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HelpTest Code LDLD Low-Density Lipoprotein (LDL) Cholesterol, Beta-Quantification, Serum
Reporting Name
LDL Cholesterol (Beta-Quant), SUseful For
Evaluation of cardiovascular risk
Verification of estimated low-density lipoprotein cholesterol (LDL-C) in patients with hypertriglyceridemia or extremely low LDL-C
Diagnosis of familial hypobetalipoproteinemia and abetalipoproteinemia
Method Name
Ultracentrifugation/Selective Precipitation/Enzymatic Colorimetric
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumNecessary Information
Indicate patient's age and sex.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 3 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial. Send refrigerated.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 10 days | |
| Frozen | 60 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | Reject |
Reference Values
The National Lipid Association and the National Cholesterol Education Program (NCEP) have set the following guidelines for LDL-C in adults (ages 18 years and up):
Desirable: <100 mg/dL
Above desirable: 100-129 mg/dL
Borderline high: 130-159 mg/dL
High: 160-189 mg/dL
Very high: ≥190 mg/dL
The Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents has set the following guidelines for LDL-C in children and adolescents (ages 2-17 years):
Acceptable: <110 mg/dL
Borderline high: 110-129 mg/dL
High: ≥130 mg/dL
Day(s) Performed
Monday through Thursday; Saturday, Sunday
CPT Code Information
83701
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LDLD | LDL Cholesterol (Beta-Quant), S | 18261-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| LDLC | LDL Chol (Beta-Quantification), S | 18261-8 |
Clinical Information
Low-density lipoprotein cholesterol (LDL-C) is acknowledged as being causally related with atherosclerotic cardiovascular disease. LDL-C remains the primary focus for cardiovascular risk assessment and effectiveness of risk reduction interventions including diet, physical activity, and pharmacologic therapies.
Low-density lipoproteins are a heterogeneous population of lipid particles classically defined as having a density of 1.006 to 1.063 kg/L obtained by preparative ultracentrifugation. The gold standard beta-quantification (beta-quant or BQ) method combines ultracentrifugation with precipitation and yields a direct quantitative measurement of LDL-C, intermediate-density lipoprotein cholesterol, and lipoprotein(a) cholesterol.
Extremely low concentrations of LDL-C are associated with abetalipoproteinemia and hypobetalipoproteinemia. In both cases, individuals will have very low total cholesterol and diminished or absent LDL-C, apolipoprotein B, and very low-density lipoprotein cholesterol. Patients may exhibit clinical signs and symptoms of polyneuropathy, intestinal fat malabsorption, hepatosteatosis, and fat-soluble vitamin deficiencies.
Interpretation
Mayo Clinic has adopted the National Lipid Association classifications, which are included as reference values on Mayo Clinic and Mayo Clinic Laboratories reports (see Reference Values). Lipids are most commonly measured to assess cardiovascular risk. Maintaining desirable concentrations of lipids lowers the risk of heart attacks or strokes.
Establishing appropriate treatment strategies and lipid goals requires consideration of low-density lipoprotein cholesterol (LDL-C) in context with other risk factors including age, sex, smoking status, family and personal history of heart disease. All guidelines recommend aggressive lipid lowering for patients with LDL cholesterol above 190 mg/dL.
Values below 20 mg/dL in untreated patients may be consistent with hypobetalipoproteinemia. Complications due to fat malabsorption may be present in affected individuals.
Undetectable LDL-C is highly suggestive of abetalipoproteinemia. Related polyneuropathy may exist in affected individuals.
Cautions
Result can be falsely decreased in patients with elevated levels of N-acetyl-p-benzoquinone imine (NAPQI)-a metabolite of acetaminophen), N-acetylcysteine (NAC), and metamizole.
Method Description
Serum is combined with dextran sulfate and magnesium, ions precipitate the low-density lipoprotein and very low-density lipoprotein fractions, leaving the high-density lipoprotein (HDL) fraction in solution. The HDL cholesterol is then determined using an enzymatic cholesterol assay.(Package insert: HDL Cholesterol Precipitating Reagent Set [Dextran Sulfate]; Pointe Scientific, Inc; 12/2009)
Cholesterol esters are cleaved by the action of cholesterol esterase to yield free cholesterol and fatty acids. Cholesterol oxidase then catalyzes the oxidation of cholesterol to cholest-4-en-3-one and hydrogen peroxide. In the presence of peroxidase, the hydrogen peroxide formed effects the oxidative coupling of phenol and 4-aminophenazone to form a red quinone-imine dye. The color intensity of the dye formed is directly proportional to the cholesterol concentration. It is determined by measuring the increase in absorbance.(Package insert: Cholesterol Gen2 Reagent. Roche Diagnostics; V 16.0, 10/2023)