Cyclosporine by LC-MS, Plasma
Test Name: Cyclosporine by LC-MS, Plasma
Specimen: Plasma
Method: Liquid Chromatography–Mass Spectrometry (LC-MS/MS)
About the Test
Cyclosporine is an immunosuppressive medication primarily used to prevent organ rejection after transplantation. Because it has a narrow therapeutic window and significant variation between individuals, therapeutic drug monitoring may be required to help optimize dosing and reduce the risk of toxicity.
Why is this Test Done?
- To measure cyclosporine concentration in the submitted plasma sample.
- To support therapeutic drug monitoring.
- To help assess whether drug exposure is appropriate.
- To assist clinicians in evaluating possible underexposure or excessive drug exposure.
- To support dose adjustment along with clinical findings and treatment protocol.
Who May Need This Test?
It may be requested for patients receiving cyclosporine therapy, particularly:
- Organ transplant recipients
- Patients requiring long-term immunosuppressive therapy
- Patients with suspected drug toxicity or inadequate drug exposure
- Patients undergoing medication or drug-interaction changes
Sample & Preparation
Sample Type: Plasma
Method: LC-MS/MS
The collection timing relative to the last cyclosporine dose is important for interpretation. The requested specimen type and timing should follow the treating physician's or laboratory's protocol.
Interpretation
Results should be interpreted together with:
- Time of sample collection
- Time and dose of the last medication
- Transplant type and time since transplantation
- Other medications
- Patient's clinical condition
- Laboratory-specific therapeutic targets
Important: Therapeutic ranges are method-, indication-, and timing-dependent and should not be interpreted as a universal target.
Clinical Significance
LC-MS/MS provides selective measurement of cyclosporine and can reduce the influence of metabolite cross-reactivity seen with some immunoassay methods.
Note: For routine cyclosporine therapeutic drug monitoring, whole blood is commonly the preferred specimen because most circulating cyclosporine is associated with erythrocytes. Therefore, a plasma cyclosporine result should be interpreted specifically according to the laboratory's validated method and clinical protocol.
