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Test Code Billings Clinic: 4060 Prolactin, Plasma or Serum

Important Note

Pregnancy, lactation, and the administration of oral contraceptives can increase prolactin concentrations.

Performing Laboratory

Billings Clinic Laboratory: Chemistry

Useful For

  • Useful for evaluation of pituitary tumors, amenorrhea, galactorrhea, infertility, and hypogonadism.
  • It is also useful for monitoring therapy of prolactin-producing tumors.
  • Plasma prolactin levels exhibit peak levels during sleep and lowest levels in the late-morning.
  • Hyperthyroidism, renal failure, and a number of pharmaceuticals (opiates, neuroleptic agents, estrogen, oral contraceptives, and exogenous TRh) are associated with increased prolactin levels, while L-dopa, clonidine, and bromocriptine lower prolactin levels.

Methodology

Direct Chemiluminescence

Specimen Requirements

Submit only 1 of the following specimens:

Serum or plasma should be physically separated from cells as soon as possible with a maximum limit of two hours from the time of collection.

 

Plasma

  • Draw blood in a green-top (lithium heparin) tube(s).
  • Spin down and send 1.0 mL of heparinized plasma frozen.

 

Serum

  • Draw blood in a plain, red-top tube(s) or a serum gel tube(s).
  • Spin down and send 1.0 mL of serum frozen

Storage/Stability

Specimen Type Temperature Time
Plasma, Serum Refrigerated 2 days
  Frozen (preferred) 1 month
  Ambient 8 hours

 

Reject Due To

  • Specimens with greater than 1 freeze / thaw cycle
  • Specimens with apparent contamination
  • Gross hemolysis
  • Gross icterus

Reference Values

Males:

2.1 - 17.7 ng/mL

 

Females:

Non-pregnant: 2.8 - 29.2 ng/mL

Pregnant: 9.7 - >200.0 ng/mL

Post-menopausal: 1.8 - 20.3 ng/mL

 

Serum prolactin levels exhibit peak levels during sleep and lowest levels in the late morning. Hyperthyroidism, renal failure and a number of pharmaceuticals (opiates, neuroleptic agents, estrogen, oral contraceptives and exogenous TRh) are associated with increased prolactin levels, while L-Dopa, clonidine and bromcryptine lower prolactin levels.

Day(s) Test Set Up

Daily

Test Classification and CPT Coding

84146 - Prolactin

LOINC Code Information

Reporting Name LOINC Code
Prolactin 2842-3