Chromogranin A Test
Chromogranin A (CgA) is a protein released by neuroendocrine cells, which can be found in numerous organs within the body. Neuroendocrine cells exhibit traits of both hormone-producing cells and nerve cells. The chromogranin A test measures the amount of CgA in the blood sample. This test is referred to as a tumour marker test because CgA can be released at elevated levels in individuals with tumours of the neuroendocrine system. Your healthcare provider may order this test to diagnose and manage neuroendocrine tumours.
Symptoms of a neuroendocrine tumour
Initially, neuroendocrine tumours may not cause any signs or symptoms. The specific symptoms that may arise depend upon the tumour's location and its potential to overproduce hormones.
Pain
Fatigue
Losing weight without trying
Diarrhea
Frequent urination
Increased thirst
Dizziness
Shakiness
Skin rash
What is a Chromogranin A test used for?
Your healthcare provider may request this test for:
Evaluating the effectiveness of the treatment in individuals with some neuroendocrine tumours
Estimating prognosis in patients with neuroendocrine tumours
Diagnosing a neuroendocrine tumour
Preparation for the test
Overnight fasting is recommended before the test. Some medications may influence the outcome of the test. Therefore, it is crucial to inform your doctor about any medications you are currently using.
Interpretation of results
The reference range of this test is 0 – 3 nanomoles per liter (nmol/L). Elevated levels of CgA may indicate tumour progression or recurrence; however, CgA testing alone cannot provide an accurate assessment of treatment effectiveness.
FAQs
How is the sample collected for the chromogranin A test?
A healthcare provider will draw a blood sample from a vein in your arm using a needle. The blood will be collected in a test tube or vial and sent to the lab for analysis.
What are the risks associated with the chromogranin A test?
There are no known risks associated with this test. During a blood test, one may experience minor pain or bruising where the needle was inserted, but most symptoms will subside quickly.
What is the turnaround time (TAT) for the chromogranin A test result?
The chromogranin A test result is usually available within 1-2 days after the sample collection. This duration may vary depending on the diagnostic clinic.
What medications can affect my chromogranin A levels?
Chromogranin A levels can be influenced by specific medications such as proton pump inhibitors, histamine H2-receptor blockers, etc.
If my chromogranin A levels are elevated, which type of doctor should I consult?
In case of elevated chromogranin A levels, it is advisable to consult a specialist, usually an endocrinologist or oncologist, for a more thorough assessment.
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