|Downtime form:||A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery|
|Plasma Separator Tube 4.5 mL|
Pediatrics - ONE Microtainer®
< 10 μmol/L Patients with end stage renal disease may have elevated levels of cystathionine which may cause a significant positive interference in the homocysteine assay.
Cystathionine is measured with homocysteine, but in the general population the cystathionine level (0.065 to 0.03 umol/l) has a negligible effect. In very rare, end stage renal disease patients with severe metabolic disturbances, cystathionine levels may rise dramatically and cause greater than 20% interference. Refer to the SPECIFICITY section of the package insert for cross-reactivity data of this drug. Drugs, such as methotrexate, carbamazepine, phenytoin, nitrous oxide, or 6-azauridine triacetate may affect plasma concentration of homocysteine. The mechanism of action affects different parts of the metabolic pathway of homocysteine. Serum concentrations can be up to 10% higher than EDTA plasma concentrations.
Hemolysis: No significant interference up to an H index of 500 (approximate hemoglobin concentration: 500 mg/dL).
Lipemia: No significant interference up to an L index of 500 (approximate triglycerides concentration: 1000 mg/dL). Note there is poor correlation between turbidity and triglyceride concentration.
Icterus: No significant interference up to an I index of 20 (approximate conjugated and unconjugated bilirubin concentration: 20 mg/dL).
Specimens Requiring Immediate Delivery