Azathioprine (Imuran) as 6-Mercaptopurine
Use
Azathioprine is used to suppress the immune system in various clinical scenarios, such as organ transplantation and autoimmune diseases. This test measures azathioprine as its metabolite, 6-mercaptopurine, to monitor therapeutic levels and adjust dosage for optimal immunosuppressive effect. It is crucial in managing the balance between efficacy and toxicity, guiding modifications in treatment regimens based on individual patient metabolism and drug response.
Special Instructions
Blood samples should be drawn in specific tubes based on the specimen type: sodium heparin tubes for plasma and plain red-top tubes for serum. It's essential that the blood is immediately processed by spinning down and that plasma or serum is promptly refrigerated in a plastic vial to maintain stability.
Limitations
This test does not establish therapeutic or toxic serum concentration ranges; results must be interpreted in the context of clinical status and response. Variability in metabolism can occur due to genetic factors affecting enzyme activity involved in drug conversion, and therapy must be tailored accordingly. Measurements may not reflect intracellular drug levels which correlate more closely with efficacy.
New York Approved
Methodology
Mass Spectrometry (Other)
Biomarkers
LOINC Codes
- 16419-4
- 16419-4
Result Turnaround Time
5-9 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
0.3 mL
Container
Plastic vial
Collection Instructions
Draw blood in a green-top (sodium heparin) tube. Plasma gel tube is not acceptable. Spin down and send refrigerated.
Storage Instructions
Refrigerate the spun-down plasma.
Causes for Rejection
Hemolysis, lipemia, icterus, other issues as specified.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 14 days |
| Frozen | 180 days |