiologic evaluation of the pituitary as well as serum prolactin levels. Elevated prolactin may be associated with corpus luteum insufficiency or anovulation. Sequelae of hyperprolactinemia include amenorrhea, anovulation, and decreased bone density.
Special Instructions
The test is sensitive to the timing of blood sample collection due to episodic secretion and 24-hour cycle regulation of prolactin. Physiological factors like suckling and stress can naturally elevate prolactin levels, while certain drugs such as antipsychotics can induce or elevate hyperprolactinemia. Serum levels may transiently rise post-drug discontinuation like cocaine, impacting prolactin regulation. Notably, patients under neuroleptic therapy displaying galactorrhea or amenorrhea should be monitored for pituitary tumors.
Limitations
Prolactin secretion follows an episodic pattern and is subject to a 24-hour cycle. Collection timing significantly affects measured levels. Certain pharmaceuticals can elevate serum prolactin concentrations. For patients taking high doses of biotin (>5 mg/day), the sample collection should be delayed by eight hours after the last biotin intake. Cases receiving monoclonal mouse antibodies might present erroneous findings due to interference. Extremely high antibodies to ruthenium and streptavidin may interfere in rare cases. During pregnancy, postpartum, and post-bilateral oophorectomy, prolactin levels naturally rise. Destructive pituitary diseases lead to low levels.
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 2842-3
- 2842-3
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Red-top tube, gel-barrier tube
Collection Instructions
If a red-top tube or plasma is used, transfer separated serum or plasma to a plastic transport tube.
Storage Instructions
Refrigerate.
Causes for Rejection
Do not use oxalate, EDTA, or citrate plasma.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |