Serotonin, Serum
Also known as: 5-HT, Serum, 5-Hydroxytryptamine, Serum
Use
Serotonin measurement is used in conjunction with urinary 5-hydroxyindoleacetic acid (5-HIAA) and/or serum chromogranin A in the diagnosis of carcinoid syndrome.
Special Instructions
State patient's sex on the test request form for accurate processing.
Limitations
Most gastroenteropancreatic neuroendocrine carcinoid tumors do not produce elevated serotonin levels in whole blood or serum. In most cases, tests for 5-hydroxyindoleacetic acid (5-HIAA) and chromogranin A are more reliable for carcinoid syndrome assessment. Certain medications can elevate serotonin levels, while selective serotonin reuptake inhibitors may lower them. Tryptophan-rich foods do not affect serum or blood serotonin levels. The test is developed by Labcorp but not FDA cleared or approved.
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 27057-9
- 27057-9
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Separate serum from cells within 30 minutes of collection and transfer to a plastic transport tube. Serum can be transported at room temperature or frozen. For frozen samples, transfer to a plastic transport tube before freezing. If requesting multiple tests on frozen samples, submit separate frozen specimens for each test.
Patient Preparation
Monoamine oxidase inhibitor drugs should be discontinued for at least one week prior as they can increase serotonin levels.
Storage Instructions
Room temperature
Causes for Rejection
Plasma sample received; serum that is not separated from cells
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 14 days |