Carnitine, LC/MS/MS (CARNI)

Test Code

70107

Quest Code

70107

CPT Codes
82379

Includes

Carnitine, Total
Carnitine, Free
Carnitine, Esters
Esterified/Free Ratio

Preferred Specimen

1 mL serum in gold top tube

Patient Preparation
Patient should be in a well-fed state

Minimum Volume

0.5 mL

Other Acceptable Specimens

Plain red top tube; Plasma collected in a sodium heparin (green-top) tube

Instructions

Separate serum by centrifugation. Avoid hemolysis. Remove serum and place in plastic tube. Freeze immediately after separation.

Transport Container

Transport tube

Transport Temperature

Frozen

Specimen Stability

Room temperature: 5 hours
Refrigerated: 5 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Moderate and gross hemolysis • Received room temperature

Methodology
Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

PM Mon-sat

Report Available

5 days

Reference Range

See Laboratory Report

Clinical Significance

Serum carnitine analysis is useful in the diagnosis and monitoring of patients with carnitine deficiency (either primary or secondary). Primary carnitine deficiency is an autosomal recessively inherited genetic condition that affects carnitine uptake by cells and tissues through a defect in the plasma membrane carnitine transporter. Secondary carnitine deficiency can be seen in some disease states or in patients on carnitine-poor diets, but is also seen in a number of metabolic disorders. In these disorders, carnitine complexes with the accumulated substrate of the blocked metabolic step, and the resulting acylcarnitine ester is excreted in the urine, leading to a depletion of carnitine in the patient.

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.