Chromogranin - A

Last Modified: 5/25/2021 11:20:24 AM


Medical Necessity Documentation:  
Client Notes:  
Patient Preparation:
Specimen Requirements: 1.0 mL Serum from a Red Top Tube in a Plastic Vial
Collection Instructions: Treatment with proton-pump inhibitors or H2-receptor blockers will cause an increase in Chromogranin A concentrations
 
Allow blood to clot at room temperature. Centrifuge and separate the serum from the cells immediately. 
Minimum Volume: 0.5 mL Serum
Transport & Storage: Temperature/Stability: 7 days Ambient
31 days Frozen (Transport)
 
Do not store refrigerated. 
Rejection Criteria: Unspun red-top tube • Serum separator tubes • Moderate to gross hemolysis • Moderate to grossly lipemic • Icteric
Reference Range:
Chromogranin A, LC/MS/MS Adults: <311 ng/mL
Chromogranin A 25-140 ng/mL
Critical Ranges:  
Test Comments: Chromogranin A, LC/MS/MS –
 
Comment: Interpretation of patient results may be affected by a variety of conditions such as hypertension, gastritis, prostate cancer, hyperparathyroidism, and most commonly renal disease and use of proton pump inhibitors (PPIs). (Vezzosi D, et al.Chromogranin  A measurement in metastatic well-differentiated gastroenteropancreatic neuroendocrine carcinoma: screening for false positives and a prospective follow-up study. Int J Biol Markers. 2011 Apr-Jun:26(2):94-101.) This test was performed using a Liquid Chromatography Mass Spectrometry method. Values obtained from different assay methods cannot be used interchangeably. Chromogranin A levels, regardless of value, should not be interpreted as absolute evidence of the presence or absence of disease. This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics Nichols Institute San Juan Capistrano. 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.
 
Chromogranin A –
 
Comment: This test was performed using a laboratory developed ELISA Method previously available at Quest Diagnostics (discontinued April 19, 2021). Values obtained with different assay methods cannot be used interchangeably. This rebaseline code 31912 (available until April 15, 2022) is designed to permit test results from the prior ELISA to be directly compared to results from the CHROMOGRANIN A, LC/MS/MS for individual patients followed sequentially. Chromogranin A levels, regardless of value, should not be interpreted as absolute evidence of the presence or absence of disease. This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics Nichols Institute San Juan Capistrano. 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. Test performed by Quest Diagnostics Nichols Institute 33608 Ortega Hwy, San Juan Capistrano, CA 92675   Medical Director: Irina Maramica MD,PHD,MBA Test Reported by Quest, Chantilly, Quest Diagnostics Nichols Institute, 14225 Newbrook Drive, Chantilly, VA 20151 Patrick W Mason, M.D., Ph.D., Director of Laboratories CLIA 49D0221801
Methodology: Chromatography/Mass Spectometry • Immunoassay (IA)
Clinical Significance: Chromogranin A, Rebaseline - 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.
Documentation:  
Custom Panel: No

PRODUCTION SCHEDULE

Turn Around Time: 3 - 5 days
Days Performed: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday
Sites Performed: Quest - Chantilly to San Juan Capistrano
PHL Test Code: CHRGA
EPIC Test Code: IMO95
Send Out Test Code: 31912
Alternate Test Names: CgA; Chromogranin - A, Rebaseline; Chromogranin-A
Included Tests:  
CPT Coding: 86316

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