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Chromogranin A, LC/MS/MS : 31911
Test CodeCGAQ or 31911
Alias/See Also
CgA
CPT Codes
86316
Instructions
Collect blood in a standard red-top serum vacutainer tube. Allow blood to clot at room temperature. Centrifuge and separate the serum from the cells immediately. Do not store refrigerated. (Sample must not reach refrigerator temperature)
Transport Container
Specimen:
1 mL serum collected in a red-top tube (no gel)
Minimum Volume: 0.5 mL
1 mL serum collected in a red-top tube (no gel)
Minimum Volume: 0.5 mL
Transport Temperature
Frozen.
Specimen Stability
Room temperature: 7 days; Refrigerated: Unacceptable; Frozen: 31 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Unspun red-top (no gel) tubes; Serum separator tube (SST); Gross hemolysis
Methodology
Chromatography/Mass Spectrometry
Setup Schedule
Monday - Saturday
Report Available
3-4 days (From receipt at performing laboratory)
Limitations
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Reference Range
Adults < 311 ng/mL
Clinical Significance
Chromogranin A, LC/MS/MS - Chromogranin-A (CgA) is an acidic glycoprotein expressed in the secretory granules of most normal and neoplastic neuroendocrine (NE) cell types, where it is released together with peptide hormones and biogenic amines. Neuroendocrine tumors (NETs) are a form of cancer that differ from other neoplasia in that they synthesize, store, and secrete peptides, e.g., CgA and amines. CgA is secreted from neuroendocrine-derived tumors including foregut, midgut and hindgut gastrointestinal NETs, pheochromocytomas, neuroblastomas, medullary thyroid carcinomas, some pituitary tumors, functioning and non-functioning pancreatic NETs.
Significantly elevated CgA levels have been found in patients with other diseases, such as impaired renal function, untreated benign essential hypertension, gastritis, prostatic carcinoma, and hyperparathyroidism. The best-characterized circulating biomarker that identifies NETs in general is CgA. Monitoring blood CgA levels may effectively provide information that is helpful in delineating tumor burden and rate of tumor growth, predicting tumor response to therapy and providing some indication as to prognosis.
Significantly elevated CgA levels have been found in patients with other diseases, such as impaired renal function, untreated benign essential hypertension, gastritis, prostatic carcinoma, and hyperparathyroidism. The best-characterized circulating biomarker that identifies NETs in general is CgA. Monitoring blood CgA levels may effectively provide information that is helpful in delineating tumor burden and rate of tumor growth, predicting tumor response to therapy and providing some indication as to prognosis.
Performing Laboratory
Quest Diagnostics
