Macroprolactin

Macroprolactin

We remind you that independent interpretation of the results is unacceptable, the information provided below is for reference purposes only.

Macroprolactin is a complex formed when prolactin, a hormone produced by the pituitary gland, binds to an antibody or other protein in the bloodstream. This complex has a larger molecular size compared to the normal monomeric form of prolactin, and it can interfere with the accurate measurement of prolactin levels in blood tests.

Structure and Significance

Macroprolactin is a form of prolactin that has a higher molecular weight due to its association with immunoglobulins or other proteins. The exact mechanism behind the formation of macroprolactin is not fully understood, but it is believed to be related to the presence of autoantibodies or other binding proteins in the blood.

The presence of macroprolactin can lead to falsely elevated prolactin levels in blood tests, potentially leading to misdiagnosis or unnecessary treatment. It is essential to distinguish between the biologically active monomeric form of prolactin and the less biologically active macroprolactin complex.

Role of Macroprolactin

Macroprolactin is a complex formed by the binding of prolactin, a hormone produced by the pituitary gland, with immunoglobulins (antibodies). This complex has a larger molecular weight than regular prolactin, leading to an extended half-life in the bloodstream. The presence of macroprolactin can cause an elevation in measured prolactin levels, which may not reflect the biologically active form of the hormone.

Indications for Macroprolactin Testing

The measurement of macroprolactin levels is typically recommended in the following situations:

• Evaluation of hyperprolactinemia: If a patient has an elevated prolactin level, testing for macroprolactin can help determine whether the increase is due to the presence of the macroprolactin complex or an underlying condition affecting prolactin production or regulation.
• Unexplained infertility or menstrual irregularities: Elevated prolactin levels can interfere with ovulation and fertility in women and cause sexual dysfunction in men. Macroprolactin testing can help identify if the elevated prolactin levels are due to the macroprolactin complex or a true hyperprolactinemic state.
• Evaluation of galactorrhea: Galactorrhea (inappropriate or spontaneous milk production) can be a symptom of hyperprolactinemia. Macroprolactin testing can aid in determining the underlying cause.
• Monitoring treatment response: In patients being treated for hyperprolactinemia or pituitary adenomas, macroprolactin testing can help evaluate the effectiveness of the treatment by assessing the biologically active prolactin levels.

Preparation for the Macroprolactin Test

The procedure for having a blood test to determine the level of Macroprolactin is relatively simple and does not require special preparation. However, there are a few recommendations to consider:

• Diet: In most cases, the Macroprolactin blood test can be taken either fasting or after eating. However, in some situations (e.g., during a comprehensive biochemical blood analysis), you may need to observe an 8-12 hour fast before the blood draw.
• Avoiding Physical Activity: It is advisable to avoid intense physical activity on the day before the test, as it may affect the results.
• Abstaining from Alcohol and Smoking: It is recommended to refrain from consuming alcohol and smoking on the day before the test, as these can influence the level of Macroprolactin and other blood parameters.
• Maintaining Hydration: Maintaining proper hydration is essential for facilitating the blood draw process. Inadequate fluid intake can make the venipuncture procedure more challenging.
• Informing About Medications: Some medications may affect the level of Macroprolactin and other blood parameters. It is crucial to inform your healthcare provider about all medications you are taking.

Test Procedure

The blood draw for the Macroprolactin test is typically performed from a vein located in the bend of the elbow. The procedure takes a few minutes and is carried out by a healthcare professional. After the venipuncture, there may be minor bleeding or bruising, which usually resolves on its own within a few days.

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3719302/
https://pubmed.ncbi.nlm.nih.gov/16620360/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10504566/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3529459/
https://www.sciencedirect.com/topics/medicine-and-dentistry/macroprolactin
https://www.bmj.com/content/348/bmj.g3207
https://en.wikipedia.org/wiki/Macroprolactin

IMPORTANT!

It is crucial to remember that the information provided in this section is not intended for self-diagnosis or self-treatment. If you experience any pain or exacerbation of a condition, it is essential to seek medical attention for proper diagnostic testing. Only a qualified healthcare professional can make an accurate diagnosis and determine the appropriate treatment. To ensure the most accurate and consistent evaluation of test results, it is recommended to have them performed at the same laboratory. Different laboratories may use varying methods and units of measurement for similar tests.