Cyclosporin, C0 (Before Dose), by LC-MS – EDTA Whole Blood
Test Overview
Cyclosporin C0 is a therapeutic drug monitoring test that measures the trough concentration of cyclosporine in whole blood immediately before the next scheduled dose. It is primarily used to optimize immunosuppressive therapy while reducing the risk of drug toxicity and transplant rejection.
Why is this test done?
- Monitoring cyclosporine therapy after organ transplantation.
- Guiding dose adjustments to maintain adequate immunosuppression.
- Helping minimize concentration-related toxicity.
- Assessing drug levels when drug interactions or changes in therapy are suspected.
- Supporting evaluation of treatment adherence.
Sample Required
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Specimen: Whole Blood
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Anticoagulant: EDTA
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Container: Lavender-top EDTA tube
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Collection: Immediately before the next scheduled cyclosporine dose (C0/trough).
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Handling: Do not centrifuge; send whole blood in the original tube.
Method
Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS), providing specific measurement of cyclosporine in whole blood.
Result Interpretation
Cyclosporine target concentrations are individualized according to the type of transplant, time since transplantation, treatment protocol, concomitant medicines, and clinical status. A commonly cited trough range is approximately 100–400 ng/mL, but the treating transplant team’s target should be followed.
Important Note
The exact collection time and time of the last cyclosporine dose should be documented. Samples collected after the scheduled dose are not C0/trough samples, and C0 therapeutic targets should not be applied to them.
