From the Guidelines
The next step in the workup of a young female with mildly elevated prolactin levels on two occasions should be to assess baseline macroprolactin levels to determine if the elevation is due to macroprolactinemia, a condition with low biological activity. This recommendation is based on the latest consensus guideline for the diagnosis and management of pituitary adenomas in childhood and adolescence, which suggests assessing baseline macroprolactin levels where serum prolactin is found to be mildly or incidentally elevated 1. Some key points to consider in this workup include:
- Macroprolactinemia is a condition where dimeric or polymeric forms of prolactin circulate in the blood, often associated with an antibody, and has low biological activity.
- Routine assays do not distinguish between monomeric prolactin and macroprolactin, making secondary analysis necessary to detect macroprolactin.
- The presence of macroprolactinemia can be identified through specific testing, which is crucial in the initial investigation of asymptomatic individuals with hyperprolactinemia.
- In adults, macroprolactinemia is present in 10-40% of individuals with hyperprolactinemia, and while data in pediatric populations is limited, it is essential to consider this condition in the workup of mildly elevated prolactin levels 1. Given the potential for macroprolactinemia to cause elevated prolactin levels without significant clinical symptoms, assessing for macroprolactin levels is a critical step in determining the cause of hyperprolactinemia in this patient population, as it may obviate the need for further invasive testing if macroprolactinemia is identified.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Next Steps in Workup
- In a young female with mildly elevated prolactin levels on two occasions, the next step in the workup would involve excluding other causes of hyperprolactinemia, such as macroprolactinemia, prolactinoma, and other identifiable non-tumoral causes 2.
- A careful history and physical examination, routine chemistries, a pregnancy test, and a TSH test should be performed to rule out other potential causes of hyperprolactinemia 3, 4.
- Imaging with MRI or CT may be necessary to delineate the size and extent of any potential tumor, although this may not be immediately necessary for mildly elevated prolactin levels 3, 5.
Considerations for Further Evaluation
- The patient's symptoms, such as galactorrhea, menstrual cycle disorder, or infertility, should be taken into account when determining the next steps in the workup 6, 2.
- The presence of mildly elevated prolactin levels may cause luteal insufficiency in cycling women and is associated with recurrent miscarriage, and therefore, treatment may be necessary to restore fertility 2.
- The preference for treatment is cabergoline at the lowest possible dose that normalizes prolactin levels, which can restore fertility in the vast majority of cases 2, 4.