Answer
Active enzyme in an ordinary blood sample can continue breaking down arginine, producing an inaccurately low result. The laboratory must use a validated collection method that blocks this activity.
Sources for this answer
- Loargys 5 mg/ml solution for injection/infusion — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.