LDL Cholesterol, Direct

CPT Code: 83721
Order Code: C120
ABN Requirement:  No
Synonyms: LDL; LDL-C; Low-density Lipoprotein Cholesterol; Direct LDL-C; Direct LDL
Specimen: Serum
Volume: 1.0 mL
Minimum Volume: 0.5 mL
Container: Gel-barrier tube (SST, Tiger Top)

Collection:

  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Fasting: If the Direct LDL cholesterol is ordered along with a lipid panel, then a fasting sample is not required. If a Direct LDL cholesterol measurement is to be performed along with triglycerides, but not part of a lipid panel, then the patient should be fasting 9-12 hours prior to collection.

Transport: Store specimen at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box.

Stability:

Ambient (15-25°C): 6 days
Refrigerated (2-8°C): 7 days
Frozen (-20°C): 31 days

Causes for Rejection: Improper labeling; samples not stored properly; samples older than stability limits; gross hemolysis; gross icterus

Methodology: Enzymatic

Turn Around Time: 1 to 3 days

Relative Risk Range:

Age Low Risk
mg/dL
 Moderate Risk
mg/dL
 High Risk
mg/dL
<20 years <110 110-129 ≥130
≥20 years <100 100-129 ≥130

 

Clinical Significance: The direct LDL cholesterol test is used to determine LDL levels in individuals with high triglyceride levels for which the Friedewald equation for calculating LDL-C from Total cholesterol, HDL-C and triglycerides cannot be used. In addition to other lipid tests, the direct LDL cholesterol test can be ordered to help determine the risk of developing cardiovascular disease in healthy individuals as well as those with one or more risk factors, individuals with a family history of high cholesterol or heart disease, and in individuals who are obese, diabetic, or who consume a high-fat diet. Direct LDL cholesterol testing is also used to monitor the efficacy of lipid-lowering interventions, such as dietary changes, exercise and medication.

Limitations: In very rare cases gammopathy, especially monoclonal IgM (Waldenstrom’s macroglobulinemia), may cause unreliable results.

The CPT codes provided 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 payer being billed.