Plasma metanephrines

Plasma metanephrines are biochemical markers used in diagnosing pheochromocytoma and paraganglioma, which are rare tumors typically arising from chromaffin cells in the adrenal glands or extra-adrenal paraganglia. These tumors can produce and release excessive amounts of catecholamines, such as adrenaline (epinephrine) and noradrenaline (norepinephrine), leading to a variety of symptoms such as high blood pressure, palpitations, and sweating.

Metanephrines are metabolites of catecholamines, and measuring their levels in the blood can provide information about the production and release of these hormones. The two main metanephrines that are measured in plasma are metanephrine and normetanephrine.

The typical test for plasma metanephrines involves drawing a blood sample, usually collected during rest, as stress or physical activity can affect catecholamine levels. Elevated levels of plasma metanephrines may suggest the presence of a pheochromocytoma or paraganglioma. 

When To Get Tested Plasma Metanephrines?

Here are some situations in which plasma metanephrine testing might be considered:

1. Symptoms of Pheochromocytoma or Paraganglioma: If an individual is experiencing symptoms such as high blood pressure, rapid heart rate, sweating, and headache, which could be indicative of an adrenal gland tumor.
2. Incidental Findings: Sometimes, adrenal tumors are discovered incidentally during imaging studies done for other reasons. In such cases, if there’s a suspicion of a functional tumor (one that produces hormones), plasma metanephrine testing may be recommended.
3. Follow-up for Known Tumors: For individuals with a known history of pheochromocytoma or paraganglioma, plasma metanephrine testing may be used to monitor for recurrence or persistence of the tumor.
4. Genetic Testing: People with a family history of these tumors or certain genetic syndromes that increase the risk of developing adrenal tumors may undergo plasma metanephrine testing as part of genetic testing and screening.

It’s important to note that the decision to test for plasma metanephrines should be made by a healthcare professional based on the individual’s medical history, symptoms, and other relevant factors. The test is usually done after proper preparation, which may include avoiding certain medications and foods that can interfere with the results.

What does the Plasma metanephrines test result mean?

Elevated levels of plasma metanephrines can be indicative of a variety of conditions, with the most common being pheochromocytoma or paraganglioma. These are tumors that can develop in the adrenal glands or other areas of the body. These tumors can lead to excessive production of catecholamines, causing symptoms such as high blood pressure, rapid heart rate, and sweating.

The results of the Plasma Metanephrines test are typically reported in picograms per milliliter (pg/mL). It’s essential to interpret the results in the context of the patient’s overall clinical picture, including symptoms and other diagnostic tests. Abnormal results may prompt further investigation, such as imaging studies like CT scans or MRI, to locate and characterize any tumors.