Serotonin, Blood
Use
The Serotonin, Blood test is used in conjunction with or as an alternative to first-order tests for diagnosing carcinoid syndrome, particularly when symptoms such as flushing are present. It serves as a second-order test for the follow-up of patients with known or treated carcinoid tumors using whole blood specimens.
Special Instructions
Patients should not take medications that may elevate serotonin levels for 72 hours before specimen collection. This includes SSRIs like Prozac, which can lead to depletion of platelet serotonin levels and false-negative results. For non-electronic orders, include the Oncology Test Request form with the specimen.
Limitations
Circulating serotonin is mostly contained in platelets, making whole blood and platelet-rich plasma the preferred specimens. 'Ordinary' or platelet-poor plasma specimens are unsuitable. Some medications like SSRIs can lead to false-negative results by depleting serotonin levels.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 2939-7
- 2939-7
Result Turnaround Time
5-8 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
2.5 mL
Minimum Volume
1.5 mL
Container
Lavender top (EDTA); Submission Container: Serotonin tube containing ascorbic acid
Collection Instructions
Immediately transfer approximately 2.5 mL of whole blood to the serotonin tube and mix well. Immediately freeze the specimen.
Patient Preparation
Patient should not take medications that may elevate serotonin levels for at least 72 hours before specimen collection.
Causes for Rejection
Gross lipemia and icterus are acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 90 days |