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Specimen Collection

PST/Heparin tubes are not acceptable. 

Values may rise during treatment with proton pump inhibitors (PPI).  It is recommended to stop PPI treatment for at least 2 weeks before testing

4 mL Plain Blood
1 mL Paediatric SST Blood
3.5 mL SST Blood
1 mL Paediatric Microsample Whole Blood
Reference Intervals

Units: ug/L

Normal range: 0 - 102

Uncertainty of Measurement    10%

Turnaround Time: Between 1 week and 2 weeks
Assay Method

Principle:   Immunoassay

Assay:       BRAHMS

Analyser:   BRAHMS Kryptor 

Diagnostic Use and Interpretation

CGA is useful for diagnosis and monitoring of patients with carcinoid tumor, pheochromocytoma, paraganglioma,   neuroblastoma,   medullary thyroid carcinoma, islet cell tumours,   gastrointestinal APUD tumors, and some pituitary adenomas.

Some tumors that are not derived from neuroendocrine tissues, but contain cells with partial neuroendocrine differentiation, such as small-cell carcinoma of the lung or prostate carcinoma, may also display elevated CGA levels.

Carcinoid tumours are neuroendocrine tumours that usually arise from enterochromaffin cells, which are found scattered throughout the body but occur principally in the submucosa of the intestine and main bronchi. The carcinoid syndrome is caused by systemic release of one or more of the secretory products: amines, polypeptides, and or prostaglandins.

The most common manifestations of carcinoid syndrome are vasomotor changes (flushing), gastrointestinal hypermotility (diarrhoea), bronchospasm (wheezing, dyspnoea) and hypotension.
An attack of carcinoid syndrome may be provoked by emotional stress, heat, ingestion of particular foods or alcohol, straining at stool, or exogenous stimulation with adrenaline, dopamine or gastrin.
Carcinoid crisis with severe flushing and diarrhoea leading to dehydration, hypotension, and arrhythmias, along with unconsciousness, is a potentially life threatening complication.

To confirm the diagnosis, 24 hour urinary 5-HIAA is recommended (with dietary restrictions). Blood CgA and serotonin levels are useful for monitoring the treatment of established disease and may also be use when 5-HIAA levels are equivocal. CgA levels may be used to establish tumour burden.

Chromogranin A is not specific for neuroendocrine tumours and is not suitable as a screening test for primary diagnosis of carcinoid tumours. Elevated levels may also be seen in renal impairment, liver failure, inflammatory bowel disease and prostatic carcinoma. Proton pump inhibitors may also markedly elevate levels.

CATECHOLAMINES

HIAA

Contact Information

Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.

If the query concerns a specific patient please include the NHI number in your email.

If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).

Individual chemical pathologists may be contacted but will not be available at all times. 

After-hours : contact  Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.

Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402 

Dr Cam Kyle: CampbellK@adhb.govt.nz   ext 22052 

Dr Weldon Chiu: WeldonC@adhb.govt.nz   ext. 23427 

Dr Campbell Heron: CHeron@adhb.govt.nz   ext. 23427

Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427

Specimen Transport Instructions for Referring Laboratories

Instructions for Referral to Labplus
Aliquot Instructions	0.5 to 1 mL serum only (plain or SST).    Plasma samples are unsuitable
Stability	Serum needs to be frozen within 48 hours of collection Samples are stable for up to 48 hours at room temperature or refrigerated.
Aliquot Transport to LabPlus	Send to LabPlus as frozen

Last updated at 15:26:00 06/01/2025