Chromogranin A, CgA for short, is a protein from the granin family, synthesized and stored in many neuroendocrine tissues, e.g. pancreas, adrenal glands, and neurons. In addition, chromogranin A together with chromogranin B and C are produced in the granules of secretory cells of neuroendocrine tumors. For this reason, chromogranin A is used as a sensitive but nonspecific tumor marker as it can be secreted by both he althy and cancer cells.

Chromogranin A , abbreviatedCgAis a protein from the granine family, synthesized and accumulated in many tissues of a neuroendocrine nature, e.g. pancreas, adrenal glands, neurons. In addition, chromogranin A together with chromogranin B and C are produced in the granules of secretory cells of neuroendocrine tumors. For this reason, chromogranin A is used as a sensitive but nonspecific tumor marker as it can be secreted by both he althy and cancer cells.

Chromogranin A (CgA) - when to do the test?

Chromogranin A testing is ordered when neuroendocrine tumors are suspected, which may be manifested by:

  • with quick breathing and heartbeat
  • diarrhea
  • vomiting
  • difficulty breathing
  • dilated pupils
  • sweating
  • a headache
  • paroxysmal facial redness
  • anxious
  • shaking hands

After a tumor has been diagnosed, the determination of the level of chromogranin A may be used to assess the effectiveness of treatment. If your level drops, you will heal successfully.

Chromogranin A (CgA) - what is the test and how much does it cost?

The test of chromogranin A is performed on an empty stomach from venous blood taken from the elbow bend. This is very important as the concentration of chromogranin A increases after a meal. After collection in the laboratory using immunoenzymatic methods, e.g. ELISA, its level in the sample is determined.

A blood test in a commercial laboratory costs about PLN 140-180.

Additionally, the determination of chromogranin A in the collected tissue specimens is used in immunohistochemical tests to determine the stage of neuroendocrine tumors.

Chromogranina A(CgA) - norms

The norms for chromogranin A in the blood depend on the research method used and the monoclonal antibodies used. In addition, standards can be expressed in different units. Therefore, if chromogranin A is tested several times in the same person, e.g. to monitor treatment, the test should be performed in the same laboratory.

Examples of standards for chromogranin A are:

  • 1.6-5.6 ng / ml
  • 20-100 µg / l
  • <40 AU
  • <4 nmol/l

Chromogranin A (CgA) - how to interpret the test results?

The increase in chromogranin A concentration is observed in:

  • carcinoid
  • pheochromocytoma
  • neuroblastomy
  • pancreatic cancer
  • prostate cancer
  • liver cancer
  • small cell lung cancer

Additionally, very high concentrations of chromogranin A in the presence of a tumor may indicate high malignancy and poor prognosis.

The result of the chromogranin A test is best interpreted together with other tests and the clinical picture, because both too high and normal levels do not exclude a tumor.

In addition, a slight increase in chromogranin A is observed in non-cancerous states:

  • Crohn's disease
  • hyperparathyroidism
  • hyperthyroidism
  • Parkinson's disease
  • untreated hypertension
  • circulatory failure
  • kidney failure
  • prostate enlargement
  • rheumatoid arthritis
  • atrophic gastritis

It is also worth knowing that some drugs affect the concentration of chromogranin A:

  • proton pump inhibitors
  • H2 receptor blockers

Category:

Research