Sirolimus by Tandem Mass Spectrometry
Also known as: RAPAMUNE
Use
This test is used to optimize dosing and monitor patient adherence for sirolimus, an immunosuppressive drug used primarily in kidney and liver transplants to prevent rejection. The therapeutic range is specified for kidney transplants in combination with Cyclosporine, and suggestions are made for liver transplants. Monitoring sirolimus levels is critical to avoid toxicity, which can occur at levels greater than 25 ng/mL.
Special Instructions
Predose (trough) levels should be drawn for accurate monitoring. The test should adhere to specified storage and transport conditions, as clotted specimens, serum, and plasma are not acceptable. Specimens should not be stored at room temperature for more than 24 hours.
Limitations
Sirolimus concentrations can be measured by either chromatographic or immunoassay methodologies. These methodologies are not directly interchangeable. Immunoassays may show a positive bias relative to HPLC-MS/MS due to cross-reactivity with sirolimus metabolites. Reference ranges may vary depending on the assay used.
New York Approved
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 29247-4
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
1 mL
Minimum Volume
0.25 mL
Container
Lavender (EDTA) or pink (K2EDTA)
Patient Preparation
Predose (trough) levels should be drawn.
Storage Instructions
Refrigerated transport.
Causes for Rejection
Serum or plasma. Specimens left at room temperature for longer than 24 hours. Clotted specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 1 week |
| Frozen | 2 months |